[luckypenny]

Health concerns of (5) Polypropylene or PP:

In 2008, researchers in Canada asserted that quaternary ammonium biocides and oleamide were leaking out of certain polypropylene labware, affecting experimental results.[22] Since polypropylene is used in a wide number of food containers such as those for yogurt, Health Canada media spokesman Paul Duchesne, said the department will be reviewing the findings to determine whether steps are needed to protect consumers.[23]

The Environmental Working Group classifies PP as of low to moderate hazard.[24]

http://en.wikipedia.org/wiki/Polypropylene