Q. Dear Umbra,

I want to buy some mats for my 4-year-old to play on and do gymnastics at home. All the “nontoxic” kids’ playmats seem to be made of EVA foam, but I have the impression that almost anything “foam” (other than natural latex foam) might be either bad for the environment or bad for kids (i.e., flame-retardant chemicals). Is EVA foam OK? Any other options you would recommend? I did see some mats made of natural rubber, and of course they were very expensive.

Jaysa Z.
Boston, Massachusetts