The 5 Types Of Risk Assessment And When To Use Them header image

13th March, 2019

The 5 Types Of Risk Assessment And When To Use Them

In this post, we are going to look at the 5 types of risk assessment in health and safety, and when to use them. Before we start, it's important to keep in mind that different types of risk assessment can be used together. Some parts of each type might be present in a single risk assessment.

A health and safety risk assessment considers the hazards present in a task or activity. It looks at the likelihood of harm that might occur. And the severity of that harm. A risk assessment should take 5 steps:

  1. Identify the hazards
  2. Decide who might be harmed and how
  3. Evaluate the risks and decide on precautions
  4. Record your significant findings
  5. Review your assessment and update if necessary

With any type of risk assessment, the assessor should have experience in the type of work they are assessing, to know what hazards need to be managed. They should also be competent in the risk assessment process, to be able to identify high risks and what action might be needed to reduce risk.

1. Qualitative Risk Assessment

The qualitative risk assessment is the most common form of risk assessment. You will often see this type of risk assessment in workplaces. It is based on the personal judgement and expertise of the assessor. They will often use their own experience, but will also consult with others carrying out the activity and best practice guidance to reach their decisions.

Any health and safety risk assessment will start with a simple qualitative assessment. In a qualitative risk assessment, the assessor will categorise risk into levels, usually high, medium or low.

A qualitative risk assessment should be a systematic examination of what in the workplace could cause harm to people, so that decisions can be made as to whether existing precautions or control measures are adequate or whether more needs to be done to prevent harm.

A qualitative risk assessment will look at the risk of somebody being injured, and if that is high, medium or low. Just like any other type of risk assessment, any high risks will need to be addressed as a priority. Low-level risks can be looked at later, or might not need further action to be taken.

Risk = Severity x Likelihood

Just because a qualitative risk assessment doesn't need to involve numbers, the risk is still calculated by the severity of harm x likelihood of harm. Qualitative risk assessment involves making a formal judgement on the consequence (severity) and probability (likelihood).

2. Quantitative Risk Assessment

The quantitative risk assessment is used to measure risk by assigning a numerical value. This type of risk assessment will more likely be used with major hazards, like aircraft design, complex chemical or nuclear plants.

Quantities measured could be the presence of hazards from chemicals or machinery for example, or modelling techniques and estimates.

In carrying out quantitative risk assessments, special quantitative tools and techniques will be used for hazard identification, and to estimate the severity of the consequences and the likelihood of realisation of the hazards.

Often qualitative risk assessments might assign numbers to different levels of risk. Like the 3 x 3 or 5 x 5 risk matrix. This doesn't turn a qualitative risk assessment into a quantitative one. If the risk assessment is still based on the judgement of the assessor assigning risk values, it is still primarily a qualitative assessment.

Sometimes, a qualitative risk assessment might become semi-quantitative, for example when some hazards or aspects can be measured, and others are based on judgement.

3. Generic Risk Assessment

The Management of Health and Safety at Work Regulations (1999) require employers to carry out an assessment of the risks arising from their work activities.

3.—(1) Every employer shall make a suitable and sufficient assessment of

  1. the risks to the health and safety of his employees to which they are exposed whilst they are at work; and
  2. the risks to the health and safety of persons not in his employment arising out of or in connection with the conduct by him of his undertaking,

Generic risk assessments cover common hazards for a task or activity. The idea behind generic risk assessment is to cut down on duplication of effort and paperwork. This type of risk assessment will consider the hazards for an activity in a single assessment, where that activity may be carried out across different areas of the workplace or different sites.

A generic risk assessment will often be used for similar activities or equipment across different sites, departments or companies. It can act as a risk assessment template, covering the types of hazards and risks that are usually present for the activity.

It's important to remember that while the risks from an activity may be common across different sites, changes in the environment can affect risk levels, and even introduce new hazards. It's probably best to use generic risk assessments as a starting point for a site-specific risk assessment.

4. Site-Specific Risk Assessment

A site-specific risk assessment is a risk assessment that has been completed for a specific item of work, that takes account of the site-location, environment, and people doing the work.

Your site-specific risk assessment might be qualitative, or quantitative. You might start off with a generic risk assessment template. But you should finish with a site-specific risk assessment that is suitable and sufficient for the hazards present.

For example, image a generic risk assessment for drilling. It would cover risks like entanglement with rotating parts, projectiles, contact with hot parts of the tool during use, vibration and noise. But could there be unusual hazards on your site that might change the risk level? You could be drilling within a confined space. A vessel or a tank. Access may be limited. Flammable gases could be present. You could need additional controls like atmosphere testing, a permit to work, a rescue plan.

A site-specific risk assessment will do more than look at common hazards. It will also address the unusual. Hazards that might only apply to that specific situation, on that particular day.

Find out more about the difference between site-specific and generic risk assessments in our blog post.

5. Dynamic Risk Assessment

A dynamic risk assessment is a process of assessing risk in an on the spot situation. This type of risk assessment is often used to cope with unknown risks and handling uncertainty. It might be used by the emergency services, or care workers for example, who need to deal with developing and changing situations. These types of environments need to be continually assessed. If there are significant changes, is the original risk assessment still valid? Should you try to deal with the situation? Is it safe to continue?

It is not always possible to prepare for every risk or hazard. A written risk assessment should assess the level of 'unknown' risks. Where a certain element of dynamic risk analysis is required, workers need to have the skills and awareness to recognise and deal with danger.

worker on site
Circumstances can change quickly out on site

For example, if a lone worker feels uneasy about a situation, there should be a process in place to get help. Or action that can be taken, like emergency procedures, if things go wrong. Rather than relying on the assessor's judgement, a dynamic risk assessment relies on the worker's judgement. They take on the role of the risk assessor at that moment.

Where there are dynamic elements to a risk assessment, workers need to have the confidence and judgement to know when it is not safe to proceed. Extra training will help to develop these skills, particularly with lone workers who might not have anyone close by to ask advice from.


Need help with risk assessments? Use our free risk assessment calculator and browse our library of risk assessment templates.

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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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