E-numbers / Acidity regulators / E513
also: Sulfuric acid · H2SO4
A strong inorganic acid used in tiny amounts during brewing and cheese-making to keep the process pH at the right level.
Scan a barcode to check a food for sulphuric acid. NutraSafe Pro · £6.99/month · iOS
Sulphuric acid (H2SO4) is a strong mineral acid.
Sulphuric acid (H2SO4) is a strong mineral acid. In food manufacturing it is a highly dilute process aid rather than an ingredient present in any meaningful quantity in the final product. It is one of the most widely produced industrial chemicals in the world.
It lowers the pH of a liquid or mixture quickly and predictably. In brewing it adjusts mash and liquor pH to the narrow range that enzyme activity and yeast health require. In some cheese-making it acidifies the milk prior to or during curd formation. Because only very small quantities are needed and the acid reacts with the food medium, very little free acid remains in the finished product.
Most commonly used behind the scenes in beer brewing and in the production of certain hard cheeses. It is rarely listed on finished-product labels because it functions as a processing aid and the residue in the end product is negligible; when it does appear it reads as 'sulphuric acid' or 'acidity regulator (E513)'.
EFSA carried out a full re-evaluation of sulphuric acid and its sulphate salts (E513 to E517) in 2019. Because sulphuric acid is a normal metabolic product already present in the body and the amounts reaching consumers via food are tiny, the panel concluded there was no need to set a numerical acceptable daily intake. No adverse effects relevant to food use were identified.
EFSA re-evaluated sulphuric acid (E513) and its sodium, potassium, calcium and ammonium salt forms and established a group ADI of 'not specified', meaning the panel found no reason to set a numerical limit at the levels used in food.
IARC classifies sulphuric acid mists as a Group 1 carcinogen, but this classification relates exclusively to occupational inhalation exposure in industrial settings such as lead-acid battery manufacturing. Ingestion of food-grade dilute acid at permitted levels is a fundamentally different exposure route and is not covered by that classification.
IARC assigned sulphuric acid strong inorganic acid mists to Group 1 (carcinogenic to humans) based on evidence of laryngeal and lung cancer in workers with heavy occupational inhalation exposure. The classification does not apply to oral ingestion.
There is no specific group that needs to avoid E513 as a food additive at the levels encountered in food. People with reflux or oesophageal sensitivity who already limit acidic foods or drinks may wish to note that some beers and cheeses made with this process aid are themselves acidic, though the acid from E513 specifically is not the main driver of that acidity. On a label it appears as 'sulphuric acid' or 'acidity regulator (E513)'.
E513 is one of the least consumer-visible food additives because it acts during processing and very little survives into the finished product. The IARC Group 1 classification that sometimes appears in internet searches refers to industrial inhalation of acid mist, not to drinking a beer or eating a cheese made with it. The science here is well-established and the regulatory picture is unusually clear: two generations of safety committees have looked at it and concluded no numerical intake limit is needed.
No. Sulphuric acid is an approved food acidity regulator in both the UK and the EU, permitted at quantum satis levels in certain food manufacturing processes including brewing and cheese-making.
No. The IARC Group 1 classification for sulphuric acid applies to occupational inhalation of strong acid mists in industrial workplaces, such as battery factories. Oral exposure via food is a different route entirely and is not what that classification addresses.
It is most commonly used in beer brewing and in some cheese production as a processing aid to adjust acidity. It is rarely present in finished consumer products in any detectable quantity and is not used as a direct ingredient in most retail foods.
Yes. Sulphuric acid is a mineral (inorganic) compound with no animal origin.
Last reviewed: 20 June 2026
It's the only app that does thisUKJaneK
You Need This AppGmac2005
Best AppGK getting skinny UK App Store reviews
NutraSafe reads the label and puts every additive into plain English, with the source, right in the app.
NutraSafe Pro · £6.99/month · iOS
