Addressing plastic additives

Abstract

Hundreds of chemicals with known toxicity to humans and the environment are still widely used as additives in plastics. The average consumer’s knowledge of what goes into plastic products is not sufficient to make informed choices about exposure. The data collection needed to make these choices often does not exist, especially for recycled products made of mixtures of existing plastics. Though data on the toxicology of single additives in isolation may be available, there is very little data on the interaction of multiple additives in real world situations, either within a single product or between many products in a single place. Most substances are not restricted until proven toxic. As a result, damage comes first and action second. Substance-by-substance testing often results in the substitution of one hazardous molecule by another with similar toxicology. Governments and consumers should demand the use of non-toxic chemicals for use in plastics, especially given the risk of admixture of toxic substances in recycled plastic products. Consumers and producers should demand full supply chain transparency on additive presence in plastic products. Understanding the toxicology of mixtures of additives requires the generation of substantial new datasets. This data should include biomonitoring to characterise the complexity of real-world exposures. Assessments of toxicity should not assume that a low dose always means a low risk. Hazardous substances should be regulated by group rather than one-by-one to avoid substituting one harmful chemical for another. A molecular science and engineering approach is crucial to finding chemical and functional alternatives to toxic additives, and also for developing new processes to better manage the toxicity of additives which cannot be replaced or omitted.