Sorting through Harvard's recent assessment of the health risks of styrene got me pondering the precautionary principle.
Those two words come up regularly when we talk about regulating chemicals and plastics. The well-known examples are things like phthalates in vinyl products and bisphenol A in polycarbonate baby bottles. The precautionary principle is the idea that if evidence points to problems, even if you lack scientific certainty, you have to take action before the situation gets severe.
That scares industry. Companies envision cases like that of phthalates in children's toys, where products were banned in Europe without a great deal of direct evidence.
I recently attended a conference in the hope of sorting some of this out. The participants talked a little about phthalates and BPA, but what I found particularly interesting was the sense that the United States and Europe are moving closer to agreeing on what is meant by the idea of the precautionary principle.
Conventional wisdom is that that Europeans are much more likely to want government policy to formally recognize precautions. For chemical regulation, I think that's true. But a European Commission representative pointed out that the United States is much more precautionary in some areas, like approving new drugs.
Antoine van der Haagen, the minister-counselor for consumer affairs and food safety in the EC's Washington office, said Europeans are influenced heavily by memories of an inadequate government response to mad cow disease. ``We waited so long and now we have all the consequences of that,'' he said.
Bush administration regulatory czar John Graham told the group that he sees areas in which both Europe and the United States agree on precaution. And Consumers Union scientist Edward Groth (himself a leader in the precautionary push to restrict BPA in plastic baby bottles) sees a developing international convergence on how to apply the principle.
Groth sees one potential pitfall: Poor countries fear that precaution could be used by developed nations to close markets.
As obscure as that all sounds, it is important to plastics, because how regulators think about uncertainty plays a big role in how they regulate. Which brings me back to styrene.
The mice in the Harvard-reviewed study have an elevated risk of lung tumors at the equivalent human dose of 2-20 parts per million, averaged over a lifetime. That's close to the 1-ppm level, also averaged over a lifetime, that some workers reach after 10 years in the reinforced-plastics industry. Some studies have found elevated lung cancer among those workers, but the Harvard team said that's not likely to be from styrene. Harvard noted questions about the mice studies' relevance, but said we can't rule out their importance.
I know what some readers are thinking. There are much bigger risks in life from areas we have more control over. I agree.
But still, is that level of styrene exposure too close for comfort? There's no simple answer, except that deciding when we need to be cautious can be tricky. Makes me glad I'm not a regulator.
Toloken is Plastics News' Washington-based staff reporter.