What’s Happening? EPA’s current safety assessments of new chemicals proposed for market entry often fall short of effectively protecting all members of the public from risk because they don’t consider that we may be exposed to closely related chemicals that cause similar harms.
Recent Example: EPA proposed rules requiring notification of significant new uses for a group of new chemicals. Two of these chemicals, known as trimellitate esters, are very closely related, and would be expected to cause very similar harms and have very similar uses—so that people exposed to one chemical would likely be exposed to the other. Despite this, EPA did not consider the chemicals together or even use the information it had on one to inform its understanding of the safety of the other.
This doesn’t make sense.
Even though EPA said that one chemical was intended to be used as a lubricant and the other as a plasticizer (a chemical that makes plastics more flexible), it is likely that both could be used as a plasticizer or a lubricant. They may be used together or turn up in similar consumer products, such as a car’s dashboard. Further, both chemicals are very closely related to yet another plasticizer used in the auto industry, but it appears that EPA considered these nearly interchangeable chemicals in isolation from one another.
In fact, under the Toxic Substances Control Act (TSCA), EPA is required to identify such “reasonably foreseen uses,” such as ending up in the same product.
Why It Matters: Evaluating chemicals in isolation likely underestimates the exposures and risks workers, consumers, and frontline communities face. Doing so also fails to make use of all the best available science, since information on each of these two chemicals (as well as the one already being used) could inform the safety determination for the other.
Considering the combined risks from similar chemicals is not new. EPA is already doing this for another group of closely related chemicals—phthalates. Phthalates have long been widely used in a range of consumer products and are detected in almost all our bodies. Phthalates are known to impact male reproductive health. EPA is joining the ranks of other federal agencies that have considered the cumulative risks they pose.
Our Take: EPA should not stop at phthalates. They can and should be incorporating cumulative approaches from the very beginning of a chemical’s regulatory life. Considering the impact of combined exposures does not need to be complicated and EPA could make such a consideration without much extra effort.
EPA can take a first step toward doing this by considering the potential for cumulative risks when finalizing its regulation on the significant new uses for these two new closely related chemicals.
Go Deeper: Read EDF’s response to EPA’s proposed new SNURs. And check out our Cumulative Risk Assessment Framework.