Take the Quiz - Get 15% OFF your 1st Order
Search

Chapter 11: The supporting cast · Part 3: Colours

Brilliant Blue FCF

  • Contaminant risk
Also called
CI 42090, FD&C Blue No. 1, Acid Blue 9, E133
Found in
dishwashing liquid, toilet fresheners, window cleaner

The worst fact: in 2003 the US FDA issued a warning about adding it to tube feeds after 20 cases in very ill patients, including 12 deaths. One tube-fed patient's skin turned an intense green. The FDA said a causal link with the dye had "not been definitively established".

Why brands use it: the classic "fresh" blue. A chemistry reference lists its use "to dye lavatory fresheners or flushing water".

Take care if: you're caring for someone seriously ill with a leaky gut (sepsis, burns, major surgery, kidney failure). That's where the FDA's concern was. There have been "no reports of toxicity" from ordinary food use.

Comes from: 2-formylbenzenesulfonic acid and N-ethyl-N-(3-sulfobenzyl)aniline, then oxidised.

Myth check: "It's banned in Europe": no. It's an approved EU food colour (E133). It's the US that plans to remove it from food: in April 2025 the FDA said it would work with industry to eliminate it "by the end of next year".

Contaminants: unsulfonated aromatic amines (EU limit 0.01%, as aniline) and lead (EU limit 2 mg/kg). They're unlikely in a well-made product, but it's a factor you can't see on the label.

Fair to say: swallowed in normal amounts, almost all of it passes straight through (95–99.9% in rats, depending on dose), and the WHO's cancer agency says it's "not classifiable" as a human carcinogen.

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).
  • European Union. Regulation (EC) 1333/2008 Annex V; Regulation (EU) 231/2012 (food additive specifications); Regulation (EU) 2022/63 (E171); Regulation (EU) 1297/2014 (detergent capsules); Regulation (EC) 790/2009 and Delegated Regulation (EU) 2021/849 (borates); Regulation (EU) 109/2012; Regulation (EU) 2023/2055 (microplastics); Regulation (EU) 2024/1328 (D4, D5, D6); Regulation (EC) 1223/2009 (cosmetics) Annexes III and IV.
  • US FDA. Public health advisory on FD&C Blue No. 1 in enteral feedings (2003); SimplyThick consumer update (2012); 21 CFR 74.101, 74.705, 74.706, 74.1205, 74.1333, 74.2333, 201.20; phase-out of petroleum-based food dyes (22 April 2025); Color additives Q&A; 1,4-dioxane in cosmetics.
  • JECFA (FAO/WHO). Specifications and evaluations: titanium dioxide (2023), sodium carboxymethylcellulose, polyvinylpyrrolidone, Brilliant Blue FCF, tartrazine, Sunset Yellow FCF, D&C Red 33.
  • IARC. Monographs: styrene (vol. 121), titanium dioxide (vol. 93), amorphous and crystalline silica (vol. 68), ethylene oxide, Brilliant Blue FCF.
  • HSDB (US National Library of Medicine), via PubChem: manufacturing, use and impurity data.

The full source list is at the end of Chapter 11.