Corrosive poisons are those substances, which corrode (means –‘to eat away’) and destroy tissues through direct chemical action. They almost always act locally and have few systemic effects. They can be classified into two groups: (i) Strong Acids: (a) Inorganic acids (mineral acids): Sulphuric, nitric, hydrochloric and hydrofluoric acids. (b) Organic acids: Carbolic, oxalic and salicylic acids. These acids are weaker in action compared to inorganic acids and are usually absorbed into circulation promoting local and remote action. (ii) Strong Alkalies: (a) Anhydrous ammonia, (b) Potassium hydroxide, (c) Sodium hydroxide, (d) Ammonium carbonate, (e) Potassium carbonate, (f) Sodium carbonate.