Chapter 3: Builders and water softeners · Part 5: Polycarboxylates
Sodium polyacrylate
- Contaminant risk
The worst fact: it doesn't readily biodegrade. Sewage plants remove it mainly by sticking it to sludge, which can be spread on farmland, and risk assessors assume it isn't broken down without oxygen (a related copolymer only reached about 3%).
Why brands use it: it stops scale crusting onto fabric and machines, and keeps dirt from settling back on.
Take care if: no official warning found. The industry's risk assessment found it at most slightly irritating to eyes.
Comes from: acrylic acid (made from propylene, a petroleum gas), joined into long chains.
Myth check: "Polyacrylates are microplastics": not under EU law. The EU's microplastics ban excludes polymers that dissolve in water (above 2 g per litre), and detergent grades are water-soluble.
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 or consumers.
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.
- European Union. Regulation (EU) 259/2012 (phosphates in detergents); Detergents Regulation (EC) 648/2004, Annex VII; Regulation (EU) 2023/2055 (microplastics); EU Ecolabel decisions 2017/1216 and 2017/1218.
- 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.