Chapter 3: Builders and water softeners · Part 5: Polycarboxylates
Acrylic/maleic copolymer
- Contaminant risk
The worst fact: it isn't readily biodegradable. In sewage plants about 89% is removed, mainly by sticking to sludge, and without oxygen only 3 to 16% broke down in testing, the higher figure after 258 days.
Why brands use it: it stops scale and keeps dirt suspended, especially in phosphate-free powders.
Take care if: no official warning found.
Comes from: acrylic acid and maleic anhydride, both made from petroleum gases (propylene and butane).
Myth check: nil.
Contaminants: leftover acrylic acid, up to 0.5% but usually under 0.1%. It's unlikely to matter in a well-made product, but it's a factor you can't see on the label.
Fair to say: the industry's risk assessment found no risk to the environment.
Correct as of November 2026. What the badges mean
Sources
- Safe Work Australia. Hazardous Chemical Information System (HCIS): classifications for each chemical, and for formaldehyde.
- HERA. Risk assessments: STPP (2003) and STPP eutrophication note (2003); phosphonates (2004); zeolite A (2004); soluble silicates (2005); polycarboxylates parts I and II (2014).
- HSDB (US National Library of Medicine), via PubChem: production, pH and impurity data for each chemical.
The full source list is at the end of Chapter 3.