10th March, 2022

The 5 Types Of Risk Assessment And When To Use Them

Risk assessments at work are a legal requirement. But which type do you need? In this post, we look at the 5 different types of risk assessment in health and safety. And when and why you might use each one. Including qualitative, quantitative, generic, site-specific and dynamic risk assessments.

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

Not all risk assessments are the same. You can use each different type of risk assessment for different situations. And we will cover each one in this post.

Before we start looking at the different types of risk assessments, keep in mind that different types of risk assessments can be used together. It's not always an either-or situation. 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 involve 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 all types of risk assessment, the assessor should have experience in the type of work they are assessing. They need to know what hazards are present and how to manage them. 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.

Let's look at the 5 types of risk assessment and when you might want to use them.

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.

This type of risk assessment is based on the personal judgement and expertise of the assessor, who will often use their own experience to decide on the risk levels involved. The assessor will also consult with others carrying out the activity and best practice guidance to reach their decisions.

You will probably start any health and safety risk assessment 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 getting 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 any 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).

A 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. So instead of high, medium, and low, you could have 3, 2 and 1. Or the scale could be much larger than 3.

This type of risk assessment is more likely to be used with major hazards, like aircraft design, complex chemical or nuclear plants.

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

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 also assign numbers to different levels of risk. Like the 3 x 3 or 5 x 5 risk matrix. But 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 the risk values, it is still primarily a qualitative assessment.

risk matrix

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 assess 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. And be used 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 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 completed for a specific item of work. It takes account of the site location, environment, and people doing the work.

Your site-specific risk assessment might be qualitative or quantitative. And you might start 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, imagine 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, for example. Your access might 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 handle uncertainty. People who need to deal with developing and changing situations will often use dynamic risk assessments.

Dynamic risk assessments might be used by the emergency services or care workers, for example. Because the location, the situation and the people you are dealing with will change from case to case. So you must keep risk assessing the changing circumstances.

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 an element of dynamic risk analysis is required, workers need to have the skills and awareness to recognise and deal with danger.

worker 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. This training is particularly critical for lone workers who might not have anyone close by to ask advice from at the time.


Knowing the different types of risk assessment helps you use the right one at the right time. You might use one, or several, of the 5 types of risk assessment in your business.

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

share on twitter share on facebook share on linked in share by email

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.

Need Health and Safety Documents?

Search hundreds of health and safety documents ready to edit and download for your business.

Health & Safety Documents

Recent posts like this...

What Is CHAS Accreditation And When Do You Need It? image

What Is CHAS Accreditation And When Do You Need It?

CHAS is a health and safety accreditation scheme, primarily for the construction industry and often acts as a type of pre-qualification during the tender process. But, what exactly is CHAS accreditation, when do you need it, how much does it cost, and is it worth it?

Read Post
The Small Contractors Guide To SSIP Application And Approval image

The Small Contractors Guide To SSIP Application And Approval

SSIP accreditation is a big deal, especially for contractors. But who should you apply with - CHAS, SafeContractor, etc? And how do you get approved? Only 20% of businesses pass on the first attempt - follow this guide to prepare, and stand a much better chance of success.

Read Post
What Is A DSE Assessment? image

What Is A DSE Assessment?

A DSE assessment is a type of risk assessment specific to the use of computers, laptops, tablets and other display screens at work. A DSE assessment is a legal requirement for most workplaces. In this blog post, we'll look at what DSE is and how to assess it.

Read Post

Spend less time on paperwork.
Start with the free plan today.