Chapter 4: Bleaches and brighteners · Part 3: Optical brighteners
Fluorescent brightener 28
- Made from a hazardous chemical
The worst fact: it's the same dye laboratories use to stain fungi so they glow under a microscope. Australia's regulator conservatively assesses it as neither readily nor inherently biodegradable.
Why brands use it: it dissolves well, so it suits liquid detergents (under 0.8%).
Take care if: no official warning found for finished products. The raw chemical is a moderate eye irritant.
Comes from: petroleum chemicals: the same stilbene core as FWA-1, reacted with cyanuric chloride, aniline and diethanolamine. Australia classes aniline 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: "Optical brighteners cause cancer": no evidence. Canada found no sign of cancer or genetic damage.
Contaminants: nil.
Fair to say: Canada rates its risk to health and the environment as low, and Australia's regulator found the environmental risk well below the level of concern.
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
- AICIS. Evaluation statement EVA00144: Fluorescent Brightener 71 and related chemicals (2023). industrialchemicals.gov.au
The full source list is at the end of Chapter 4.