Calcium Chloride Buyer's Guide: How to Choose the Right Grade and Avoid Common Traps

Calcium Chloride Technical Data - Molecular Formula, Properties, and Specifications

Basic reference data for anhydrous calcium chloride, useful for procurement teams cross-checking supplier specification sheets or engineers doing preliminary calculations before a formal data sheet review.

Core identification data

• Molecular formula: CaCl₂
• CAS number: 10043-52-4 (anhydrous)
• Molar mass: approximately 110.98 g/mol
• Appearance: white, hygroscopic solid - available as flakes, pellets, granules, or powder depending on production process

Physical properties (anhydrous)

• Melting point: approximately 772-775°C
• Density: approximately 2.15 g/cm³ for the solid; bulk density varies by form and packing (loose vs compacted), typically in the range suppliers list separately on their spec sheets
• Solubility in water: highly soluble, with solubility increasing with temperature - roughly 74.5 g per 100 g water at 20°C, rising further at higher temperatures
• Heat of solution: dissolution is exothermic - noticeable heat generation when dissolving in water, which is a practical consideration for handling and brine mixing rather than just a lab curiosity

A note on the dihydrate form

Calcium chloride dihydrate (CaCl₂·2H₂O) is a distinct hydrate form with two water molecules incorporated into its crystal structure, giving it a different molar mass (approximately 147.01 g/mol) and different labeled CaCl2 content (typically 74-77% when sold commercially). If you're doing dosage calculations, confirm which form your supplier's product actually is - the water content difference matters for any calculation based on active CaCl2 mass.

Where to get authoritative data

For anything beyond general reference - toxicological data, detailed physical property tables across temperature ranges, or regulatory classification specifics - the safety data sheet (SDS) from your specific supplier is the correct source, not a general web reference. Properties can vary slightly depending on production process and purity grade, and regulatory classifications differ by jurisdiction. PubChem and similar public chemical databases are useful for cross-checking basic identification data, but procurement decisions and safety documentation should rely on the SDS tied to the actual product being purchased.

Why this matters for sourcing

A supplier who can't produce a proper, product-specific SDS and COA on request is worth treating with some caution, regardless of how competitive the price looks. Basic technical data like the figures above is publicly available and easy for anyone to copy onto a product listing - what actually confirms you're getting the product you're paying for is documentation tied to the specific batch you're buying, not general reference values.

Calcium Chloride Buyer FAQ - Storage, Dosage, and Common Questions

Answers to the questions that come up most often from buyers sourcing calcium chloride for the first time or evaluating a new supplier.

How should calcium chloride be stored?

Keep it dry and sealed. Both anhydrous and dihydrate forms are hygroscopic and will absorb moisture from humid air if packaging is compromised or bags are left open. Store off damp warehouse floors (pallets, not direct floor contact), away from areas with significant humidity swings like loading dock doors, and keep bags sealed until use. Properly stored, calcium chloride has a long practical shelf life - the product itself doesn't degrade chemically over time in normal storage, but it can lose effective usability if it absorbs enough moisture to clump or partially dissolve within its packaging.

What's the solubility of calcium chloride in water?

Anhydrous calcium chloride is highly soluble - roughly 74.5 g per 100 g of water at 20°C, and solubility increases further with temperature. This high solubility, combined with the exothermic heat of dissolution, is why it dissolves quickly and generates noticeable heat when mixed into water, especially at higher concentrations.

How do I calculate dosage for my application?

This depends entirely on the specific application - de-icing dosage, concrete accelerator dosage, and brine density targets for drilling fluid all use different calculation methods and reference different standards. There isn't a universal dosage formula. For de-icing, check your local DOT or municipal application rate guidelines. For concrete, reference ACI 212 or your project specification. For brine density work, use your supplier's or fluids engineer's density chart rather than estimating - the concentration-to-density relationship isn't linear, especially near saturation.

Does calcium chloride expire?

Not in the sense of chemical breakdown under normal conditions - it doesn't have a hard expiration date the way some organic chemicals do. What actually limits effective shelf life is moisture exposure during storage. Product that's been properly sealed and kept dry remains usable indefinitely for practical purposes. Product exposed to humidity can clump, cake, or partially dissolve within its packaging well before any "expiration," which is really a storage condition issue rather than a product aging issue.

What's the difference between the CAS numbers for anhydrous and dihydrate?

Anhydrous calcium chloride has CAS number 10043-52-4. Dihydrate has a different CAS number due to the distinct crystal structure and bound water content. If you're doing regulatory documentation or import paperwork, confirm you're using the correct CAS number for the specific form you're actually importing - using the wrong one on customs or safety documentation can cause processing delays.

Why do quotes for what looks like the same product vary so much between suppliers?

Usually one of a few things: different purity grades being compared as if equivalent, different Incoterms (FOB vs CIF pricing looks very different but represents different scope), different packaging formats affecting cost per ton, or genuinely different quality tiers where a lower price reflects looser quality control or less consistent COA documentation. When comparing quotes, confirm you're comparing the same purity, the same Incoterm, and the same packaging format before assuming one supplier is simply cheaper than another.

Is a lower price always a red flag?

Not automatically, but it's worth understanding why before committing to volume. Ask for a recent, batch-specific COA and, if possible, a small sample order before scaling up with a new low-cost supplier. The cost of a bad shipment - product that's off-spec, contaminated, or doesn't match its documentation - is usually far higher than whatever was saved on unit price.

Other Industrial Uses of Anhydrous Calcium Chloride

Beyond the high-volume applications - drilling fluid, de-icing, desiccant use - calcium chloride shows up in a handful of smaller, more specialized industrial roles. None of these move the tonnage that de-icing or oilfield brine does, but for buyers in these specific industries, it's worth knowing where and why it's used.

Leather tanning and pickling

In the leather industry, calcium chloride is used during the pickling stage, where hides are treated in an acidic salt solution to prepare them for tanning. Its role here is mainly as a bulking salt in the pickle liquor, helping control the osmotic balance in the hide fibers alongside the acid treatment. It's a supporting chemical in this process, not the primary tanning agent - chrome or vegetable tannins do that work later in the process.

Textile finishing

Calcium chloride appears in some textile finishing and dyeing auxiliary formulations, generally as an electrolyte that helps control dye uptake and fixation on certain fiber types. Usage here is formulation-specific and varies significantly by mill and by the particular dye chemistry being used - this isn't a one-size application, and a textile buyer sourcing for this purpose should confirm the specific role it plays in their existing process before assuming a generic industrial-grade product is an automatic fit.

Mining flotation

In mineral processing, calcium chloride is used in some flotation circuits as a modifying agent, affecting the surface chemistry of certain minerals to improve separation efficiency. This is a fairly technical, process-specific application - the correct dosage and role depend heavily on the ore being processed and the flotation reagent scheme already in use at a given operation. It's worth talking to a process metallurgist rather than assuming a standard dosage applies across different ore types.

Pulp and paper

Calcium chloride has some use in pulp bleaching processes, generally as a minor process chemical rather than a primary bleaching agent. Its role tends to be plant-specific, tied to particular bleaching sequences and water chemistry conditions rather than a universal step in paper production.

Tire ballast

Calcium chloride brine is used as tire ballast in agricultural and heavy equipment tires - adding weight and improving traction, particularly for tractors doing field work. The brine also has an antifreeze effect at the concentrations typically used, which matters for equipment that sits outdoors through winter. This is a fairly established, low-tech application with straightforward mixing guidelines available from most agricultural equipment suppliers or tire dealers.

Water treatment

Calcium chloride is used in some water treatment processes as a source of calcium ions, useful for adjusting water hardness or supporting certain coagulation and flocculation processes. It's one option among several calcium sources used in this context, and the choice between calcium chloride and alternatives typically comes down to cost, solubility requirements, and whether the chloride ion itself is acceptable for the specific treatment application and discharge requirements involved.

A general note on these applications

For all of the uses above, dosage and process integration are specific enough to the individual plant or operation that generic guidance only goes so far. If you're sourcing calcium chloride for one of these applications, it's worth having a conversation with your process engineer about the actual requirement before placing a large order - the wrong grade or an assumption carried over from a different industry's use case is a common and avoidable source of wasted purchase.