POTASSIUM CHROMATE (K₂CrO₄)

SYNONYMS
None known.
GENERAL PRECAUTIONS
Extremely toxic.
Potential carcinogen.
Use a fume hood.
Avoid skin and eye contact ­ corrosive.
Avoid inhalation.
Avoid ingestion.
Wash hands thoroughly after handling.
CHARACTERISTICS
Bright yellow crystalline powder.
HEALTH HAZARD DATA
Potassium chromate is a suspected carcinogen and is extremely toxic. It is a strong oxidising agent and is corrosive. It attacks the lungs, nasal cavity and paranasal sinus, stomach and larynx. The most detrimental routes of exposure are by inhalation of the powder or ingestion. Eye contact will cause burning and pain. Skin contact will cause localised burning and pain.
TREATMENTS
Skin ­ remove contaminated clothing and immediately wash the affected area with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). If burning or pain persist seek medical attention.
Eyes ­ immediately wash the affected eye with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). If burning or pain persist seek immediate medical attention.
Inhalation ­ remove from the area of exposure to fresh air. If breathing has stopped apply artificial respiration. Keep warm and allow to rest. Seek immediate medical attention.
Ingestion ­ if the victim is conscious wash the mouth with water and give two to four glasses of water to drink. Induce vomiting by touching a finger to the back of the throat. Seek immediate medical attention. If the victim has ceased breathing apply artificial respiration.
INCOMPATIBILITY
Unknown.
STORAGE
Store in a cool, dry atmosphere.
HANDLING
Use a fume hood to avoid inhalation of the powder. Wear protective clothing to avoid skin contact. A long sleeved laboratory coat or gown, rubber gloves, safety goggles and a face mask as a minimum standard.
DISPOSAL
WEAR:
Rubber gloves, face shield and laboratory coat. A body shield should be available for the more active agents. Replace the face shield with self contained breathing apparatus for such agents as chlorine and bromine.
SPILLS:
Gas leak: if the valve is leaking because it cannot be closed, the gas can be bubbled through a reducer (sodium sulphite) and excess sodium bicarbonate solution. Be sure to include a trap in the line to prevent the solution being sucked back into the cylinder. If this cannot be done the cylinder should be placed in or adjacent to a fume hood and left to bleed off. If the leak is in the valve assembly, a plastic bag can be fastened over the head of the cylinder which can then be taken outside or to a fume hood.
Liquid or solid: cover with a reducer (sodium thiosulphate, a bisulphite or a ferrous salt not carbon, sulphur or strong reducing agent). Mix well and spray with water. A sulphite or a ferrous salt will require addition of 3mol/l sulphuric acid to promote a rapid reduction. Scoop the slurry into a container of water and neutralise with soda ash. Discharge to sewer with a large excess of water. Wash the site thoroughly with a soap solution containing some reducer.
PACKAGE LOTS:
Add to a large volume of concentrated solution of reducer (sodium thiosulphate, a bisulphite or a ferrous salt and acidify with 3mol/l sulphuric acid). When the reduction is completed add soda ash or dilute hydrochloric acid to neutralise the solution. Discharge to sewer with a large excess of water.
ENVIRONMENT:

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