Chapter 11: The supporting cast · Part 3: Colours
Acid Red 33
- Made from a hazardous chemical
- Contaminant risk
The worst fact: the US allows up to 25 parts per million of aniline in it, against 100 parts per billion in the food dye Yellow 5: 250 times more. Benzidine is allowed at 20 ppb, against 1 ppb.
Why brands use it: a bright pink-red, also used in mouthwash, toothpaste and lipstick.
Take care if: no specific group. The US limits it to 3% of a lip product and 0.75 mg per daily dose of a swallowed medicine; it isn't allowed in US food.
Comes from: aniline, diazotised and coupled with H-acid. Australia classes aniline as "Suspected of causing genetic defects; May cause cancer". That doesn't mean it's in the product, but it's not a great starting point for something you clean with.
Myth check: "Cosmetic colours are tested like food colours": the WHO's food additive committee withdrew its specification for it in 1984.
Contaminants: aniline, 4-aminobiphenyl and benzidine (US limits above). They're unlikely in a well-made product, but it's a factor you can't see on the label.
Fair to say: the EU allows it in cosmetics, and in hair dye up to 0.5%.
Correct as of November 2026. What the badges mean
Sources
- Safe Work Australia. Hazardous Chemical Information System (HCIS): classifications for calcium chloride, boric acid, borax, and for N-vinylpyrrolidone, vinyl acetate, ethylene oxide, 1,4-dioxane, hydrazine, aniline, p-toluidine, styrene, chloromethane, carbon monoxide and octamethylcyclotetrasiloxane (D4).
- JECFA (FAO/WHO). Specifications and evaluations: titanium dioxide (2023), sodium carboxymethylcellulose, polyvinylpyrrolidone, Brilliant Blue FCF, tartrazine, Sunset Yellow FCF, D&C Red 33.
The full source list is at the end of Chapter 11.