I picked up a can of the non-chlorinated CRC stuff last time I bought it, and apparently it is less harsh on some materials like plastics. However, it appears that it is much more flammable and possibly toxic (the back of the can says not for sale in California and for professional use only- statements absent on the regular stuff). So I would guess that means it is better (typically with these kinds of cleaners/solvents, the more toxic/dangerous, the more effective), as long as you don't live in California (the nanny state of all nanny states....).