If I was to hazard a guess, I think you might be referring to radon. Radon is a natural element in our environment, though toxic at high levels.
Please read the GreenHomeGuide Q&As below to learn more about radon in countertops.
- Is it really possible to get a radon-free granite counter?
- Where can I find radon testing equipment for granite countertops? And what are safe levels?
- What's your opinion on Corian? I'm looking for a green and cost friendly countertop.
Another substance, related to countertops, which may be toxic is the sealant that is used to seal a variety of natural stone materials such as granite, limestone, soap stone, etc. Sealants are typically applied in the field rather than in the shop.
- Talk to your countertop fabricator about what they use and what the VOC levels are.
- One such product we have used with success with people with chemical sensitivities is Meta Creme (available to consumers, not just the trades).
Recognize that the off-gassing period for noxious sealants will depend on a variety of factors including the time of year that the countertops are installed and whether the windows are open, how warm the interior temperature of the house is as well as the over volume of the space.
Good luck with your countertop selection process!!