SAFETY
Safe practices in school laboratories reduce the risk of accidents and
offers students safer places to experience the excitement of practical
chemistry. This section contains some practical suggestions for teachers
to put into practice in their laboratories, if they have not done so already.
More detailed instructions on the best practice in school science and
dealing with chemicals in schools can be obtained from “Safety in
School Science” and “Safety in the School Laboratory” published by
the Department of Education and Science and circulated to all schools.
General Laboratory Guidelines
1
Laboratory coats and eye protection should be worn at all times
during practical work.
2
Gloves should be worn when necessary especially when handling
corrosive and toxic materials.
3
Eating, drinking or smoking must never be allowed in the
laboratory.
4
Long hair must always be tied back securely.
5
Any cut, burn or other accident must be reported at once to the
teacher. Details of any accident, however trivial, must be entered
as soon as possible on the Laboratory Accident Record Book and
then on the school accident report form and submitted to the
school management.
6
Classes in other practical subjects should not be conducted in
biology, chemistry or physics laboratories.
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Non practical subjects should not be taught in the biology,
chemistry or physics laboratories.
8
Laboratory doors should be locked when not in use.
9
Every laboratory should have good ventilation. The build up of
corrosive or flammable fumes should be kept to a minimum.
Liquids with high vapour pressure should be kept out of the sun.
10 Hazardous chemicals should not be kept in the laboratory but if
they have to be, they should be locked in cupboards. The
quantities of made up solutions kept available in the laboratory
should be kept to a minimum.
11 Everybody using the laboratory should know the location of the
master control shut off valves for electricity, gas and water.
12 A means of communication to the main office is recommended.
13 Teachers and students should wash their hands after using
chemicals and before leaving the laboratory.
14 It is advisable to use daily, weekly and once a term checklists.
15 The following extra safety apparatus should be available in the
laboratory.
• Safety screen
• Face shield (for teachers only)
• Eye wash/shower – an eye wash stand or eye wash bottle or
a fixed rubber tube on a convenient tap.
• Fire extinguishers (CO2 /dry powder)
• Fire blankets
• Fire buckets
• Chemical spill Clean up kit
• First aid kit.
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Chemical Storage
Storage of laboratory chemicals presents an ongoing safety hazard for
school science departments. There are many chemicals that are
incompatible with each other.
Improper storage of chemicals is the cause of many laboratory accidents.
Chemical Storage Groups
The organisation of storage of chemicals should be simple and
straightforward and in such a way as to minimize possible hazards. The
shelves should be clearly labelled or colour coded. All people using the
chemical store should have some indication of where each substance is
stored. A suggested system for categorising chemicals is to use six
different storage groups each with its own colour code. The shelves and
cupboards in the chemical store should also be colour coded. This will
prevent incompatible chemicals from being near neighbours.
STORAGE GROUPS
RED
Flammable storage
GREY
General chemicals no particular
storage hazard
BLUE
Toxic or health hazard
YELLOW
Oxidising chemicals
GREEN
Corrosives – alkaline
WHITE
Corrosives – acids
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Further Segregation
Segregation of Flammables. Flammable liquids should be stored
separately from flammable solids. Two fire resistant cupboards would be
ideal, one larger one for bottles of flammable liquids and a smaller
version for the flammable solids.
Harmful chemicals can be further isolated by using (i) plastic tray/boxes
or (ii) outer container.
(i) Plastic Trays/Boxes
A number of compatible chemicals are placed in a plastic tray or plastic
box and a label put on the outside of the tray/box to indicate what
chemicals are stored within.
(ii) Outer Container
Put the container in a heavy duty plastic bag (freezer bag), tie the bag,
place it in an outer container (an unused paint can or a snap open secure
container) with some absorbing agent and securely fix on the lid.
Further considerations which should be taken into account when
storing chemicals safely include:
• Only authorised persons should have access to chemical stores, which
should be locked when not in use.
• Chemicals that are no longer required should be carefully disposed of.
• The chemical store should be well ventilated: this includes forced
ventilation from floor to ceiling.
• Chemicals should not be stored in shelves above eye level. If
chemicals have to be stored above this level it should be restricted to
smaller bottles and steps should be available.
• Avoid floor chemical storage, if possible.
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• Shelves should have anti-roll off lips and should not be overcrowded.
A chemical should not be hidden behind a larger container.
Containers should not be stacked upon each other.
Ideally shelf assemblies should be of wood construction and should be
firmly secured to walls. Island assemblies should be avoided.
• Chemicals should be returned to storage area immediately after use.
• Chemicals should not be stored in fumecupboards while the cupboard
is designated for other purposes.
• Chemicals should not be stored in a household refrigerator.
All electric devices should be non sparking.
• Fire, smoke and heat detectors should be fitted.
• Appropriate fire extinguishers should also be fitted.
• There should be an emergency evacuation plan and a means of
spillage control.
Spill Control
A means of controlling spillages and releases within the storage area is
required. A chemical spill Clean up kit should contain:1. A bucket of dry sand.
2. A bucket of an absorbing agent.
3. A bucket of anhydrous sodium carbonate (for acid spills).
4. Plastic dust pan and brush.
5. Heavy duty plastic bags.
6. Two warning notices
Provide precautions against skin and eye contact. Material Safety Data
Sheets (MSDS), and the Department of Education and Science
publication “Safety in the School Laboratory” will detail any specific
precautions.
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Chemical Storage contd.
Any storage system should fulfil the following requirements:1. Chemicals should not be stored in alphabetical order as this can result
in incompatible neighbours e.g.
ammonia vapour and bromine :- unstable nitrogen tribromide is
formed and an explosion may result
sodium nitrate and sodium thiosulfate :- A mixture of dry materials
may result in an explosion.
2. Chemicals should not be stored according to poorly chosen categories:
all acids together or all organics together.
Some acids are also reducing agents and some are oxidising agents
(ethanoic acid and nitric acid).
Some oxidising agents are incompatible with each other e.g. hydrogen
peroxide and potassium manganate(VII).
3. Store flammable liquids away from sources of heat and ignition.
Ensure containers are securely closed and specifically designed for the
purpose. They should be stored in a fire resistant cupboard. If this is
not possible they should be stored in a cool well ventilated area so that
they cannot come in contact with oxidising agents, particularly nitric
acid, hydrogen peroxide and potassium manganate(VII).
4. Flammable solids e.g. Group I (Li,Na,K) and Group II (Be,Mg) metals
and some hydrides (NaBH4, LiAlH4) should be stored separately in a
different fireproof cabinet, if possible, with phosphorous being kept
apart from flammable metals.
5. Corrosive substances burn skin and eyes and may also react with
incompatible packaging or metals like storage racking. Store away
from flammable liquids and gases, oxidising agents and organic
peroxides.
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6. Methanal is a class 3 carcinogen. Fumes of hydrochloric acid and
methanal when mixed form the potent carcinogen
chloromethoxychloromethane. These two chemicals should be stored
in separate rooms.
7. Oxidising substances can assist other materials to burn rapidly. Most
oxidisers are extremely reactive and should be kept away from
flammable materials. Store with other strong oxidising agents
provided they are compatible. Organic peroxides should be stored
separately from flammable, corrosive and toxic materials.
8. The main risk with toxic substances during storage is failure of
containment. Consult label and MSDS for degree of toxicity. Store
away from flammables and oxidising agents.
9. All explosive material should be stored well away from other
chemicals.
The Department of Education and Science and the members of the
Chemistry Support Service will not be held responsible for any loss
damage or injury arising in the context of the implementation of the
recommendations contained in this document.
References
Safety in School Science
Department of Education and Science
Safety in the School Laboratory
Department of Education and Science
Safeguards in the School Laboratory
ASE
Topics in Safety
ASE
Flinn Chemical Catalogue
Flinn Scientific
Hazardous Chemicals
(A manual for Science Education)
SSERC
HAZCARDS
CLEAPSS
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Emergency Services
Fire
Doctor
Hospital
Gardai
Water
Electricity
Gas
National Poisons Information Centre
Beaumont Hospital
Dublin 9
Telephone (01) 8379964 / (01) 8379966
Ring 999 or 112 for all Emergency services
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Colour codes for L.C. Chemicals
Chemical Name
Aluminium foil
Aluminium Metal Sheets (20 pack)
Aluminium Oxide
Aluminium Powder
Aluminium Sulfate
Ammonia 0.88
Ammonium Chloride
Ammonium Iron(II) Sulfate
Ammonium Metavanadate
Ammonium Molybdate
Ammonium Nitrate
Ammonium Phosphate
Ammonium Sulfate
Anti-bumping granules
Barium Chloride
Benzaldehyde
Benzoic Acid
Bismuth (III) Chloride
Bleach (liquid)
Bleaching Powder
Bromine
Buffer Solutions, pH 4,7,10
Butan-1-ol
Butanal
Butanoic Acid
Butanone
Calcium Carbide
Calcium Carbonate
Calcium Carbonate - Marble Chips
Calcium Chloride
Calcium Granules
Calcium Hydroxide
Calcium Oxide
Candles
Carbon Electrodes (packet)
Citric Acid
Cloves
Cobalt Chloride
Copper (I) Oxide
Copper (II) Carbonate
Copper (II) Chloride
Copper (II) Oxide
Storage Group
Grey
Grey
Red
Red
Grey
Green
Grey
Grey
Blue
Grey
Yellow
Grey
Grey
Grey
Blue
Red
Grey
Grey
Yellow
Yellow
White
Grey
Red
Red
White
Red
Red
Grey
Grey
Grey
Red
Grey
Blue
Grey
Grey
Grey
Grey
Grey
Grey
Grey
Blue
Grey
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Chemical Name
Copper (II) Sulfate
Copper (II) Sulfate Anhydrous
Copper Electrodes
Copper Turnings
Copper wire (bare 22 swg)
Cyclohexane
Decon 90
Detergent
Dyes, Water Soluble, Red & Blue
EDTA Disodium Salt
Ethanal
Ethanedioic Acid (Oxalic Acid)
Ethanoic Acid
Ethanol 95% (Industrial Methylated Spirits)
Ethyl Benzoate
Ethyl Ethanoate
Fehling's Solution No. 1
Fehling's Solution No. 2
Glass Wool
Glucose - Anhydrous
Glycerol
Heptane
Hexane
Hydrochloric Acid
Hydrochloric acid-Ampoules (box)
Hydrogen Peroxide - 100 vol
Indicator paper box (selection)
Iodine
Iron (II) Sulfate
Iron (III) Chloride
Iron tablets (packet)
Lard
Lauroyl Peroxide
Lead Bromide
Lead Electrodes
Lead Ethanoate
Lime Water (Calcium Hydroxide)
Lithium
Lithium Chloride
Litmus Powder
Lycopodium Powder
Magnesium Carbonate
Magnesium Powder
Magnesium Ribbon
Magnesium Sulfate
Manganese Dioxide
Manganese Sulfate Dihydrate
Storage Group
Grey
Grey
Grey
Grey
Grey
Red
Grey
Grey
Grey
Grey
Red
White
Red
Red
Red
Red
Grey
Green
Grey
Grey
Grey
Red
Red
White
White
Yellow
Grey
Yellow
Grey
Grey
Grey
Grey
Yellow
Blue
Grey
Blue
Green
Red
Grey
Grey
Grey
Grey
Red
Red
Grey
Grey
Grey
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Chemical Name
Methanal (Formaldehyde Solution)
Methanoic Acid (Formic Acid 90%)
Methanol
Methyl orange powder
Methylated Spirits
Methylbenzene (toluene)
Nichrome Wire
Nitric Acid
Octane
Paraffin - liquid
Paraffin - Light
Pentane
Petroleum Ether (40/60)
Petroleum Jelly
Phenothalien solid
Platinum Wire
Poly(chloroethene) -PVC
Poly(ethene) (low density)
Poly(ethene)(high density)
Polypropene
Polystyrene (Poly(phenylethene)
Polytetrafluoroethene (PTFE)
Potassium Bromide
Potassium Chloride
Potassium Chromate
Potassium Dichromate, crystalline
Potassium Hydroxide
Potassium Iodate
Potassium Iodide
Potassium Metal
Potassium Nitrate
Potassium Permanganate
Potassium Permanganate -Ampoules (box)
Potassium Sodium Tartrate
Potassium Thiocyanate
Propan - 1 - ol
Propan - 2 - ol
Propanal (propionaldehyde)
Propanone
Silver Nitrate
Sodium Carbonate - Anhydrous
Sodium Carbonate - Hydrated
Sodium Chloride
Sodium Dichromate - Crystalline
Sodium Ethanoate
Sodium Hydrogencarbonate
Sodium Hydroxide
Storage Group
Blue
White
Red
Grey
Red
Red
Grey
Yellow
Red
Red
Red
Red
Red
Red
Grey
Grey
Grey
Grey
Grey
Grey
Grey
Grey
Grey
Grey
Blue
Blue
Green
Yellow
Grey
Red
Yellow
Grey
Grey
Grey
Grey
Red
Red
Red
Red
Yellow
Grey
Grey
Grey
Blue
Grey
Grey
Green
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Chemical Name
Sodium Hydroxide - Ampoules
Sodium Hypochlorite Solution
Sodium Metal in paraffin
Sodium Sulfate
Sodium Sulfite
Sodium Thiosulfate
Solochrome Black
Sphere poly:pk/100 25mm
Starch - soluble
StrontiumChloride
Styrene (Phenylethene)
Sugar
Sulfur - Fine Powder
Sulfuric Acid
Tin Plate or Foil (25 mm2)
Trimethylpentane, 2, 2, 4, (iso-octane)
Universal Indicator Solution
Urea
Vinegar
Wooden Splints (100 Pack)
Zinc Carbonate
Zinc Electrodes
Zinc Granulated
Zinc Powder
Storage Group
Green
Yellow
Red
Grey
Grey
Grey
Grey
Grey
Grey
Grey
Red
Grey
Grey
White
Grey
Red
Grey
Grey
Grey
Grey
Blue
Grey
Grey
Grey
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