Patent Blue V
The short version
A synthetic blue dye used in sweets and drinks (and blended for greens); not approved for food in the US.
A synthetic blue dye (Patent Blue V). It's cosmetic only and can occasionally cause allergic-type reactions in sensitive people, which is why we flag it.
Where it comes from
A synthetic triarylmethane blue dye.
How it's used
Blue colorant, often blended with yellows to make greens, in confectionery, drinks, and desserts. It is also used medically to map lymph vessels.
Safety profile
ADI 5 mg/kg body weight (EFSA re-evaluation). Can rarely cause allergic-type reactions — including, when injected medically, anaphylaxis. Historically banned as a food color in several countries.
Physical & chemical properties
Dark blue-violet water-soluble powder.
Regulation worldwide
EU-permitted; not approved for food use in the US; varies elsewhere.
Educational information only. Not medical or dietary advice.