ABC of Safety in the Biological Sciences
SODIUM HYPOCHLORITE (NaOCl)
SYNONYMS
Bleach, liquid pool chlorine.
GENERAL PRECAUTIONS
Avoid skin and eye contact.
Avoid inhalation or ingestion.
Keep away from heat.
Keep away from light.
Keep away from metal surfaces.
Keep away from oxidising or reducing agents.
Wash hands thoroughly after handling.
CHARACTERISTICS
Faintly yellow liquid with slight chlorine odour.
HEALTH HAZARD DATA
Sodium hypochlorite is a strongly corrosive substance. Skin
contact results in burns unless the liquid is removed quickly.
It can act as a sensitiser. Eye contact results in burns and
damage may be permanent. Inhalation will cause coughing and
respiratory difficulties. Ingestion will cause severe local
burns to the mouth, oesophagus and stomach.
TREATMENTS
Skin immediately remove contaminated clothing and wash the
affected area with soap or mild detergent and large amounts of
water until all evidence of the chemical has been removed
(approximately 15 minutes). Burns will need medical treatment.
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 irritation or pain persist seek
immediate medical attention. Burns will require immediate
medical attention.
Inhalation remove from the area of exposure to fresh air. If
breathing has ceased apply artificial respiration. Keep warm and
allow to rest. If irritation persists or develops seek medical
attention.
Ingestion wash out the mouth thoroughly with water and give
water or milk to drink. Do not induce vomiting. Seek immediate
medical advice.
INCOMPATIBILITY
Heating produces toxic fumes of chlorine. Incompatible with
acids, strong oxidising and reducing agents, metals and metallic
salts.
STORAGE
Store in a cool, dry atmosphere in the dark away from heat and
incompatible substances.
HANDLING
Use a fume hood to minimise exposure to this substance. 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, 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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