E513 - Sulphuric acid

At a glance

Here’s a quick overview before we dive deeper.

• What it is: a strong mineral acid with the formula H2SO4, also called “oil of vitriol.”
• What it does: works as an acidity regulator and pH control agent during food processing.
• Where it shows up: mainly in manufacturing steps; it is not a common front‑label ingredient on everyday foods.
• Regulation: in the U.S. it is “GRAS” (Generally Recognized As Safe) as a pH control agent when used under good manufacturing practice; in the EU it is an authorized additive listed as E 513 with official purity criteria.

Why is Sulphuric acid added to food?

Manufacturers use sulphuric acid to adjust pH—a measure of how acidic or basic something is—so recipes process consistently and safely. In the United States, sulfuric acid is affirmed as GRAS (Generally Recognized As Safe) as a pH control agent when used in line with good manufacturing practice (GMP).¹ In the European Union, it is an authorized food additive with specifications under the code E 513, meaning it must meet strict purity criteria when used in foods.²

Unlike flavor acids such as citric acid, E513 is chosen for its strong, precise pH effect in industrial settings. After it does its job, the food is typically neutralized or sufficiently diluted as part of the process.

What foods contain Sulphuric acid?

You might occasionally see “sulfuric acid,” “sulphuric acid,” or “E513” on an ingredient list, usually on more technical or industrial-style products. In many cases it is used during processing and may be present only in very small amounts in the finished food. Because other acids are milder and add flavor, they are more common on retail labels.

If you want to check, look directly at the ingredient list on the package. Regulations allow listing by name or by E‑number (in the EU), so any use should appear as “sulfuric acid,” “sulphuric acid,” or “E513.”

What can replace Sulphuric acid?

Depending on the food and the target taste, texture, or process needs, formulators often choose other food acids:

• citric acid
• lactic acid
• phosphoric acid
• malic acid
• acetic acid
• L‑tartaric acid

These provide acidity and, in many cases, a familiar tart flavor.

How is Sulphuric acid made?

Food‑grade sulphuric acid is the same chemical made industrially: sulfur trioxide (SO3) is reacted with water to form H2SO4. The SO3 typically comes from oxidizing sulfur dioxide; high‑purity grades are produced under controlled conditions to meet food specifications.³

Is Sulphuric acid safe to eat?

For food use, safety comes down to purity, dose, and context. In the U.S., sulfuric acid is GRAS as a pH control agent when used according to GMP—meaning only the amount needed for the intended effect may be used.¹ In the EU it is authorized as E 513 with defined identity and purity criteria, and use must follow applicable EU rules.²

Concentrated sulphuric acid is highly corrosive and must be handled by trained professionals; this is a workplace hazard issue, not a property of the tiny, diluted amounts used in foods.⁴

Does Sulphuric acid have any benefits?

• Precise pH control: It lets manufacturers hit exact acidity targets, which can support consistent texture, color development during cooking, and reliable shelf stability.
• Processing reliability: Small pH adjustments can make certain manufacturing steps work better, helping batches turn out the same every time.

Who should avoid Sulphuric acid?

• People who need to limit acidic foods (for example, on medical advice for reflux) may prefer products acidified with milder‑tasting acids—or fewer acidified foods overall.
• If you are sensitive to preservatives called sulfites, note that E513 is not a sulfite. It is a sulfate source and is chemically different from sulfite preservatives such as sodium metabisulphite.

When in doubt, discuss specific products with your healthcare provider.

Myths & facts

• “It’s battery acid, so it can’t be in food.” Fact: battery acid and food‑grade acid are the same chemical, but food use relies on high‑purity material and tiny, controlled amounts under strict rules.
• “It stays as sulphuric acid in my food.” Fact: in practice it is diluted or neutralized as part of the process, leaving a safe, intended acidity in the final product.
• “It’s the same as sulfites.” Fact: sulphuric acid (a source of sulfate) is different from sulfites; sulfite sensitivity does not automatically apply to E513.

Sulphuric acid in branded foods

Use the ingredient list to spot it. It may appear as “sulfuric acid,” “sulphuric acid,” or “E513.” If you don’t see it named, the product likely uses other acids like citric acid or phosphoric acid for flavor and pH control.

References

Footnotes

1. 21 CFR 184.1095 — Sulfuric acid. eCFR, U.S. Food and Drug Administration. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-184/subpart-B/section-184.1095 ↩ ↩²

2. Commission Regulation (EU) No 231/2012 — Specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008. EUR-Lex. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0231 ↩ ↩²

3. Sulfuric acid — PubChem Compound Summary (CID 1118). National Institutes of Health. https://pubchem.ncbi.nlm.nih.gov/compound/Sulfuric-acid ↩

4. NIOSH Pocket Guide to Chemical Hazards: Sulfuric acid. Centers for Disease Control and Prevention. https://www.cdc.gov/niosh/npg/npgd0577.html ↩