Wednesday, March 04, 2015

Is Tritan Plastic Free of Estrogenic Activity (Part 3)

[Note: This is the third part of a 3-part series taking a critical look at the work of University of Texas - Austin neuroscience Professor George Bittner regarding estrogenic activity in plastics. Here is Part 1, which gives general criticisms of his work in this area, and here is Part 2 which looks critically at the results of a 2014 publication.]

The second of two recent papers by George Bittner et al. looking at the estrogenic activity (EA) in BPA-free plastics was also published in the journal Environmental Health. It is also open access, so again, feel free to pull a copy and read along with me.

This paper is very similar to the paper discussed in part 2 and so I won't bother repeating my earlier criticisms as they are still valid. However, they researchers have finally begun to address the issue of a naturally-aged control. But they still didn't manage to not screw it up.
"Natural sunlight stresses: plaques were placed individually between a quartz glass plate on top and aluminum foil on a porcelain plate below. The two plates were clamped together using binder clips. To control for heat versus sunlight effects, some of these plaques were wrapped in thick aluminum foil. These plaques were placed on the roof of CCi’s facility for 1–14 days in summer." (Note: CCi = Certichem Inc, the company for which the researchers work)
Natural sunlight - good. Quartz glass - bad (it will trap heat). Aluminum foil beneath the samples - bad (it will reflect back the UV). Wrapping everything in thick aluminum foil - ??? And how is this suppose to work? Better yet, did it work? And your proof of this is ________? Or does your new "control" need another control?

And the data is still being cherry picked:
"The greatest %RME2 response of 4–8 dilutions of a test chemical or extract run in triplicate was considered detectable if it produced an effect whose average %RME2 was greater than 15% RME2..."
That's right. Run the test 3 times and if just one of the samples is positive, the whole set of experiments is positive.

Unlike the previous work, ethanol is now the preferred extraction solvent, to which again, I ask "why"? Tritan bottle are generally used as reusable water bottles, not reusable drink bottles. And even if alcoholic drinks are place in the bottles, the alcohol itself has plenty of estrogenic activity, possibly more than enough to make moot concerns of chemicals with EA in the plastic.

For the life of me, I cannot figure out why the researchers haven't run the simplest and most appropriate test of all. Take a bottle of Tritan or whatever other glassy plastic you are trying to skewer this year, wash it out with soap and water (like a normal consumer would before their initial use), fill it up with water and let it sit for 2 weeks. Let it sit in the fridge or let it sit in a car or let it sit up on the roof of the CCi building and then look for EA in the water. Just do something with it that a normal person would do instead of acting like that's not good enough. The researchers have had 3 whole years to do this, but instead have entirely focussed on horribly-erroneous stress-tests that render their entire results worthless.

Is that really asking too much? Because if you did that, if you actually used the bottle like a normal person would and if you saw chemicals with EA being transferred to the water, then no one would be able to seriously question the results, would they?

Previous Years

March 4, 2013 - Two Oobleck Videos - 1 Good, 1 Bad

March 4, 2011 - More Thoughts on "Materials Science"

March 4, 2011 - Good News on the BPA Front

March 4, 2010 - Chemical (er... Biological) Switching


Dan Burke said...

"But they still didn't manage to screw it up" - I bet the "didn't" is out of place there! Nice posts.

John said...

Thanks for the catch. Actually, I was trying to say "But they still didnt' manage to not screw it up", which I have since corrected.

It's a double negative, but it conveys the message better.

Anonymous said...

Thanks for this thorough analysis, John. It is mighty suspicious that they did not indeed employ simple real-life tests like you suggest. Then again, I haven't read about Eastman using such a test to disprove this study, so...

I found another study that says all plastics pretty much leach EA chemicals, including ones previously thought not to leach- HDPE, PP, etc. Do you think Tritan is any better in that respect? (To be honest, though, this study too was done by the Bittner group, so I don't know what to make of it...)

John said...


That report is what got this whole thing started including the lawsuit by Eastman. I took some swipes at it in this post.