Most modern health and safety legislation requires employer’s to assess the risk as part of their basic duties to protect their workforce.
Our blog series on the 5 Steps of Risk Assessment takes you through each step in detail, including the really important step which requires you to Assess the Risk.
In this section, we will show how to effectively use severity and likelihood in risk assessment. You can jump to  21:00mins on our tutorial video above to watch the part on using severity and likelihood to assess the risk using a risk matrix.Â
Also, if you would like to certified on risk assessment for your workplace, don’t miss our free online Risk Assessment training course.
What are the 5 Steps of Risk Assessment?
The 5 steps of risk assessment are a model used to help us work through the process of risk assessment. There are different versions (see image), but our preferred method goes like this:

As you can see, Step 3 is to ‘Assess the Risk‘. In this tutorial, we will teach you how to assess the risks in your business. Let’s get started….
Why should you Assess the Risk?
When you need to assess the risk in a business, one of the toughest parts of the process is identifying how much risk actually exists.
In this masterclass, we will show you how to assess the risk in your workplace environment.
Once you are confident enough to assess the risk, you will be on your way to sufficiently managing health and safety within your business.Â
Step 3 | Assess the Risk
This step in the risk assessment process is vitally important – you have identify the significant hazards, now it’s time to assess the risk.
A common method of assessing the level of risk is to assign a value to each of two component parts – Likelihood and Severity.Â
As explained in the video and shown on the risk matrix below, a combination of Severity x Likelihood = Risk.
As shown in the risk matrix, the number chosen for each element (Likelihood and Severity) represents a level of significance e.g. high, medium or low.
Severity – How bad is the outcome likely to be i.e. the severity of injury or illness?
Likelihood – What are the chances of it happening with the current controls in place?

Using a risk matrix for your workplace risk assessment allows you to look at each hazard separately and decide how significant the risk might be.
The example above is a basic ‘Risk Matrix’ – it is quite simple, but of course that makes it easy to interpret and it does just fine for most applications.You may find matrices that are much more detailed or complex, but they usually work along the same principles.
Likelihood and Severity Risk Assessment
It’s important to note, that the intention of a risk matrix is not to provide a specific, ‘quantitative’ measurement of risk. We aren’t ‘measuring’ anything physically. It does, however, allow the assessor to prioritise according to the perceived risk level.Â
It’s up to us to decide the following for each hazard or work activity:
- Likelihood (1-3) – how likely an accident it is that someone will come to harm.
- Severity (1-3) – the seriousness of the potential injury or illness
Likelihood
Firstly, the Likelihood should be determined. We must decide which of the following best reflects the chance of the outcome happening – Very Likely (3), Possible (2) or Unlikely (1)
Once we’ve taken a note of that, we need to look at Severity. How severe would the outcome be if the worst was to happen? – Major Injury (3), Minor Injury (2) or Trivial (1)
Severity
When we have assigned a number to both Likelihood and Severity, we can then multiply them to produce our ‘risk rating’.Â
As you can see, the risk matrix does this for you. It also provides a traffic light colour to make interpretation of the results even easier.
Let’s look at an health and safety risk assessment example to explain a little further…
Let’s think back to our Risk Matrix. How would you rate the following scenario (image below) when thinking about the ‘Severity’ and ‘Likelihood’ of a collision between the forklift and a pedestrian?

Let’s look at how we interpreted the level of severity and likelihood when assessing the risk in the example;
Severity – if a pedestrian was hit by the forklift truck, what might the consequences be?Â
The weight, build & function of a counter-balance forklift makes serious injury a common outcome. Hopefully you will agree that the potential severity of the injuries could be very high. In many cases, this type of collision can be fatal.Â
So with those factors in taken into account, we would have to score this as a 3 (Major Injury) in our risk matrix.
Likelihood – when considering the chance that a collision would happen in this specific scenario, how likely would it be?
The driver is moving with a raised load (obscured view) and there is no physical segregation between the person and the forklift. The pedestrian is not wearing anything to make him easily visible to the driver.
Given these factors, we would have to say that a collision is highly likely.
Does your business need Health and Safety support?
How Does It Look On Our Risk Matrix?Â

If we rate the Severity as 3 (Major) and the Likelihood as 3 (Very Likely), that means we end up with a risk assessment rating of 9.
As you can see if you look back at the risk matrix, 9 is the highest score. This would normally indicate that there is much room for improvement and also that action should be urgently prioritised.
As you can see below, there are lots of factors that may contribute to the likelihood being high or low when you come to assess the risk. As for severity, there usually aren’t so many variables that will change the degree of harm that will be caused.
This is most often the case, unless there is a significant change made to remove the hazard or substitute the methods used.

Now, we have covered the initial process of how to assess the risk. We will go on to talk about how these risks can now be evaluated, before deciding if we need to add (or remove) controls measures.
Before we do that, I wanted to let you know about an awesome Risk Assessment support offer available from the H&S professionals at Safeti.
Evaluate the Risk & Add Controls

Once you have taken the time to assess the risk, we need to decide if the current risk level is acceptable, or if we need further control measures. Control measures include actions that can be taken to reduce the potential of exposure to the hazard.Â
These risk control strategies can vary extensively in terms of effectiveness, and if the risk is high, multiple layers of control may need to be considered.
So, if we are looking at a specific hazard, how do we assess the options for reducing risk?
Assess the Risk | Useful Examples
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If you would like to learn more about the next step in the Risk Assessment process, go to STEP 4 – Evaluating Risk and Add Controls. Alternatively, if you missed How to Identify Hazards, go back STEP 2.
If you would like to take a free Course version of this training, head on over to our Risk Assessment Training Course page.


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One thought on “Assess the Risk | Likelihood and Severity | How to Use a Risk Matrix”
That’s great