Sodium nitrite is an industrial salt. It is a white opaque crystal that looks like salt. Nitrite is harmful to human body, which can oxidize low iron hemoglobin in blood into methemoglobin, lose the ability to transport oxygen, and cause tissue hypoxia damage. Nitrite is not only a carcinogen, but can cause food poisoning when ingested at 0.2-0.5g, and it can kill at 3g. Nitrite is a kind of food additive, which plays the role of coloring and antisepsis, and is widely used in animal foods such as cooked meat, enema and canned food. In view of the many beneficial effects of nitrite in meat crispness, countries all over the world still allow it to be used for curing meat, but the dosage is strictly limited.

Most animals have blood, so they are all harmful.