Science · Inquiry & data skills
Lab Safety: WHMIS 2015 & Product Symbols
A hazard symbol is information. The real skill is reading what a label tells you and turning it into a safe handling decision.
You do not need to memorize every chemical in a lab to stay safe. You need to read the label. WHMIS 2015 (the Workplace Hazardous Materials Information System) and the symbols on household products are designed so that a picture, a signal word, and a short statement tell you everything you need to act.
That is exactly the kind of thinking the CAEC science test rewards. It is a skills and scientific-inquiry test, 35 questions in 90 minutes, with a calculator allowed, not a memory quiz. So instead of asking "what does this chemical do," this lesson teaches a transferable skill: read a hazard label as a source of evidence, then decide what action it calls for.
The skill: read the label, then decide
Every WHMIS-labelled container gives you the same four pieces of information. Read them in order and the safe action almost names itself:
- The pictogram, a red-bordered diamond with a black symbol inside. It tells you the type of hazard at a glance.
- The signal word, either "Danger" (more severe) or "Warning" (less severe). This is the seriousness dial.
- Hazard statements, short phrases like "Causes severe skin burns" that name the actual risk.
- Precautionary statements, the instructions: how to store, handle, and what to do if exposed.
A reference for the main WHMIS 2015 pictograms
You do not have to memorize this table, on the real test the label will be shown to you. Use it to practise translating a symbol into the action it implies.
| Pictogram | What it warns about | What it tells you to do |
|---|---|---|
| Flame | Flammable; can catch fire easily | Keep away from heat, sparks, and open flame; store cool |
| Flame over circle | Oxidizer; can intensify a fire or make other things burn | Keep away from flammables and fuels; store separately |
| Exploding bomb | Explosive or self-reactive; unstable | Avoid heat, shock, and friction; handle with great care |
| Gas cylinder | Gas under pressure (compressed, liquefied, or dissolved) | Protect from heat; secure cylinders so they cannot fall |
| Corrosion | Corrosive; burns skin and eyes or eats away metal | Wear gloves and eye protection; rinse spills, store carefully |
| Skull and crossbones | Acute (immediate) toxicity; can poison quickly | Avoid contact and inhalation; do not eat or drink near it |
| Health hazard | Serious longer-term effects (e.g. organ or respiratory harm) | Read the SDS; use ventilation and the protection it specifies |
| Exclamation mark | Irritant; less severe skin, eye, or breathing effects | Avoid contact; wash after handling; ventilate |
| Biohazardous (infectious) | Biological material that can cause disease | Use proper containment and protective equipment; dispose as directed |
| Environment | Toxic to aquatic life (not required on all Canadian labels) | Do not pour down drains; dispose through hazardous-waste routes |
Consumer product symbols use a different shape
Household products (bleach, drain cleaner, oven cleaner) carry Canadian consumer hazard symbols, and the shape tells you the seriousness while the picture tells you the hazard. Reading the shape is itself a data skill.
- A symbol inside a triangle means the container is dangerous (it can leak, spray, or explode).
- A symbol inside an octagon means the contents are dangerous (poison, corrosive, flammable, or explosive).
- The inner picture, flame, skull, a hand being eaten away, names which hazard it is, and the words "Danger," "Warning," or "Caution" grade how severe it is.
Worked example: putting away three bottles
A lab assistant has three labelled bottles to store at the end of the day. Bottle A shows a flame pictogram and the word "Danger." Bottle B shows a flame over circle pictogram. Bottle C shows corrosion with the statement "Causes severe skin burns and eye damage." Which two bottles must not be stored next to each other, and what protective equipment is needed to handle bottle C?
Read each label, name the hazard, then let the action follow:
- Bottle A (flame): flammable, it can catch fire. "Danger" means the more severe end of the scale.
- Bottle B (flame over circle): an oxidizer, it does not just burn, it feeds fire and can ignite other materials.
- Bottle C (corrosion): the hazard statement tells you it burns skin and eyes, so the precaution is obvious: protect skin and eyes.
"A and C are both dangerous, so keep those two apart." This misreads the symbols. A corrosive and a flammable do not feed each other. The real conflict is the oxidizer next to the flammable.
Keep A (flammable) and B (oxidizer) apart, an oxidizer can make a flammable far more dangerous. To handle C, wear chemical-resistant gloves and eye or face protection, exactly as its statement implies.
From label to action: storage, handling, disposal
Once you can read a label, the safe practices fall into a few repeatable rules:
- Store by compatibility, not alphabetically. Separate oxidizers from flammables, and corrosives from metals and from each other (acids away from bases).
- Handle with the protection the label specifies. Gloves, goggles, and ventilation are chosen from the precautionary statements, not guessed.
- Keep containers labelled. A workplace label or supplier label must stay legible; never decant into an unmarked bottle.
- Dispose through the right route. The environment symbol and disposal statements tell you when something cannot go down a drain or in regular trash, it goes to hazardous-waste collection.
Your turn: practice questions
For each one, read the described label like evidence and decide the action. Try before you reveal.
- A container shows a skull and crossbones. A coworker plans to eat a snack at that bench. Is that safe, and why?
- Two products both show a flame, but one says "Danger" and the other says "Warning." Which signals the more severe hazard?
- A bottle shows the environment pictogram. A student wants to rinse the leftover down the sink. What does the symbol tell them to do instead?
Tap to reveal the answers
- 1. Not safe. The skull and crossbones means acute toxicity, the substance can poison quickly. Eating, drinking, or putting hands near the mouth at that bench risks ingesting it. The precaution is to keep food away and wash hands after handling. Answer: no, it is an acute-toxicity hazard.
- 2. The signal word grades severity: "Danger" is used for the more severe hazards and "Warning" for the less severe ones. Same picture, different seriousness. Answer: the "Danger" product.
- 3. The environment symbol warns the product is toxic to aquatic life, so it must not go down the drain. Collect it and dispose of it through the proper hazardous-waste route per the label or SDS. Answer: do not pour it down the sink; use hazardous-waste disposal.
Why this matters for the CAEC
The CAEC science test is built around scientific inquiry and data skills, not fact recall. Roughly 60–85% of the marks come from skills like interpreting information and evaluating situations. Reading a hazard label is a perfect example: the symbol is the data, and your job is to interpret it and choose a sound action, the same reasoning you will use on graphs, tables, and experiment descriptions.
Want more inquiry practice like this? Explore the Science lessons, pick up the CAEC Ready Workbook, or start with a free sample to test yourself.
Disclaimer
This article is a general study lesson. CAEC Ready is an independent study resource and is not affiliated with or endorsed by any government, ministry of education, or official CAEC testing provider.