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Safety in physics practicals

Edexcel IAL Physics · WPH13 Practical Skills in Physics I

Planning questions ask for safety precautions. Generic answers score nothing: name the hazard in this experiment and a precaution that deals with it.

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Hazard, risk, precaution

A hazard is something that could cause harm; the risk is how likely and how serious that harm is; a precaution reduces the risk. A good answer names all three in one sentence: 'The wire could snap and whip back, so wear eye protection.'

Common hazards in AS practicals

Learn the specific hazards of each practical and a precaution that matches each one:

Hazard	Specific precaution
Wire under tension snapping (CP3, CP5)	Wear eye protection; keep the loaded wire short of breaking stress
Falling masses (CP3, CP5, free fall)	Sand tray or cushion below; keep feet clear
Laser beam (CP6)	Never look into the beam or reflections; tinted goggles filtering that wavelength; remove shiny surfaces
Hot wire at high current (CP7)	Use a low current; switch off between readings; do not touch the wire
Hot liquids (viscosity at higher temperatures)	Heat-resistant gloves or tongs; stable beaker on a heatproof mat
Glass tubes of liquid (CP2)	Clamp the tube upright so it cannot fall over; clean spills to prevent slipping

What is not credited

'Be careful', 'wear safety equipment', 'wear goggles' with no link to the hazard.
Ordinary goggles for a laser (they must be tinted to filter the light).
Precautions for hazards not in the experiment.
More precautions than asked for (only the first ones are marked).

Worked example

Give one safety precaution for core practical 6 using a laser and a diffraction grating.

Hazard: the laser beam (or its reflections) entering the eye can damage the retina.
Precaution: never look along the beam; remove reflective objects from the bench; use a low-power laser.

Answer: Do not look into the laser beam or its reflections, as it can damage the eye

Key idea: Name the specific hazard and a precaution that controls it. Generic advice, ordinary goggles for lasers and extra unasked-for points are not credited.

Check yourself

In a Young modulus experiment with a loaded wire, which precaution is most appropriate?
- Wear a lab coat
- Work in a darkened room
- Wear eye protection in case the wire snaps
- Use insulating gloves
Show answer
Wear eye protection in case the wire snaps. A snapping wire under tension can whip back into the face.
Why are ordinary clear safety goggles not an acceptable precaution with a laser?
- They do not filter the laser light, so the beam can still damage the eye
- They are too heavy
- They make it hard to read the metre rule
- Lasers produce no hazard
Show answer
They do not filter the laser light, so the beam can still damage the eye. Laser goggles must be tinted for the wavelength used.
Which precaution deals with masses that might fall from a hanger?
- Wear eye protection
- Use a low current
- Place a sand tray or cushion beneath them and keep feet clear
- Switch off the power supply
Show answer
Place a sand tray or cushion beneath them and keep feet clear. It deals directly with the falling-mass hazard.
In core practical 7, why should the current be switched off between readings?
- To save the battery
- To stop the wire heating up, which could burn and also changes its resistance
- To reset the voltmeter
- To remove zero error
Show answer
To stop the wire heating up, which could burn and also changes its resistance. A hot wire is a burn hazard and its resistance rises with temperature.
Which safety statement would examiners credit for heating a liquid?
- Be careful
- Wear safety equipment
- Make sure the experiment is safe
- Use heat-resistant gloves or tongs to handle the hot beaker
Show answer
Use heat-resistant gloves or tongs to handle the hot beaker. It names the hazard (hot beaker) and a specific precaution.
State one hazard and a precaution for core practical 2 using a tall tube of glycerol.
Show answer
The tall tube could fall over and break, so clamp it securely upright; or spilled glycerol makes the floor slippery, so wipe up spills immediately.. Hazard and matching precaution.

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Last updated 8 November 2026. Spotted a mistake? Tell us.