Chapter 4: Bleaches and brighteners · Part 3: Optical brighteners
FWA-5
- Made from a hazardous chemical
- Contaminant risk
The worst fact: bacteria can't break it down, and about 56% of what reaches sewage plants ends up in sludge. Most company notifications to Europe's chemicals agency class the raw powder as an eye irritant, and a quarter as causing serious eye damage.
Why brands use it: it gives more whiteness than older brighteners and survives chlorine. It's used at 0.02 to 0.1%.
Take care if: no official warning found for finished products. A 1% solution didn't irritate eyes in testing.
Comes from: petroleum: biphenyl from crude-oil refining, reacted with formaldehyde and other chemicals. Australia classes formaldehyde as "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: "Brighteners are banned in Europe": no. They're widely used there. The Nordic Swan ecolabel does ban them in labelled detergents.
Contaminants: manufacturing by-products. Under 1.2% of the trade product is by-products. They're unlikely to matter in a well-made product, but it's a factor you can't see on the label.
Fair to say: sunlight breaks down more than 70% of it in 28 days, and the breakdown products biodegrade. It isn't a skin allergen.
Correct as of November 2026. What the badges mean
Sources
- Safe Work Australia. Hazardous Chemical Information System (HCIS): classifications for each chemical, and for borax. hcis.safeworkaustralia.gov.au
- HERA. Risk assessments: sodium percarbonate (2002); hydrogen peroxide (2005); sodium perborate (2002); TAED (2003); FWA-1 (2004); FWA-5 (2003). heraproject.com
- Nordic Ecolabelling. Laundry detergents and stain removers, criteria and background.
The full source list is at the end of Chapter 4.