Which conformal coating chemistries are safe for use on XBee modules?

Different conformal coating chemistries such as acrylic, silicone, urethane, and varnish require different curing processes.

Considering each chemistry’s curing requirements, such as solvent evaporation, elevated temperature, UV irradiation, or others, which are safe for use on XBee modules?

Try looking at http://knowledge.digi.com/articles/Knowledge_Base_Article/What-conformal-coating-material-is-used-on-the-industrial-rated-radios/?q=conformal+coating&l=en_US&fs=Search&pn=1

It has in it what one Digi uses.