When sourcing sulfite-based sanitizers for industrial or food-processing operations, procurement managers frequently evaluate potassium metabisulfite for sanitizing alongside the more widely used sodium metabisulfite. While both compounds release sulfur dioxide (SO2) â the active antimicrobial and reducing agent â their differences in cation composition, solubility, cost, and availability make each better suited to specific scenarios. In this comprehensive guide, we unpack the chemical, practical, and economic factors that drive the decision, helping you select the optimal metabisulfite for your water dechlorination, food preservation, winery sanitizing, or gold mining detoxification needs. We also demonstrate why high-purity sodium metabisulfite from Weifang Hailei Fine Chemical Co., Ltd. delivers exceptional performance and value for the vast majority of sanitizing applications.
Metabisulfites are inorganic salts that contain the metabisulfite anion S2O52−. Upon dissolution in water, they hydrolyze to bisulfite (HSO3−) and then gradually release sulfur dioxide (SO2), which is the key reactive species. In acidic conditions, the equilibrium shifts strongly toward SO2, making metabisulfites powerful reducing agents and antimicrobial compounds. The two most common industrial variants are sodium metabisulfite (Na2S2O5, CAS 7681-57-4) and potassium metabisulfite (K2S2O5, CAS 16731-55-8).
Because the active SO2 is identical regardless of the cation, the choice between sodium and potassium often comes down to secondary factors: the impact of sodium or potassium ions on the process, regulatory limits, price per kilogram of available SO2, and handling characteristics. These factors are especially relevant when you are considering potassium metabisulfite for sanitizing in sensitive environments like wineries, breweries, or food contact surfaces where residual sodium can affect flavor, corrosion, or ion balance.
Potassium metabisulfite for sanitizing is most commonly specified in potable alcohol production and certain food processing niches. Winemakers often prefer it because the potassium ion is naturally present in grapes and does not introduce exogenous sodium that could alter the wineâs taste profile or contribute to haze formation with tartrates. In breweries, potassium metabisulfite is sometimes used in sanitizing solutions for fermentation vessels and kegs, though its higher cost and lower solubility at cold temperatures compared to sodium metabisulfite limit its adoption.
Typical sanitizing-strength solutions of potassium metabisulfite are prepared at 1â2% w/v, generating roughly 50â100 mg/L free SO2. The solution is applied as a rinse or soak for equipment, barrels, and hoses, then thoroughly drained to avoid sulfite residues in the final product. Because potassium metabisulfite contains approximately 18% less SO2 by weight than sodium metabisulfite (57.6% SO2 equivalent vs. 67.4% for Na2S2O5), you need about 1.17 times more potassium salt to deliver the same sanitizing power. In bulk procurement, this efficiency gap directly translates into higher logistics and storage costs, making potassium metabisulfite for sanitizing an expensive choice for large-scale operations unless the sodium-free specification is mandatory.
For the majority of industrial and municipal sanitizing applications that do not involve ingestion of trace sodium, sodium metabisulfite is the superior choice. Its high SO2 content, rapid dissolution rate, and global availability make it the backbone of chlorine removal in water treatment, cyanide detoxification in gold mining, pulp bleaching, and textile anti-chlorine processes. When you use sodium metabisulfite to remove chlorine from process water, it reacts instantaneously with hypochlorous acid (HOCl) according to the stoichiometric equation:
Na2S2O5 + 2HOCl + H2O â 2NaHSO4 + 2HCl
Thus, 1.34 grams of pure sodium metabisulfite neutralizes 1 gram of active chlorine. This rapid kinetics reduces total dissolved solids less than alternative dechlorinators like sodium sulfite, making it the preferred reducing agent for RO membrane protection, boiler feedwater, and municipal wastewater effluent polishing. Many water treatment plants that historically used bulk sodium sulfite have switched to sodium metabisulfite precisely because of its higher chlorine-removal capacity per kilogram, lowering freight and storage footprint.
In food preservation, food-grade sodium metabisulfite (meeting FCC or EU E223 standards) is widely used to inhibit enzymatic and non-enzymatic browning in dried fruits, frozen seafood, and vegetable processing. It doubles as a sanitizing agent for food contact surfaces when applied at regulated concentrations and rinsed thoroughly. Hailei Chemical supplies both food-grade (purity ⥠97%) and industrial-grade (purity ⥠98%) sodium metabisulfite, supporting a broad spectrum of sanitizing requirements without the premium price tag of potassium-based alternatives.
Understanding how is sodium metabisulfite made is critical for buyers who demand consistent quality and supply chain transparency. Industrial production follows a three-step wet process route:
At Hailei Chemicalâs manufacturing base in Shandong, China, this process is executed under ISO 9001:2015 quality management, with in-line monitoring of SO2 gas purity, crystallization temperature, and final moisture content (â¤0.1%). This ensures that every shipment meets the 97â98% Na2S2O5 specification, with iron (Fe) below 10 ppm and heavy metals below control limits. The result is a robust, consistent product that performs reliably whether used for sanitizing, dechlorination, or gold leaching.
Safety is a top priority when handling any sulfite compound. Sodium metabisulfite is classified as a mild irritant (Xi) under GHS; it releases SO2 gas upon contact with acids or moisture, which can trigger respiratory irritation in poorly ventilated areas. To support safe procurement, Hailei Chemical makes the sodium metabisulfite msds pdf (Material Safety Data Sheet) available for download on our product page. Key handling recommendations include:
Comparing safety profiles, potassium metabisulfite for sanitizing carries similar GHS hazard statements (H318, EUH031). However, because potassium salt is typically used in smaller, artisanal settings like micro-breweries, the volume-related exposure risk is lower per site. For large industrial consumers, sodium metabisulfiteâs established safety data, globally harmonized documentation, and decades of operational experience make it a well-understood, manageable chemical when proper engineering controls are in place.
When buying in metric-ton quantities, the logistics and cost structure shift dramatically. Sodium metabisulfite typically trades at USD 350â550 per metric ton FOB China (depending on grade and market conditions), while potassium metabisulfite commands a premium of 40â60% due to higher potassium hydroxide input costs and smaller production volumes. For a 20-foot container loading 25 metric tons, choosing sodium over potassium can save $7,000â$12,000 per shipment.
Some water treatment plants also evaluate bulk sodium sulfite (Na2SO3) as a dechlorination alternative. Sodium sulfite contains a similar SO2 equivalent (50.8% vs 67.4%) but requires higher dosage to neutralize chlorine and introduces more sodium sulfate into the treated water. Sodium metabisulfiteâs higher reduction potential and lower total dissolved solids contribution generally yield a lower total cost of ownership, especially for high-throughput RO or demineralization lines. Hailei Chemical offers both sodium metabisulfite and bulk sodium sulfite, allowing buyers to optimize their chemical spend across specific process needs. Our export team assists with full documentationâCertificate of Analysis, MSDS, fumigation certificatesâand arranges container or break-bulk shipment to any major port worldwide.
Beyond sanitizing, the unique properties of sodium metabisulfite make it the compound of choice for several high-volume industrial processes where potassium metabisulfite for sanitizing would be impractical or cost-prohibitive:
Hailei Chemicalâs sodium metabisulfite is backed by over two decades of fine chemical manufacturing expertise. We offer:
Whether you are comparing potassium metabisulfite for sanitizing against sodium metabisulfite for your disinfection protocol, or sourcing bulk material for cyanide detox or pulp bleaching, Hailei Chemical delivers the quality and cost-effectiveness you need to stay competitive.
Yes, many wineries successfully use sodium metabisulfite for barrel and equipment sanitizing. The key is to rinse thoroughly to avoid sodium accumulation in the wine, which can affect taste and cold stability. For must and juice sulfiting, potassium metabisulfite is often preferred to prevent excess sodium. Procurement teams often buy both: sodium for cost-effective equipment sanitizing, potassium for must additionsâbut many mid-size to large wineries have switched to 100% sodium metabisulfite with appropriate rinse protocols, citing significant cost savings.
A 10% w/v stock solution of sodium metabisulfite will neutralize approximately 50 grams of chlorine per liter. For continuous water treatment, the typical dosing rate is 1.5â2.5 mg/L of Na2S2O5 per 1 mg/L of residual chlorine, with slight overfeed to maintain a sulfite residual of 0.5â1 mg/L for complete dechlorination.
Overall hazard classifications are similar, but the specific emergency procedures and storage incompatibilities differ slightly. Always obtain the sodium metabisulfite msds pdf from your supplier for your facilityâs safety data sheet library. Hailei Chemical provides the latest SDS revision with every shipment.
Yes, we supply both grades. Food-grade sodium metabisulfite is manufactured in dedicated, sanitary equipment and meets GB 1886.7-2015 and FCC standards. Please specify your grade requirement when requesting a quote.
Stop overpaying for potassium metabisulfite in applications where sodium metabisulfite delivers equal or better performance. Partner with a manufacturer that understands the nuances of sulfite chemistry and global logistics. Contact our team today to request a competitive quotation, sample, or the latest certificate of analysis.
Request your sodium metabisulfite quote now and explore our full product specifications. Let Hailei Chemical be your trusted source for bulk sulfites.
When industrial buyers search for bulk sodium sulfite, they are often looking for a reliable reducing agent, oxygen scavenger, or preservative—but what many don’t realize is that sodium metabisulfite (Na2S2O5) can perform the same functions, often with greater efficiency and at a lower delivered cost. The confusion is understandable: both are inorganic sulfites, both release sulfur dioxide (SO2) in acidic conditions, and both appear similar as white crystalline powders. Yet the chemical and commercial differences matter, especially when you are ordering by the container load.
Sodium sulfite (Na2SO3) has traditionally been used for boiler water treatment, pulp bleaching, and as a preservative. Sodium metabisulfite, commonly referred to as sodium pyrosulfite, is a closely related compound with a higher equivalent SO2 content—typically around 65–67% versus sodium sulfite’s 25–50%, depending on the grade. This means you need less sodium metabisulfite to achieve the same reducing power. For procurement managers and chemical engineers evaluating bulk sodium sulfite alternatives, sodium metabisulfite offers a compelling value proposition: better stability, easier handling, and broader regulatory acceptance across food, pharmaceutical, and water treatment applications.
At Weifang Hailei Fine Chemical Co., Ltd., we have been exporting high-purity sodium metabisulfite for over a decade, helping clients in more than 40 countries switch from sulfite-based solutions to our food grade and industrial grade sodium metabisulfite. In this article, we will break down the chemistry, applications, shelf life, and sourcing considerations so you can make the best purchasing decision for your operation.
If you currently buy bulk sodium sulfite, you might be paying for water and inert material without realizing it. Commercial sodium sulfite typically contains 85–95% active ingredient, with the balance being sodium sulfate and moisture. By contrast, our sodium metabisulfite is consistently 97–98% pure (food grade) and follows the same stoichiometric logic for oxygen scavenging and reduction reactions. Let’s compare their effectiveness in key reactions:
For water dechlorination, the reaction with hypochlorite is:
Sodium sulfite: Na2SO3 + ClO− → Na2SO4 + Cl−
Sodium metabisulfite: Na2S2O5 + 2ClO− + H2O → 2NaHSO4 + 2Cl−
From these equations, 1 mole of sodium sulfite (126 g) neutralizes one equivalent of chlorine, while 1 mole of sodium metabisulfite (190 g) neutralizes two equivalents of chlorine—so 95 g of metabisulfite does the same work as 126 g of sulfite. In practice, 1.0–1.2 kg of sodium metabisulfite can replace 1.5–2.0 kg of commercial sodium sulfite in a water treatment plant. For a facility buying several tons per month, this translates into direct savings on freight, storage, and product cost.
Municipal water treatment plants and industrial cooling towers must remove residual chlorine before discharge or membrane protection. While both sulfite and metabisulfite can neutralize free chlorine, sodium metabisulfite has become the standard in reverse osmosis (RO) pretreatment because it reacts faster and does not contribute dissolved solids at the same rate. The reaction time with 1 ppm chlorine is under 10 seconds at neutral pH, compared to 15–30 seconds for sulfite. When operators search for “sodium metabisulfite to remove chlorine,” they typically need a grade that complies with NSF/ANSI 60 for drinking water chemicals. Our sodium metabisulfite meets this standard, ensuring safe use in potable water systems.
Gold leaching operations rely on cyanide to extract precious metals from ore. After extraction, residual cyanide must be destroyed to meet environmental discharge limits. Sodium metabisulfite acts as an effective cyanide detox reagent through the sulfur dioxide/air process. When dissolved in water, it generates SO2 in situ, which converts toxic free cyanide to harmless cyanate. Mining chemical buyers often consider bulk sodium sulfite for this purpose, but sodium metabisulfite is preferred because it releases SO2 more controllably and is less hygroscopic, making it easier to store and meter at remote mine sites. Hailei Chemical supplies large mining operations in Africa, Latin America, and Central Asia with 25 kg bags or 1,000 kg supersacks, optimized for cyanide destruction circuits.
In the food industry, sodium metabisulfite is widely accepted as a preservative (E223) for dried fruits, wine, shrimp, and vegetable processing. It releases SO2 upon contact with water and acid, inhibiting microbial growth and enzymatic browning. Many buyers mistakenly search for “sodium bisulfite food preservative,” but in solid form, sodium metabisulfite is the more stable and economical choice. Sodium bisulfite (NaHSO3) exists mainly as a solution; dry food-grade sodium metabisulfite offers the same preservative effect with far better shelf life and shipping economics. Our food-grade sodium metabisulfite is FCC/GB 25590-2010 compliant, with heavy metal limits below 5 ppm lead and 2 ppm arsenic, ensuring suitability for global food safety standards.
Mechanical pulp bleaching with hydrogen peroxide requires a stabilizer to prevent wasteful decomposition. Sodium metabisulfite acts as both a reducing agent and a chelating aid, improving brightness while reducing chemical consumption. Compared to sodium sulfite, the metabisulfite version introduces no sulfate shock to the process water, which can be critical for closed-loop mills. Our industrial-grade sodium metabisulfite (98% purity, Fe ≤ 15 ppm) is specifically formulated for pulp and paper applications, helping mills achieve target brightness with fewer bleaching stages.
After bleaching cotton or synthetic fabrics, residual chlorine must be neutralized before dyeing to prevent color loss and fiber damage. Sodium metabisulfite baths at 0.1–0.3% concentration quickly eliminate chlorine, allowing consistent dye uptake. Textile mills across South Asia and the Middle East prefer our low-iron sodium metabisulfite because it prevents yellow stains on finished fabric, a common complaint with lower-grade sulfites.
A critical question for importers is “how long does sodium metabisulfite last?” Unlike sodium sulfite, which readily oxidizes to sulfate when exposed to air, metabisulfite is significantly more stable under proper storage. In our accelerated aging tests, properly sealed sodium metabisulfite retains over 95% of its original assay after 24 months when stored at temperatures below 30°C and relative humidity under 60%. In contrast, sodium sulfite can lose 10–15% activity within 6 months under the same conditions due to its higher affinity for oxygen and moisture.
To maximize shelf life, always store sodium metabisulfite in a cool, dry warehouse away from acids and oxidizing agents. Original sealed bags (25 kg or 1,000 kg) with a polyethylene inner liner provide an excellent moisture barrier. Once opened, the product should be used within 30 days, as exposure to ambient humidity initiates gradual decomposition. We print batch numbers and manufacturing dates on every bag, and our quality department can provide a certificate of analysis (COA) showing the initial purity and SO2 content. For customers ordering bulk sodium sulfite alternatives, this stability advantage reduces waste and ensures consistent process performance, even when inventory turns are slow.
Whether you are replacing an existing bulk sodium sulfite contract or sourcing sodium metabisulfite for a new project, consider the following procurement criteria:
Food-grade sodium metabisulfite should be ≥ 97% Na2S2O5, with iron below 20 ppm, lead below 2 ppm, and arsenic below 1 ppm. Industrial grade can tolerate slightly higher iron (≤ 30 ppm) but must still be free from visible discoloration or clumping. Ask your supplier for a typical COA, not just a maximum specification sheet.
Sodium metabisulfite can cake during ocean transit due to humidity and pressure. We add a food-grade anti-caking agent (tricalcium phosphate) at 0.2–0.5% to ensure free-flowing powder upon arrival. This is particularly important for customers in tropical climates who unload containers in high-humidity ports.
Choosing the right packaging reduces handling costs and product loss. Common options include 25 kg PE woven bags, 50 kg bags, 1,000 kg supersacks, and 1,200 kg jumbo bags. For high-volume buyers, we offer 20-metric-ton container shipments or 25-ton break-bulk vessel loading. Custom labeling and palletization are available.
Ensure the product meets the applicable standards for your region and application: Food Grade (FCC, GB 25590, EU 231/2012), NSF/ANSI 60 for drinking water, or GMP for pharmaceutical excipients. At Hailei, our documentation package includes COA, MSDS, food-grade license, and ISO 9001 certificate.
With over 10 years of experience as a leading Chinese chemical exporter, Weifang Hailei Fine Chemical Co., Ltd. has built a reputation for consistent quality, logistical reliability, and technical support. We produce sodium metabisulfite in our own factory in Shandong, enabling strict quality control from raw materials to finished product. Our annual production capacity of 60,000 metric tons ensures we can fulfill spot orders and multi-year contracts alike.
When you switch from bulk sodium sulfite to our sodium metabisulfite, you gain a technical partner who can help optimize dosage rates, storage practices, and regulatory filings. We regularly assist water treatment consultants with pilot trials, provide sample kits for mining laboratories, and ship FCL/LCL orders to any major port. Our documentation is meticulous, including fumigation certificates, GSP Form A for duty preferences, and any third-party inspection you require (SGS, Bureau Veritas).
Take the next step in securing a reliable supply of high-purity sodium metabisulfite for your water treatment plant, gold mine, or food processing facility. Request a quote today or visit our sodium metabisulfite product page for detailed specifications and packaging options. Our team will respond within 24 hours with a competitive price, shipping schedule, and the documentation you need to approve a trial order.
Understanding how sodium metabisulfite works is essential for procurement managers and chemical engineers who depend on this multi-functional inorganic compound in water dechlorination, cyanide detoxification, food processing, and textile bleaching. Sodium metabisulfite (Na2S2O5, CAS 7681-57-4) serves as a powerful reducing agent, oxygen scavenger, and preservative, making it a staple in industrial operations worldwide. This article unpacks the chemistry behind how sodium metabisulfite functions in each key application, compares it with sodium sulfite and potassium nitrate, outlines industrial production methods, and provides actionable insights into pricing and sourcing from China.
At the heart of every application lies the compound’s ability to donate sulfur dioxide (SO2) and act as a reducing agent. When dissolved in water, sodium metabisulfite dissociates to form sodium bisulfite (NaHSO3), which readily releases SO2 under slightly acidic conditions. This SO2 generation is the key reactive species that dechlorinates water, reduces metallic ions, inhibits enzymatic browning, and destroys residual oxidizing agents.
The standard reduction half-reaction for metabisulfite in an aqueous medium can be represented as:
Na2S2O5 + H2O → 2 Na+ + 2 HSO3−
followed by oxidation of bisulfite to sulfate or dithionate, depending on the acceptor. This behavior explains why only 1 ppm of sodium metabisulfite can neutralize roughly 1.0–1.5 ppm of free chlorine—a highly efficient stoichiometry that minimizes chemical usage and cost.
In municipal water treatment plants and industrial cooling towers, chlorine is widely used for disinfection but must be removed before water enters sensitive processes or is discharged to the environment. Sodium metabisulfite is the preferred dechlorination agent because of its rapid, irreversible reaction with free chlorine and chloramines.
The dechlorination mechanism follows this overall pathway:
Na2S2O5 + Cl2 + H2O → 2 NaHSO4 + 2 HCl
In practice, an excess of 1.0–1.5 mg/L of sodium metabisulfite per 1.0 mg/L of chlorine ensures complete neutralization within seconds. This reliability is critical for compliance with the U.S. Clean Water Act and EU Water Framework Directive, where residual chlorine limits are often set below 0.02 mg/L. For boiler feedwater, the chemical also scavenges dissolved oxygen, preventing pitting corrosion in steel tubes.
Using a high-purity grade (97–98% sodium metabisulfite from Hailei Chemical) avoids introducing harmful impurities like heavy metals or chlorides, which could foul reverse osmosis membranes or compromise drinking water safety. Industrial buyers typically specify food-grade or NSF/ANSI 60-certified product to guarantee consistent quality.
Gold extraction via cyanide leaching generates large volumes of toxic effluents containing free cyanide (CN−) and weak acid dissociable (WAD) cyanide complexes. Environmental regulations, such as the International Cyanide Management Code, mandate thorough detoxification before tailings discharge. Sodium metabisulfite offers an effective, low-cost method through the INCO SO2/air process.
The reaction uses SO2 released from metabisulfite in the presence of a copper catalyst (usually copper sulfate) to oxidize cyanide to the much less toxic cyanate (OCN−):
CN− + SO2 + O2 + H2O (Cu2+ catalyst) → OCN− + H2SO4
Typically, 3.0–5.0 grams of sodium metabisulfite are required per gram of WAD cyanide, depending on pH and temperature. The process operates optimally at pH 8.0–9.0 and can reduce cyanide levels below 0.5 mg/L, meeting stringent discharge limits.
Mine operators value the safety advantages: sodium metabisulfite is a solid, non-flammable powder that is far easier to handle than gaseous SO2. At Hailei Chemical’s supply, standard 25 kg bags with moisture-proof liners prevent caking in humid mine-site storage conditions, ensuring reliable dosing all year.
In the food industry, sodium metabisulfite is registered as E223 in the EU and is generally recognized as safe (GRAS) by the U.S. FDA when used within prescribed limits. Its preservative action stems from the release of SO2, which inhibits the growth of bacteria, yeast, and molds, while also acting as an antioxidant to prevent enzymatic browning in fruits, vegetables, and seafood.
How sodium metabisulfite works in this context: SO2 interferes with microbial enzyme systems by cleaving disulfide bonds and disrupting the cellular metabolism. It also reacts with quinones—the brown pigments formed from polyphenol oxidase—thereby preserving the natural color of products like dried apples, apricots, and potatoes. In winemaking, a small dose (typically 50–150 mg/L) of sodium metabisulfite is added to must or wine to suppress wild yeasts and protect against oxidation. Similarly, frozen shrimp and lobster are dipped in a 1.25–2.5% solution to prevent melanosis (black spot).
Quality control is paramount: residual SO2 levels must comply with Codex Alimentarius standards (e.g., not exceed 2,000 mg/kg in dried fruit). Food-grade sodium metabisulfite from Hailei Chemical meets purity specifications of ≥97% and is tested for heavy metals, arsenic, and iron to satisfy even the strictest international buyers.
The pulp and paper industry employs sodium metabisulfite as a reductive bleaching agent for mechanical pulps, often in combination with sodium hydrosulfite. In this role, the chemical reduces colored carbonyl and quinoid groups in lignin, brightening the pulp without degrading cellulose strength. Typical addition rates are 0.5–2.0% on oven-dry pulp, achieving ISO brightness gains of 3–6 points.
In textile processing, sodium metabisulfite serves as an anti-chlorine agent after hypochlorite bleaching. Residual chlorine can yellow fabrics and weaken fibers. A 1–3 g/L metabisulfite bath at 30–50°C neutralizes all chlorine within 10–20 minutes, permitting safe subsequent dyeing. The reaction is swift and leaves behind only chloride and sulfate ions, which are easily rinsed away.
Additionally, the compound functions as a boiler water oxygen scavenger and a sulfonating agent in the synthesis of optical brighteners, expanding its footprint beyond the primary industries.
Both chemicals provide SO2 equivalents, but they differ significantly in acidity, effective SO2 content, and typical applications. Understanding how sodium metabisulfite works versus sodium sulfite (Na2SO3) helps buyers optimize formulation and cost.
| Parameter | Sodium Metabisulfite | Sodium Sulfite |
|---|---|---|
| Chemical formula | Na2S2O5 | Na2SO3 |
| Available SO2 content (approx.) | 65–67% | 50% (anhydrous) |
| pH (10% solution) | 4.0–5.0 (acidic) | 9.0–10.5 (alkaline) |
| Primary uses | Dechlorination, cyanide detox, preservation | Oxygen scavenger in neutral/alkaline boilers, photographic developer |
| Solubility in water at 20°C | 540 g/L | 220 g/L (anhydrous) |
Sodium metabisulfite is more cost-effective per unit of available SO2 and dissolves faster, making it the preferred choice for water treatment and mining where acidic conditions are tolerated. Sodium sulfite, on the other hand, is favored in closed boiler systems that require an alkaline environment to minimize corrosion. Chemical buyers should align selection with system pH and desired reducing power—a decision where Hailei Chemical’s technical team can provide data-based guidance.
A common query among industrial newcomers is “sodium metabisulfite vs potassium nitrate.” These two compounds are fundamentally different in their chemical behavior and industrial use, and they are not interchangeable. Potassium nitrate (KNO3) is a strong oxidizing agent and a source of nitrate ions, while sodium metabisulfite is a reducing agent. Comparing them highlights the importance of proper chemical selection: never use a reducer where an oxidizer is required, or vice versa.
In gold processing, potassium nitrate is occasionally used as an auxiliary oxidant in cyanide leaching to enhance gold dissolution by raising the redox potential. Sodium metabisulfite, conversely, is employed at the tail end of the circuit to destroy residual cyanide. The two chemicals serve opposite functions and cannot substitute each other. Using metabisulfite where an oxidizer is needed would halt gold extraction; using nitrate in detoxification could generate toxic nitrogen compounds.
Understanding how sodium metabisulfite works as a reducer while potassium nitrate works as an oxidizer is essential for safe and effective plant operations. Always consult the process chemistry and safety data sheets before incorporating any new chemical into your workflow.
The large-scale manufacture of sodium metabisulfite is an energy-intensive, staged process that begins with elemental sulfur. Knowing how to make sodium metabisulfite helps buyers appreciate the cost drivers and quality variables behind this commodity chemical.
The typical synthesis route:
Quality control tests include purity analysis (≥97.0–98.0%), iron content (<50 ppm), heavy metals (<10 ppm), and a clear solution appearance. Hailei Chemical’s production units are ISO 9001:2015 certified, and every batch is shipped with a certificate of analysis (CoA) that verifies these specifications.
China dominates global sodium metabisulfite supply, accounting for roughly 60% of international trade. Understanding the price of sodium metabisulfite in China helps procurement managers negotiate favorable contracts and anticipate market movements.
Currently, spot FOB Qingdao prices for 97% food-grade product range between $400 and $600 per metric ton, depending on packaging, order volume, and contractual terms. Industrial-grade material often trades at a $20–30/ton discount. Key cost drivers include:
To secure a stable, competitive price of sodium metabisulfite in China, buyers should partner with an established exporter like Hailei Chemical, which offers long-term contracts, price hedging options, and consistent product quality recognized across more than 40 countries.
With over a decade of experience in fine chemical export, Weifang Hailei Fine Chemical Co., Ltd. supplies food-grade and industrial-grade sodium metabisulfite that consistently meets 97–98% purity. Our product is available in 25 kg PE-lined woven bags, 1,000 kg big bags, or customized packaging to suit your logistical needs. We maintain a buffer inventory that ensures lead times as short as 14 days after order confirmation, supported by reliable sea freight partnerships.
Our technical team can assist with dosage calculations, blending requirements, and regulatory documentation (SDS, CoA, REACH, etc.). Whether you need a single container or a monthly shipment of 500 metric tons, we provide transparent pricing, flexible payment terms, and dedicated after-sales support.
Ready to leverage how sodium metabisulfite works for your operation? Connect with our experts to discuss your specific application and receive a tailored quotation. Request your sodium metabisulfite quote today.
The search for sodium metabisulfite suppliers in South Africa often begins with a pressing operational need—whether it’s cyanide detoxification in a gold mine, dechlorination at a municipal water plant, or sulfite preservation in a food processing line. South Africa’s robust mining sector and stringent water regulations make Na₂S₂O₅ a mission-critical chemical. Yet, domestic production capacity remains limited, so most procurement managers must evaluate international suppliers who understand South African logistical challenges, quality standards, and industry-specific requirements. This comprehensive guide draws on decades of chemical export experience to help you evaluate suppliers, compare grades, and secure a consistent, cost-effective sodium metabisulfite supply chain.
South Africa’s economy is uniquely positioned as a top global gold producer and a water-scarce nation deeply invested in water reuse. In both contexts, sodium metabisulfite plays an irreplaceable role. Gold mining operations rely on the molecule’s powerful reducing properties to destroy residual cyanide in tailings slurry, preventing environmental contamination and meeting ICMC (International Cyanide Management Code) compliance. Municipal and industrial water treatment plants use it for rapid chlorine removal before discharge or reverse osmosis membrane protection. The food and beverage sector employs food-grade sodium metabisulfite as an antioxidant and preservative in dried fruit, wine, and maize products—staples of the South African agricultural economy.
Because these applications cannot tolerate inconsistent quality or supply disruptions, sodium metabisulfite suppliers in South Africa must prove adherence to rigorous specifications. A purity variance of just one percentage point can alter dosing calculations in mining, while heavy metal traces can disqualify a batch for sensitive food or pharmaceutical use. The right supplier becomes a strategic partner, not just a vendor.
When sourcing Na₂S₂O₅ for South African operations, insist on detailed certificates of analysis (CoA) covering at least the following parameters. Industrial grade typically offers ≥97.0% purity, while food grade (E223) meets FCC or JECFA monographs with 97.5% minimum and strict limits on arsenic (≤3 mg/kg), lead (≤5 mg/kg), and iron (≤50 mg/kg).
For mining specific applications, many South African buyers also request free-flowing white granular or powder form that dissolves rapidly in alkaline cyanide-bearing slurries. Hailei Chemical supplies precisely these customized physical forms, with anti-caking treatment available for bulk shipments that may encounter humid coastal conditions in Durban or Cape Town ports.
A deep understanding of the sodium metabisulfite reaction with water is essential for safe handling and effective process control. When dissolved, Na₂S₂O₅ hydrolyzes to form sodium bisulfite (NaHSO₃):
Na₂S₂O₅ + H₂O → 2 NaHSO₃
This equilibrium solution then acts as the active reducing agent. In acidic conditions, especially below pH 4, bisulfite further generates sulfur dioxide gas:
HSO₃⁻ + H⁺ → SO₂ + H₂O
For gold mining cyanide destruction processes (often conducted at pH 9–11), the dissolved metabisulfite provides the sulfite ions that react with dissolved oxygen to convert free cyanide to cyanate. Water treatment operators value the same chemistry to neutralize chlorine residuals. However, the exothermic nature of dissolution and potential for SO₂ off-gassing means storage must be dry, cool, and well-ventilated. Bulk tanks and day bins require appropriate materials—stainless steel 316 or HDPE are preferred due to the chemical’s corrosive properties when moist. Reputable suppliers will provide detailed SDS and handling guidance, a hallmark of expertise that separates transactional vendors from true partners.
Many South African operations, particularly in wine making and pulp bleaching, face the choice between direct SO₂ gas injection and using solid sodium metabisulfite. The sulphur dioxide vs sodium metabisulfite decision hinges on safety, ease of use, and cost-in-use.
Cylinder-based sulfur dioxide gas offers rapid, pH-independent availability of SO₂ but carries significant handling hazards—pressurized toxic gas, specialized equipment, and strict regulatory oversight under OHS Act. Solid sodium metabisulfite, by contrast, is a stable, transportable powder that generates SO₂ gradually upon dissolution and acidification. For a small winery in Stellenbosch, a 25kg bag of food-grade metabisulfite provides a safe, measurable source of sulfite without the capital investment in gas handling. Large-scale pulp mills, however, sometimes prefer liquid SO₂ for high-volume bleaching sequences. Yet even there, the trend is shifting toward metabisulfite due to improved logistics and safety profiles. Understanding this trade-off ensures you procure the form that aligns with your operational maturity and risk appetite.
Food and beverage sanitization frequently brings up the potassium vs sodium metabisulfite debate. Both release SO₂ as the active antimicrobial agent, but the choice of cation influences sodium content and solubility. Potassium metabisulfite (K₂S₂O₅) is often used in potassium metabisulfite sanitizing solution formulations for winemaking and brewing equipment because winemakers are cautious about adding extra sodium, which can affect sensory profiles. However, sodium metabisulfite is far more cost-effective per kilogram of available SO₂, and for most non-beverage sanitizing applications—such as food contact surfaces in seafood processing or vegetable washing—sodium metabisulfite is the economical standard.
A typical sanitizing solution for equipment uses 1–2% metabisulfite acidified with citric acid to pH 3.0, which generates 500–1000 ppm free SO₂. In this scenario, the potassium variant provides about 57% SO₂ by weight, while sodium metabisulfite delivers approximately 67%. For potassium metabisulfite sanitizing solution users who want to avoid sodium, Hailei Chemical also offers pharmaceutical-grade potassium metabisulfite, but our South African mining and industrial clients overwhelmingly select sodium metabisulfite due to its superior economy and proven performance in large-scale processes.
It’s impossible to discuss sodium metabisulfite procurement in South Africa without spotlighting gold mining. The Witwatersrand Basin and newer Mpumalanga operations process millions of tons of ore annually, with cyanide leaching followed by mandatory detoxification before tailings disposal. Typical consumption rates range from 3–5 kg of Na₂S₂O₅ per ton of ore, translating to multi-container orders monthly for a single mid-tier mine.
The INCO SO₂/Air process—the most widely adopted cyanide destruction technology—uses sodium metabisulfite as the SO₂ source in the presence of a copper catalyst (usually CuSO₄·5H₂O). The reaction requires precise control: maintaining dissolved oxygen >8 mg/L and pH around 9 to achieve <20 mg/L WAD cyanide in the effluent. Any variability in metabisulfite purity or dissolution rate directly impacts detox efficiency and could lead to non-compliance penalties. That is why procurement managers at mines like Harmony Gold or Gold Fields prioritize sodium metabisulfite suppliers in South Africa who can deliver consistent quality, technical support, and just-in-time inventory from bonded warehouses in Johannesburg or Durban.
When shortlisting suppliers, move beyond unit price comparisons and assess total cost of ownership. Key evaluation criteria include:
As a leading manufacturer and exporter, Hailei Chemical’s sodium metabisulfite meets all the above demands with both industrial and food grade options packed to ISO and HACCP standards. Our long-standing presence in the African market gives us first-hand insight into port procedures, documentation requirements, and the seasonal demand peaks of the mining sector.
Beyond mining, food preservation drives steady demand. South Africa’s dried fruit industry (raisons, apricots, mango) uses metabisulfite to inhibit enzymatic browning and microbial growth. Maize processing (mabele and sorghum porridge mixes) sometimes includes sulfites as a dough conditioner. The South African Department of Health permits sulfites in specified foods under Regulation R. 2356, with strict labeling for concentrations above 10 mg/kg. Food-grade sodium metabisulfite from Hailei Chemical carries full JECFA and FCC compliance, with documentation packages that simplify your regulatory submissions.
Municipalities like eThekwini (Durban) and City of Cape Town employ sodium metabisulfite for dechlorination of treated effluent before environmental release or reuse. The compound rapidly neutralizes free chlorine and monochloramine, preventing toxic byproduct formation. For pulp and paper mills in Mpumalanga, Na₂S₂O₅ serves as a reducing bleach agent in the TCF (Totally Chlorine Free) sequence and as an anti-chlor after chlorine dioxide stages. The ability to ship large volumes in bulk bags reduces handling costs significantly. Our export team routinely optimizes container loads to lower landed cost per kilogram—often a deciding factor when choosing among sodium metabisulfite suppliers in South Africa.
For processors building a HACCP plan, the question of potassium metabisulfite sanitizing solution often arises. While potassium metabisulfite (available from Hailei Chemical) is preferred where sodium sensitivity is critical, the majority of food equipment sanitizing can be accomplished more economically with sodium metabisulfite. A typical CIP rinse using 0.1% sodium metabisulfite acidified to pH 3.5 with citric acid yields >200 ppm active SO₂, sufficient for yeast and mold control. The sodium variant also dissolves faster, an advantage in automated dosing systems. Weigh the marginal benefit of a potassium salt against your product profile and budget; for most South African applications, sodium metabisulfite wins on cost-efficiency.
Recent global disruptions have taught procurement teams to seek suppliers with diversified manufacturing bases and flexible shipping routes. Hailei Chemical’s production facilities in Weifang operate year-round with dedicated lines for metabisulfite, ensuring capacity even during peak demand. We offer sea freight to Durban, Cape Town, and Port Elizabeth, with options for air freight emergency top-ups. By maintaining open communication and transparent lead times, we help you build a resilient supply chain—the ultimate requirement from all sodium metabisulfite suppliers in South Africa.
When reaching out to suppliers, be ready with this information to accelerate quotation and order processing:
Our team at Hailei Chemical responds with a pro-forma invoice within 24 hours, including freight options and estimated transit time. We can arrange samples for compatibility testing, a practice highly recommended before large orders—especially for mining circuits with variable water quality.
Ready to secure a reliable source of high-purity sodium metabisulfite for your South African operation? Request a quote today and let our experts tailor a supply solution that meets your technical and commercial requirements. For detailed product specifications, visit our sodium metabisulfite product page and discover why discerning buyers across Africa partner with Hailei Chemical.
The search for sodium metabisulfite suppliers in South Africa often begins with a pressing operational need—whether it’s cyanide detoxification in a gold mine, dechlorination at a municipal water plant, or sulfite preservation in a food processing line. South Africa’s robust mining sector and stringent water regulations make Na₂S₂O₅ a mission-critical chemical. Yet, domestic production capacity remains limited, so most procurement managers must evaluate international suppliers who understand South African logistical challenges, quality standards, and industry-specific requirements. This comprehensive guide draws on decades of chemical export experience to help you evaluate suppliers, compare grades, and secure a consistent, cost-effective sodium metabisulfite supply chain.
South Africa’s economy is uniquely positioned as a top global gold producer and a water-scarce nation deeply invested in water reuse. In both contexts, sodium metabisulfite plays an irreplaceable role. Gold mining operations rely on the molecule’s powerful reducing properties to destroy residual cyanide in tailings slurry, preventing environmental contamination and meeting ICMC (International Cyanide Management Code) compliance. Municipal and industrial water treatment plants use it for rapid chlorine removal before discharge or reverse osmosis membrane protection. The food and beverage sector employs food-grade sodium metabisulfite as an antioxidant and preservative in dried fruit, wine, and maize products—staples of the South African agricultural economy.
Because these applications cannot tolerate inconsistent quality or supply disruptions, sodium metabisulfite suppliers in South Africa must prove adherence to rigorous specifications. A purity variance of just one percentage point can alter dosing calculations in mining, while heavy metal traces can disqualify a batch for sensitive food or pharmaceutical use. The right supplier becomes a strategic partner, not just a vendor.
When sourcing Na₂S₂O₅ for South African operations, insist on detailed certificates of analysis (CoA) covering at least the following parameters. Industrial grade typically offers ≥97.0% purity, while food grade (E223) meets FCC or JECFA monographs with 97.5% minimum and strict limits on arsenic (≤3 mg/kg), lead (≤5 mg/kg), and iron (≤50 mg/kg).
For mining specific applications, many South African buyers also request free-flowing white granular or powder form that dissolves rapidly in alkaline cyanide-bearing slurries. Hailei Chemical supplies precisely these customized physical forms, with anti-caking treatment available for bulk shipments that may encounter humid coastal conditions in Durban or Cape Town ports.
A deep understanding of the sodium metabisulfite reaction with water is essential for safe handling and effective process control. When dissolved, Na₂S₂O₅ hydrolyzes to form sodium bisulfite (NaHSO₃):
Na₂S₂O₅ + H₂O → 2 NaHSO₃
This equilibrium solution then acts as the active reducing agent. In acidic conditions, especially below pH 4, bisulfite further generates sulfur dioxide gas:
HSO₃⁻ + H⁺ → SO₂ + H₂O
For gold mining cyanide destruction processes (often conducted at pH 9–11), the dissolved metabisulfite provides the sulfite ions that react with dissolved oxygen to convert free cyanide to cyanate. Water treatment operators value the same chemistry to neutralize chlorine residuals. However, the exothermic nature of dissolution and potential for SO₂ off-gassing means storage must be dry, cool, and well-ventilated. Bulk tanks and day bins require appropriate materials—stainless steel 316 or HDPE are preferred due to the chemical’s corrosive properties when moist. Reputable suppliers will provide detailed SDS and handling guidance, a hallmark of expertise that separates transactional vendors from true partners.
Many South African operations, particularly in wine making and pulp bleaching, face the choice between direct SO₂ gas injection and using solid sodium metabisulfite. The sulphur dioxide vs sodium metabisulfite decision hinges on safety, ease of use, and cost-in-use.
Cylinder-based sulfur dioxide gas offers rapid, pH-independent availability of SO₂ but carries significant handling hazards—pressurized toxic gas, specialized equipment, and strict regulatory oversight under OHS Act. Solid sodium metabisulfite, by contrast, is a stable, transportable powder that generates SO₂ gradually upon dissolution and acidification. For a small winery in Stellenbosch, a 25kg bag of food-grade metabisulfite provides a safe, measurable source of sulfite without the capital investment in gas handling. Large-scale pulp mills, however, sometimes prefer liquid SO₂ for high-volume bleaching sequences. Yet even there, the trend is shifting toward metabisulfite due to improved logistics and safety profiles. Understanding this trade-off ensures you procure the form that aligns with your operational maturity and risk appetite.
Food and beverage sanitization frequently brings up the potassium vs sodium metabisulfite debate. Both release SO₂ as the active antimicrobial agent, but the choice of cation influences sodium content and solubility. Potassium metabisulfite (K₂S₂O₅) is often used in potassium metabisulfite sanitizing solution formulations for winemaking and brewing equipment because winemakers are cautious about adding extra sodium, which can affect sensory profiles. However, sodium metabisulfite is far more cost-effective per kilogram of available SO₂, and for most non-beverage sanitizing applications—such as food contact surfaces in seafood processing or vegetable washing—sodium metabisulfite is the economical standard.
A typical sanitizing solution for equipment uses 1–2% metabisulfite acidified with citric acid to pH 3.0, which generates 500–1000 ppm free SO₂. In this scenario, the potassium variant provides about 57% SO₂ by weight, while sodium metabisulfite delivers approximately 67%. For potassium metabisulfite sanitizing solution users who want to avoid sodium, Hailei Chemical also offers pharmaceutical-grade potassium metabisulfite, but our South African mining and industrial clients overwhelmingly select sodium metabisulfite due to its superior economy and proven performance in large-scale processes.
It’s impossible to discuss sodium metabisulfite procurement in South Africa without spotlighting gold mining. The Witwatersrand Basin and newer Mpumalanga operations process millions of tons of ore annually, with cyanide leaching followed by mandatory detoxification before tailings disposal. Typical consumption rates range from 3–5 kg of Na₂S₂O₅ per ton of ore, translating to multi-container orders monthly for a single mid-tier mine.
The INCO SO₂/Air process—the most widely adopted cyanide destruction technology—uses sodium metabisulfite as the SO₂ source in the presence of a copper catalyst (usually CuSO₄·5H₂O). The reaction requires precise control: maintaining dissolved oxygen >8 mg/L and pH around 9 to achieve <20 mg/L WAD cyanide in the effluent. Any variability in metabisulfite purity or dissolution rate directly impacts detox efficiency and could lead to non-compliance penalties. That is why procurement managers at mines like Harmony Gold or Gold Fields prioritize sodium metabisulfite suppliers in South Africa who can deliver consistent quality, technical support, and just-in-time inventory from bonded warehouses in Johannesburg or Durban.
When shortlisting suppliers, move beyond unit price comparisons and assess total cost of ownership. Key evaluation criteria include:
As a leading manufacturer and exporter, Hailei Chemical’s sodium metabisulfite meets all the above demands with both industrial and food grade options packed to ISO and HACCP standards. Our long-standing presence in the African market gives us first-hand insight into port procedures, documentation requirements, and the seasonal demand peaks of the mining sector.
Beyond mining, food preservation drives steady demand. South Africa’s dried fruit industry (raisons, apricots, mango) uses metabisulfite to inhibit enzymatic browning and microbial growth. Maize processing (mabele and sorghum porridge mixes) sometimes includes sulfites as a dough conditioner. The South African Department of Health permits sulfites in specified foods under Regulation R. 2356, with strict labeling for concentrations above 10 mg/kg. Food-grade sodium metabisulfite from Hailei Chemical carries full JECFA and FCC compliance, with documentation packages that simplify your regulatory submissions.
Municipalities like eThekwini (Durban) and City of Cape Town employ sodium metabisulfite for dechlorination of treated effluent before environmental release or reuse. The compound rapidly neutralizes free chlorine and monochloramine, preventing toxic byproduct formation. For pulp and paper mills in Mpumalanga, Na₂S₂O₅ serves as a reducing bleach agent in the TCF (Totally Chlorine Free) sequence and as an anti-chlor after chlorine dioxide stages. The ability to ship large volumes in bulk bags reduces handling costs significantly. Our export team routinely optimizes container loads to lower landed cost per kilogram—often a deciding factor when choosing among sodium metabisulfite suppliers in South Africa.
For processors building a HACCP plan, the question of potassium metabisulfite sanitizing solution often arises. While potassium metabisulfite (available from Hailei Chemical) is preferred where sodium sensitivity is critical, the majority of food equipment sanitizing can be accomplished more economically with sodium metabisulfite. A typical CIP rinse using 0.1% sodium metabisulfite acidified to pH 3.5 with citric acid yields >200 ppm active SO₂, sufficient for yeast and mold control. The sodium variant also dissolves faster, an advantage in automated dosing systems. Weigh the marginal benefit of a potassium salt against your product profile and budget; for most South African applications, sodium metabisulfite wins on cost-efficiency.
Recent global disruptions have taught procurement teams to seek suppliers with diversified manufacturing bases and flexible shipping routes. Hailei Chemical’s production facilities in Weifang operate year-round with dedicated lines for metabisulfite, ensuring capacity even during peak demand. We offer sea freight to Durban, Cape Town, and Port Elizabeth, with options for air freight emergency top-ups. By maintaining open communication and transparent lead times, we help you build a resilient supply chain—the ultimate requirement from all sodium metabisulfite suppliers in South Africa.
When reaching out to suppliers, be ready with this information to accelerate quotation and order processing:
Our team at Hailei Chemical responds with a pro-forma invoice within 24 hours, including freight options and estimated transit time. We can arrange samples for compatibility testing, a practice highly recommended before large orders—especially for mining circuits with variable water quality.
Ready to secure a reliable source of high-purity sodium metabisulfite for your South African operation? Request a quote today and let our experts tailor a supply solution that meets your technical and commercial requirements. For detailed product specifications, visit our sodium metabisulfite product page and discover why discerning buyers across Africa partner with Hailei Chemical.
The search for sodium metabisulfite suppliers in South Africa often begins with a pressing operational need—whether it’s cyanide detoxification in a gold mine, dechlorination at a municipal water plant, or sulfite preservation in a food processing line. South Africa’s robust mining sector and stringent water regulations make Na₂S₂O₅ a mission-critical chemical. Yet, domestic production capacity remains limited, so most procurement managers must evaluate international suppliers who understand South African logistical challenges, quality standards, and industry-specific requirements. This comprehensive guide draws on decades of chemical export experience to help you evaluate suppliers, compare grades, and secure a consistent, cost-effective sodium metabisulfite supply chain.
South Africa’s economy is uniquely positioned as a top global gold producer and a water-scarce nation deeply invested in water reuse. In both contexts, sodium metabisulfite plays an irreplaceable role. Gold mining operations rely on the molecule’s powerful reducing properties to destroy residual cyanide in tailings slurry, preventing environmental contamination and meeting ICMC (International Cyanide Management Code) compliance. Municipal and industrial water treatment plants use it for rapid chlorine removal before discharge or reverse osmosis membrane protection. The food and beverage sector employs food-grade sodium metabisulfite as an antioxidant and preservative in dried fruit, wine, and maize products—staples of the South African agricultural economy.
Because these applications cannot tolerate inconsistent quality or supply disruptions, sodium metabisulfite suppliers in South Africa must prove adherence to rigorous specifications. A purity variance of just one percentage point can alter dosing calculations in mining, while heavy metal traces can disqualify a batch for sensitive food or pharmaceutical use. The right supplier becomes a strategic partner, not just a vendor.
When sourcing Na₂S₂O₅ for South African operations, insist on detailed certificates of analysis (CoA) covering at least the following parameters. Industrial grade typically offers ≥97.0% purity, while food grade (E223) meets FCC or JECFA monographs with 97.5% minimum and strict limits on arsenic (≤3 mg/kg), lead (≤5 mg/kg), and iron (≤50 mg/kg).
For mining specific applications, many South African buyers also request free-flowing white granular or powder form that dissolves rapidly in alkaline cyanide-bearing slurries. Hailei Chemical supplies precisely these customized physical forms, with anti-caking treatment available for bulk shipments that may encounter humid coastal conditions in Durban or Cape Town ports.
A deep understanding of the sodium metabisulfite reaction with water is essential for safe handling and effective process control. When dissolved, Na₂S₂O₅ hydrolyzes to form sodium bisulfite (NaHSO₃):
Na₂S₂O₅ + H₂O → 2 NaHSO₃
This equilibrium solution then acts as the active reducing agent. In acidic conditions, especially below pH 4, bisulfite further generates sulfur dioxide gas:
HSO₃⁻ + H⁺ → SO₂ + H₂O
For gold mining cyanide destruction processes (often conducted at pH 9–11), the dissolved metabisulfite provides the sulfite ions that react with dissolved oxygen to convert free cyanide to cyanate. Water treatment operators value the same chemistry to neutralize chlorine residuals. However, the exothermic nature of dissolution and potential for SO₂ off-gassing means storage must be dry, cool, and well-ventilated. Bulk tanks and day bins require appropriate materials—stainless steel 316 or HDPE are preferred due to the chemical’s corrosive properties when moist. Reputable suppliers will provide detailed SDS and handling guidance, a hallmark of expertise that separates transactional vendors from true partners.
Many South African operations, particularly in wine making and pulp bleaching, face the choice between direct SO₂ gas injection and using solid sodium metabisulfite. The sulphur dioxide vs sodium metabisulfite decision hinges on safety, ease of use, and cost-in-use.
Cylinder-based sulfur dioxide gas offers rapid, pH-independent availability of SO₂ but carries significant handling hazards—pressurized toxic gas, specialized equipment, and strict regulatory oversight under OHS Act. Solid sodium metabisulfite, by contrast, is a stable, transportable powder that generates SO₂ gradually upon dissolution and acidification. For a small winery in Stellenbosch, a 25kg bag of food-grade metabisulfite provides a safe, measurable source of sulfite without the capital investment in gas handling. Large-scale pulp mills, however, sometimes prefer liquid SO₂ for high-volume bleaching sequences. Yet even there, the trend is shifting toward metabisulfite due to improved logistics and safety profiles. Understanding this trade-off ensures you procure the form that aligns with your operational maturity and risk appetite.
Food and beverage sanitization frequently brings up the potassium vs sodium metabisulfite debate. Both release SO₂ as the active antimicrobial agent, but the choice of cation influences sodium content and solubility. Potassium metabisulfite (K₂S₂O₅) is often used in potassium metabisulfite sanitizing solution formulations for winemaking and brewing equipment because winemakers are cautious about adding extra sodium, which can affect sensory profiles. However, sodium metabisulfite is far more cost-effective per kilogram of available SO₂, and for most non-beverage sanitizing applications—such as food contact surfaces in seafood processing or vegetable washing—sodium metabisulfite is the economical standard.
A typical sanitizing solution for equipment uses 1–2% metabisulfite acidified with citric acid to pH 3.0, which generates 500–1000 ppm free SO₂. In this scenario, the potassium variant provides about 57% SO₂ by weight, while sodium metabisulfite delivers approximately 67%. For potassium metabisulfite sanitizing solution users who want to avoid sodium, Hailei Chemical also offers pharmaceutical-grade potassium metabisulfite, but our South African mining and industrial clients overwhelmingly select sodium metabisulfite due to its superior economy and proven performance in large-scale processes.
It’s impossible to discuss sodium metabisulfite procurement in South Africa without spotlighting gold mining. The Witwatersrand Basin and newer Mpumalanga operations process millions of tons of ore annually, with cyanide leaching followed by mandatory detoxification before tailings disposal. Typical consumption rates range from 3–5 kg of Na₂S₂O₅ per ton of ore, translating to multi-container orders monthly for a single mid-tier mine.
The INCO SO₂/Air process—the most widely adopted cyanide destruction technology—uses sodium metabisulfite as the SO₂ source in the presence of a copper catalyst (usually CuSO₄·5H₂O). The reaction requires precise control: maintaining dissolved oxygen >8 mg/L and pH around 9 to achieve <20 mg/L WAD cyanide in the effluent. Any variability in metabisulfite purity or dissolution rate directly impacts detox efficiency and could lead to non-compliance penalties. That is why procurement managers at mines like Harmony Gold or Gold Fields prioritize sodium metabisulfite suppliers in South Africa who can deliver consistent quality, technical support, and just-in-time inventory from bonded warehouses in Johannesburg or Durban.
When shortlisting suppliers, move beyond unit price comparisons and assess total cost of ownership. Key evaluation criteria include:
As a leading manufacturer and exporter, Hailei Chemical’s sodium metabisulfite meets all the above demands with both industrial and food grade options packed to ISO and HACCP standards. Our long-standing presence in the African market gives us first-hand insight into port procedures, documentation requirements, and the seasonal demand peaks of the mining sector.
Beyond mining, food preservation drives steady demand. South Africa’s dried fruit industry (raisons, apricots, mango) uses metabisulfite to inhibit enzymatic browning and microbial growth. Maize processing (mabele and sorghum porridge mixes) sometimes includes sulfites as a dough conditioner. The South African Department of Health permits sulfites in specified foods under Regulation R. 2356, with strict labeling for concentrations above 10 mg/kg. Food-grade sodium metabisulfite from Hailei Chemical carries full JECFA and FCC compliance, with documentation packages that simplify your regulatory submissions.
Municipalities like eThekwini (Durban) and City of Cape Town employ sodium metabisulfite for dechlorination of treated effluent before environmental release or reuse. The compound rapidly neutralizes free chlorine and monochloramine, preventing toxic byproduct formation. For pulp and paper mills in Mpumalanga, Na₂S₂O₅ serves as a reducing bleach agent in the TCF (Totally Chlorine Free) sequence and as an anti-chlor after chlorine dioxide stages. The ability to ship large volumes in bulk bags reduces handling costs significantly. Our export team routinely optimizes container loads to lower landed cost per kilogram—often a deciding factor when choosing among sodium metabisulfite suppliers in South Africa.
For processors building a HACCP plan, the question of potassium metabisulfite sanitizing solution often arises. While potassium metabisulfite (available from Hailei Chemical) is preferred where sodium sensitivity is critical, the majority of food equipment sanitizing can be accomplished more economically with sodium metabisulfite. A typical CIP rinse using 0.1% sodium metabisulfite acidified to pH 3.5 with citric acid yields >200 ppm active SO₂, sufficient for yeast and mold control. The sodium variant also dissolves faster, an advantage in automated dosing systems. Weigh the marginal benefit of a potassium salt against your product profile and budget; for most South African applications, sodium metabisulfite wins on cost-efficiency.
Recent global disruptions have taught procurement teams to seek suppliers with diversified manufacturing bases and flexible shipping routes. Hailei Chemical’s production facilities in Weifang operate year-round with dedicated lines for metabisulfite, ensuring capacity even during peak demand. We offer sea freight to Durban, Cape Town, and Port Elizabeth, with options for air freight emergency top-ups. By maintaining open communication and transparent lead times, we help you build a resilient supply chain—the ultimate requirement from all sodium metabisulfite suppliers in South Africa.
When reaching out to suppliers, be ready with this information to accelerate quotation and order processing:
Our team at Hailei Chemical responds with a pro-forma invoice within 24 hours, including freight options and estimated transit time. We can arrange samples for compatibility testing, a practice highly recommended before large orders—especially for mining circuits with variable water quality.
Ready to secure a reliable source of high-purity sodium metabisulfite for your South African operation? Request a quote today and let our experts tailor a supply solution that meets your technical and commercial requirements. For detailed product specifications, visit our sodium metabisulfite product page and discover why discerning buyers across Africa partner with Hailei Chemical.
Sodium metabisulphite (Na₂S₂O₅) is one of the most versatile chemicals in industrial processing, yet knowing how to use sodium metabisulphite correctly is essential to unlocking its full potential while protecting your workforce and end products. Whether you’re dosing water treatment systems, detoxifying cyanide in gold mining circuits, preserving food, bleaching wood pulp, or neutralising chlorine in textiles, improper handling can lead to reduced efficiency, equipment corrosion, or serious health risks—including sodium metabisulfite allergy reactions. As a trusted supplier with decades of experience, Hailei Chemical provides both food grade sodium metabisulphite and industrial grade Na₂S₂O₅ meeting stringent purity standards, and this guide consolidates all you need to apply it safely and effectively.
Before diving into application-specific methods, it’s critical to appreciate what you’re working with. Sodium metabisulphite (CAS 7681-57-4) is a white to yellowish crystalline powder with a pungent sulphur dioxide odour. It dissolves readily in water, releasing SO₂, the active agent responsible for its reducing, antimicrobial, and antioxidant properties. Hailei Chemical supplies two main grades:
Understanding the grade is the first step in knowing how to use sodium metabisulphite because food-grade material carries stricter heavy metal limits, while industrial grade may have slightly different dissolution behaviour. Always request a Certificate of Analysis (CoA) from your sodium metabisulfite supplier to verify purity, iron content, and SO₂ release.
One of the most common uses is dechlorination in municipal and industrial water treatment. When free chlorine (HOCl/OCl⁻) is present, sodium metabisulphite acts as a rapid reducing agent. The reaction stoichiometry is: Na₂S₂O₅ + 4H₂O + 2Cl₂ → 2NaHSO₄ + 6HCl. In practice, about 1.0–1.5 mg/L of sodium metabisulphite is required per mg/L of chlorine, though overdosing 10–20% ensures complete removal. Proper procedure for how to use sodium metabisulphite in dechlorination includes:
For those searching for sodium sulfite for dechlorination, note that sodium metabisulphite is often preferred because it provides more SO₂ per unit weight and is more cost-effective, though sodium sulfite (Na₂SO₃) has a slightly higher pH and lower odour. Both chemicals work; however, the metabisulphite version delivers the same sulphite ion after hydrolysis. Our sodium metabisulphite meets AWWA B601-17 standards for drinking water treatment.
In gold extraction, sodium metabisulphite plays a vital role in detoxifying cyanide tailings before discharge. The process relies on the conversion of toxic free cyanide (CN⁻) to less harmful thiocyanate (SCN⁻) or oxidation to cyanate (OCN⁻), often catalysed by copper. Knowing how to use sodium metabisulphite in this context is crucial for regulatory compliance and environmental safety. The typical dosage ratio is 2.5–4.0 kg of sodium metabisulphite per kg of cyanide, depending on the presence of heavy metals and pH. The procedure:
Procurement managers from the Philippines and other mining hubs frequently ask: is there a reliable sodium metabisulfite supplier in the Philippines? While Hailei Chemical ships directly from China with consistent quality and competitive pricing, we can arrange logistic solutions tailored to Southeast Asian ports. Our export packaging includes 25 kg HDPE bags with inner liners and 1000 kg supersacks, all properly labelled according to IMDG Class 9 (UN 2693 for sodium bisulphite solution, but sodium metabisulphite is regulated under UN 1759 Class 8 when wet—our dry product falls under Class 9). Learn more about our mining-grade chemical specifications.
As a food preservative (E223), sodium metabisulphite inhibits microbial growth, prevents enzymatic browning, and preserves colour in dried fruits, wine, and seafood. However, residual sulphite levels are strictly regulated because of potential sodium metabisulfite allergy in sensitive individuals. EU regulations limit sulphite residues (as SO₂) to 10–2000 mg/kg depending on the food category. If you process foods, this is how to use sodium metabisulphite safely:
Operators handling food-grade material must also be aware that repeated inhalation of dust or SO₂ vapours can trigger asthmatic symptoms even in non-allergic individuals. A proper risk assessment and PPE are essential, as we discuss later.
In pulp and paper mills, sodium metabisulphite is used as a reducing agent to brighten mechanical pulp or to eliminate residual chlorine after bleaching sequences. Similarly, in textile finishing, it serves as an anti-chlorine agent to neutralise hypochlorite bleaches and prevent fibre damage. Here’s how to use sodium metabisulphite in both sectors:
These industries benefit from the high purity and low iron content of Hailei Chemical’s industrial grade product, as iron impurities can cause dark spots in pulp and fabric. Explore our product specifications for pulp and textile applications.
The term “sodium metabisulfite allergy” is often searched by industrial hygienists and importers concerned about sulfite sensitivity. While true IgE-mediated allergy is rare, sulfite sensitivity—manifesting as bronchospasm, urticaria, or anaphylactoid reactions—affects 3–10% of asthmatics. For industrial users, the main hazards are inhalation of dust and SO₂ gas, skin and eye corrosion, and potential sensitisation with repeated exposure. Implementing the following safety measures is part of understanding how to use sodium metabisulphite responsibly:
Proper training and accessible Safety Data Sheets (SDS) are non-negotiable. Hailei Chemical provides comprehensive SDS and technical support with every shipment.
Even the best quality sodium metabisulphite will degrade if stored incorrectly. The product is hygroscopic and slowly oxidises to sulphate on exposure to air and moisture, losing SO₂ content. To preserve the purity and ensure predictable performance when you learn how to use sodium metabisulphite, follow these storage guidelines:
Buyers who buy sodium metabisulfite in bulk should work with a supplier that offers climate-controlled logistics. Our 25 kg and 1000 kg bags are shipped in desiccated containers with moisture indicators, critical for long-haul deliveries to humid regions like the Philippines.
Procurement professionals need more than just a price list. When you decide to buy sodium metabisulfite, evaluate suppliers against a consistent framework to avoid operational interruptions. Key evaluation criteria include:
For mining companies in the Philippines searching for a “sodium metabisulfite supplier in the Philippines”, direct import from Hailei Chemical eliminates middlemen and ensures factory-direct pricing. Our logistic partners offer weekly sailings to Manila, with transit time of 8–12 days. Contact us to discuss stocking programs and consignment inventory options.
Summarising the critical usage parameters across applications simplifies daily operations. The table below offers a practical reference:
| Application | Typical Dosage | Mix Concentration | Key Control Parameter |
|---|---|---|---|
| Water dechlorination | 1.0–1.5 mg/L per mg Cl₂ | 5–10% w/v | ORP <450 mV, residual Cl₂ <0.1 mg/L |
| Gold mining cyanide detox | 2.5–4.0 kg/kg CN⁻ | 20% w/v | pH 9–10, residual CN⁻ <1 mg/L |
| Food preservation (dried fruit) | 0.1–1.0% on weight | 0.5–2.0% bath | Residual SO₂ per local regulation |
| Pulp bleaching (activation) | 5–15 kg/tonne pulp | 10% w/v with NaOH | pH 5.5–6.5, °C 60–80 |
| Textile anti-chlorine | 1–2% w/v on fabric | 1–2% solution | Negative starch-iodide test |
Adapt dosages to local conditions, and always run lab-scale trials before full-scale implementation. A small investment in testing can prevent costly off-spec batches.
Comprehensive knowledge of how to use sodium metabisulphite—from precise dosing in water dechlorination and cyanide detox to safe food preservation and textile processing—sets the benchmark for industrial efficiency and worker safety. By pairing best practices with high-purity product and responsible handling, you can mitigate the risks of sodium metabisulfite allergy and ensure regulatory compliance.
When you’re ready to buy sodium metabisulfite, partner with Hailei Chemical, a leading exporter with proven expertise in the Philippines and global markets. Our food-grade and industrial-grade sodium metabisulphite delivers consistent quality, competitive pricing, and dedicated customer service. Request a quotation today or explore full product details and specifications. Let us help you optimise your chemical procurement and application processes.
When sourcing chemicals for sanitization, buyers often encounter two common metabisulfite salts: sodium metabisulfite (Na2S2O5) and potassium metabisulfite for sanitizing purposes. While both release sulfur dioxide (SO2) as the active sanitizing agent, their chemical properties, cost profiles, and suitability differ across industries. This comprehensive guide examines the role of potassium metabisulfite for sanitizing in comparison with sodium metabisulfite, helping procurement managers, water treatment engineers, food processors, and winemakers make informed purchasing decisions. Whether you require a consistent supply of food-grade sodium metabisulfite or are evaluating alternatives for large-scale dechlorination, understanding the nuances between these two salts is critical for operational efficiency and regulatory compliance.
Metabisulfite compounds are inorganic salts that function primarily through the release of sulfur dioxide in aqueous solutions. The general reaction is:
S2O52- + H2O → 2 HSO3– → SO2 + SO32- + H2O
The liberated SO2 acts as a potent antimicrobial agent, antioxidant, and reducing agent, making metabisulfites invaluable for sanitization across multiple industries. Potassium metabisulfite (K2S2O5) and sodium metabisulfite (Na2S2O5) share this core chemistry, but their counter-ions—potassium versus sodium—introduce differences in solubility, hygroscopicity, and regulatory acceptance in certain applications.
Potassium metabisulfite is a white to yellowish crystalline powder with a strong SO2 odor. Its primary sanitization attributes include:
The term potassium metabisulfite for sanitizing frequently appears in specifications for cold-sterilization of wine bottles, barrels, and packaging lines, where its rapid SO2 release and potassium ion compatibility with fermentation processes make it the standard choice.
Sodium metabisulfite, with CAS 7681-57-4, is available in food-grade (purity ≥97%) and industrial-grade (≥98%) specifications from major exporters like Hailei Chemical. Key parameters include:
Procurement managers evaluating potassium metabisulfite for sanitizing often discover that sodium metabisulfite delivers equivalent antimicrobial performance at a significantly lower price point, particularly when sanitizing large volumes of water or process streams.
For effective sanitization, the concentration of free SO2 must be maintained at ≥0.8–1.5 mg/L in aqueous systems, depending on pH and contact time. The following comparison illustrates practical dosing:
| Application | Potassium Metabisulfite Dose | Sodium Metabisulfite Dose |
|---|---|---|
| Brewery equipment sanitization (per 100 L water) | 10–20 g | 8–17 g (due to higher SO2 content) |
| Winemaking must treatment (per tonne of grapes) | 5–10 g | 4–8 g |
| Water dechlorination (per m³ water with 1 mg/L Cl2) | 3.5 g | 2.9 g |
| Food surface sanitizing (dipping solution, per 10 L water) | 5–15 g | 4–12 g |
The higher SO2 efficiency of sodium metabisulfite means less product is required to achieve the same sanitizing result, directly reducing shipping costs and storage volumes for industrial buyers. This efficiency is one reason why global water treatment plants and gold mining operations overwhelmingly prefer Na2S2O5 over potassium alternatives.
A common question among winemakers and food procurement teams is how much sodium metabisulfite per litre of wine should be used. While potassium metabisulfite for sanitizing is widely known in the wine industry, sodium metabisulfite is equally effective as a preservative and sanitizer, often at a lower cost. The critical parameter is the level of free molecular SO2 required to inhibit spoilage microorganisms and prevent oxidation.
For sanitizing wine barrels and tanks before storage, a 1–2% sodium metabisulfite solution (10–20 g per litre of water) is commonly circulated, followed by a rinse. For direct addition to wine as a preservative, the typical dose ranges from 0.1 to 0.3 g/L, which equates to 100–300 mg/L. This translates to:
Using food-grade sodium metabisulfite instead of potassium metabisulfite for sanitizing requires careful calculation of SO2 contribution; because the molecular weight differs, 1 g of sodium metabisulfite yields approximately 0.676 g of SO2, while the same mass of potassium metabisulfite yields about 0.574 g. Thus, winemakers can achieve the same sanitizing effect with roughly 15% less sodium metabisulfite by weight—an advantage that scales significantly in large cooperatives.
The question why is sodium metabisulfite used in food is closely linked to its sanitizing and preservative roles. Sodium metabisulfite (E223 in the EU; INS 223 internationally) is a permitted food additive because it effectively inhibits microbial growth, prevents enzymatic browning, and extends shelf life. Key food applications include:
These sanitization and preservation uses are backed by rigorous toxicological evaluations by JECFA (Joint FAO/WHO Expert Committee) and CODEX. When selecting potassium metabisulfite for sanitizing in food environments, buyers must consider labeling requirements: sodium metabisulfite adds sodium (a concern for low-sodium products), while potassium adds potassium ion, which may be preferable for certain dietary trends. However, the active antimicrobial agent remains the same, and our food-grade sodium metabisulfite meets FCC, USP, and EU purity standards, ensuring compliance with major global food safety regulations.
An essential resource for any procurement team is the sodium metabisulfite MSDS (Material Safety Data Sheet), which outlines hazards, safe handling practices, and emergency procedures. Although sodium metabisulfite is generally recognized as safe in food use, the concentrated chemical poses risks that require proper management:
For large-scale industrial sanitization using either sodium or potassium metabisulfite for sanitizing, operators must ensure engineering controls such as local exhaust ventilation and emergency shower/eyewash stations. Hailei Chemical provides full MSDS documentation, GHS-compliant labeling, and regulatory support with every shipment, minimizing liability for importers and end-users.
Understanding how to make sodium metabisulfite gives buyers insight into purity variations and contaminant profiles that impact sanitization performance. The primary industrial synthesis route involves reacting sulfur dioxide with sodium carbonate (soda ash) or sodium hydroxide in a controlled aqueous environment, followed by crystallization and drying.
Two common methods are:
Critical quality parameters include:
By maintaining rigorous in-house quality control at our Shandong production facility, Hailei Chemical ensures that every batch of sodium metabisulfite delivers consistent SO2 release for reliable sanitization—an advantage that substitutes like potassium metabisulfite for sanitizing cannot match without equally stringent multi-step purification.
For industrial buyers, the decision to purchase potassium metabisulfite for sanitizing instead of sodium metabisulfite often boils down to a few practical criteria:
| Factor | Potassium Metabisulfite | Sodium Metabisulfite (Hailei Chemical Grade) |
|---|---|---|
| Cost per tonne | 25–40% higher | Benchmark |
| SO2 yield | ~57% | ~65.6% |
| Shelf life (dry) | 12 months (hygroscopic) | 12–24 months (lower moisture sensitivity) |
| Regulatory approvals | Narrower, often wine-centric | Broad food, water, mining approvals |
| Typical buyers | Wineries, breweries, specialty food | Water utilities, gold mines, pulp mills, food processors |
Except for cases where potassium ion is required for sensory or labelling reasons, sodium metabisulfite provides superior value, higher active ingredient efficiency, and broader acceptance for water and industrial sanitization. Major water treatment plants globally rely on sodium metabisulfite to dechlorinate potable water and wastewater, a task where the use of potassium metabisulfite for sanitizing would be cost-prohibitive.
One of the largest sanitization-related applications of sodium metabisulfite is the neutralization of chlorine and chloramine disinfectants in municipal drinking water, cooling towers, and reverse osmosis pretreatment. The reaction is instantaneous:
Na2S2O5 + 3 H2O + 2 Cl2 → 2 NaHSO4 + 4 HCl
Typically, 1.5–2.0 mg of sodium metabisulfite is required to neutralize 1 mg/L of chlorine. For a 10 MLD water plant, daily consumption exceeds 150 kg, emphasizing the need for cost-effective bulk supply. In gold mining, sodium metabisulfite detoxifies cyanide tailings by converting free cyanide to cyanate, preventing environmental contamination. Neither application is practical with potassium metabisulfite due to its 40% higher price and inferior SO2 content.
Hailei Chemical’s industrial-grade sodium metabisulfite is supplied in 25 kg HDPE bags, 1000 kg FIBCs, or customized packaging, with consistent 98% purity and low iron content essential for avoiding staining in water lines and process equipment.
International procurement of sanitization chemicals like potassium metabisulfite for sanitizing or sodium metabisulfite requires a supplier with robust logistics, regulatory expertise, and rapid responsiveness. Hailei Fine Chemical exports to over 50 countries, offering:
For buyers currently using potassium metabisulfite for sanitizing in applications like wine barrel sanitation, food preparation surfaces, or vegetable wash water, transitioning to high-purity sodium metabisulfite can yield annual savings of 20–30% without compromising antimicrobial performance. Our technical team can provide comparable dosing tables and migration support.
Yes, in most cases. A 1% sodium metabisulfite solution provides equivalent sanitizing power to a 1.2% potassium metabisulfite solution due to higher SO2 release. Ensure that the bottle drainage or residual rinse allows no more than 0.2 mg/L of sodium into the final wine batch, a level well below taste thresholds.
Excellent. Sodium metabisulfite solutions at 0.5–1.0% are non-corrosive to stainless steel and effective against bacteria, yeast, and molds. Recirculate for 15–20 minutes at ambient temperature, then flush with potable water. Potassium metabisulfite for sanitizing is similarly used but is less cost-effective for large pipe networks.
Both salts oxidize to sulfate ions, which are naturally present in water. Sodium metabisulfite adds sulfate and sodium; potassium adds sulfate and potassium. Neither accumulates as persistent pollutants if discharged in compliance with local water quality standards. Our products meet REACH and K-REACH registration requirements.
You can download the latest sodium metabisulfite MSDS directly from our website or request a shipment-specific version from our quality assurance team when placing an order.
Whether you are evaluating potassium metabisulfite for sanitizing as a niche solution or sourcing sodium metabisulfite for large-scale water treatment, food preservation, and gold processing, the chemical you select must deliver reliable purity, competitive pricing, and international certifications. Hailei Chemical’s sodium metabisulfite consistently meets these demands, with the added advantage of a higher SO2 content than potassium alternatives and broad regulatory acceptance worldwide.
For procurement managers seeking to optimize sanitization costs, simplify supply chains, and maintain rigorous quality control, explore our sodium metabisulfite product specifications and see why leading industrial buyers choose Hailei Chemical as their long-term partner.
Ready to discuss your sanitization chemical requirements? Contact our export team today for a competitive quotation, free sample, or technical consultation. Request a quote now and experience the reliability of China’s premier metabisulfite manufacturer.