Sodium nitrate is a raging carcinogen if you char grill it.
Sulfur dioxide can cause problems in some people. It's relatively safe (as in, as safe as you can get for a preservative), but can induce asthma in some people. See http://www.ncbi.nlm.nih.gov/pubmed/7426352.
> Sulfur dioxide can cause problems in some people.
Right, and gluten does a real number on the (relatively few) people with celiac disease; gluten is a naturally-occurring protein that is perfectly healthy for most people, so we can't judge a chemical entirely by what it does to some people.
Sulfur dioxide can cause problems in some people. It's relatively safe (as in, as safe as you can get for a preservative), but can induce asthma in some people. See http://www.ncbi.nlm.nih.gov/pubmed/7426352.