Wednesday, March 05, 2014

Mother Jones Tries to Raise the Dead with a "New" Expose of an Old Issue

Mother Jones this week published an article, "The Scary New Evidence on BPA-Free Plastics". I'm not sure what dictionary MJ uses as a reference, but to me, evidence that is 3 years old hardly qualifies as "new".

This is a topic that I've followed closely over the years, so I'm not sure what reason MJ has to try and resurrect the issue now. I've strongly criticized the research in the past (I'll give a quick synopsis of that in a minute), and the researchers were sued (and lost) last year by Eastman. And that was it. Nothing more has happened since then, so I am very confused as to why this is resurfacing, especially under the guise of being new. Sadly, MJ knows how the PR game works and the story has been picked up and repeated by numerous sites (1, 2, 3), all of which unquestioningly use the "new" adjective.

Of course, this is just window dressing as none of the "evidence" qualifies as evidence. The original research that started all of this was deeply flawed. The researchers took a number of different plastic samples, exposed them to abusive conditions and then ran tests to determine if the abused plastics exhibited estrogenic activity (EA). While there have been numerous researchers arguing about the validity of the EA test, I was far more concerned about the abuse that the samples underwent. For instance the UV exposure was to a 254 nm lamp. Such a lamp is highly energetic, capable of inducing countless free-radical reactions in any organic material including plastics. Quite simply put, the plastic sample after this exposure was not the same as the plastic sample prior to the exposure. It had new chemicals in it. Unfortunately, the chemicals that exhibited EA were never clearly identified via analysis, so it is impossible to say that the EA came from what was in the original plastic or what the plastic had been morphed into after the UV exposure.

Similarly, the researchers used an autoclave (water at 134 C) to simulate a dishwasher. Again, a very abusive test, but one they had to run since dishwashers aren't available in the Austin, Texas area.

I've spent a number of years working on accelerated aging of plastics, including making a presentation at a technical conference on how easy it is to completely botch the testing. Without prior experience, people assume that you can just crank on the sample with the worst jungle test you can imagine, such as exposing the sample to 254 nm light rather than the the 340 - 400 nm light that dominates the UV light on the earth's surface. Such abusive testing will give you the wrong answer. There are many subtleties that researchers have found over the years that are surprising, such as the case with polyolefins, where shutting the light source off every once in a while actually ages your sample faster than having it on continually.

The fact that one of the largest chemical companies in the world screwed up their accelerated aging testing [*] shows how easy it easy to do it wrong. That these neurobiologists would make similar mistakes is hardly surprising, but it is time that their errors be fully noted. Rerun the tests, rerun them properly and then you will have my support.

[*] I know because I was professionally involved in helping a client company successfully sue them...

Previous Years
March 5, 2012 - Here Come the Patent Trolls

March 5, 2010 - Reducio ad Absurdum

March 5, 2009 - Some Hints on the Rheology of Ketchup

March 5, 2007 - Information Just Wants to be Free

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