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Assessing Risk

This post ‘Assessing Risk’ or ‘Risk Assessment’ is extracted from Module 2 – Assessing Risks of IOSH Managing Safely course. The article gives you summarized knowledge of the risk assessment with steps, procedure and examples.

Key learning points of Assessing Risk are:

  • Definitions of the terms ‘hazard’, ‘hazardous event’ and ‘risk’
  • Definition of the term ‘risk assessment’
  • Definition of the terms ‘likelihood’ and ‘consequence’
  • Risk assessment process and risk rating systems
  • The benefits of carrying out risk assessment

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IOSH Managing Safely Exam Questions

IOSH Managing Safely Training Notes


What is Hazard?

A hazard is the potential of a substance, activity or process to cause harms e.g. electricity, chemicals, working from a ladder and the use of machinery.

As per OSH: “Anything that has the potential to cause harm.

As per HSG65: “This is anything with the potential to cause harm, damage, production losses or increased liability.


What is Hazardous event?

This occurs when someone or something interacts with the hazard and harm results.

EXAMPLES- Release of gas, fire, loss of buoyancy.


What is a Risk?

The likelihood that a hazards will cause harm in combination with severity of injury, damage or loss that might foreseeably occur.

Examples of risk at workplace:

A wet floor is a hazard. The risk is how likely it is that someone will slip on the floor, and how severe is their injury going to be.

A damaged ladder is a hazard. The risk is how likely it is that someone will use it and how severe is their injury going to be if a fall should occur.


What is a Risk Assessment?

It is a formalized process of identifying hazards, evaluating risk and then either eliminating or controlling that risk to an acceptable level.

The main objective of a risk assessment is the prevention of accidents and ill-health.

Risk assessment example:

Now let’s do a simple example- Identify the hazards that are present in the workplace or in the room that you are now and write it down.

Hazards types can be of:

  • Physical – such as heat, lighting, noise, vibration, pressure etc.
  • Chemical – Any acids and alkalis, metals, gases etc.
  • Biological – these may be animal borne such as anthrax, rabies
  • Ergonomical – poor layout of workstation
  • Psychological – Stress, unsocial work hours, lone working

Risk Assessment Steps

Risk assessment can be described as a five steps process:

  1. Identify the hazards
  2. Identify the people who might be harmed and how
  3. Evaluate the risk and decide on precautions
  4. Record the significant findings and implement them
  5. Review and update as necessary.
5 Steps Of Risk Assessment

5 Steps Of Risk Assessment

Identifying Hazards

The first step in the risk assessment process is to identify all the significant hazards associated with the work. Hazards are the things with the potential to cause harm. It is important to identify both the safety hazards that might give rise to immediate physical injury and the health hazards that might cause disease or ill-health. This hazard identification might be done by task analysis, reference to guidance or manufactures information or by inspection of the workplace.

Identifying the people at risk

When identifying people at risk, think not only of those carrying out particular activities, but also of those who may be affected by those activities. Individuals do not need to be named; rather general groups or populations identified. Some of the examples of people at risk are:-

  • Workers / Operators
  • Maintenance Staff
  • Cleaners
  • Contractors
  • Visitors
  • Members of the public

Evaluating the risk and decide on precautions

Having identified a particular hazards and the people who might be harmed by it the next step in the risk assessment process is to answer a simple question; Is the level of risk generated by the hazard acceptable or does it need to be reduced?

The question may be simple, but the answer can at times be complex.

Risk is a combination of the likelihood that a hazard will cause harm in combination with the foreseeable severity of injury should harm occur. Risk can be qualitatively described using words such as “Very High”, “High”, “Medium”, ”Low”.

What is Likelihood?

Likelihood is A qualitative description of probability or frequency.

An alternative approach that is commonly adopted is to break risk down into its two component parts and define each separately:

Risk = Likelihood x Severity

Risk = Likelihood x Severity

Then by simple substation of word for a score it is possible to calculate a risk rating for a particular hazard.

For Example

Likelihood Severity
1 = extremely Unlikely 1 = very minor injury
2 = Unlikely 2 = First aid injury
3 = Possible 3 = Lost time injury
4 = Likely 4 = Hospital treatment
5 = Very probable 5 = Disabling Injury
Risk Severity Matrix

Risk Severity Matrix

Once we get the risk rating we can decide on what actions to be taken. Below is an example.

Risk Rating Action and Timescale
15 and above Unacceptable. Work may not start. Additional controls must be introduced to reduce below 9.
9 to 14 Tolerable. Additional controls must be introduced as soon as possible and no later than 24 hours after assessment.
5 to 8 Tolerable. Must be reduced to below 5 within one week.
4 or below Acceptable. If simple action can reduce further then must be done within one week.

Based on the same principle, we can use a five-point scale to estimate likelihood and consequence (severity), with five descriptions for likelihood and five for consequence. 

Likelihood could be ranked as:

  1. Very unlikely -There is 1 in a million chance of the hazardous event happening.
  2. Unlikely – There is 1 in 100,000 chance of the hazardous event happening.
  3. Fairly likely – There is 1 in 10,000 chance of the hazardous event happening.
  4. Likely – There is 1 in 1,000 chance of the hazardous event happening.
  5. Very likely – There is 1 in 100 chance of the hazardous event happening.

Consequence would be ranked as:

  1. Insignificant -No injury.
  2. Minor – injuries needing first aid.
  3. Moderate -Up to three days’ absence.
  4. Major -More than three days’ absence.
  5. Catastrophic -Death.


Record Significant Findings

The significant findings of risk assessment should be recorded to provide a statement of the hazards in the workplace, the extend of the risks that they present and the action taken to control those risks.

There are no standard format for risk assessment. So different organisations can adopt a format that is most appropriate to their circumstances.

Typical content would include:

  • Identification of the activity / area assessed and of the significant hazards
  • Identification of groups at risk and those especially at risk
  • Evaluation of the risks and the adequacy of existing control measures
  • Action plans for implementing further precautions needed
  • Date of assessment and name of the competent person carrying out the assessment
  • Review date.


Risk assessment review

There are a number of situations that might trigger a review of a risk assessment.

  • Process- the way in which the job is done
  • Substance- change of material
  • Equipment- change of equipment
  • Workplace environment- change of the workplace
  • Personnel- change in people
  • Legal standards- change in legal standard
  • Accident
  • Near miss
  • Ill health

It is also a good practice to review risk assessment on a regular basis. An annual review of the risk assessment is a common practice in many workplace.

A risk assessment should be suitable and sufficient. In other words it should be good enough to fulfill legal requirements and prevent foreseeable injuries and ill health from happening.



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