Assessing Hazards and Risks
Evaluate risks before and during practical work: identify hazards (a substance, flame or procedure that could cause harm), judge how likely and how serious the harm would be, and choose sensible control measures to reduce the risk
What a learner can do afterwards
- Identify the hazards in a planned experiment (e.g., acid can burn skin, a beaker of hot water can scald)
- Distinguish a hazard from a risk, judging the risk by how likely harm is and how serious it would be
- Choose sensible precautions for an experiment (e.g., wear goggles, tie hair back, heat gently, use a smaller amount)
1 · Read
You already read a written method all the way through before touching any equipment. That first read is also when you spot hazards. A hazard is anything that could cause harm: a flame, a sharp blade, a hot beaker, an acid. Finding a hazard does not mean you cannot run the practical. It means you plan for it and check the plan with a teacher or another adult first.
A risk is different from a hazard. To judge a risk, ask two questions: how likely is it that harm happens, and how bad would it be if it did? A candle flame is a hazard whether you touch it for one second or ten, but holding your hand there for ten seconds is a much bigger risk. A precaution lowers a risk by making harm less likely, less serious, or both.
Priya plans to heat vinegar in a test tube over a candle. She spots the hazard: hot glass and steam could burn her hand. She judges the risk as fairly likely if she is careless, and a burn would hurt. So she picks a precaution: she holds the tube with tongs, points the open end away from her face, and heats it gently.
Before you start any experiment, ask three questions: what could go wrong, how likely and how bad is that, and what one change makes it safer.
Spot the hazard, weigh how likely and how serious the harm could be, then choose one sensible precaution before you start.
The rewritten readings were written for this dataset.
2 · Watch
Take it off screen
Where it sits
Where this leads
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.