Coaching Centre
Lab safety
What to wear in the lab, the GHS hazard pictograms on chemical labels, the lab rules and the reasons behind them, and what to do if there is a burn, a spill, a chemical in the eye or a fire.
A school lab has things a normal classroom doesn't: open flames, glass, gas taps, and chemicals that can burn skin. It is still one of the safest rooms in the school, because everyone in it follows the same rules. Every rule exists because somebody, somewhere, got hurt.
What to wear
| Wear | Why |
|---|---|
| Safety glasses | Eyes are the part of you most easily damaged by splashes and flying glass, and they don't grow back. Wear them over normal glasses. |
| Lab coat, done up | Keeps chemicals off your skin and uniform. A loose open coat can catch on equipment or drape into a flame. |
| Closed leather shoes | Dropped glass and spilled acid land on your feet. Canvas soaks chemicals straight through. |
| Long hair tied back | Hair catches fire in a second near a Bunsen burner. |
| Gloves (when told) | For chemicals that irritate or are absorbed through skin. Take them off before touching your face, phone or door handles. |
Hazard pictograms
A picture warns faster than words, and works in any language. Chemical containers in Australian schools and workplaces use the GHS pictograms (the Globally Harmonised System, used in Australia since 2017): a black symbol on a white diamond with a red border. Learn what each means, because you will see them on every bottle in the prep room.
Chemical labels also come with a Safety Data Sheet (SDS), a document that explains the dangers, the protective gear needed and the first aid for that chemical. Your teacher checks the SDS before any practical, and does a risk assessment: what could go wrong, how likely it is, and what will be done to prevent it. In Stage 5 you will write your own.
The lab rules, and the reasons behind them
| Rule | Because |
|---|---|
| Never eat or drink in the lab, or drink from lab taps and glassware | Benches and glassware may have traces of chemicals. Lab taps may not carry drinking water. |
| Walk, don't run. No pushing. | People are carrying glass and hot liquids. |
| Keep bags off the floor and books away from flames and chemicals | Bags are trip hazards; paper burns. |
| Only do experiments your teacher has approved. Never mix chemicals "to see what happens". | Some harmless-looking chemicals react violently or make toxic gases. |
| Point test tubes away from people when heating | Liquid can boil suddenly and shoot out ("bumping"). |
| Never look down into a container while heating or mixing | Splashes go straight into your eyes. |
| Smell by wafting the air towards your nose with your hand | A direct sniff of a strong gas such as ammonia can damage your nose and lungs. |
| Carry big bottles with two hands, one under the base | Necks can snap off. |
| Report every breakage, spill, cut or burn straight away, however small | Your teacher knows how to clean up each chemical safely and how to treat each injury. |
| Put solids in the bin, not the sink. Only pour liquids down the sink when told. | Solids block drains; some chemicals harm waterways. |
| Wash your hands at the end of every practical | Removes traces of chemicals you can't see. |
- There are 10 unsafe things happening in this lab. Tap each one you find to see why it's dangerous and what should happen instead.
- Stuck? Look at feet, hair, food, flames and where test tubes are pointing.
When something goes wrong
Whatever happens, the first step is always the same: tell your teacher immediately. Then:
| Accident | What to do |
|---|---|
| Burn or scald | Hold it under cool running water for 20 minutes. Remove rings or watches nearby before it swells. No ice, butter or creams. |
| Chemical on skin | Rinse with lots of running water. Remove contaminated clothing. |
| Chemical in the eye | Go straight to the eyewash station and rinse for at least 15 minutes, holding the eye open. |
| Broken glass | Don't pick it up with your fingers. Your teacher sweeps it into the broken-glass bin. |
| Small fire in a beaker | Turn off the gas if safe. Your teacher smothers it with a fire blanket or a heatproof mat. |
| Clothing on fire | Stop, drop and roll. Others wrap the person in a fire blanket. |
| Gas smell | Turn off all gas taps and tell your teacher. No flames. |
Know where these are in your lab before you need them: the eyewash station, safety shower, fire blanket, fire extinguisher, first aid kit, gas isolation switch and the exit.
Test yourself
A student gets a small burn from a hot tripod. What should they do first, after telling the teacher?
Cool running water for 20 minutes. Ice and creams can make it worse.
The correct way to smell a chemical is to
Wafting brings a small, diluted amount to your nose. Only do it when your teacher asks.
A GHS pictogram showing a flame in a red diamond means the substance is
Flame = flammable. A flame over a circle means oxidising; an exploding bomb means explosive.
The pictogram showing liquid dripping onto a hand and a surface, eating into them, means
Corrosive substances, such as strong acids, damage skin, eyes and metals.
Why should you never point a test tube at someone while heating it?
This is called bumping. Point it at the wall, not a person.
Some acid splashes into a student's eye. The best action is to
Lots of water, for a long time, straight away. The teacher will call for first aid.
Which of these is NOT a reason for wearing closed leather shoes in the lab?
Shoes protect your feet. Nobody should be moving fast in a lab anyway.
Put the steps for dealing with a burn in order.
Safe or unsafe lab behaviour?
Explain why each of these is a lab rule: (a) tie long hair back, (b) never eat in the lab, (c) report all spills to the teacher.
(a) Long hair can fall into a Bunsen flame and catch fire, or dip into chemicals. (b) Lab benches and your hands may have traces of chemicals on them, which you could swallow with food. (c) Some spills are dangerous, and the teacher knows what the chemical is and how to clean it up safely, so nobody touches it or slips on it.
Explain why hazard warnings on chemicals use pictograms rather than only words.
A pictogram can be understood in a glance, which matters in an emergency. It also works for people who speak any language or who can't read the label well, and because GHS is used worldwide, the same symbol means the same thing in every country.