Reacts with water in the air and attacks metals such as aluminium, tin, lead and zinc to form hydrogen gas
Generates heat on exposure to acids
Emits toxic fumes of carbonates, peroxides and sodium oxides when heated to decomposition. Reacts with metals to produce hydrogen gas causing a fire hazard
In the event of a fire involving sodium hydroxide, use fine water spray and liquid tight chemical protective clothing with breathing apparatus
Health
Toxic by all routes of exposure
CHIP classification: corrosive
Inhalation causes irritation of the eyes and nose with sore throat, cough, chest tightness, headache and confusion
Ingestion will burn the mouth, throat and stomach
Skin contact can result in severe burns
Eye contact causes pain, twitching of the eyelid, tearing, inflammation, sensitivity to light and severe burns
Sodium hydroxide is not considered to be carcinogenic
Environment
Avoid release into the environment
Inform the Environment Agency of substantial releases
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