Researchers at the University of Alberta in Canada have identified two chemicals leaching from the commonly used polypropylene as the cause for ruining an experiment that they were conducting.  The chemicals are quaternary ammonium biocides and oleamide.

According to The Toronto Globe & Mail, the researchers were “conducting experiments on a human enzyme that is the target for drugs to treat Parkinson’s disease.”  In the course of their experiments, they encountered a “mystery substance” that was interfering with their tests.  After more investigation, they found it to be oleamide that was leaching from the polypropylene plastic tubes. It’s used to “improve the fluidity of molten plastic” and is fairly commonly found in many food containers such as yogurt cups and cream cheese containers. These containers are marked with the recycling code 5.

For more information on this topic, I’d recommend In Search of Safe Plastics by Olga Naidenko, Ph.D on Enviroblog, as well as the article in The Globe and Mail.

For us, it really isn’t an issue about whether what’s leaching is safe or not.  It’s about the safety of any leaching.  Why not make a simple choice to avoid it with a metal water bottle?