Ross Raven wrote:But we are here to talk about #4. Oxidisation. Oxygen chemically reacting with your food. I'm not a chemist so I cant help you with the chemistry questions. Another old way to do this is using dry ice. Oxygen being lighter than nitrogen, the oxygen would lift out of the bucket.
Air activated hand warmers contain cellulose, iron, water, activated carbon (evenly distributes heat), vermiculite (water reservoir) and salt (catalyst) and produce heat from the exothermic oxidation of iron when exposed to air.