POTASSIUM HYDROXIDE (KOH)

SYNONYMS
Caustic potash.
GENERAL PRECAUTIONS
Avoid skin and eye contact.
Avoid inhalation of the powder or mist.
Keep away from non­ferrous metals.
Keep the lid tightly closed.
Wash hands thoroughly after handling.
CHARACTERISTICS
White or grey deliquescent pellets.
HEALTH HAZARD DATA
A strong corrosive substance. Contact with aluminium, zinc and other non­ferrous metals may release potentially explosive hydrogen gas. Acute exposure to the eyes causes severe irritation and burning. Blurred vision may result. Skin contact may cause irritation and burns. Inhalation of powder or mist will cause coughing and irritation. Prolonged exposure will cause burning of the respiratory epithelium. Ingestion will cause burns to the mouth, oesophagus and stomach with localised pain.
TREATMENTS
Skin ­ remove contaminated clothing immediately and wash the affected area with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). If irritation or burning persist seek medical attention. Wash contaminated clothing before re­use.
Eyes ­ immediately wash the affected eye with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). Seek immediate medical advice.
Inhalation ­ remove from the area of exposure to fresh air. If breathing has ceased apply artificial respiration. Keep warm and allow to rest. Seek immediate medical attention.
Ingestion ­ rinse out the mouth with water and give plenty of water or milk to drink. Do not induce vomiting. Seek immediate medical attention.
INCOMPATIBILITY
Potassium hydroxide is incompatible with:
Acids, organic materials, zinc, aluminium and some other non­ferrous metals ­ releases potentially explosive hydrogen gas.
STORAGE
Store in a tightly sealed container in a cool, dry atmosphere away from incompatible substances. Suitable contact materials for storage are ­ mild steel, stainless steel, nickel, rubber epoxy coating and PVC.
HANDLING
Use a fume hood that will keep the level of exposure below the recommended threshold limit, ie. 2 mg/m³. If the level of exposure is expected to exceed this limit then a respirator is recommended. Wear protective clothing. A long sleeved laboratory coat or gown, rubber gloves, safety goggles and a face mask as a minimum standard.
DISPOSAL
WEAR:
Rubber gloves, large face shield, all purpose or special canister respirator for ammonia and laboratory coat.
SPILLS:
Solid: sweep up, dilute and neutralise with 6M hydrochloric acid, in a large bucket. Discharge to sewer with a large excess of water.
Solution: neutralise and mop up.
PACKAGE LOTS:
Pour into a large tank of water and neutralise. Discharge into sewer with a large excess of water.
ENVIRONMENT:

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