E-numbers / Other additives / E519
also: Cupric sulphate · Copper(II) sulphate · Blue vitriol
A copper salt not currently permitted as a food additive in the UK or EU. Used in agriculture and animal feed; toxic in excess.
Scan a barcode to check a food for copper sulphate. NutraSafe Pro · £3.99/month · iOS
Copper accumulates in the liver.
Why it’s worth knowing. Copper accumulates in the liver. High intake damages the liver and kidneys. Acute exposure causes vomiting and gastrointestinal injury. People with Wilson's disease or liver conditions are especially vulnerable. It is not on the UK list of approved food additives, so you will not normally see this E number on a UK label.
Copper sulphate (also written copper sulfate; chemical name cupric sulphate pentahydrate, CuSO4.5H2O) is a bright blue crystalline salt formed from copper and sulphuric acid. It is one of the most common copper compounds and has wide industrial, agricultural, and veterinary uses.
As a mineral salt, copper sulphate can act as a source of the essential trace element copper, a preservative, and an antimicrobial agent. In agriculture it is used as a fungicide and algicide. In animal feed it is a regulated source of supplemental copper for livestock. It is not currently authorised as a food additive for human food in the UK or EU.
Copper sulphate is not authorised for use as an additive in UK or EU human food products under the food additives regulation (assimilated EU Regulation 1333/2008, Annex II). It does appear as an authorised feed additive in animal nutrition. Some copper nutritional supplements use cupric sulphate as a copper source, but these are regulated as food supplements rather than food additives. If present in a supplement it may appear as 'copper sulphate', 'cupric sulphate', or 'copper (as copper sulphate)' on the label.
Copper is an essential trace element but accumulates in the liver when intake is excessive. EFSA re-evaluated copper health-based guidance values in 2023 and set an acceptable daily intake of 0.07 mg per kilogram of body weight per day (roughly 5 mg per day for an adult), based on preventing copper retention in the liver as the earliest marker of harm. Acute overdose of copper sulphate causes nausea, vomiting, abdominal pain, and in severe cases liver and kidney failure.
EFSA set a health-based guidance value (acceptable daily intake) for copper of 0.07 mg/kg body weight per day, derived from liver copper accumulation as the critical endpoint, applying to copper from all dietary sources.
Acute copper sulphate ingestion at doses above 1 g causes vomiting, gastrointestinal haemorrhage, hepatic necrosis, and renal failure; fatalities have been documented in case series.
People with Wilson's disease have a genetic defect that prevents normal copper excretion, leading to copper accumulating in the liver, brain, and other organs. For this group, any additional copper source including copper sulphate in supplements poses serious risk. The condition affects roughly 1 in 30,000 people in the UK.
Wilson's disease (ATP7B gene mutations) causes progressive copper overload and liver damage; patients must avoid supplemental copper sources entirely.
Copper sulphate does not appear in Annex II of the assimilated EU Regulation 1333/2008 on food additives, which is the legal basis for food additive use in the UK post-Brexit. It is therefore not a lawfully authorised food additive for human food in Great Britain or the EU. Its use is regulated separately as an animal feed additive and as an agricultural input. The FSA approved-additives database does not list E519.
E519 copper sulphate is not listed among approved food additives in the UK FSA approved-additives register.
Cupric sulphate pentahydrate is authorised as a feed additive (source of copper, nutritional additive) for all animal species under EU feed additive regulations, with maximum copper levels set per animal category.
People with Wilson's disease or other conditions affecting copper metabolism should avoid any products containing copper sulphate or supplemental copper. Infants and young children are more vulnerable to copper toxicity than adults. Anyone taking copper supplements should check labels for 'copper sulphate', 'cupric sulphate', or 'copper (as copper sulphate)' and not exceed recommended amounts.
Copper sulphate is not authorised for use in UK food and should not appear in ordinary food products as an additive. The main real-world exposure route is copper nutritional supplements, where it is used as a cheap and soluble copper source. The essential versus toxic question for copper is a genuine scientific tension: the body needs copper (the UK recommended intake is roughly 1.2 mg per day for adults), but the gap between the nutritional requirement and the level that causes liver damage is not wide. The 2023 EFSA re-evaluation specifically tightened the health-based guidance value because of accumulated evidence on liver copper retention. For most people eating a varied diet, supplemental copper is unnecessary. The concern is not hypothetical: acute copper sulphate poisoning cases exist in medical literature.
No. Copper sulphate (E519) is not listed among the approved food additives under UK food law (assimilated EU Regulation 1333/2008, Annex II). It should not be present as an additive in food products sold in Great Britain.
Yes, in excess. Copper accumulates in the liver; intake above roughly 5 mg per day for an adult (EFSA's guidance value) can lead to liver retention over time. Acute ingestion of larger amounts causes vomiting, liver injury, and in serious cases organ failure. People with Wilson's disease face additional risk because they cannot excrete copper normally.
Copper sulphate is not permitted in UK food products. It can appear in nutritional supplements as a source of copper. It is also used in animal feeds and in agriculture as a fungicide, but these uses are regulated separately from food additives.
Copper sulphate itself is a mineral compound with no animal origin. However, because it is not permitted in UK food, the vegan status question only arises for supplements containing it as a copper source, where the mineral form is vegan.
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 · £3.99/month · iOS
