GCSE · Chemistry · Edexcel · Spec 1CH0

Hazard symbols on chemical containers

You're handed a bottle in the lab. A symbol on the label already tells you how it could hurt you. Can you read it, and know what to do?

Chemistry · Hazard symbols

Match the danger to its symbol

Which hazard symbol signposts this danger?

Still to sort

Flammable symbol (0)

Where the line is: Flammable is about catching fire. If the danger is what the substance does to a fire that is already burning, look at the oxidising symbol instead.

Oxidising symbol (0)

Where the line is: Oxidising is about what a substance does to a fire: it can provide oxygen for it. If the danger is that the substance could easily ignite, that is the flammable symbol.

Explosive symbol (0)

Corrosive symbol (0)

Toxic symbol (0)

The skull and crossbones.

Where the line is: Toxic is poison that could cause death. Skin irritation points to health hazard, and breathing issues with organ damage point to serious health hazard.

Health hazard symbol (0)

The exclamation mark.

Where the line is: Health hazard is skin irritation or allergic reactions. Breathing issues and organ damage point to serious health hazard, and poison that could cause death points to toxic.

Serious health hazard symbol (0)

Where the line is: Serious health hazard is breathing issues and organ damage. Skin irritation or allergic reactions point to health hazard, and poison that could cause death points to toxic.

Environmental hazard symbol (0)

Compressed gas symbol (0)

Radioactive symbol (0)

10 of 10 still to sort.

Each card describes a danger. Pick a card, then pick the symbol that signposts it. Commit first; the reason appears after you place it.

Chemistry · Three words

Hazard, risk, precaution

Your teacher holds up a bottle and asks, 'What's the hazard, and what's the risk?' Four pupils answer.

Which pupil sounds most like you?

Hazard and risk mean the same thing. They're just two ways of saying 'dangerous'.The risk is the dangerous substance itself. The bottle is the risk.The hazard is the danger, the risk is the chance it causes harm, and a precaution is an action that prevents or reduces that risk.The hazard symbol is the precaution. Once it's on the bottle, the safety job is done.

How sure are you?

I'm sureI think soI'm guessing

Hazard and risk mean the same thing. They're just two ways of saying 'dangerous'.

This is a common misconception

Easy mistake, because both words sound like danger. But they do different jobs. The hazard is the danger associated with a substance or a piece of apparatus. The risk is the chance of that hazard actually causing harm.

The risk is the dangerous substance itself. The bottle is the risk.

This is a common misconception

You've pointed at the thing instead of the chance. The danger that comes with the substance is the hazard. The risk is the chance of that hazard causing harm, so the bottle carries a hazard and the risk is whether harm happens.

The hazard is the danger, the risk is the chance it causes harm, and a precaution is an action that prevents or reduces that risk.

This matches the evidence

That's it. Danger, chance, action: three words doing three jobs.

The hazard symbol is the precaution. Once it's on the bottle, the safety job is done.

This is a common misconception

The symbol is a warning, not an action. It signposts in what way the substance might be dangerous. A precaution is something you do to prevent or reduce the risk, like wearing goggles when using chemicals.

Hazard is the danger. Risk is the chance it causes harm. Precaution is what you do to prevent or reduce that risk.

From symbol to precaution

Reason it through

A bottle carries the flammable symbol. How do you get from the symbol to what you actually do?

Link 1 of 3

First link · your turn

What is the flammable symbol telling you about this substance?

Locked — reveal the link above first

Predict, then check

An industrial cleaner's label shows three symbols: environmental hazard, health hazard and flammable.

How many separate dangers do you need to plan for?

Chemistry · Risk assessment

Write the mini risk assessment

A tub of oven cleaner has the corrosive symbol and the flammable symbol on its label. For each symbol, write the hazard, the associated risk and one precaution. [6 marks]

Your answer

0 words · your answer stays on this page and is not sent anywhere.

The mark scheme

Corrosive hazard: it can cause severe skin burns or damage the eyes. (1 mark)
Corrosive risk: someone could actually be burned if it touches their skin, or have their eyes damaged if it gets in them. (1 mark)
Corrosive precaution: wear chemical-resistant gloves (or goggles to protect the eyes). (1 mark)
Flammable hazard: it could easily ignite if it is exposed to heat or sparks. (1 mark)
Flammable risk: a fire could start if it meets a naked flame. (1 mark)
Flammable precaution: keep it away from naked flames. (1 mark)

Model answer

The corrosive symbol means the cleaner can cause severe skin burns or damage the eyes. That is the hazard. The risk is that someone gets burned if it touches their skin or gets in their eyes, so I would wear chemical-resistant gloves and goggles. The flammable symbol means it could easily ignite if it is exposed to heat or sparks. The risk is a fire if it meets a naked flame, so I would keep it away from naked flames.

Two symbols means two hazards, and each one gets its own risk and its own precaution.

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

A little symbol on a label tells you how a substance could hurt you, and that decides what you do about it.

What you need to know

Symbols on chemical containers signpost how a substance might be dangerous, so reading them correctly keeps you safe in the lab.
Hazard: the danger. Risk: the chance it causes harm. Precaution: an action that prevents or reduces the risk.
Have a goSam says hazard, risk and precaution are all just 'dangerous'. Label each one: (1) acid can burn skin, (2) the chance you get burned, (3) wearing goggles.
(1) hazard, (2) risk, (3) precaution.
The hazard is the danger itself, the risk is the chance it causes harm, and a precaution is an action you take to cut that risk.
Flammable could easily ignite near heat or sparks; oxidising can provide oxygen and intensify a fire.
Have a goZara says, 'Oxidising means it catches fire easily.' Which symbol is she really describing, and what does oxidising actually mean?
She is describing flammable. Oxidising means it can provide oxygen for a fire.
Flammable is about igniting, while oxidising is about what a substance does to a fire, which is intensify it.
Explosive might explode from heat, a shock or friction; corrosive means severe skin burns or eye damage.
Toxic, the skull and crossbones, means poisonous: it could cause death if swallowed, breathed in or absorbed through the skin.
Health hazard, the exclamation mark, means skin irritation or allergic reactions; serious health hazard means breathing issues and organ damage.
Have a goA label warns of skin irritation or allergic reactions. Is that the toxic, health hazard or serious health hazard symbol?
Health hazard, the exclamation mark.
Serious health hazard is for breathing issues and organ damage, and toxic is for poison that could cause death.
Environmental hazard means the substance could damage plants and animals, for example through the water system, so disposal needs care.
Compressed gas brings risks of explosion, asphyxiation and frostbite, and radioactive means the substance can emit ionising radiation.
One container can carry several hazard symbols, and each one must be interpreted.
Risk assessments use the symbols to choose precautions: goggles, chemical-resistant gloves, flammables kept from naked flames, or a fume cupboard.

The big picture

Hazard symbols signpost in what way a chemical might be dangerous, from fire and explosions to burns, poisoning and harm to the environment. Reading them correctly lets you tell a hazard from a risk from a precaution, and choose sensible precautions in a risk assessment.

Key points

1A hazard symbol signposts in what way a substance might be dangerous.

2A hazard is the danger, a risk is the chance of that hazard causing harm, and a precaution is an action to prevent or reduce the risk.

3Flammable and oxidising are both fire warnings: flammable can easily ignite, oxidising can provide oxygen and intensify a fire.

4Toxic, health hazard and serious health hazard warn about different harm to the body, so match the harm to the symbol.

5Every symbol on a container is interpreted, and the symbols guide the precautions in a risk assessment.

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Worked example

Problem

A bottle of copper chloride carries the environmental hazard symbol. Work out the hazard, the risk and the precaution.

⚠ Watch out

Treating hazard and risk as the same word, or reading only one symbol when a container carries several. The hazard is the danger, the risk is the chance it causes harm, and every symbol needs interpreting.

🧠

Memory hook

Hazard is the danger, risk is the chance, precaution is the action. And two fire warnings: flammable can catch fire, oxidising can make a fire worse.

✓

Check yourself

Close the page and explain to a friend, in your own words, why flammable and oxidising are both fire warnings but need different thinking.

Flashcards

(14)

Flammable symbol: what does it warn about?

The substance could easily ignite if it is exposed to heat or sparks, so keep it away from naked flames.

Oxidising symbol: what does it warn about?

An oxidising agent can provide oxygen for a fire, so it would intensify the fire.

Which symbol means the substance might explode from heat, a shock or friction?

The explosive symbol.

Corrosive symbol: what does it warn about?

The substance can cause severe skin burns or damage the eyes. Sulfuric acid carries it.

Toxic symbol (skull and crossbones): what does it warn about?

The substance is poisonous and could cause death if swallowed, breathed in or absorbed through the skin.

Which symbol warns of skin irritation or allergic reactions?

The health hazard symbol, the exclamation mark.

Serious health hazard symbol: what does it warn about?

The substance may cause breathing issues and organ damage.

Environmental hazard symbol: what does it warn about?

The substance could damage plants and animals, for example if it gets into the water system, so care is needed over disposal.

Which symbol warns of explosion, asphyxiation and frostbite?

The compressed gas symbol. Asphyxiation means not being able to breathe.

Radioactive symbol: what does it warn about?

The substance can emit ionising radiation, which can cause serious health issues such as cancer after a lot of exposure.

Hazard, risk, precaution: what is each one?

A hazard is the danger, a risk is the chance of that hazard causing harm, and a precaution is an action that prevents or reduces the risk.

A container shows more than one hazard symbol. What do you do?

Interpret every symbol. Each one is a separate hazard.

What does a risk assessment identify?

The specific hazards, the associated risks and the precautions to minimise them.

What precaution suits a substance that is harmful if inhaled?

Use it in a fume cupboard or a well-ventilated space.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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Match the danger to its symbol

Hazard, risk, precaution

Write the mini risk assessment

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