I've heard it's not even the latex pieces that can cause problems. I've heard cases on other Sci-Fi shows where even the colored skin makeup caused medical issues (Virginia Hey on "Farscape" developed kidney problems from the blue face paint she used for her character.)
LeVar Burton has complained that wearing the Visor prop caused him vision issues.
One of the actors on ANDROMEDA had to quit the show because the heavy alien makeup was causing health issues. And I believe that Roddy McDowall had skin issues from doing so many PLANET OF THE APES movies and TV episodes . . . .