ABC of Safety in the Biological Sciences
POTASSIUM DICHROMATE (K2Cr2O7)
SYNONYMS
Potassium bichromate.
GENERAL PRECAUTIONS
Use a fume hood.
Avoid skin and eye contact.
Avoid inhalation or ingestion of the powder.
Wash hands thoroughly after handling.
CHARACTERISTICS
Orange red crystals or crystalline powder.
HEALTH HAZARD DATA
This substance is a known carcinogen and must be handled with
extreme care. It may cause fire when in contact with combustible
material. It is a corrosive and will cause permanent damage to
eyes and skin. Frequent exposure of skin to the dust can cause
ulceration. Inhalation and ingestion can cause permanent liver
and kidney damage especially if contact is prolonged.
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
irritation or discomfort persist seek immediate 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). If burning or pain persist seek
immediate medical attention.
Inhalation remove from the area of exposure to fresh air. Keep
warm and allow to rest. If irritation or pain persist seek
medical attention.
Ingestion wash out the mouth thoroughly with water and give
plenty of water to drink. Seek immediate medical attention.
INCOMPATIBILITY
Potassium dichromate is incompatible with anhydrous
hydroxylamine, it explodes violently on contact.
STORAGE
Store in a cool, dry atmosphere.
HANDLING
Use a fume hood that will keep the level of exposure below the
recommended threshold limit, ie. 0.05 mg/m3. Wear
protective clothing. A long sleeved laboratory coat or gown,
rubber gloves, safety goggles and a face mask as a minimum
standard. Handle with extreme care.
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:
BACK to the
top of the Glossary Contents List
BACK to the top of the
Chemical Contents List