Ecotoxicological effects of polyacrylamides and polyacrylates in agriculture
To date, no soil conditioners containing polyacrylamides or polyacrylates acid have been approved in Switzerland. Cross-linked polyacrylamides and polyacrylates can absorb large quantities of water and therefore improve the water storage capacity of the soil. Combined with fertilisers, they lead to a slow release of nutrients. Linear polyacrylamides, on the other hand, are used as flocculants and therefore appear as production residues in some fertilisers. However, since most chemical regulations do not apply to polymers, little is known about their ecotoxicological effects.
Polyacrylamides and polyacrylates sorb strongly to particles and are therefore only slowly degraded in the soil. The polymers could therefore pose a risk, especially for sediment and soil animals. More bioassay data are needed to assess the toxicity of the substances. The degradation of the substances should also be better characterised in field trials to rule out the possible toxicity of degradation products. An Ecotox Centre report summarises the current state of knowledge on the products.