What are plastic additives?
Chemical substances are added to plastics for a variety of reasons. To make a product flexible, for example, plasticizers such as phthalates are used. Flame retardants are added to furniture and electronics to make them more heat resistant. While these are just two examples, many more substances are used in order to increase a product’s durability, create water repelling properties or to add a particular colour, for example. In plastic packaging alone, over 4000 chemicals are likely or possibly used. While chemicals aren’t necessarily harmful, at least 63 of these have been identified as hazardous for human health.
Apart from intentionally added chemicals, plastics also contain many non-intentionally added substances, named NIAS. These substances can be breakdown products of chemicals that are added during manufacturing, side products or contaminants. Most of the detected chemicals in a plastic product are NIAS, and as these substances are unknown, their toxicity is unknown too. What does this mean? Biologist dr. Pete Myers explains that as a result, “no plastic has been tested thoroughly  for all the plausible and important health effects that may be related to it.  None. Zip. Zero. Nada”. Further leaving a hole in our understanding of the harmful effects of not only plastic, but the chemicals found in plastic products as well.
Toxicity of plastic additives
While there is a lot we don’t know about plastic additives, there is also a lot we do know. For example, the health consequences of plastic additives have been studied for several decades, and Prof. dr. Dick Vethaak highlights that “there is mounting evidence  that plastic additives can be toxic, carcinogenic or endocrine disrupting”. Also the World Health Organization (WHO) expressed its concerns, concluding that endocrine disrupting chemicals (EDCs) are a global threat to public health, further signifying the harmful effects of plastic on human health.
EDCs mimic the hormones in our bodies and as a result can interfere with hormone regulation. This is troubling as hormones play an essential role in the development of foetuses, newborns and children, and these age groups are therefore considered particularly vulnerable to these chemicals. In addition, hormones drive many regulatory processes throughout our lifetime such as mood regulation, metabolism and sexual function, and these processes can therefore be disrupted as well. Moreover, hormones have significant impact at very low concentrations in our bodies, in part per billion, or even part per trillion concentrations. Here is a helpful analogy to illustrate this. Picture an Olympic sized swimming pool, and then picture one droplet of water. This one droplet of water equals a part per trillion and as Prof. Dr. Laura Vandenberg explains, “at that concentration, testosterone is what makes baby boys, boys”.
Similarly, EDCs also have significant impact at very low concentrations in our bodies, and scientists have demonstrated that exposure to these chemicals can be linked to various health issues such as infertility, obesity, diabetes, prostate cancer and breast cancer, among others. Moreover, some plastic additives have been associated with neurodevelopment disorders such as ADHD and autism. Though scientific evidence of the harmful effects of EDCs is overwhelming, regulation of these chemicals is lagging behind considerably, and research is continued to be done to ultimately restrict or ban harmful groups of chemicals.