Step 2 - Initial Risk Rating

Now that we’ve identified a realistic hazard and who could potentially be at risk, the next step is to evaluate how likely the accident is to happen & what the consequences might be using our risk assessment matrix.

Remember that you are assessing the hazard before you’ve put in any safety measures. We’ll assess the hazard again later to show how our control measures have reduced the risk factor.

Risk ratings are essentially subjective and two people may assess the same hazard slightly differently. If in doubt, get someone else from your team to review your risk ratings and see if they agree that they are realistic for the hazard you are assessing.

Likelihood

Estimate how likely the hazard is to cause injury or damage to equipment or the environment based on the Likelihood matrix.

Our matrix is made up of two factors, the likelihood of an accident happening and the severity of the consequences. We rate each factor out of 5.

Risk Rating Likelihood Explanation
5 Probable It is inevitable that an incident would result, with an immediate danger to health and safety of the public, staff or property and resources.

For example, there may be a 1 in 100 chance of the hazardous event happening.

4 Likely A similar incident is known to have occurred in the past, and likely to occur again in the future one or more times.

For example, there may be a 1 in 1,000 chance of the hazardous event happening.

3 Possible An incident is possible to occur over time if the hazard is not corrected, or when additional factors are present.

For example, there may be a 1 in 10,000 chance of the hazardous event happening.

2 Very Unlikely An incident will require a combination of factors, multiple failures of safety and/or management systems but otherwise should not occur.

For example, there may be a 1 in 100,000 chance of the hazardous event happening.

1 Very Unlikely An incident will require an unusual combination of factors, otherwise harm will seldom occur.

For example, there may be a 1 in a million chance of the hazardous event happening.

You can think of it like this – for something to get a risk rating of ‘5 – Probable’ it means that the person undertaking the risk assessment believes that, for every 100 times that activity is undertaken, at least one time it will go wrong and someone will get hurt.

If you were to undertake the same activity twice a week for a year, that means you would expect to have that incident occur about once a year.

Severity

Now assess, if an accident was to take place how serious it would be based on the Severity Matrix

Risk Rating Severity Explanation
5 Major Death, major injury or illness causing long term disability to more than one person OR

Damage to equipment with enough severity to result in operations ceasing OR

Long term impact to the environment with a recovery time of more than 12 months

4 Serious Death, major injury or illness causing long term disability to one person, or more than one person suffering work time loss injuries and illness causing short term disability OR

Damage to equipment with enough severity to result in operations being temporarily halted, where repairs to, or replacement of equipment is required OR

Medium term impact to the environment with a recovery time of between 1 and 12 months

3 Moderate Hospitalisation, minor injury or persistent health effects for one person with work time loss OR

Minor damage to equipment where local repairs can enable operations to recommence OR

Short term impact to the environment with a recovery time of up to 1 month

2 Very Unlikely First aid treatment (on premises), reversible illness with no work time loss OR

Aesthetic damage only with no impact on use or operation of equipment OR

Minimal impact to the environment with a recovery time of one day

1 Negligible Slight injury or health implications with no work time loss OR

No damage or physical loss to equipment OR

No impact to the environment

Risk Rating

The combination of these value gives you an initial ‘Risk Rating’ for the hazard you’ve identified. These risk ratings are broadly inline with BS 8800 for risk management.

Hazards with a risk rating above 5 will require you to implement control measures to try and reduce that risk rating down to an acceptable level. When managing your project, the hazards with an initial risk rating of ‘Unacceptable’ should always be the priority to address as these are the most likely to cause serious injury or damage.

Risk Rating Explanation
20 – 25 Substantial – Resources might have to be allocated to reduce the risk, urgent action should be taken.
10 – 16 Moderate – Look at risk reduction measures, which should take cost into account and should be implemented within a defined time period.

Priority for improving control measures should be given to risks with greater consequences than those with greater likelihood.
5 – 9 Tolerable – No major additional precautions required. However, there might be a need for reasonably practicable improvements that involve minor or limited cost.
1 – 4 Trivial – No action is required and no detailed records need to be kept