Science Safety

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Appendix B

Laboratory Safety Instructions ­ Student Handout

These guidelines are intended for your protection. They are listed by the main types of hazards found in the school laboratory. You will find an extra copy of the handout posted in your science laboratory.

Fire
Disposal of Waste Chemicals
Handling of Chemicals and Equipment
Handling of Biological Specimens

Fire (One of the greatest hazards in any laboratory)

• When a large fire occurs, evacuate the room, make sure nobody is left behind and close the doors. Ring the fire alarm in the hallway.
• In the case of a small fire, always use a fire extinguisher to smother the flames. Never use water on a chemical fire.
• If clothing catches fire, do not walk around (you will spread the fire). Lie down and the teacher will smother the flames by wrapping you in a safety blanket or douse them using the shower.
• Never pour solvents down the sink as they are highly flammable. All flammable liquids should be disposed of into a solvent waste can.
• All solvents must be stored in an approved flammables storage cabinet (metal). Never store solvents in the lab.
• Never leave a Bunsen burner flame (almost colourless) unattended.
• Never use an open flame near a flammable liquid.

Disposal of Waste Chemicals (Many of the chemicals used in science laboratories can be hazardous if their disposal is not correctly handled.)

• With the approval of the teacher, some chemicals may be flushed down the drain using copious amounts of water. Never use this method of disposal unless specifically approved by the teacher.
• Solid chemicals should be disposed of into specially marked containers.
• In case of a mercury spill (e.g., from a broken thermometer), notify the teacher. A mercury spill clean-up kit is required for the safe disposal of spilled mercury.
• Large spills of acid, base, or solvent will be looked after by the teacher with appropriate spill kits.
• Small spills of diluted acid or base can be neutralized with bicarbonate of soda or diluted acetic acid, respectively.
• Broken glassware should be placed in a special container marked Broken Glass Only. Never place broken glass in waste paper bins.
• Sharp objects for disposal should be placed in the appropriately labelled container.
• Never return excess chemicals to original stock bottle.
• Dispose of animals in special biohazard waste bags.
• At the end of an experiment, all cultures must be collected in special biohazard bags, autoclaved (or sterilized in an oven), and consigned for disposal.

Handling of Chemicals and Equipment

• When heating a chemical solution in a test tube, use a test tube holder, hold the test tube at an angle and do not point its mouth at anyone. Move the test tube gently while heating.
• Glass or steel wool should be handled with gloves. Gloves should also be worn when handling certain chemicals.
• When inserting glass tubing or a thermometer into (or removing) a rubber stopper, lubricate with silicone grease or glycerol (not water) and protect hands with gloves or towelling. If any difficulty is encountered, ask the teacher or lab technician for help. Remove glass tubing from stoppers after each use unless otherwise instructed.
• Never pull an electric plug out of a socket by the cord. Electrical shocks may occur and equipment can be damaged.
• When using a reagent, make sure you have the correct chemical and concentration for the experiment. Read the label on the container twice before using. Read all safety labels.
• Label all containers when preparing solutions.
• Never use a chemical from an unlabelled bottle and do not try to identify its contents by smelling the opened bottle. If in doubt, ask the teacher.
• Always pour reagents from the side opposite the label.
• Always use minimal amounts of required chemicals.
• Never pipette by mouth; always use pipettor or bulb.
• Add acid to water; never water to acid (Always Add Acid).

Handling of Biological Specimens

• While dissecting animals, wear gloves and use a sharp scalpel. Always cut away from yourself.
• Handle animals and poisonous plants with care. Always wash your hands thoroughly after working with plants and animals.
• Micro-organisms must always be handled carefully. Make sure that you are familiar with the appropriate techniques before handling cultures of micro-organisms.

Safety Practices

• Always alert the teacher in case of any accident.
• If a chemical reagent comes in contact with your skin, rinse off immediately with large amounts of water.
• In case of large chemical spills on your skin or clothing, use the safety shower.
• When any foreign substance enters the eye, rinse the eye immediately for 15 minutes with temperature regulated water. Then contact a doctor.
• Wear approved safety glasses or goggles which are appropriate to the experiment being done. Check with your teacher for the type of eye protection you need.
• If you wear contact lenses, notify the teacher. If you wear contact lenses always use splash-proof goggles during experiments.
• Wear protective clothing and closed shoes during laboratory sessions ­ no open-toed shoes.
• Long hair should be tied back.
• Do not use cracked or chipped laboratory glassware.
• Read all directions in your lab manual before starting an experiment.
• Safety considerations in the laboratory demand responsible behaviour at all times.
• Chemicals are to be used in the lab only.
• Bottles should never be held by the neck.
• Taste nothing unless you are instructed to do so.
• Never eat, drink, or chew gum in the laboratory.
• Become familiar with the location of safety equipment.
• Never enter the chemical storeroom without permission.
• Always clean off bench and sink after completion of an experiment.
• At the end of the laboratory session wash your hands thoroughly with warm water and soap.