Teaching Lab Safety Effectively

Most students can recite “wear goggles” and “tie hair back”. Fewer can explain why, and fewer still apply safety thinking to a situation they haven’t met before. Yet that’s the real goal: not obedience to a poster, but students who recognise hazards and make sensible decisions, in school and later in their lives. This guide offers practical strategies for teaching safety so it becomes a habit of thought.

Principle 1: Teach the reason, not just the rule

Rules without reasons are easily forgotten, or ignored when they seem inconvenient. Every rule should come with a short, concrete explanation:

Rule	Reason to share
Eye protection on until everyone has finished	Splashes come from other people’s experiments too; eye damage can be permanent.
Add acid to water	Dilution releases heat; water added to concentrated acid can boil and spit.
Never heat a sealed container	Gas expands; pressure builds until the container bursts.
No food or drink	Invisible contamination on hands and benches can be swallowed.
Stand while working	You can move away quickly from a spill or fire.

A student who understands the reason for “never heat a sealed container” can apply it to a situation the rules never mentioned.

The lab safety rules article explains the reasons in student-friendly language; the lab safety myths article tackles common wrong beliefs.

Principle 2: Model it, every time

Students copy what teachers do, not what they say. If you wear eye protection while demonstrating, check the SDS before a new practical, and put your bag under the bench, students see safety as normal professional behaviour. If you skip eye protection “just for a moment”, they learn that rules are optional.

Principle 3: Start early and build up

Teach safety explicitly in the first lab lessons of the year, then keep revisiting it in context.

First lessons:

• A tour of the lab: exits, eyewash, fire blanket, gas and electricity isolation switches, first-aid kit, where broken glass goes.
• Routines for entering, collecting equipment and clearing up.
• The meaning of hazard symbols.
• Lighting a Bunsen burner safely, with the safety flame.

Throughout the year:

• Before each practical, pick one safety point to discuss in depth.
• Gradually hand more responsibility to students, from following a given risk assessment to writing their own.

Activities that work

Hazard-spotting pictures

Show a drawing or photo of a lab scene with deliberate hazards: a bag in the walkway, a test tube pointing at a person, an unlabelled beaker, a solvent bottle next to a Bunsen flame, someone eating. Students find and explain as many as they can. It’s quick, engaging and very revealing about misconceptions.

Symbol matching

Students match GHS pictograms to their meanings and then to real chemicals from the prep room (with labels visible). Discuss why some chemicals carry more than one pictogram.

“What would you do if…?” scenarios

Short cards with realistic incidents:

• Your partner splashes dilute sodium hydroxide in their eye.
• A small amount of ethanol in a dish catches fire.
• You drop a beaker and it breaks.
• You notice a smell of gas.

Groups decide on actions, then compare with the correct response. See the lab safety quiz for ready-made questions with explanations.

Student-written risk assessments

For suitable practicals, students identify hazards, risks and control measures before starting. Use a simple template:

Hazard	Risk (what could go wrong?)	Control measure	Emergency action

Check them before the practical and give feedback. Common weak spots: vague controls (“be careful”) and forgetting products formed during the reaction. See risk assessment in chemistry and how to read a safety data sheet.

Real case studies (age-appropriate)

Older students engage strongly with real incidents and what they taught. Choose respectful, well-documented cases and focus on the systems and decisions involved rather than blame. See famous lab accidents and the safety lessons they taught.

Drills

Practise the stop signal, evacuation routes and fire blanket use. Students who’ve practised respond calmly in a real emergency.

Making safety specific in exam answers

Students often lose marks on safety questions by being vague. Teach them a structure:

Hazard + precaution + reason

• Weak: “Wear goggles.”

• Strong: “Wear eye protection because sodium hydroxide is corrosive and can cause serious eye damage.”

• Weak: “Be careful with the Bunsen.”

• Strong: “Use a water bath instead of a Bunsen burner because ethanol is highly flammable.”

Dealing with incidents and near-misses

When something goes wrong (and minor things will):

1. Deal with it calmly and immediately; first aid comes first.
2. Report it according to your school’s procedures.
3. Afterwards, discuss it with the class without blaming individuals: What happened? Why? What could we change?
4. Encourage students to report near-misses, and thank them when they do. A culture where students hide mistakes is dangerous.

Behaviour and supervision

• Never leave a class unsupervised during practical work.
• Set clear consequences for unsafe behaviour, such as being removed from the practical for that lesson, and apply them consistently.
• Consider group size and class layout; smaller groups and clear walkways reduce risk.
• Know your students: additional needs, allergies, and any medical conditions relevant to practical work.

Safety for different age groups

• Younger students: focus on a small number of clear routines, the reasons behind them, and practising the stop signal. Keep practicals short and closely supervised, and use microscale techniques to reduce quantities.
• Middle years: introduce hazard symbols, simple risk assessments and the idea that the same chemical can be more or less hazardous depending on concentration.
• Older students: expect them to find hazard information on safety data sheets themselves, write full risk assessments, and discuss real incident reports. Treat them as trainee professionals.

Using the technician’s expertise

Technicians often see hazards teachers miss: a solution that has become more concentrated through evaporation, equipment that is wearing out, a chemical that has deteriorated. Invite your technician to contribute a short safety briefing for a practical, or to explain how they prepare and dispose of chemicals. It shows students that safety is shared work across the whole department.

Building a positive safety culture

Safety shouldn’t feel like a list of prohibitions. Frame it as professional competence: real chemists work safely because it allows them to do exciting, ambitious work. Praise good safety behaviour as specifically as you praise good results. Invite students to suggest improvements to procedures.

A one-term safety scheme

Week	Focus
1	Lab tour, routines, emergency equipment
2	Hazard symbols and labels
3	Bunsen burner and heating safely
4	Handling acids and alkalis; diluting safely
5	Hazard-spotting picture and scenario cards
6	First student-written risk assessment
7	Glassware and spills
8	Waste disposal; see disposing of chemical waste
9	Fume cupboards and gases; see what is a fume cupboard for
10	Review quiz and evaluation

Key takeaways

• Explain the reason behind every rule so students can apply it to new situations.
• Model safe behaviour consistently; students copy what you do.
• Use active tasks: hazard spotting, scenarios, drills and student-written risk assessments.
• Teach precise safety language for exam answers: hazard, precaution and reason.
• Build a blame-free culture where near-misses are reported and learned from.