MYP 6.1.1: Safety in the laboratory
- To introduce the students to a new and potentially hazardous environment
and explain safe practice.
Discuss the need for specialised apparatus for the handling of chemicals
Potential Chemical Hazards:
- Toxic by skin absorption and inhalation.
- Acute (immediate effect) poisons e.g. cyanide, chlorine gas
- Chronic (accumulative effect) poisons e.g. lead and heavy metal compounds
- Carcinogens (explain as chemicals whose effects may appear years later
- Skin irritants - allergens
- Flammable liquids
Demonstrate some examples from the chemical store:
- Toxic: Lead salts - show formation of lead iodide
- Flammable: 5 drops cyclohexane on a watch glass and ignite using a
- Corrosive: Piece of magnesium ribbon into 10cm3 sulphuric
acid (pop gas).
- Oxidant: Glycerine and potassium manganate(VII) - delay!
- Explosive: Picric acid - no demo
Explain safe disposal - Environment!
Symbols used to convey information about chemicals
||Harmful or irritant
||Oxidising (helps other things to burn)
Emphasise that the scientist's job is to be able to handle these materials
safely and link this with the laboratory rules:
- Always use the correct apparatus
- Always take appropriate safety precautions (safety glasses, fume cupboard
- Always report and clean up spillages appropriately (certain materials
need to be cleaned up in a specific way)
- Always follow instructions
- Never eat or drink in the laboratory
- Wash hands after handling chemicals
Possible Class activity
Draw hazard symbols in exercise books and explain what each one means.
Science 7: p4-5