The Skeptical Environmentalist #2: The downside of banning harmful chemicals.
What if banning harmful chemicals from everyday items doesn’t really lead to a nontoxic product?
When we discover that a particular compound (or class of compounds) can be toxic to humans or wildlife, we often call for a widespread ban on these substances to reduce health risks associated with exposure to these chemicals.
The first well-known case began in the 1960s with the release of “Silent Spring” by biologist Rachel Carson, bringing attention to the ecological damage caused by DDT. Since then, many other compounds such as polychlorined biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), perfluorinated chemicals (PFCs), and bisphenol A (BPA) have been subjected to similar scrutiny upon discovery of their harmful effects.
Part of my research as an environmental toxicology student involves examining the suitability of existing and potential chemical substitutes of infamously ‘bad’ compounds, developed in response to pressure from consumers and advocacy groups. Often these groups want to eliminate toxic chemicals from production of everyday items such as frying pans, pizza boxes and water bottles. From a consumer standpoint, chemical substitutes should provide a non-toxic alternative to these ‘bad’ compounds.
Recently, several media outlets have warned consumers that BPA-free plastic water bottles and baby bottles might not be as safe as we were led to believe. Reports show that many water bottles previously containing BPA have since been replaced with a different-but-similar compound, bisphenol S (BPS), which is linked to issues with brain development in zebrafish.
We are inclined to believe that the 'BPA-free' version of water bottles is safe compared to water bottles containing BPA. But what did they use to replace BPA?
Even if initial toxicity tests on a potential substitute reveal that it is a ‘better’ substance, it is often challenging to model how a compound will actually behave in nature over time. This can be particularly hard with substances that are persistent (stick around in the environment for a long time) and bioaccumulative (build up in organisms and food webs over time). It is especially difficult to adequately evaluate these persistent and bioaccumulative substances in a laboratory setting.
(So, don’t be surprised when we find out that ‘PFOA-free’ frying pans are bad for us too).
In many cases, simply removing a particular chemical from a product without an adequate chemical substitute is not feasible. Manufacturers of water bottles did not originally use BPA ‘just because’. A substitute just like BPA is still likely going to be found in water bottles – and it's probably just the next most similar compound, which could be just as toxic, bioaccumulative or persistent as the compound consumers are so excited to get rid of.
So, nobody is lying when BPA free water bottles are marketed as ‘BPA-free'. Consumers didn't want BPA in their water bottles, and they got what they asked for. Instead, they now have BPS.
This is what many "Ban [insert specific chemical name here]!" petitions lead to: immense greenwashing. But this is more than just false ideas about environmental safety. This carries over into false notions about consumer health as well.
Instead of signing a petition to ban just one compound, think about whether there is more to the story – would a similar chemical substitute really help to solve the issue, or are you just helping manufacturers maintain good PR? I am not advocating against efforts to eliminate toxic compounds from products, but rather I hope to prevent consumer manipulation via chemical trickery.