4th March, 2021

The Difference Between Hazard And Risk Explained

What is the difference between a hazard and a risk? If you carry out a risk assessment, one of the first steps you will need to take is to identify the hazards, then you can assess the risk. These two terms are often confused with each other, and in this blog post, we explain the difference.

The Difference Between Hazard And Risk Explained header image

If you carry out a risk assessment, one of the first steps you will need to take is to identify the hazards. After this, you can assess the risks. But what is the difference between a hazard and a risk?

These two terms are often confused with each other, so if you're wondering what the difference is you are not alone.

The two terms go hand in hand. Without a hazard, there is no risk. But they are different, and understanding the differences is an important part of risk assessment. So let's look at what makes hazards and risks different, and how they are connected.

What is a hazard?

A hazard is something with the potential to cause harm. A hazard has the potential to cause death, injury, damage or other loss.

A hazard could be a substance, machines, activity, method of work or process. Hazards are found in nearly every workplace, home and any environment. At work, we need to identify hazards when we are carrying out a risk assessment, which is a legal requirement.

For example, a hazard could be a forklift truck. It has the potential to cause harm, to those using it, and to those working around it. Before we look at the risk associated with this hazard, let's talk about what a risk is.

forklift truck

What is a risk?

A risk is the chance that somebody could be harmed by the hazard. A risk calculates how likely it is that someone will be hurt, and how severely.

The risk is assessed based on the severity of the harm and the likelihood of harm occurring. A risk may be high or low taking into account these two factors.

Likelihood x Severity = Risk

The risk level is a calculation of likelihood and severity. You will often see a risk matrix when looking at how a risk assessment has been carried out... like this:

Slight Moderate Extreme
Low Very Low Risk Low Risk Medium Risk
Medium Low Risk Medium Risk High Risk
High Medium Risk High Risk Intolerable Risk

The severity of harm could range from minor short-term harm to major life-changing injuries or death. The likelihood of harm occurring from the hazard could range from very unlikely to highly likely.

If you need help calculating risk, you can use our free risk assessment calculator tool, and develop your own risk register.


The difference between hazard and risk

A hazard can generate various risks, as it may have the potential to cause harm in a number of ways. In our hazard example, we used a forklift truck. There are several ways harm could occur from the use of a forklift truck, including:

Let's look at the first item on our list, contact with pedestrians, and calculate the risk level. Remember, when calculating risk, we consider likelihood x severity.

How likely is it you wouldn't hear a forklift truck coming and get out of the way? Well, it could be quite likely, especially if you were in a noisy work environment and concentrating on your own job. The driver might not see you either if they are carrying a large load.

And contact with pedestrians could be pretty severe. I wouldn't fancy being run over by a forklift, they weigh more than double a car. It's easy to see how that could seriously injure you or even be fatal.

So it sounds like our risk level is pretty high. But what about our control measures? What if all pedestrians had to wear hi-viz to make them more visible to drivers. What if we had physical barriers preventing access between pedestrians and traffic routes, only at designated crossing points that were marked and had a traffic light system. Well, that reduces the likelihood of contact right down. And therefore, the risk level is reduced.

Let's take another hazard for example. A toxic substance in the workplace would be a hazard. It could be classified as a highly hazardous substance. And it certainly fits the definition of a hazard, something with the potential to cause harm.

toxic symbol

And what about the risks? Well if a worker accidentally ingested the substance, since it's toxic, it could make them seriously ill. Or worse, kill them.

However, the risk can be controlled, by implementing management procedures. Remember, the risk is based on likelihood and severity. The severity could be reduced, for example by only allowing a very small amount of the substance to be accessed, so that even if an employee was exposed, the quantity would be so small that the effects would be limited. The likelihood of harmful exposure could also be reduced, by the installation of ventilation and exclusion zones, and the enforcing of wearing personal respiration equipment (RPE).

A combination of control measures can significantly reduce the risk level, ensuring that something with the potential to cause harm (the hazard) is not able to actually cause harm or that the harm is minimised (the risk). Often a task may be classified as high risk when it is, in fact, high hazard. Just because a task or activity involves hazards, doesn't mean it is high risk. Hazardous work can be made safe providing that each risk is controlled so that the work can be carried without harm. The hazard is still there, but the risk is controlled.


So you should now know what a hazard is (something with the potential to cause harm) and what a risk is (the chance that somebody could be harmed by the hazard). It is important to distinguish between hazard and risk.

Activities may have many hazards, but the level of risk can be reduced by good management and controls. In fact, the whole purpose of risk assessments is to control risks so that work can be carried out safely. Where you can eliminate hazards, you can remove the risk. In circumstances where hazards cannot be removed, they can be controlled and the risks reduced. By identifying hazards, and the risks associated with them, you can put in place control measures and careful management, so that the remaining (residual) risk is low.

Need help completing your risk assessments? Start with the free risk assessment template or find a risk assessment for your activity.

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This article was written by Emma at HASpod. Emma has over 10 years experience in health and safety and BSc (Hons) Construction Management. She is NEBOSH qualified and Tech IOSH.

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