A wet floor in an empty corridor hurts nobody. The same floor at the door of a busy shop hurts someone by lunchtime. The floor is the same. What changed is who walks on it, and how often. Safety people keep two words for this, and the whole subject rests on telling them apart.
The hazardthe wet floor
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The riskthe chance, and the size
A hazard is anything that could cause harm: the wet floor, a sharp blade, a loud machine, a tall ladder. A risk is the chance that the harm actually happens, together with how bad it would be. The hazard is the thing. The risk is the chance and the size.
The wet floor
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The chance someone slips
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The yellow sign
A corridor has just been mopped. Which of these is the hazard?
The yellow sign.
Not yet. The sign was put there to lower the risk. It cannot cause the harm, so it is not the hazard; it is an answer to one.
The chance that someone slips.
Not yet. That is the risk, not the hazard. The chance depends on who comes along; the floor is wet either way.
The wet floor.
Right. The hazard is the thing that could do the harm. The floor is that thing, whether or not anyone is about to walk on it.
likely 3, bad 1Paper cut
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likely 1, bad 3Fall from a roof
Two scores, multiplied. A made-up scale that many real ones resemble.
To size a risk, people ask two questions. How likely is the harm? How bad would it be? Many workplaces give each a score from 1 to 3 and multiply the two. A paper cut that happens daily scores high on likely and low on bad. A fall from a roof is rare, and deadly.
Set how likely the harm is and how bad it would be. The score is the two numbers multiplied: 1 to 3 for each, so 1 to 9 in all. A made-up scale, like many real ones.
This risk's score1 out of 9
The highest score9 out of 9
Rare · A bruiseRare, and the harm would be a bruise. 1 times 1: the risk scores 1 out of a possible 9.
This risk's score2 out of 9
The highest score9 out of 9
Rare · A broken boneRare, and the harm would be a broken bone. 1 times 2: the risk scores 2 out of a possible 9.
This risk's score3 out of 9
The highest score9 out of 9
Rare · A deathRare, and the harm would be a death. 1 times 3: the risk scores 3 out of a possible 9.
This risk's score2 out of 9
The highest score9 out of 9
Sometimes · A bruiseSometimes, and the harm would be a bruise. 2 times 1: the risk scores 2 out of a possible 9.
This risk's score4 out of 9
The highest score9 out of 9
Sometimes · A broken boneSometimes, and the harm would be a broken bone. 2 times 2: the risk scores 4 out of a possible 9.
This risk's score6 out of 9
The highest score9 out of 9
Sometimes · A deathSometimes, and the harm would be a death. 2 times 3: the risk scores 6 out of a possible 9.
This risk's score3 out of 9
The highest score9 out of 9
Often · A bruiseOften, and the harm would be a bruise. 3 times 1: the risk scores 3 out of a possible 9.
This risk's score6 out of 9
The highest score9 out of 9
Often · A broken boneOften, and the harm would be a broken bone. 3 times 2: the risk scores 6 out of a possible 9.
This risk's score9 out of 9
The highest score9 out of 9
Often · A deathOften, and the harm would be a death. 3 times 3: the risk scores 9 out of a possible 9.
Which scores higher: a bruise that happens often, or a death that is rare?
The death. A death always scores highest.
Not yet. A death scores 3 for how bad, but rare scores 1 for how likely, and the two are multiplied. Rare pulls the deadly harm down to 3.
The bruise. Often beats rare.
Not yet. Often is a 3, but a bruise is a 1, and 3 times 1 is 3. The rare death also comes to 3. Neither beats the other on this scale.
They score the same, 3 each. A common small harm and a rare deadly one can land on one number.
Right. Often times a bruise is 3 times 1. Rare times a death is 1 times 3. The score is a sorting tool, and this is its weak spot: it cannot tell those two apart.
Move both controls.
Bruise, often3 out of 9
Death, rare3 out of 9
Broken bone, often6 out of 9
So a score like that is a sorting tool, not a truth. Two risks can share a number and need very different answers. A company puts up with daily bruises. It never puts up with a rare death, because a death cannot be undone. The score tells you where to look first, not what to accept.
Three hazards in one warehouse, each scored the same way. Tap the one with the biggest risk.
Tap the part of the picture that answers it.
likely 3, bad 1Wet floor by the door
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likely 1, bad 3Bare wire in a store room
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likely 2, bad 3Forklift in a busy aisle
Forklift in a busy aisle
Right. Sometimes, and a death: 2 times 3 is 6. It is neither the most likely harm nor the worst, and it is the biggest risk because it is bad on both counts at once.
Wet floor by the door
Not yet. The most likely of the three, but 3 times 1 is 3. A harm that is nearly certain and nearly harmless is a middling risk, not the biggest.
Bare wire in a store room
Not yet. The worst harm of the three, but 1 times 3 is 3. Hardly anyone goes in there, and the score counts that. It still needs fixing; it is just not first.
Trained, twice a yearlower risk
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New, every hourhigher risk
One ladder.
The same hazard carries a different risk for different people. A ladder is one risk for a trained worker who climbs it twice a year, and another for a new starter sent up it every hour. Risk belongs to a situation, not to an object.
Each card is one or the other. Is it a hazard, or a risk?
One card at a time. Tap the pile it belongs to.
Card 1 of 5
A chainsaw.
A one-in-ten chance that a delivery rider is hit by a car this year.
Boxes stacked three metres high.
A high chance of burns in a kitchen with no oven gloves.
Bleach kept in an old lemonade bottle.
A chainsaw. → A hazard
Not yet. A hazard. It is a thing that could cause harm, and it is a hazard sitting switched off in a locked shed too.
A one-in-ten chance that a delivery rider is hit by a car this year. → A risk
Not yet. A risk. It is a chance of a harm, with a size: one in ten, and a crash. The hazard behind it is the traffic.
Boxes stacked three metres high. → A hazard
Not yet. A hazard. The stack could fall on someone. How likely that is depends on who works under it, and that part would be the risk.
A high chance of burns in a kitchen with no oven gloves. → A risk
Not yet. A risk. It names a chance, high, and a harm, burns. The hot oven is the hazard; the missing gloves are what make the chance high.
Bleach kept in an old lemonade bottle. → A hazard
Not yet. A hazard. Something that could cause harm, made worse by its disguise. The risk would be the chance that someone drinks from it.
Hazarda thing
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Riska chance, and a size
Right. If the card names a thing, it is a hazard. If it names a chance of harm, and how bad, it is a risk. Every risk has a hazard behind it; a hazard on its own has no number.
Twelve-year-oldstwice a week
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Same lab, same chemicals
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Trained sixth-formersonce a month
Two schools have the same science lab and the same chemicals. One uses it with twelve-year-olds twice a week. The other uses it with trained sixth-formers once a month. Which is true?
Same hazards, same risks. The chemicals are what matter.
Not yet. The chemicals decide what harm is possible. They do not decide how likely it is; the people and the timetable do, and those differ.
Same hazards, different risks. The first lab's risk is higher: more people with less training meet the chemicals more often.
Right. The chemicals are the hazards, and they are the same in both. The risk is the chance of harm, and it moves with who is in the room and how often.
Different hazards. More pupils means more hazards.
Not yet. Pupils are the people who might be harmed, not the hazards. The hazards are the chemicals, and both labs have the same ones.
Lesson complete
A hazard is a thing that could cause harm; a risk is how likely the harm is, and how bad.