How long will cat food go bad when exposed to the air?

15 days to more than 30 days. Because the air contains oxygen, cat food will be oxidized when exposed to the air for a long time, and the fat, protein and some vitamins in cat food are easily oxidized. When they come into contact with air, they will accelerate the oxidation reaction and lead to the deterioration of cat food. Placing/kloc-for 0/5 to 30 days will also breed bacteria, so cat food will deteriorate if it is exposed to air for more than 15 to 30 days.