Science Safety

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Chapter 4

Middle and Senior Years

Safety Equipment for Science Classrooms
Personal Protective Equipment for Students
Equipment for Clean-up and Disposal of Spills and Waste
First Aid Kit Contents
Potential Structural Hazards in Laboratories and Storerooms

The teacher should be familiar with the location and use of safety equipment. This safety equipment should be located for easy access by the teacher and students.

Frequently used safety items should be placed on a separate, centrally located cart for easy access. It is recommended that science rooms have both windows and extractor fans. Science safety posters should be displayed. Emergency lighting must be available. A hand-held drench hose may be installed to supplement safety shower and eye wash units.

Safety Equipment for Science Classrooms
Equipment Comments
One pair heat resistant gloves Gloves should be made of treated textured silica or woven fabric. Do not use asbestos gloves.
One eye wash station A plumbed-in type is preferred, provided the water supply is free of grit and contaminants. The water supply should be tempered by mixing hot and cold water.
One fire blanket with wall stand mounted low on wall The only use is to smother clothing fires. Replace existing asbestos blankets with fire-proofed wool/rayon fabric.
One ABC type dry chemical fire extinguisher After use, the extinguisher will require service. Demonstrations must not be carried out with this extinguisher. A spare extinguisher should be reserved for that purpose.
Sand bucket (approximately 20 L of sand) Use sand buckets for small fires only.
One clear plastic face shield or one pair protective goggles for each teacher/demonstrator Teachers must wear eye protection whenever there is the risk of eye injury.
One pair of beaker tongs If necessary, use tongs with heat resistant gloves when handling very hot equipment. Extreme care should be taken to avoid accidents with heated material.
One fume hood with working extractor fan and adequate lighting (controls must be placed outside the hood) A fume hood is necessary in each chemistry or general science classroom at the S1-S4 level. The hood should be inspected regularly and its optimum level of performance maintained. The fume hood must have minimum airflow as stated in the standards and codes.
Simple handwashing facilities Handwashing facilities should be in or near each science classroom.
Emergency shower as specified in the Material Safety Data Sheets (MSDS) for chemicals used in the classroom or storeroom If large quantities of caustic or flammable stock are used in the lab, a deluge shower is required as specified on the chemical's MSDS. If diluted caustic or small amounts of flammable stock are used, a hand-held, telephone-style shower is sufficient.
Containers suitable for waste chemicals and solvents Commercial kits are available for solvents, acids, bases, and mercury. Follow supplier's instructions.
Spill kits Spill kits absorb spills or dilute solutions of chemicals.
Pails containing 12 to 15 L of kitty litter or bentonite Containers should be clearly labelled and contents disposed of safely.
Separate waste containers for glass and/or sharp objects Each chemical should be collected separately and properly labelled (WHMIS). Waste solvents should be collected only in a safety disposal can with automatic pressure release closure.
Large container of dry Na2HCO3 (baking soda) Use baking soda to neutralize strong acids before disposal.
Laboratory first aid kit Refer to First Aid Kit Contents.
One plastic hand dustpan and brush Use the dust pan and brush for brushing up used sand, Vermiculite, and broken glass. As both pan and brush will be contaminated after use, wash and clean them thoroughly.
One pair 45 cm long chemically resistant rubber gloves (usually included with spill kits) Always wear gloves when dealing with spills. Often broken glassware is involved, and the danger of toxic chemicals entering through open cuts is serious.
One pack heavy-duty garbage bags (also useful as biohazard bags) For disposal of all solid waste, including used sand, vermiculite, and chemically contaminated broken glass. Double bag if necessary. Dispose of each spill separately. Tie bags very securely and label. For disposal of biological specimens and cultures, use designated biohazard bags or extra thick garbage bags.
Goggles sterilizing cabinet (using an ultraviolet [UV] source) with interlocking door (it is recommended in Middle Years and required in Senior Years classrooms) This cabinet is used for sterilizing goggles worn by students. The door cannot be opened when the UV light is on. One cabinet can serve a number of classrooms.

 

Personal Protective Equipment for Students

If injuries to students result from the failure to have or use personal protective equipment, negligence may be claimed.

The use of laboratory coats is recommended for protection of persons and clothing when working with chemicals, and when appropriate in other science activities (e.g., biology). Sleeve protectors should also be worn by students when needed.

Eye protection must be used in all situations where there is any risk of eye injury.

Gloves should be worn in all work involving hazardous chemicals or in any other situation as instructed by the teacher.

Safety training is an integral part of learning laboratory techniques. Though infrequently put to the test, safety training is an excellent way of ensuring that safety becomes a lifelong practice.

Student Protective Equipment Comments
Each student should have protective goggles or plastic face shields (protective equipment should be splash-proof if used for chemistry)

Note: Some facility or procedure for sterilizing goggles after use is strongly recommended. UV cabinets or disinfectant solutions are commonly used.

 Eye damage is one of the most frequent injuries in chemical laboratories. The goggles should have fitted side-shields. If glasses are normally worn, goggles should be able to fit over them.
Laboratory coat (optional) Laboratory coats should be made of approved laboratory material only.
Sleeve protectors (wear when needed) Sleeve protectors should be worn when required.
Gloves (plastic is preferred because it does not cause allergic reactions which are characteristic of latex gloves) Gloves should always be worn when handling hazardous chemicals, and in biological experiments to prevent contact with dyes, or possible infectious materials.
Suitable eye protection against UV radiation must be worn when UV sources are in use Sources include discharge tubes, mercury or ion arcs, and lamps for fluorescent "black light" experiments.

Additional information is available from Health Canada (see Appendix J).

Equipment For Clean-Up and Disposal of Spills and Waste

Keep clean-up equipment in a clearly identified and accessible location. All spills should be dealt with individually and disposed of completely without delay. It is hazardous to place spilled or waste chemicals in a waste bin (e.g., reaction with paper, with other contents, or with further additions). Avoid the temptation to keep a general spill bin, rather than to dispose of each individual spill.

Small Spill Clean-up Kit Checklist
Items Comments
Mercury, acid, base, and solvent spill kits Use these kits for clean-up of small spills (follow manufacturer's instructions).
Spill control pillows Pillows are used to absorb spilled liquids (follow manufacturer's instructions).
Four litres fine sand, in container with scoop For spills of solid chemicals (especially powders), and viscous or sticky liquids. The sand contains and scours the spill. Brush up and dispose of sand after use (see instructions for disposal of a harmful substance in chapter 7).
Twenty litres expanded vermiculite in container with scoop (an alternative is bentonite or kitty litter) Vermiculite is absorbent (unlike sand) and is useful for spills of organic solvents, and aqueous solutions. Brush up and dispose of Vermiculite after use.

Note: Vermiculite will not control vapours from organic solvents.

Note: Commercial spill kits are preferable to homemade equipment.

First Aid Kit Contents

First aid kits are available from St. John Ambulance, Canadian Red Cross, and most science supply companies. Make sure the kit is large enough to supply the number of students using the laboratory.

A first aid kit should contain

  • four hand cleansers and 12 gauze cleansing pads
  • one 50 mL container of antiseptic
  • six packs of 25, 2.5 x 7.5 cm adhesive/dressing strips individually wrapped (have a good supply available)
  • two packs of four 5 cm compress dressings
  • six packs of one 10 cm compress dressings
  • two eye dressing kits (eye shield, 2 gauze pads)
  • two (5 cm x 6 m) gauze bandages and one (5cm x 5m) adhesive tape
  • one triangular bandage
  • twelve safety pins
  • one pair of stainless steel scissors
  • one pair of stainless steel forceps (tweezers)
  • one pack of individually packed sterilized cotton pads
  • a first aid manual (if not included in the kit, obtain one)

Potential Structural Hazards in Laboratories and Storerooms

Be aware of any potential structural hazards. Once hazards are identified, take particular care until effective improvements are made.

Facilities Comments
Floors
  • should be level throughout, preferably with no steps in the laboratory/stores area.
  • should be without defects (e.g., loose or broken pieces, uneven patches, cracks).
  • should be made of sheet flooring or hard surface tiles.
  • chemical storerooms should be adequately drained at the lowest point to cope with flooding.
Doors
  • should be free of defects that cause the door to jam.
  • should open toward the nearest safety exit without use of a key.
Exits
  • should be readily available (at least two). If one of these exits is through a storeroom, it must be unlocked when room is in use. Otherwise, replace it with a direct exit.
  • should be clearly marked.
  • should have route markers with non-slip surfaces painted on the floor, or have a fire exit map posted near each classroom door.
Ceilings
  • should be non-flammable (flammable ceiling materials, such as polystyrene tiles, should be removed and replaced with materials having a low flame spread rating (e.g., fire-rated drywall).
Plumbing
  • should be without defects (e.g., leaks or cracks).
  • should be equipped with drains made of chemical resistant material (i.e., not copper or brass).
  • should be equipped with worktops lipped towards sink (spills will then flow into the sink rather than outwards onto the floor).
Fume hood systems
  • should have a minimum air flow as stated in the standards and codes.
  • should have adequate lighting as stated in the standards and codes.
  • should have all operation controls located outside the fume hood.
  • must not have vents connected to a common duct.
  • must have ventilation systems that do not recirculate discharged air into the laboratory or other work areas.
Extractor fans
  • should adequately ventilate laboratories with extractor fans other than the fume hood system as stated in the standards and codes.
Fire blanket(s)
  • should be mounted low on the wall so they can be reached by a person rolling on the floor without needing to stand or sit up (if clothing catches on fire and the person needs to stand up, the flames will reach his or her face).