Polyester and epoxy are inert when fully cured. The problem that many people have is that they proceed with alien compounds long before the epoxy or poly is fully cured which can take weeks.

A new kayak smells (out gassing) like polyester for many months after being made, and epoxy blushes and out-gasses for quite a while too.

Some interesting reading for tech people.

http://www.redrockstore.com/resin.htm