What E131 actually is
Patent Blue V is a deep blue colour used in sweets, ice cream, and decoration. It is one of the older synthetic dyes and has narrowed in use over time, partly because Brilliant Blue (E133) is more stable and partly because of the regulatory split between markets.
What it is made from
Synthesised from petrochemical feedstock, with no plant or animal input.
Vegan, vegetarian, and halal status
Fully synthetic, so it suits vegan, vegetarian, halal, and kosher diets.
Is E131 safe?
Two things distinguish this one. It is not permitted in US food, so the same product looks different across markets. And it has a better-documented allergy profile than most food colours, because the same dye is injected during sentinel lymph node mapping in cancer surgery, where anaphylaxis occurs at a measurable rate. That surgical exposure is far larger than any dietary one, so the rate does not transfer directly to food, but it is why Patent Blue V is one of the colours with a real, recorded hypersensitivity signal. EFSA re-evaluated it in 2013 and set an acceptable daily intake of 5 mg per kg of body weight per day.
- Documented anaphylaxis risk from surgical injection, a much larger exposure than dietary use
- Not permitted in US food, though the same dye is used medically there
- Intolerance reported in some people with existing sensitivities
- EFSA acceptable daily intake of 5 mg per kg of body weight per day
Where regulators stand
- EFSA (EU)
- Re-evaluated in 2013. Acceptable daily intake of 5 mg per kg of body weight per day.
- FDA (US)
- Not permitted as a colour additive in food.
Foods it turns up in
- Sweets and confectionery
- Ice cream and desserts
- Cake decoration
- Some liqueurs
Names it hides behind
- E131
- Patent Blue V
- Acid Blue 3
- Colour (E131)
Common questions
- Is Patent Blue V banned in the US?
- It is not permitted in US food, though the same dye is used medically there for lymph node mapping.
- Can Patent Blue V cause an allergic reaction?
- There is a documented anaphylaxis rate from surgical injection, which is a far larger exposure than eating it. It is one of the few food colours with a real recorded hypersensitivity signal.
- Is E131 vegan and halal?
- Yes. It is entirely synthetic with no animal-derived input.
- What is the difference between E131 and E133?
- Both are blue. E133 Brilliant Blue is more stable and is permitted in both the EU and the US; E131 is permitted in the EU only.
- Does it carry the children's warning?
- No. Patent Blue V is not one of the six Southampton colours, so it does not require the activity and attention statement.
Checking a real pack
This page answers the code. The pack in your hand is what decides, because the same code can come from different sources depending on the manufacturer. LabelWise, formerly SafeChoice, scans the label and explains what is in front of you.
LabelWise content is educational and describes how additives are made, regulated, and labelled. It is not medical, dietary, or religious advice. For certification questions, the mark on the pack and the certifying body are the authority.