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A1.5 · Plan and carry out investigations using safe practices and WHMIS

Learn to plan and carry out investigations using safe practices and whmis through clear examples and targeted practice.

Ontario Grade 9 Science

STEM Skills, Careers, and Connections

Ontario Grade 9 Science • Study-guide topic A1.5

A science investigation begins with a question, but it also begins with a safety check. Imagine comparing how quickly two classroom plants grow. You need a clear plan for what to observe, what to keep the same, and how to care for the plants. You also need to think about possible hazards, such as spilled water near electrical equipment. A safe investigation is planned before it begins, carried out as planned, and stopped if an unexpected risk appears. WHMIS provides important information about hazardous products used in workplaces, including school laboratories.

What you will learn

Turn a science question into a simple, fair investigation plan.
Identify hazards and choose safe ways to reduce risk.
Use WHMIS information to understand and handle workplace products safely.
Record observations clearly and explain what the evidence can and cannot show.

From an observation to a testable question

An observation is something noticed or measured. For example, one plant on a windowsill may look taller than a plant farther from the window. That observation suggests a question: does the amount of light affect plant growth? A useful investigation question is focused enough to guide a plan. It should identify what will be changed or compared and what evidence will be collected.

A variable is a factor that can change. In a simple investigation, identify the factor you will compare, the result you will observe, and the conditions you will keep alike. Keeping other conditions alike makes it easier to judge whether the comparison is useful. This is sometimes called a fair test. It does not guarantee a perfect answer; it helps make the evidence clearer.

Before starting, decide what materials and steps are needed. Ask what could go wrong, who could be affected, and how the risk can be reduced. Follow the teacher's instructions and school procedures. Do not begin if the plan is unclear or the required safety equipment or supervision is missing.

A focused question guides what evidence to collect.
List what is compared, what is observed, and what is kept alike.
Plan safety measures before handling materials or starting a procedure.

Safety and WHMIS information

A hazard is something that could cause harm. Risk is the chance that harm may happen in a particular situation. A product can have a hazard even when it is used carefully. Safe practices lower risk; they do not make every hazard disappear. Follow the teacher's directions, use required protective equipment, keep work areas orderly, and report spills, breakage, or injuries right away. Never taste laboratory materials. Do not touch or use a product unless the teacher has told you to do so.

WHMIS means Workplace Hazardous Materials Information System. It is Canada's system for communicating information about hazardous products in workplaces. In a school laboratory, teachers use WHMIS information and school rules to help keep people safe. A supplier label may show a product name, hazard pictograms, a signal word, hazard statements, precautionary statements, and supplier details. A pictogram is a standardized symbol that warns about a type of hazard. The signal word, such as “Danger” or “Warning,” indicates the seriousness of the hazard within the WHMIS label system.

A Safety Data Sheet, or SDS, gives more detailed information about a hazardous product. It includes information such as hazards, safe handling, storage, first aid, and what to do in an emergency. The teacher or other trained supervisor should direct students to the relevant label and SDS. Do not guess what a pictogram means, rely on memory alone, or use an unfamiliar product. Ask for help and follow the school's procedures.

WHMIS is not a substitute for safe behaviour or supervision. It communicates hazards and precautions; it does not approve an experiment or guarantee that a procedure is safe. A plan must consider the actual activity, the people involved, and the setting.

Hazard means a possible source of harm; risk concerns the chance of harm in a situation.
Use the label and SDS as information, and follow teacher directions and school procedures.
Stop and ask for help if a product, instruction, or hazard is unclear.

Carry out the plan and judge the evidence

Once a plan is approved, follow its steps in order. Use only the materials and quantities authorized by the teacher. Record observations as they happen, using clear labels and units when a measurement has units. Separate what you directly observed from what you think it may mean. For example, “the leaf looks pale” is an observation; “it lacks a nutrient” is a possible explanation that needs evidence.

Evidence is information gathered through observations or measurements that helps answer a question. A conclusion should match the evidence. It should also mention limits. A limitation is a feature of an investigation that makes the conclusion less certain or less widely applicable. For example, comparing only two plants may not represent all plants. Do not change or invent results to fit an expected answer.

A model is a simplified representation used to help explain or plan. A safety checklist, for example, can remind a team to check labels and clear the work area. The checklist is not evidence that a product is harmless, and it cannot replace the product's label, SDS, or teacher instructions. Likewise, scientific evidence can support a claim about what was observed; it does not by itself settle a social or ethical judgment about what people ought to do.

Follow the approved steps and record observations honestly.
Keep observations separate from explanations.
State a limitation and avoid claiming more than the evidence supports.

A repeatable planning routine

Use a short routine before an investigation: state the question; list the comparison and observations; identify what should stay alike; list materials and steps; check hazards, labels, and the SDS when relevant; decide on safety measures with the teacher; then carry out the approved plan and record evidence. At the end, clean up as directed and report any problem.

The routine applies across science topics. In biology, a class might compare observations of teacher-provided plant samples. In chemistry, students might first review a teacher-selected product's label and SDS without handling it. In electricity, students can plan around a teacher-supervised classroom setup rather than experimenting with household wiring. In space science, a class can plan observations using published images or data. In each case, the question and evidence differ, but safety planning and honest records still matter.

Use the routine before, during, and after the investigation.
The teacher approves materials and procedures and sets required safety steps.
A safe plan depends on the actual activity and setting.

What to check when planning

Planning question	What to do
What am I asking?	State a focused question and the evidence needed.
What could cause harm?	Identify possible hazards and ask the teacher about precautions.
What information is available?	Use the label and SDS for relevant hazardous products, with guidance.
How will I record evidence?	Use clear observations and identify the materials or source.
What are the limits?	State what the observations do not establish.

Worked example

Planning a plant-growth comparison

A class notices that plants near a bright window look different from plants on a shelf. Plan a safe classroom investigation about whether light level is related to plant growth.

Make the question focused
Ask whether plants receiving different amounts of light show different growth over the same period. This names the comparison and the result to observe without claiming that light is the only possible cause.
Plan the comparison
Use teacher-approved plants and locations. Keep the plant type, container, watering plan, and observation schedule alike where possible. Record a clear observation, such as plant height if the teacher approves that measure. These steps make the comparison easier to interpret.
Check safety and limits
Keep water away from electrical equipment, use materials only as directed, and tell the teacher about spills. The class should not move plants or equipment without permission. If only a few plants are compared, the result may not apply to all plants or conditions.

Answer: A suitable plan compares teacher-approved plants under different light conditions, keeps other care conditions as alike as practical, records observations on a set schedule, and follows classroom safety instructions.

Check: The investigation can show a pattern in the plants observed. It cannot prove that light alone caused every difference.

Worked example

Reading safety information before a product is used

A teacher is preparing a class activity that may use a hazardous product. A student is asked to help plan the activity. What should the student do before the product is handled?

Do not guess
The student should not handle an unfamiliar product or decide that it is safe based on appearance. Ask the teacher for instructions before proceeding.
Check the information with the teacher
The teacher should identify the product and explain the relevant supplier label and SDS. The student can look for the stated hazards, safe handling directions, required precautions, and emergency information under the teacher's guidance.
Follow the approved procedure
Use the product only if the teacher authorizes it and gives the required directions and protective equipment. If information is missing or confusing, stop and ask. An SDS provides information but does not replace supervision or school rules.

Answer: Before handling the product, consult the teacher, review the relevant WHMIS label and SDS with guidance, and follow the approved safety procedure. Do not proceed when instructions are unclear.

Check: The student's role is to use safety information and follow directions, not to independently approve a hazardous product or procedure.

Worked example

Planning a safe space-science investigation

A group wants to investigate how the Moon's appearance changes over time. They will use published images selected by the teacher. How can they plan the investigation and describe its limits?

Set the question and evidence
Ask how the Moon's visible appearance differs among the selected images. Record the image date or sequence label and describe the visible shape. Using teacher-selected published images avoids the need to observe the Sun directly.
Plan a consistent comparison
Use the same description method for every image, such as noting whether the visible bright part appears narrow, half-shaped, or broad. Record the source supplied by the teacher so that another student can identify the images used.
State what the evidence cannot show
The images provide evidence about the appearance shown in those images. They may not include every date or viewing location. The group should not claim that the selected images represent every possible observation. Do not look directly at the Sun to carry out this investigation.

Answer: Use a teacher-selected set of published images, apply the same observation method to each, and record the image source and sequence information. Describe the pattern only for the images examined.

Check: The conclusion is limited to the selected images; it is not a complete record of all possible Moon observations.

Common mistakes and how to avoid them

Assuming a familiar-looking product is harmless.

Correction: Do not judge safety by appearance. Follow teacher directions and consult the relevant label and SDS.

Treating a WHMIS label as permission to use a product.

Correction: A label communicates hazards and precautions. The teacher and school procedures determine whether and how students may use the product.

Changing several conditions and then claiming one caused the result.

Correction: Keep other conditions alike where practical and describe the comparison honestly.

Writing an explanation as if it were a direct observation.

Correction: Record what was observed first. Mark possible explanations as ideas that require evidence.

Continuing when a step or hazard is unclear.

Correction: Stop, keep others safe, and ask the teacher before continuing.

Lesson summary

Plan the question, comparison, observations, materials, and steps before beginning.
Identify hazards and follow teacher directions, school procedures, and required precautions.
Use WHMIS labels and SDS information with guidance; never guess about an unfamiliar product.
Record evidence honestly, separate observations from explanations, and state limitations.

Check your understanding

Question 1

A student finds an unfamiliar product on a laboratory bench. What is the safest first action?

Open it carefully to identify its smell.
Ask the teacher and do not handle it until given directions.
Use a small amount because the container is already open.
Move it to another bench without telling anyone.

Show answer and explanation

Ask the teacher and do not handle it until given directions.

The student should not handle or identify an unfamiliar product by testing it. Ask the teacher and follow the approved procedure.

Question 2

What does an SDS provide?

Detailed information about a hazardous product, including hazards and safe handling.
Proof that a product is safe for every classroom activity.
A replacement for teacher supervision and school rules.
A record of the results of every experiment using the product.

Show answer and explanation

Detailed information about a hazardous product, including hazards and safe handling.

An SDS provides product safety information. It does not approve an activity or replace supervision and school procedures.

Question 3

A class compares two plants and notices different growth. Which statement is best supported?

Light must be the only cause of the difference.
The two plants show a difference under the conditions observed.
All plants will grow in the same way as these plants.
The class can change its records to match its prediction.

Show answer and explanation

The two plants show a difference under the conditions observed.

The observation supports a claim about the plants and conditions examined. It does not establish a single cause or apply to every plant.

Key terms

Observation: Information noticed or measured during an investigation.
Variable: A factor in an investigation that can change.
Hazard: Something that could cause harm.
Risk: The chance that harm may happen in a particular situation.
WHMIS: Workplace Hazardous Materials Information System, Canada's system for communicating information about hazardous products in workplaces.
Pictogram: A standardized symbol that communicates a type of hazard.
SDS: Safety Data Sheet; a document with detailed information about a hazardous product and its safe handling.
Evidence: Information from observations or measurements used to help answer a question.

Continue through SNC1W

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About this lesson and its review

Published by DoAssignment. This reviewed lesson follows Ontario Grade 9 Science (SNC1W), expectation A1.5. It is a study resource, not an official curriculum publication.

Before publication, content is checked for structure, mathematical or chemical notation, calculations, course boundaries, and readability. Errors can still occur, so corrections are welcomed.

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