One challenge in publishing a consumer research blog is that we sometimes get information off the record. We regularly point readers to the ZRecs Guide because it allows us to assign "confidence" ratings, which we often cite as allowing us to consider a company's track record when evaluating statements they make. What we don't usually like to spell out is that we also base our confidence ratings, at times, on information we have acquired but cannot publish.

BPA researcher Frederick vom Saal's statements in an article in The Star today have given us the opportunity to let something come out that we weren't previously at liberty to share. Vom Saal stated that he tested SIGG bottles several years ago and found leaching in the parts per trillion range. Based on an agreement we have made with a party that provided us with testing data off the record during our investigation of SIGG last month, we are now able to share some information that we believe independently supports Vom Saal's claim.

Two out of two labs agree: SIGGs leached BPA

Two weeks ago, we were provided with BPA leach testing results for a SIGG water bottle purchased in July, that had SIGG's older, BPA-containing liner. The test was conducted in a 3% acetic acid solution at 40 degrees Celsius, with a stated limit on quantitation (minimum detection level) of .5 parts per billion, or 500 parts per trillion. The bottle was found to leach BPA at 1.25 micrograms per liter, which is roughly equivalent to 1.25 parts per billion. In relative terms, this is more than what Vom Saal states he had found, although he has not yet provided many details of his tests. In absolute terms, both values are very, very small. Everyone - you included - is exposed to BPA at higher levels from other sources, many of them entirely outside of your control. Canned foods tested by the Environmental Working Group contained up to 385 ppb, and even if you avoid those, there are plenty of others. Labs testing water bottles for BPA have to correct for background BPA in the water - sometimes up to 2 ppb. (We have confirmed, for the record, that this test made such a correction as a matter of standard procedure.)

As for SIGG's specific situation, we aren't sure this is particularly damning. They tested to 2 ppb - a level that others in the industry, including company heads we know to be aggressive in their own testing and have no love lost with SIGG, told us was a reasonable threshold for commercial testing of a product. Spinning this into "0.0% leaching," as SIGG often did, is another story.

How can we get more information on the record?

Most of the information we accept off the record is product testing data we would never get otherwise. We scrutinize it carefully, and if it checks out, we may negotiate with the provider of the information to see if there is some way we can use the information that protects their anonymity. In this case, there was no agreement that worked for both sides until Vom Saal went public with his own testing, at which point our source agreed to let us share the findings and the methodology of the testing they had performed, although we agreed to continue to protect the name of the lab and the source of the information.

Accepting information off the record is never ideal, but it allows us access to a lot of information we can use indirectly to provide guidance to consumers through our listings in the ZRecs Guide. We encourage you to pay attention to product listings that are not flagged for a chemical but have "low" confidence assigned to that status, as well as products you might have believed were free of BPA or some other chemical but are flagged as containing it. Most of these are based on our knowledge of a company's track record of trustworthiness, but some are based on information we have acquired but are not in a position to share.

There is another way to get around off-the-record testing: Testing products ourselves based on good leads. The problem is that that costs money. We considered testing an older SIGG bottle for BPA so we could get a clean lab result we could share openly, but it would have cost about $350 that we do not have.

But we have been thinking about a different way of doing testing to find out things that our community of readers want to know. What if ZRecs readers were willing to contribute small amounts to a fund that would test a product we believe, for reasons we cannot disclose, is highly likely to contain a harmful substance its manufacturer believes claims it is free of? What if ZRecs as a community engaged in grassroots product testing?

We'll be making an offer to ZRecs readers to do just that very soon.

More on this story

• SIGG's BPA Confession


• Two warnings before you request a replacement SIGG bottle


• The ZRecs 2009 BPA-Free Water Bottle Showdown


• ZRecs evidence of misleading statements by SIGG representatives


• our interview with SIGG CEO Steve Wasik