Industrial salt can not be used to soak feet, may lead to body damage, aggravate the body kidney burden. Common industrial salt contains sodium chloride (NaCl), but also contains sodium nitrite (NaNO₂), NaNO₂ is a toxic substance, prohibited for consumption or use in the human body for other purposes. The use of industrial salt foot soak may produce a variety of hazards, such as industrial salt foot soak can make the skin come into contact with toxic substances, which may lead to damage to the organism. Industrial salt contains NaCl, long-term use of industrial salt foot soak may aggravate the burden on the kidneys, and even cause kidney damage. In summary, industrial salt is harmful to the human body, the use of industrial salt foot soak should be prohibited to avoid exposure of the organism to toxic chemicals. In addition, salt foot soak has a certain bactericidal effect, but it should also be noted that it can not be used for a long time.