The good news is, there aren't many teethers out there that contain Bisphenol-A(BPA), but there are many companies still use phthalate-free PVC, which is emerging as a new material of potential concern and also takes a substantial toll on the environment and on factory workers due to the heavy use of chlorine in its production.
I will only list teethers which you should absolutely avoid (contain BPA), or should be cautious(Contain phthalate-free PVC):
Products to Avoid: Contain BPA, Do not buy; if purchased, returen or discard.
Manhattan Toy's
Tulu Rattle
Sassy's
Circle Rattle
Products to be cautious: Contain phthalate-free PVC,Do not buy; if already owned, continue to use.
Infantino's
Cuddly Teether Blanket
Any Infantino's
Water-Filled Teethers, such like:

Learning Curve/1st Years'
Soft Friends Cooling Teether
Learning Curve's
Cool Animal Teethers
Disney Friends Teether
Floating Friends Teether
Munchkin's
Dora the Explorer Soothing Ring Teether 
Munchkin's
Twisty Teether Ball