I purchased about 500 of these from eBay, and the sellers/manufacturer claimed that they're PVC free, but they're not. They're vinyl flips, but with lower levels of plasticizers. The way I determined this is you can use acetone to "seal" the flips by rubbing some with a Q-tip along the surface and squeezing it together. So, if you're looking for long-term archival storage solutions, avoid these Safe-T or sometimes called "Safety" flips.
SAFLIPS are PVC free. I thought these were safe. TPGs require them to submit coins. Dealers use them all the time. http://www.aeternitascoins.com/ProductPages/Specials/Supplies.html
I know Doug doesn't believe this, but if you take a copper wire and heat it up in a flame until it glows, then touch the plastic to be tested and put it back in the flame, it will show a green flame if the plastic contains chlorine (PVC = polyvinylCHLORIDE). I have done this in the lab with a bunsen burner but not with a lighter or some such, but it should work. Look it up, it is called the Beilstein Test.
