Laboratory safety: rules, hazard warning labels and the fire triangle
FoundationA laboratory is purpose-built for scientific inquiry: recognise hazard warning labels, follow the safety rules, understand the fire triangle, and handle accidents correctly — then experiments can be done safely.
- The laboratory is purpose-built for inquiry — learn where the safety equipment is first
- Safety rules are practical accident prevention; make them habits
- Hazard is the cause of harm, risk the chance of it; protection lowers risk
§Text Passage
1A laboratory is purpose-built for scientific inquiry: it holds chemicals, heating equipment and glassware, along with safety features such as fire extinguishers, fire blankets and eyewash stations. On your first visit, curiosity matters — but so does learning to protect yourself and your classmates, because inquiry begins with safety.
2The hazard warning labels on chemical bottles are the most direct guide: a flame means flammable, a skull means toxic, a corroding hand means corrosive, an exclamation mark means irritant. Reading the labels tells you what an experiment may safely involve and what protection to wear. Also keep hazard and risk apart: concentrated sulfuric acid is a hazard, but dilution, gloves and the correct steps bring the risk right down.
3Burning needs fuel, oxygen and heat together — the fire triangle. Firefighting removes one side: capping an alcohol lamp cuts the oxygen, dousing with water removes the heat, clearing combustibles takes away the fuel. Oil and electrical fires must not meet water; use an extinguisher or cut the power first. Turning off the Bunsen burner at the end of a session is the fire triangle at its most everyday.
4When an accident happens, remember the order: protect yourself first, tell the teacher, then act. Chemicals in the eye mean at least ten minutes under the eyewash; a spill means moving classmates away first. A calm report is not weakness — it is the first step to keeping the harm as small as possible, and part of the scientific attitude itself: honesty, responsibility and respect for safety.
1Summary 重點摘要
A laboratory is purpose-built for scientific inquiry: recognise hazard warning labels, follow the safety rules, understand the fire triangle, and handle accidents correctly — then experiments can be done safely.
2Vocabulary cards Vocabulary
A factor that can potentially cause harm.
The chance that a hazard will actually cause harm; it can be reduced by precautions.
A pictogram showing the type of hazard a chemical poses.
Catches fire easily when near a flame or spark.
Able to attack and destroy skin, eyes and metals.
Harmful or lethal when it enters the body.
The three things a fire needs: fuel, oxygen and heat — remove one and the fire goes out.
Emergency equipment for rinsing the eyes after a chemical splash.
3Step by step Steps
- The laboratory is a place for scientific inquiryA laboratory differs from an ordinary classroom because it is purpose-built for scientific inquiry: it holds gas taps, chemicals and heating equipment no classroom has, along with safety features such as fume cupboards, fire extinguishers, fire blankets and eyewash stations. On your first visit, learn where everything is and how it works: which corner holds the extinguisher, where the eyewash and emergency shower are, and how the escape route runs. Knowing this makes routine experiments calmer and lets you react at once if something goes wrong.
- Follow the laboratory safety rulesThe safety rules are not regulations to memorise but practical ways to prevent accidents. The core ones: listen to the instructions before any experiment and ask if anything is unclear; never eat or drink in the laboratory, so chemicals cannot enter by the mouth; tie back long hair and secure loose clothing so it cannot catch fire or knock over apparatus; no running or chasing, and watch the bench as you move; never run extra experiments without approval; before leaving, wash the apparatus, return the chemicals and clean your hands. Turn the rules into habits and safety follows.
- Tell hazard from riskHazard and risk are two different ideas: a hazard is a factor that can cause harm in itself — concentrated sulfuric acid burning skin is a hazard — while risk is the chance that the hazard actually causes harm. The same hazard carries very different risk depending on how it is handled: diluted acid is far less risky than the concentrated kind; goggles, gloves and the correct procedure cut the risk further. So before every step ask three questions: what is the hazard? how big is the risk? how can it be reduced? Answering them makes an experiment far safer.
- Recognise the hazard warning labelsEvery chemical bottle carries a hazard warning label that shows its danger at a glance: a flame means flammable, igniting near a spark; a hand corroding means corrosive; a skull and crossbones means toxic, harmful or lethal even in small amounts; an exploding bomb means explosive; an exclamation mark means irritant or harmful. Treat any labelled chemical with extra care: never touch it directly, never mix it casually, and return it to its place straight after use. Labels are the chemicals' identity cards — learn to read them first.
- The fire triangle and putting fires outBurning needs three things at once: fuel, oxygen and heat — drawn as the fire triangle. Remove any one and the fire cannot start or dies out; that is exactly how firefighting works: smothering an alcohol lamp with a fire blanket or a cap cuts off the oxygen; dousing a wood fire cools it and removes the heat; clearing away nearby combustibles removes the fuel. But not every fire can be doused with water: water splashes burning oil and conducts electricity, so oil and electrical fires need an extinguisher or the power cut first. When heating in the lab the fire triangle is right before you — switch the Bunsen burner off after use.
- Handling accidents: stay calm, act correctlyWhen an accident happens the first response is always to tell the teacher — never improvise or hide it. The correct responses to the common ones: chemicals in the eye, rinse with the eyewash for at least ten minutes; on the skin, flush with plenty of water; a spill, move classmates away first and then report; a fire, get clear, call out loudly, and let the teacher decide between the extinguisher and evacuation. Remember the order: protect yourself first, then call for help, then deal with the spill. Most laboratory accidents grow worse through panic and concealment; a calm report is the cheapest safety measure there is.
4Diagrams Diagrams
5Worked example Example
Scenario: during an experiment you splash a liquid labelled 'corrosive' onto your finger. What should you do?
- Hold the finger under the tap at once and flush with plenty of water
- Tell the teacher what happened and which chemical it was
- Keep rinsing or take further action as the teacher directs
- Clean the bench and check no classmate was splashed
- Answer: The hazard is that a corrosive chemical burns skin; prompt action slashes the risk. First flush with plenty of running water to wash the chemical away; second, tell the teacher, whose experience decides whether more is needed. Never try to 'neutralise' it with another chemical — the reaction may give out heat and cause a second injury. Protect yourself first, call for help, then deal with the rest: the safety rules and accident procedure are both in play.
6Common mistakes Mistakes
7Quick check Quick check
Q1What are the three elements of the fire triangle?
Q2What is the difference between hazard and risk?
Q3What special care does a corrosive-labelled chemical need?
Q4What should you do the moment chemicals enter the eye?
Q5Why is eating and drinking banned in the laboratory?
8Recap Recap
- The laboratory is purpose-built for inquiry — learn where the safety equipment is first
- Safety rules are practical accident prevention; make them habits
- Hazard is the cause of harm, risk the chance of it; protection lowers risk
- Hazard warning labels show a chemical's danger at a glance
- Remove one side of the fire triangle and the fire dies; report accidents before handling them