Hydrochloric Acid
CAS 7647-01-0 HCl
- CAS number
- 7647-01-0
- EC number
- 231-595-7
- Formula
- HCl
- Molar mass
- 36.46 g/mol
- HS code
- 2806.10
Supply of Hydrochloric Acid
- Grades
- Commercial strengths run 30–33%, quoted in some markets by density as 20 Baumé (about 31.45%) or 22 Baumé (about 35.2%). The division that matters more than assay is origin: synthetic acid, burned from hydrogen and chlorine, is low in organics and is the basis of food and high-purity grades, while by-product acid recovered from chlorination processes is the cheaper bulk material and can carry traces of the chemistry it came from. Technical, food grade meeting Food Chemicals Codex test requirements, reagent, low-metal electronic and inhibited oilfield grades are traded. Specify strength, origin and grade.
- Packaging
- 30–35 kg jerricans and carboys · HDPE drums (~200–250 kg net), IBC · Rubber-lined or FRP ISO tanks and road tankers · Bulk
- Documents
- CoA, SDS and TDS on request; certificate of origin where the destination requires it.
- Delivery
- Worldwide, including the United States, Canada, the United Kingdom, Germany and the rest of the EU, the United Arab Emirates, India, Singapore, Malaysia and Australia. Quoted EXW, FOB, CIF or DAP.
Hydrochloric acid, also known as muriatic acid, is a strong acid used to remove rust and scale from steel, to regenerate water-softening resins, to adjust pH in water and food processing, and in oil wells to open up the rock. It is usually sold as a 30–33% solution. It gives off irritating fumes and attacks most metals, so it is stored in plastic or rubber-lined tanks.
Technical details
Hydrochloric acid is used where the acid must leave no residue behind: it neutralises cleanly, its calcium and sodium salts are soluble, and it regenerates ion-exchange resin without the sulfate scaling that sulfuric acid can cause. Almost all of it is a by-product, either recovered from chlorinating organics or burned deliberately from hydrogen and chlorine at a chlor-alkali plant, and the origin determines the grade: synthetic burner acid is the clean material behind food and pharmaceutical grades, while by-product acid is the cheaper bulk stream and carries traces of its parent chemistry. The rest of the specification is usually strength, quoted as 30 to 33% or in older markets as degrees Baumé. One practical advantage over the alkalis and over sulfuric acid is that it does not freeze in any realistic storage temperature, so an outdoor tank needs no heat tracing. Against that, it fumes, and it attacks metals that hold the other acids without trouble. Ehlinar supplies synthetic and by-product acid in technical, food and high-purity grades.
Appearance: A clear, colourless to faintly yellow liquid with a sharp penetrating odour; the yellow tint is iron picked up in handling rather than a property of the acid. At the usual 31–33% commercial strength the density is around 1.16 g/mL, and the acid fumes visibly in moist air. It does not freeze in practical storage: a 32% solution stays liquid to about −46 °C.
Applications
How we supply
- Certificate of Analysis (CoA), lot-specific where available
- Safety Data Sheet (SDS / MSDS)
- Technical Data Sheet (TDS)
- Certificate of Origin / Certificate of Conformity
Independent third-party inspection can be arranged on request, with the agency and scope agreed per trade. Representative samples can be requested for qualification, subject to supplier availability. We recommend incoming quality control against the agreed CoA.
Quoted on standard Incoterms (e.g. EXW, FOB, CIF, DAP) as agreed per trade. Delivery region, packaging and grade are confirmed per quote.
Documents and services above are subject to supplier availability and confirmed per quote; nothing here is an offer.
Typical / indicative values — not a binding specification
| Property | Typical |
|---|---|
| Commercial strengths | 30–33%; quoted as 20 Bé (~31.45%) or 22 Bé (~35.2%) |
| Density at 20 °C (32%) | ~1.16 g/mL |
| Freezing point (32%) | ~−46 °C — no heat tracing needed |
| Origin | Synthetic (burner) or by-product; decides organic and colour limits |
| Iron | Grade-dependent; the usual cause of a yellow tint |
| Materials of construction | Rubber-lined steel, FRP, PVC, CPVC, PP, PVDF or PTFE — never bare steel, stainless, aluminium or copper alloys |
Also known as
Muriatic acid · Spirits of salt · Chlorohydric acid · Hydrogen chloride solution · 20 Baumé acid · Pool acid
Frequently asked questions
- What is the difference between synthetic and by-product hydrochloric acid?
- How it was made, which decides what else is in it. Synthetic acid is produced by burning hydrogen with chlorine and absorbing the gas in water, giving a low-organic, consistent material that food, pharmaceutical and high-purity grades are built on. By-product acid is recovered from processes that chlorinate organic compounds, so it is cheaper and plentiful but can carry traces of the chemistry it came from, sometimes with a faint colour or odour. For pickling or bulk neutralisation the difference rarely matters; for anything entering food, pharma or a sensitive product it decides the supplier.
- What do 20 and 22 Baumé mean?
- Density readings that the trade still quotes instead of assay. Twenty degrees Baumé is roughly 31.45% hydrochloric acid and 22 degrees is roughly 35.2%. Both are standard commercial strengths, 20 Bé being the common one. As with sulfuric acid, agree the percentage assay in the contract rather than relying on the Baumé figure alone, because the conversion depends on temperature.
- Why is it not sold much stronger than 33%?
- Vapour pressure. Above roughly 33% the acid fumes heavily at ordinary temperatures, which makes it unpleasant and hazardous to handle, causes it to lose strength in storage as hydrogen chloride escapes, and requires much more careful containment. The commercial strengths sit just below where that becomes a serious problem. If a process genuinely needs anhydrous hydrogen chloride, that is a different product bought as a liquefied gas, not as a stronger solution.
- What can I store it in?
- Nothing bare and metallic. Hydrochloric acid attacks carbon steel, stainless steel, aluminium and copper alloys, releasing hydrogen as it goes; stainless is the trap, because it is right for so many other duties. Use rubber-lined steel, FRP, PVC, CPVC, polypropylene, PVDF or PTFE for tanks, lines, pumps and gaskets alike, and check every valve and instrument in the line rather than the tank alone.
- Why is it preferred over sulfuric acid for regenerating ion-exchange resin?
- Solubility of the salts it forms. Regenerating a cation resin releases the calcium and magnesium the resin has captured, and calcium chloride is freely soluble while calcium sulfate is not. Using sulfuric acid there risks precipitating calcium sulfate inside the resin bed, which fouls it, so sulfuric regeneration is done in careful stepped concentrations. Hydrochloric acid avoids the problem, which is why demineralisation plants generally choose it despite a higher cost per unit of acidity.
- Is hydrochloric acid a controlled chemical?
- Yes, as a drug precursor rather than an explosives one. It is a category 3 scheduled substance in the EU and a List II chemical in the United States, both under the framework of the 1988 UN convention, because it is used in illicit drug processing. Industrial supply is entirely normal, but customer identification, end-use documentation and reporting of suspicious orders are part of the trade, and unusually small or cash-basis orders attract scrutiny for good reason.
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Related products
Figures and identifiers here are compiled from public references and provided for general information; they are indicative, not a specification. See all products.