1, edible salt is relatively pure sodium chloride, industrial salt not only has sodium chloride, but also has a high content of sodium nitrite.

2. Salt is neutral after melting, and alkaline after industrial salt is melted.

3. Salt is relatively stable and will not change at will. Industrial salt is relatively stable when it is dry, but it will gradually absorb oxygen in the air and eventually become nitric acid.

4. Industrial salt is sulfate and nitrate, which is harmful. Eating edible salt is harmless to the body.