Key Detergent Polymers Pose Low Risk to Surface Waters

Newly published research indicates that an important ingredient used in detergents and cleaning products poses a low ecological risk to waterways.

The study, “Environmental risk assessment of polycarboxylate polymers used in cleaning products in the United States,” is published in Chemosphere and is now available via open access. The research was conducted by American Cleaning Institute (ACI), Integral Consulting, Inc. and The Procter and Gamble Company.

The authors note that water-soluble polymers are important ingredients providing multiple functions and unique performance benefits to cleaning products. Polycarboxylate polymers are found in laundry products and automatic dishwashing products to improve performance by preventing redeposition of soil. They have played a role in recent years replacing phosphates, which were phased out of laundry and dish care products in past decades.

With interest heightened in the potential environmental impact of polymers ACI is assessing the state of the science regarding their environmental safety.

In this study, acrylic acid homopolymers and acrylic acid-maleic acid copolymers were evaluated using historical ecotoxicity data that have been reported over the past three decades. The evaluation included an environmental exposure assessment that is based on recent information regarding the occurrence of those ingredients in cleaning products and market sales data for cleaning products sold in the US.

The ecotoxicity of polycarboxylate polymers is generally low. Consequently, the potential environmental risks associated with their use in cleaning products in the US are low even when applying very conservative assumptions to the environmental exposure assessment, according to the authors. The PEC-PNEC (predicted environmental concentration- predicted no effect concentration) ratios were <1 for all conditions evaluated, which indicates the potential environmental risks are low.

“The alignment of findings from this screening level risk assessment with assessments by authoritative bodies from around the world supports the conclusion that current uses of polycarboxylate polymers in cleaning products do not pose a significant risk to the aquatic environment,” said Kathleen Stanton, associate VP-technical & international affairs, ACI, who is an author on the study.

In addition, there are recent supporting conclusions from assessments by the governments of Australia and Canada that polycarboxylate polymers are polymers of low concern, and the US Environmental Protection Agency has included a number of polycarboxylate polymers among the ingredients on its Safer Chemical Ingredients List based on their low hazard profile.