Wish I could find someone to do this for me. Char Griller has no plans as of yet. Noticed on LP tank that California has determined that LP gas is a carcinogen! I'd rather use Natual gas.
I would not lose too much sleep over it.
Formaldehyde has been classified as a human carcinogen (cancer-causing substance) by the International Agency for Research on Cancer and as a probable human carcinogen by the U.S. Environmental Protection Agency.
Formaldehyde can also be released by burning wood, kerosene, natural gas, or cigarettes; through automobile emissions; or from natural processes.
Benzene - a known carcinogen; causes cancer; long-term exposure to high-levels in the air can cause leukemia and cancer of the blood-forming organs; can damage the immune system.3
Burning LP gas releases Benzene.
My point is either way you go, there is a small risk. So cook, eat and do not let it worry you too much.