Alkalies:

Alkalies (bases) are corrosive caustic substances which dissociate within water and yield hydroxyl ions (OH^-). Alkalies involves: ammonium hydroxide, ammonia; oxide and calcium hydroxide; potassium, potassium hydroxide and carbonate; sodium, sodium hydroxide; carbonate, silicate and peroxide; and trisodium phosphate.

Alkalies, whether in concentrated liquid solution or solid form, are more destructive to tissue than most acids. It dusts, mists, and sprays might cause irritation of the eyes and respiratory tract and lesions of the nasal septum. Tough alkalies merge along with tissue, causing severe burns, often deep ulceration, and ultimate scarring. Severe burns result not just from contact along with solid alkalies, but also from solutions of these compounds.  The Potassium and sodium hydroxide are the most active materials within this group.  Still dilute solutions of the stronger alkalies tend to soften the epidermis (skin) and emulsify or dissolve the skin fats.  Experience to atmospheres contaminated along with alkalies might result in damage to the upper respiratory tract and to lung tissue and depending upon the severity of the exposure.  An effect of inhalation might vary from mild irritation of the nasal mucous membranes to severe inflammation of a lung.

Ingestion causes various damage to mucous membranes or deeper tissues within that contact is made.   Perforation of these tissues might follow, or there might be severe and extensive scar formation.  Death might result if penetration within vital areas occurs.

Even by alkalies are not flammable and will not support combustion, more heat is evolved while the solid material is dissolved in water.  Thus, cold water must be used to dissolve solid alkalies, or else the solution might boil, and splatter corrosive liquid over a huge area.