Corrosive

Corrosive injuries are chemical burns. The damage begins as soon as the material touches tissue and can continue until the chemical is removed or neutralized by flushing. Some corrosives, such as hydrofluoric acid, may cause little pain at first while serious injury develops, which makes early first aid critical.

In the GHS, skin corrosion is divided into sub-categories 1A, 1B and 1C based on how quickly tissue is destroyed. Serious eye damage is a separate class, since the eye can be injured by materials that would only irritate skin. The label carries the corrosion pictogram, the signal word Danger and statements such as H314.

Corrosive hazards to health should not be confused with corrosivity to metals, which is a physical hazard class with the same pictogram. A product can attack steel but be mild to skin, or burn skin and leave metals alone. The SDS lists each separately. Corrosive solids, mists and fumes can also damage the lungs and throat when inhaled.

pH gives a rough clue, since very low or very high values suggest corrosivity, but pH alone does not decide classification. Concentration, buffering and the chemical itself all matter.