Used in canned meats etc. to prevent botulism a. Good against yeasts and molds, poorer against bacteria 2. Good against molds 3. Can taste at 500 ppm, more effective in acid pH 2. Used in wines, dehydrated fruits, salads 4.
Some people are quite allergic to sulfites and react to extremely small quantities.
E. Nitrites and Nitrates - nitrites are most effective. Gut bacteria convert nitrates to nitrites in the gut 1. Makes meet look red and fresh. Also converts your hemoglobin to methemoglobin which doesn't carry oxygen 5. Slows O 2 in oils converting unsaturated fatty acids to peroxides which are cancer causing.