Resource 2: Risk Assessment
Teacher resource to support teaching approaches
When teachers do practical work they should consider the hazards of the experiment and risks linked to the group of children in the room. They should then consider safety precautions and the instructions they give to students. Every time you do practical work you must consider all the potential hazards and take the necessary precautions.
- If available, students should always wear safety goggles. If they are not available, you need to use very dilute solutions. The most dangerous chemical as far as eyes are concerned is sodium hydroxide. Above 0.5M it can cause permanent eye damage. Students must not use sodium hydroxide that is stronger than 0.1M, without safety goggles.
- In chemistry it is helpful to be able to heat chemicals. If you are able to do experiments using heat, you must have a fire extinguisher, a bucket of water or a bucket of sand available. Liquids that are very flammable should only ever be heated in a water bath.
- You need to have drinking water, running water (or a large bucket of water) and a first aid kit available if you are dealing with chemicals or glass.
Common laboratory accidents include:
- Chemicals in the eye. You must wash the student’s eye with large amounts of cold water.
- Burns. The area of skin that is burnt should be held under running cold water for at least 10 mins. If it still hurts, soak a paper towel or tissue in cold water and tell the student to hold the wet pad on the affected area. If it forms a blister, you will need to seek medical attention.
- Chemicals on the skin. If you limit your experiments to dilute solutions, the danger is irritation rather than blistering or burning. Wash the affected area with quantities of cold water. Do not be tempted to treat an acid burn with alkali or vice versa – you might make the situation worse.
- Splashes from demonstrations. When you do a demonstration, think carefully about how you position the students. Don’t let them get too close. If you have safety goggles, make sure the students are wearing them, especially if the solutions are stronger than 0.1 M.
- Chemicals in the mouth. If students are handling chemicals, they might spill them on their hands and then put their hands in their mouth. If this happens they should wash their mouths out with lots of water.
- Cuts for broken glass. If a student cuts themselves, the affected area should be raised above their heart to stop the bleeding, washed with clean water and covered with a plaster. If possible antiseptic cream should also be applied.
There are specific hazards associated with individual chemicals. The hazards are well documented and you should consult an experienced teacher, your university tutor or an appropriate manual whenever you do an experiment.
Resource 1: Making indicators from plants
Resource 3: Neutralisation Circus