When sourcing industrial reducing agents, procurement professionals often face the decision: sodium hydrosulfite vs sodium sulfite. Both chemicals serve as powerful reducing agents, but their distinct chemistries, handling requirements, and application profiles make each suited to very different processes. Choosing the wrong product can lead to efficiency losses, safety incidents, and inflated operating costs. In this comprehensive buyer’s guide, we break down the key differences, examine technical specifications, review safety data sheets (SDS), and provide practical procurement insights to help you make an informed choice.
At the molecular level, sodium hydrosulfite (also called sodium dithionite, Na₂S₂O₄) and sodium sulfite (Na₂SO₃) differ fundamentally. Sodium hydrosulfite contains sulfur in an oxidation state of +3, while sulfite has sulfur at +4. This difference gives hydrosulfite a much stronger reducing capability, but also makes it more reactive, unstable, and hazardous. Sodium sulfite is a milder, more stable reducing agent that is easier to handle and store.
Key chemical properties at a glance:
These chemical profiles directly impact how each product is used in industrial settings. Hydrosulfite’s aggressive reactivity is essential for rapid bleaching operations, while sulfite’s stability and controlled release of sulfite ions make it ideal for long-duration processes like boiler water deoxygenation.
Sodium hydrosulfite is the reducing agent of choice when high reduction power and speed are critical. It is widely used in:
Its ability to reduce dyes and colored impurities rapidly makes it indispensable in these color-sensitive sectors. However, the instability of hydrosulfite demands stringent storage (cool, dry, airtight conditions) and short shelf life.
Sodium sulfite’s moderate and stable reducing action finds a different set of heavy industrial uses:
A procurement manager for a power plant will find sodium sulfite essential for corrosion control, while a textile finishing plant manager may need both chemicals for different steps in their workflow. Understanding these specific roles is critical when comparing sodium hydrosulfite vs sodium sulfite.
When procuring sodium sulfite, technical buyers must verify that the offered grade meets their process tolerances. Typical industrial grade sodium sulfite specifications from a reliable supplier like Weifang Hailei Fine Chemical Co., Ltd. include:
| Parameter | Specification (Typical) |
|---|---|
| Purity (Na₂SO₃) | ≥ 96.0% (anhydrous), ≥ 98.0% for certain grades |
| Iron (Fe) | ≤ 0.005% |
| Water Insoluble Matter | ≤ 0.03% |
| pH (5% aqueous solution) | 9.0 – 10.5 |
| Heavy Metals (as Pb) | ≤ 0.002% |
| Appearance | White to slightly yellowish crystalline powder or granules |
Buyers should pay special attention to iron content and water insolubles, as these can foul boiler internals or discolor pulps. Sodium sulfite is available in anhydrous (Na₂SO₃) and heptahydrate (Na₂SO₃·7H₂O) forms, with the anhydrous grade offering higher active content and lower shipping weights—a key logistics consideration. For detailed technical data, download the full specification sheet on our sodium sulfite product page.
Understanding how sodium sulfite in water behaves is essential for safe and effective use. Sodium sulfite is highly soluble: about 28 grams dissolve in 100 mL of water at 20°C, forming a clear, mildly alkaline solution (pH ~9.5 for a 5% solution). The dissolution process is slightly endothermic, causing a minor temperature drop.
In boiler water treatment, the sulfite ion (SO₃²⁻) reacts with dissolved oxygen to form sulfate (SO₄²⁻), a stable and non-corrosive byproduct. The reaction is fast at elevated temperatures (>80°C), making sulfite an excellent oxygen scavenger. A typical maintenance dosage is 30-60 mg/L of sodium sulfite, depending on feedwater oxygen levels and system metallurgy. Overdosing can increase boiler water solids, so precise control is recommended.
When preparing solutions, always add sodium sulfite to water slowly with agitation, wearing appropriate PPE. Avoid direct contact with acids, as this can release toxic sulfur dioxide gas. For large-volume users, Hailei Chemical can provide soluble bag or pre-dissolved delivery advice to simplify handling.
Industrial safety managers rely on the Safety Data Sheet (SDS) to assess hazards and establish safe handling protocols. The sodium sulfite SDS classifies the product as a skin and eye irritant, as well as a respiratory irritant. Typical GHS hazard statements include H315 (Causes skin irritation), H319 (Causes serious eye irritation), and H335 (May cause respiratory irritation). The corresponding GHS pictogram is the exclamation mark.
In contrast, sodium hydrosulfite carries more severe hazards: it is classified as a self-heating substance (H251), can ignite spontaneously if exposed to moist air, and releases toxic sulfur dioxide fumes upon decomposition. Its SDS will show both the flame (GHS02) and exclamation mark (GHS07) pictograms, along with stricter storage and handling requirements.
Key safety recommendations for sodium sulfite:
The SDS should always be consulted before use. Hailei Chemical provides compliant SDS documentation with every shipment, ensuring full regulatory transparency for importers and end-users.
While this guide focuses on industrial technical grades, the keyword sodium sulphite in food frequently appears in procurement conversations. Sodium sulfite is recognized as food additive E221 and functions as a preservative and antioxidant in certain foods such as dried fruits, fruit juices, and wine making. It prevents browning and microbial growth. However, food-grade sodium sulfite must meet strict purity criteria (typically ≥ 98.5%, heavy metals < 5 ppm, etc.) and is supplied under a separate certification program.
Hailei Chemical’s standard sodium sulfite is a technical grade product intended for industrial applications like water treatment, pulp, and textiles. If your facility requires food-grade material, please contact our technical team to discuss feasibility and custom specification options. We always advise buyers to clearly state intended use to ensure you receive the appropriate grade, avoiding costly rejections at customs.
When evaluating sodium hydrosulfite vs sodium sulfite, total cost of ownership often tips the scale toward sulfite for many applications. Sodium hydrosulfite is typically 2–3 times more expensive per ton, has tighter storage constraints (often requiring air-conditioned warehousing), and a shorter shelf life (6-12 months) compared to sodium sulfite’s 2-year shelf life when stored properly. Shipping also differs: hydrosulfite is classified as a hazardous material (Class 4.2 self-heating substance) under international transport regulations, triggering stricter packaging and handling surcharges. Sodium sulfite is generally classed as non-dangerous for transport (unless mixed with certain additives), simplifying logistics and lowering freight costs.
From a supply security perspective, sodium sulfite benefits from a more mature and diversified global production base. Chinese manufacturers like Hailei have robust capacity, ensuring stable quarterly pricing and reliable container lead times. For high-volume consumers such as power plants or pulp mills, the consistent quality and cost stability of sodium sulfite make it a safer long-term procurement choice.
Weifang Hailei Fine Chemical Co., Ltd. has been a trusted partner for industrial chemical buyers worldwide for over a decade. Our sodium sulfite is produced in modern ISO-certified facilities to consistent purity levels, with regular third-party testing. We offer flexible packaging options—25 kg woven bags, 1,000 kg supersacks, or custom requests—and assist with all export documentation, including Certificate of Analysis (CoA) and MSDS in multiple languages.
Our technical support team can help you optimize dosage, compare material cost per unit of active reducing power, and even arrange trial samples for your plant trials. Visit our dedicated sodium sulfite page for full product details and a downloadable preliminary specification.
Whether you are finalizing your boiler water treatment program, scaling up a textile desizing line, or evaluating alternative suppliers, the right choice between sodium hydrosulfite and sodium sulfite begins with accurate technical data and reliable supplier support. Hailei Chemical is ready to deliver the high-quality sodium sulfite you need, on time and on spec.
Request a competitive quote today or speak with one of our industrial chemical specialists for personalized assistance in selecting the optimal reducing agent for your process.
When sourcing industrial reducing agents, procurement professionals often face the decision: sodium hydrosulfite vs sodium sulfite. Both chemicals serve as powerful reducing agents, but their distinct chemistries, handling requirements, and application profiles make each suited to very different processes. Choosing the wrong product can lead to efficiency losses, safety incidents, and inflated operating costs. In this comprehensive buyer’s guide, we break down the key differences, examine technical specifications, review safety data sheets (SDS), and provide practical procurement insights to help you make an informed choice.
At the molecular level, sodium hydrosulfite (also called sodium dithionite, Na₂S₂O₄) and sodium sulfite (Na₂SO₃) differ fundamentally. Sodium hydrosulfite contains sulfur in an oxidation state of +3, while sulfite has sulfur at +4. This difference gives hydrosulfite a much stronger reducing capability, but also makes it more reactive, unstable, and hazardous. Sodium sulfite is a milder, more stable reducing agent that is easier to handle and store.
Key chemical properties at a glance:
These chemical profiles directly impact how each product is used in industrial settings. Hydrosulfite’s aggressive reactivity is essential for rapid bleaching operations, while sulfite’s stability and controlled release of sulfite ions make it ideal for long-duration processes like boiler water deoxygenation.
Sodium hydrosulfite is the reducing agent of choice when high reduction power and speed are critical. It is widely used in:
Its ability to reduce dyes and colored impurities rapidly makes it indispensable in these color-sensitive sectors. However, the instability of hydrosulfite demands stringent storage (cool, dry, airtight conditions) and short shelf life.
Sodium sulfite’s moderate and stable reducing action finds a different set of heavy industrial uses:
A procurement manager for a power plant will find sodium sulfite essential for corrosion control, while a textile finishing plant manager may need both chemicals for different steps in their workflow. Understanding these specific roles is critical when comparing sodium hydrosulfite vs sodium sulfite.
When procuring sodium sulfite, technical buyers must verify that the offered grade meets their process tolerances. Typical industrial grade sodium sulfite specifications from a reliable supplier like Weifang Hailei Fine Chemical Co., Ltd. include:
| Parameter | Specification (Typical) |
|---|---|
| Purity (Na₂SO₃) | ≥ 96.0% (anhydrous), ≥ 98.0% for certain grades |
| Iron (Fe) | ≤ 0.005% |
| Water Insoluble Matter | ≤ 0.03% |
| pH (5% aqueous solution) | 9.0 – 10.5 |
| Heavy Metals (as Pb) | ≤ 0.002% |
| Appearance | White to slightly yellowish crystalline powder or granules |
Buyers should pay special attention to iron content and water insolubles, as these can foul boiler internals or discolor pulps. Sodium sulfite is available in anhydrous (Na₂SO₃) and heptahydrate (Na₂SO₃·7H₂O) forms, with the anhydrous grade offering higher active content and lower shipping weights—a key logistics consideration. For detailed technical data, download the full specification sheet on our sodium sulfite product page.
Understanding how sodium sulfite in water behaves is essential for safe and effective use. Sodium sulfite is highly soluble: about 28 grams dissolve in 100 mL of water at 20°C, forming a clear, mildly alkaline solution (pH ~9.5 for a 5% solution). The dissolution process is slightly endothermic, causing a minor temperature drop.
In boiler water treatment, the sulfite ion (SO₃²⁻) reacts with dissolved oxygen to form sulfate (SO₄²⁻), a stable and non-corrosive byproduct. The reaction is fast at elevated temperatures (>80°C), making sulfite an excellent oxygen scavenger. A typical maintenance dosage is 30-60 mg/L of sodium sulfite, depending on feedwater oxygen levels and system metallurgy. Overdosing can increase boiler water solids, so precise control is recommended.
When preparing solutions, always add sodium sulfite to water slowly with agitation, wearing appropriate PPE. Avoid direct contact with acids, as this can release toxic sulfur dioxide gas. For large-volume users, Hailei Chemical can provide soluble bag or pre-dissolved delivery advice to simplify handling.
Industrial safety managers rely on the Safety Data Sheet (SDS) to assess hazards and establish safe handling protocols. The sodium sulfite SDS classifies the product as a skin and eye irritant, as well as a respiratory irritant. Typical GHS hazard statements include H315 (Causes skin irritation), H319 (Causes serious eye irritation), and H335 (May cause respiratory irritation). The corresponding GHS pictogram is the exclamation mark.
In contrast, sodium hydrosulfite carries more severe hazards: it is classified as a self-heating substance (H251), can ignite spontaneously if exposed to moist air, and releases toxic sulfur dioxide fumes upon decomposition. Its SDS will show both the flame (GHS02) and exclamation mark (GHS07) pictograms, along with stricter storage and handling requirements.
Key safety recommendations for sodium sulfite:
The SDS should always be consulted before use. Hailei Chemical provides compliant SDS documentation with every shipment, ensuring full regulatory transparency for importers and end-users.
While this guide focuses on industrial technical grades, the keyword sodium sulphite in food frequently appears in procurement conversations. Sodium sulfite is recognized as food additive E221 and functions as a preservative and antioxidant in certain foods such as dried fruits, fruit juices, and wine making. It prevents browning and microbial growth. However, food-grade sodium sulfite must meet strict purity criteria (typically ≥ 98.5%, heavy metals < 5 ppm, etc.) and is supplied under a separate certification program.
Hailei Chemical’s standard sodium sulfite is a technical grade product intended for industrial applications like water treatment, pulp, and textiles. If your facility requires food-grade material, please contact our technical team to discuss feasibility and custom specification options. We always advise buyers to clearly state intended use to ensure you receive the appropriate grade, avoiding costly rejections at customs.
When evaluating sodium hydrosulfite vs sodium sulfite, total cost of ownership often tips the scale toward sulfite for many applications. Sodium hydrosulfite is typically 2–3 times more expensive per ton, has tighter storage constraints (often requiring air-conditioned warehousing), and a shorter shelf life (6-12 months) compared to sodium sulfite’s 2-year shelf life when stored properly. Shipping also differs: hydrosulfite is classified as a hazardous material (Class 4.2 self-heating substance) under international transport regulations, triggering stricter packaging and handling surcharges. Sodium sulfite is generally classed as non-dangerous for transport (unless mixed with certain additives), simplifying logistics and lowering freight costs.
From a supply security perspective, sodium sulfite benefits from a more mature and diversified global production base. Chinese manufacturers like Hailei have robust capacity, ensuring stable quarterly pricing and reliable container lead times. For high-volume consumers such as power plants or pulp mills, the consistent quality and cost stability of sodium sulfite make it a safer long-term procurement choice.
Weifang Hailei Fine Chemical Co., Ltd. has been a trusted partner for industrial chemical buyers worldwide for over a decade. Our sodium sulfite is produced in modern ISO-certified facilities to consistent purity levels, with regular third-party testing. We offer flexible packaging options—25 kg woven bags, 1,000 kg supersacks, or custom requests—and assist with all export documentation, including Certificate of Analysis (CoA) and MSDS in multiple languages.
Our technical support team can help you optimize dosage, compare material cost per unit of active reducing power, and even arrange trial samples for your plant trials. Visit our dedicated sodium sulfite page for full product details and a downloadable preliminary specification.
Whether you are finalizing your boiler water treatment program, scaling up a textile desizing line, or evaluating alternative suppliers, the right choice between sodium hydrosulfite and sodium sulfite begins with accurate technical data and reliable supplier support. Hailei Chemical is ready to deliver the high-quality sodium sulfite you need, on time and on spec.
Request a competitive quote today or speak with one of our industrial chemical specialists for personalized assistance in selecting the optimal reducing agent for your process.
When sourcing industrial reducing agents, procurement professionals often face the decision: sodium hydrosulfite vs sodium sulfite. Both chemicals serve as powerful reducing agents, but their distinct chemistries, handling requirements, and application profiles make each suited to very different processes. Choosing the wrong product can lead to efficiency losses, safety incidents, and inflated operating costs. In this comprehensive buyer’s guide, we break down the key differences, examine technical specifications, review safety data sheets (SDS), and provide practical procurement insights to help you make an informed choice.
At the molecular level, sodium hydrosulfite (also called sodium dithionite, Na₂S₂O₄) and sodium sulfite (Na₂SO₃) differ fundamentally. Sodium hydrosulfite contains sulfur in an oxidation state of +3, while sulfite has sulfur at +4. This difference gives hydrosulfite a much stronger reducing capability, but also makes it more reactive, unstable, and hazardous. Sodium sulfite is a milder, more stable reducing agent that is easier to handle and store.
Key chemical properties at a glance:
These chemical profiles directly impact how each product is used in industrial settings. Hydrosulfite’s aggressive reactivity is essential for rapid bleaching operations, while sulfite’s stability and controlled release of sulfite ions make it ideal for long-duration processes like boiler water deoxygenation.
Sodium hydrosulfite is the reducing agent of choice when high reduction power and speed are critical. It is widely used in:
Its ability to reduce dyes and colored impurities rapidly makes it indispensable in these color-sensitive sectors. However, the instability of hydrosulfite demands stringent storage (cool, dry, airtight conditions) and short shelf life.
Sodium sulfite’s moderate and stable reducing action finds a different set of heavy industrial uses:
A procurement manager for a power plant will find sodium sulfite essential for corrosion control, while a textile finishing plant manager may need both chemicals for different steps in their workflow. Understanding these specific roles is critical when comparing sodium hydrosulfite vs sodium sulfite.
When procuring sodium sulfite, technical buyers must verify that the offered grade meets their process tolerances. Typical industrial grade sodium sulfite specifications from a reliable supplier like Weifang Hailei Fine Chemical Co., Ltd. include:
| Parameter | Specification (Typical) |
|---|---|
| Purity (Na₂SO₃) | ≥ 96.0% (anhydrous), ≥ 98.0% for certain grades |
| Iron (Fe) | ≤ 0.005% |
| Water Insoluble Matter | ≤ 0.03% |
| pH (5% aqueous solution) | 9.0 – 10.5 |
| Heavy Metals (as Pb) | ≤ 0.002% |
| Appearance | White to slightly yellowish crystalline powder or granules |
Buyers should pay special attention to iron content and water insolubles, as these can foul boiler internals or discolor pulps. Sodium sulfite is available in anhydrous (Na₂SO₃) and heptahydrate (Na₂SO₃·7H₂O) forms, with the anhydrous grade offering higher active content and lower shipping weights—a key logistics consideration. For detailed technical data, download the full specification sheet on our sodium sulfite product page.
Understanding how sodium sulfite in water behaves is essential for safe and effective use. Sodium sulfite is highly soluble: about 28 grams dissolve in 100 mL of water at 20°C, forming a clear, mildly alkaline solution (pH ~9.5 for a 5% solution). The dissolution process is slightly endothermic, causing a minor temperature drop.
In boiler water treatment, the sulfite ion (SO₃²⁻) reacts with dissolved oxygen to form sulfate (SO₄²⁻), a stable and non-corrosive byproduct. The reaction is fast at elevated temperatures (>80°C), making sulfite an excellent oxygen scavenger. A typical maintenance dosage is 30-60 mg/L of sodium sulfite, depending on feedwater oxygen levels and system metallurgy. Overdosing can increase boiler water solids, so precise control is recommended.
When preparing solutions, always add sodium sulfite to water slowly with agitation, wearing appropriate PPE. Avoid direct contact with acids, as this can release toxic sulfur dioxide gas. For large-volume users, Hailei Chemical can provide soluble bag or pre-dissolved delivery advice to simplify handling.
Industrial safety managers rely on the Safety Data Sheet (SDS) to assess hazards and establish safe handling protocols. The sodium sulfite SDS classifies the product as a skin and eye irritant, as well as a respiratory irritant. Typical GHS hazard statements include H315 (Causes skin irritation), H319 (Causes serious eye irritation), and H335 (May cause respiratory irritation). The corresponding GHS pictogram is the exclamation mark.
In contrast, sodium hydrosulfite carries more severe hazards: it is classified as a self-heating substance (H251), can ignite spontaneously if exposed to moist air, and releases toxic sulfur dioxide fumes upon decomposition. Its SDS will show both the flame (GHS02) and exclamation mark (GHS07) pictograms, along with stricter storage and handling requirements.
Key safety recommendations for sodium sulfite:
The SDS should always be consulted before use. Hailei Chemical provides compliant SDS documentation with every shipment, ensuring full regulatory transparency for importers and end-users.
While this guide focuses on industrial technical grades, the keyword sodium sulphite in food frequently appears in procurement conversations. Sodium sulfite is recognized as food additive E221 and functions as a preservative and antioxidant in certain foods such as dried fruits, fruit juices, and wine making. It prevents browning and microbial growth. However, food-grade sodium sulfite must meet strict purity criteria (typically ≥ 98.5%, heavy metals < 5 ppm, etc.) and is supplied under a separate certification program.
Hailei Chemical’s standard sodium sulfite is a technical grade product intended for industrial applications like water treatment, pulp, and textiles. If your facility requires food-grade material, please contact our technical team to discuss feasibility and custom specification options. We always advise buyers to clearly state intended use to ensure you receive the appropriate grade, avoiding costly rejections at customs.
When evaluating sodium hydrosulfite vs sodium sulfite, total cost of ownership often tips the scale toward sulfite for many applications. Sodium hydrosulfite is typically 2–3 times more expensive per ton, has tighter storage constraints (often requiring air-conditioned warehousing), and a shorter shelf life (6-12 months) compared to sodium sulfite’s 2-year shelf life when stored properly. Shipping also differs: hydrosulfite is classified as a hazardous material (Class 4.2 self-heating substance) under international transport regulations, triggering stricter packaging and handling surcharges. Sodium sulfite is generally classed as non-dangerous for transport (unless mixed with certain additives), simplifying logistics and lowering freight costs.
From a supply security perspective, sodium sulfite benefits from a more mature and diversified global production base. Chinese manufacturers like Hailei have robust capacity, ensuring stable quarterly pricing and reliable container lead times. For high-volume consumers such as power plants or pulp mills, the consistent quality and cost stability of sodium sulfite make it a safer long-term procurement choice.
Weifang Hailei Fine Chemical Co., Ltd. has been a trusted partner for industrial chemical buyers worldwide for over a decade. Our sodium sulfite is produced in modern ISO-certified facilities to consistent purity levels, with regular third-party testing. We offer flexible packaging options—25 kg woven bags, 1,000 kg supersacks, or custom requests—and assist with all export documentation, including Certificate of Analysis (CoA) and MSDS in multiple languages.
Our technical support team can help you optimize dosage, compare material cost per unit of active reducing power, and even arrange trial samples for your plant trials. Visit our dedicated sodium sulfite page for full product details and a downloadable preliminary specification.
Whether you are finalizing your boiler water treatment program, scaling up a textile desizing line, or evaluating alternative suppliers, the right choice between sodium hydrosulfite and sodium sulfite begins with accurate technical data and reliable supplier support. Hailei Chemical is ready to deliver the high-quality sodium sulfite you need, on time and on spec.
Request a competitive quote today or speak with one of our industrial chemical specialists for personalized assistance in selecting the optimal reducing agent for your process.
For Francophone industrial buyers and global procurement managers seeking a reliable oxygen scavenger, le sulfite de sodium (sodium sulfite, Na2SO3) remains a cornerstone of effective boiler water treatment and numerous industrial processes. Whether you are evaluating chemical specifications, optimizing dosing in high-pressure steam systems, or comparing bulk supply options from China, a thorough understanding of sodium sulfite’s chemistry, applications, and procurement logistics is essential. This comprehensive guide explores every critical aspect of le sulfite de sodium—from its chemical formula and anhydrous properties to its reaction in water and the key factors you must consider when you buy sodium sulphite as a powder or crystal. As a leading Chinese manufacturer, Hailei Chemical provides industrial-grade sodium sulfite with consistent quality, backed by technical expertise that helps you achieve efficient and cost-effective operations.
The term le sulfite de sodium is the French equivalent of sodium sulfite, a widely used inorganic compound. Its chemical formula is Na2SO3, indicating two sodium ions (Na+) and one sulfite ion (SO32−). In solid form, it appears as a white crystalline powder or granular material, highly soluble in water, and moderately stable when kept dry. Sodium sulfite is commercially available in two principal grades: anhydrous (Na2SO3, no water of crystallization) and heptahydrate (Na2SO3·7H2O).
When dissolved in water, sodium sulfite dissociates completely into sodium and sulfite ions. The sulfite ion is a potent reducing agent, which is the key to its industrial value. In boiler water chemistry, sulfite reacts rapidly with dissolved oxygen to form harmless sulfate (SO42−), thereby preventing oxygen-induced corrosion of steel surfaces. The same reducing property makes le sulfite de sodium invaluable in textile bleaching neutralization, pulp processing, and several niche applications such as photographic developers and leather dehairing.
For buyers, understanding the sodium sulfite formula and its implications is the first step in selecting the correct product for your process. The anhydrous form delivers a higher concentration of active sulfite per unit mass, while the heptahydrate offers easier handling in some ambient conditions but contains over 50% water by weight. At Hailei Chemical, we supply sodium sulfite with a guaranteed Na2SO3 purity of 96–98%, available in both anhydrous and heptahydrate forms. Visit our sodium sulfite product page for detailed technical data and packaging options.
A common question from procurement teams is what is sodium sulfite anhydrous and how it differs from the hydrated version. The answer lies in water content and logistics.
As a buyer, your decision hinges on freight costs, storage conditions, and process requirements. Anhydrous sodium sulfite offers more “bang for your buck” in terms of active chemical delivered per container, typically lowering total landed cost despite a higher unit price. Hailei Chemical can supply both forms from our production base in Weifang, China, and our technical team can help you evaluate the total cost of ownership before you place a bulk order. For a full breakdown of technical specifications, review our product data sheet.
The most critical industrial use of le sulfite de sodium is as an oxygen scavenger in steam-generating boilers. Understanding sodium sulfite in water and its reaction kinetics is essential for achieving effective corrosion protection while avoiding excessive chemical waste.
When sodium sulfite is injected into boiler feedwater, it quickly dissociates and then reacts with dissolved oxygen according to the following stoichiometric equation:
2Na2SO3 + O2 → 2Na2SO4
Theoretically, 7.88 parts of pure Na2SO3 are required to remove 1 part of dissolved oxygen. In practice, an excess of sulfite is maintained—typically 20–40 mg/L as SO3 residual in the boiler water—to ensure complete oxygen removal and to provide a safety margin against momentary oxygen ingress. The reaction rate is strongly dependent on temperature and pH; at ambient feedwater temperatures, the reaction is slow, but it accelerates dramatically above 70°C and with the aid of a catalyst (cobalt or copper salts) when treating cold water.
Because the anhydrous form dissolves quickly and provides consistent active content, it is the first choice for most modern power plants and industrial boiler houses. Hailei Chemical supplies high-purity sodium sulfite that dissolves rapidly with minimal insolubles, ensuring trouble-free injection. For custom dosing guidance or to discuss your specific boiler operating pressure and feedwater quality, our engineers are available through your free quote request.
While water treatment accounts for the largest market share, le sulfite de sodium finds diverse use across multiple industries. Understanding these applications can help buyers source a single chemical for multiple in-house processes or qualify a supplier who meets broader industry standards.
In chemical pulping, sodium sulfite is used as a cooking liquor component in neutral sulfite semi-chemical (NSSC) processes, where it helps delignify wood chips mildly, preserving more hemicellulose and producing high-yield pulp for corrugated medium. It also serves as a reducing agent in bleaching sequences to neutralize residual chlorine or chlorine dioxide, preventing fiber degradation.
After bleaching cotton or synthetic textiles with hydrogen peroxide or chlorine-based bleaches, sodium sulfite acts as an antichlor to remove excess oxidants, which could otherwise weaken fibers or interfere with subsequent dyeing. The result is a more uniform finish and longer-lasting fabric quality. Textile finishing plants particularly value the anhydrous grade for its rapid dissolving and precise chemical control.
In black-and-white photographic developers, sodium sulfite serves as a preservative that scavenges oxygen and prevents the developing agent (such as hydroquinone) from oxidizing prematurely. While digital imaging has reduced demand, there remains a niche market for high-purity sodium sulfite from industrial chemical suppliers.
Sodium sulfite is added to lime-sulfide solutions in the leather beamhouse to accelerate the unhairing of hides while reducing the required concentration of sodium sulfide. This reduces environmental load and improves working conditions. Leather tanneries in North Africa and Francophone West Africa are significant consumers of le sulfite de sodium, often importing directly from Chinese manufacturers.
Beyond boiler feedwater, sodium sulfite is employed to dechlorinate municipal drinking water or treated wastewater before discharge. It neutralizes free chlorine and chloramines more rapidly than sulfur dioxide gas, making it a safer choice for small to medium plants. The anhydrous powder is dosed as a dilute solution to meet dechlorination targets.
For each application, purity requirements may differ slightly. Photographic grade might require lower iron and heavy metal content, while water treatment grades focus on consistent activity. Hailei Chemical can provide tailored specifications upon request, ensuring your purchase matches the end-use without paying for unneeded premium purity. Contact us to discuss your application-specific needs.
Procurement professionals looking to buy sodium sulphite in bulk must scrutinize beyond the nominal purity figure. The following quality parameters directly influence performance, handling, and regulatory compliance:
| Parameter | Typical Value (Anhydrous) | Importance |
|---|---|---|
| Na2SO3 Assay | ≥96.0% | Direct indicator of oxygen-scavenging capacity; lower assay means higher consumption and cost. |
| Sodium Sulfate (Na2SO4) | ≤2.5% | Inert byproduct from oxidation; high sulfate increases dissolved solids and blowdown. |
| Sodium Carbonate (Na2CO3) | ≤0.5% | Minor alkalinity contributor; excessive levels may affect pH control. |
| Iron (Fe) | ≤0.003% | Critical for photographic and some textile applications; can catalyze unwanted oxidation. |
| Heavy Metals (as Pb) | ≤0.002% | Required for food-contact (e.g., dechlorination of potable water) and environmental compliance. |
| Water Insoluble Matter | ≤0.03% | Avoids clogging of dosing lines and strainers. |
| pH of 1% solution | 8.5–9.5 | Mild alkalinity aids boiler water chemistry. |
When evaluating Chinese suppliers, request a Certificate of Analysis (CoA) for each batch and verify that the testing methods follow GB/T 9005 or ISO 3627 standards. Reputable manufacturers like Hailei Chemical provide full traceability and will accommodate third-party inspection at our factory or loading port. Bulk shipments typically arrive in 25 kg HDPE bags, 1-ton FIBCs, or custom packaging, all with inner liners that minimize moisture ingress. Our sales team can help you decide the optimal packaging and freight arrangement to match your port facilities and storage inventory. For immediate requirements, request a quote for sodium sulphite today.
Global buyers across Francophone Africa, Europe, and Asia are increasingly turning to Chinese exporters to secure consistent, cost-effective supplies of le sulfite de sodium. However, successful sourcing requires more than comparing prices; you must navigate product specifications, logistics, and regulatory considerations.
China is the world’s largest producer of sodium sulfite, leveraging integrated sulfur and soda ash supply chains. This means competitive pricing, flexible production scales, and short lead times. Hailei Chemical, located in Weifang, Shandong Province, benefits from proximity to major raw material sources and the Qingdao port, one of China’s busiest chemical export hubs.
Sodium sulfite is classified as a non-hazardous chemical for transport under most regulations (IMDG, ADR). It does not require DG labeling, which simplifies freight booking and lowers shipping costs. Still, proper shipper’s declaration and a Safety Data Sheet (SDS) in the local language are mandatory. Hailei Chemical provides SDS in English, French, and other languages, along with all necessary certificates (CoA, country of origin, REACH compliance if applicable).
To mitigate the risk of receiving off-spec material, buyers should:
Hailei Chemical has a long track record of meeting international specifications for water treatment, pulp, and textile customers. We treat every order as a partnership, providing technical support, regular quality updates, and flexible logistics coordination. When you’re ready to secure your supply chain for le sulfite de sodium, use our online form to get a detailed offer within one business day.
Choosing the right manufacturer for your sodium sulfite supply is critical for uninterrupted plant operations. Hailei Chemical offers distinct advantages for B2B buyers:
Our sodium sulfite is already trusted by power plants in West Africa, textile mills in Southeast Asia, and leather processing units across the Mediterranean. We welcome you to join this community of satisfied clients. Visit our dedicated product page for complete specifications, and when you’re ready to discuss volumes, pricing, and delivery schedules, submit your request for a quotation—we’ll respond with a tailored proposal.