This document provides guidelines for the safe storage and use of different types of chemicals including toxic, harmful, irritating, flammable, oxidizing, corrosive, explosive, and environmentally dangerous chemicals. Key recommendations include storing chemicals in properly ventilated areas based on their hazards, using personal protective equipment, and disposing of chemicals properly to avoid pollution.

1. SAFE USE AND STORAGE OF
CHEMICAL AND REAGENTS

2. TOXIC, HARMFUL AND IRRITATING CHEMICALS
toxic substance is one that can cause serious acute or chronic effects, even
death
• Toxic chemicals:
potassium cyanide, mercury, mercury, mercuric nitrate, sodium
azide, sodium nitroprusside, thiosemicarbazide, formaldehyde
solution, chloroform, barium chloride, diphenylamine, and
methanol.
harmful substance is one that can cause limited effects on health
• Harmful chemicals:
barium chloride, benzoic acid, potassium oxalate, saponin, xylene,
iodine, and sulphanilic acid.
irritating chemical is one that can cause inflammation and irritation of the
skin, mucous membranes, and respiratory tract.
• Irritants:
ammonia solution, acetic acid, sulphosalicylic acid, potassium
dichromate, and formaldehyde vapour

3. Safe storage and use of toxic chemicals
• Storage
potassium cyanide must be kept in a locked cupboard.
Stock solutions or solids of harmful and irritating chemicals should
be stored safely in a cupboard, not on an open shelf.

4. • Safe use
1. wash the hands immediately after use. Wear suitable protective
gloves and suitable eye protectives.
2. eyewash bottle is accessible to rinse the eyes should a toxic, harmful
or irritating chemical enter the eye
3. Always lock away highly toxic chemicals immediately after use and
never leave such chemicals unattended
4. handle chemicals with an irritating or harmful vapour in a fume
cupboard.
5. Before opening a chemical with an irritating vapour, place a cloth
over the neck of the container and cap.
6. Keep containers tightly closed.
7. Never mouth-pipette any chemical or reagent, always use automatic
dispensor or pipettor.

5. FLAMMABLE CHEMICALS
• A flammable substance is one that readily ignites (catches alight) and
burns
• Extremely flammable: acetone, diethyl ether. (flash point below 0°C and a
boiling point of 35°C or below)
• Highly flammable: Liquids with a flash point below 21°C, substances which
are spontaneously combustible in air at ambient temperature.
ethanol and methanol, 70% and above ethanol and methanol, methylated
spirit, isopropanol (isopropyl alcohol), toluene, alcoholic Romanowsky
stains, acid alcohol, other alcoholic reagents and indicators.
• Flammable: Liquids with a flash point of 21°C or more and below or equal
to 55°C, e.g. glacial acetic acid, acetic anhydride, xylene

6. Safe storage and use of flammable chemicals
• Storage
Extremely or highly flammable in a closed steel or thick
plywood box at ground level
preferably in an outside locked store that is cool and well ventilated
including ventilation at or near floor level because the vapours of
most highly flammable liquids are heavier than air.
Label the container Flammable.
Do not store flammable and oxidizing chemicals together.

7. • Safe use
1. well ventilated to prevent any build up of flammable gases and vapours
2. Before opening a bottle containing a flammable liquid, always make sure
there is no open flame within 2 metres.
3. Ensure stock bottles and dispensing containers are closed after use
4. Do not light a match or use a lighted taper near to a flammable chemical
5. Display ‘no smoking’ notices
6. Place dispensing containers of acetone, acid alcohol, methanol, and
alcoholic Romanowsky stains well away from the rack used to heat stain
7. If needing to heat a flammable liquid, use a waterbath.

8. OXIDIZING CHEMICALS
• An oxidizing substance is one that produces heat or evolves oxygen in
contact with other substances causing them to burn strongly or become
explosive or spontaneously combustible.
• Oxidizing chemicals:
hydrogen peroxide and other strong peroxides, nitric acid,
ammonium nitrate, sodium nitrite, perchloric acid, sodium chlorate,
chromic acid, potassium dichromate, calcium hypochlorite bleach
powder, and potassium permanganate

9. Safe storage and use of oxidizing chemicals
• Storage
must be stored well away from flammablechemicals and other
chemicals with which they can react dangerously
• Safe use
Always handle oxidizing chemicals with care. Besides being fire-
promoting, most oxidizing substances are dangerous to skin and eyes

10. CORROSIVE CHEMICALS
• A corrosive chemical is one that can destroy living tissue and is also
capable of damaging inanimate substances
• phenol, strong acids such as concentrated sulphuric acid, nitric acid, glacial
acetic acid, trichloroacetic acid, o-phosphoric acid, caustic alkalis such as
sodium hydroxide (caustic soda), and potassium hydroxide (caustic
potash),

11. Safe storage and use of Corrosive chemicals
• Storage
Corrosive chemicals should be stored at low level.
Do not store potassium hydroxide or sodium hydroxide in a bottle having a
ground glass stopper because these chemicals absorb carbon dioxide from
the air forming carbonates which can cement the stopper in the bottle.

12. • Safe use
Never mouth-pipette a corrosive chemical
Always pour a corrosive chemical at below eye level
Wear suitable protective gloves and a face visor or at least
eyeshields, when opening a container of a corrosive chemical and
when pouring it.
Dissolve a solid corrosive chemical such as sodium hydroxide in
water with great care
NEVER ADD WATER TO ACID
Always use a strong carrier to transport bottles of corrosive
chemicals

13. EXPLOSIVE CHEMICALS
• Sodium azide:
This can form explosive products when in contact with metals such as
copper and lead
• Perchloric acid:
If allowed to dry on woodwork, brickwork or fabric, this chemical will
explode and cause a fire on impact
• Picric acid and pricrates:
Picric acid must be stored under water. If allowed to dry it can
become explosive
• Diethyl-ether and other ethers:
When exposed to air and sunlight, ether can form shock-sensitive
explosive peroxides
Always read carefully the manufacturers’ instructions regarding the storage
and handling of explosive chemicals

14. ENVIRONMENTALLY DANGEROUS CHEMICALS
• Some chemicals can cause immediate orlong term harm to aquatic life,
fauna and flora, or pollute the atmosphere. Laboratory staff have a duty to
avoid chemical pollution of the environment.
• ensure that the drainage and waste disposal systems oflaboratories are
safe, adequate and in good repair.
• Hazardous chemicals and reagents must not be discharged into open
drains or disposed of on open ground.
• Sufficient water must be used when flushing hazardous chemicals and
reagents through the plumbing system
• The sewer system should not be used to dispose of highly toxic chemicals,
water-immiscible chemicals,