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Risk Assessment

What is a risk assessment?

Risk assessment is the process where you:

  • Identify hazards.
  • Analyze or evaluate the risk associated with that hazard.
  • Determine appropriate ways to eliminate or control the hazard.

In practical terms, a risk assessment is a thorough look at your workplace to identify those things, situations, processes, etc that may cause harm, particularly to people. After identification is made, you evaluate how likely and severe the risk is, and then decide what measures should be in place to effectively prevent or control the harm from happening.

For definitions and more information about what hazards and risks are, please see the OSH Answers document Hazard and Risk.

Why is risk assessment important?

Risk assessments are very important as they form an integral part of a good occupational health and safety management plan. They help to:

  • Create awareness of hazards and risks.
  • Identify who may be at risk (employees, cleaners, visitors, contractors, the public, etc).
  • Determine if existing control measures are adequate or if more should be done.
  • Prevent injuries or illnesses when done at the design or planning stage.
  • Prioritize hazards and control measures.

What is the goal of risk assessment?

The aim of the risk assessment process is to remove a hazard or reduce the level of its risk by adding precautions or control measures, as necessary. By doing so, you have created a safer and healthier workplace.

How do you do a risk assessment?

Assessments should be done by a competent team of individuals who have a good working knowledge of the workplace. Staff should be involved always include supervisors and workers who work with the process under review as they are the most familiar with the operation.

In general, to do an assessment, you should:

  • Identify hazards.
  • Evaluate the likelihood of an injury or illness occurring, and its severity.
  • Consider normal operational situations as well as non-standard events such as shutdowns, power outages, emergencies, etc.
  • Review all available health and safety information about the hazard such as MSDSs, manufacturers literature, information from reputable organizations, results of testing, etc.
  • Identify actions necessary to eliminate or control the risk.
  • Monitor and evaluate to confirm the risk is controlled.
  • Keep any documentation or records that may be necessary. Documentation may include detailing the process used to assess the risk, outlining any evaluations, or detailing how conclusions were made.

When doing an assessment, you must take into account:

  • The methods and procedures used in the processing, use, handling or storage of the substance, etc.
  • The actual and the potential exposure of workers.
  • The measures and procedures necessary to control such exposure by means of engineering controls, work practices, and hygiene practices and facilities.

By determining the level of risk associated with the hazard, the employer and the joint health and safety committee can decide whether a control program is required.

It is important to remember that the assessment must take into account not only the current state of the workplace but any potential situations as well.

See a sample risk assessment form.

How are the hazards identified?

Overall, the goal is to find and record possible hazards that may be present in your workplace. As mentioned, it may help to work as a team and include both people familiar with the work area, as well as people who are not – this way you have both the "experienced" and "fresh" eye to conduct the inspection.

To be sure that all hazards are found:

  • Look at all aspects of the work.
  • Include non-routine activities such as maintenance, repair, or cleaning.
  • Look at accident / incident / near-miss records.
  • Include people who work "off site" either at home, on other job sites, drivers, teleworkers, with clients, etc.
  • Look at the way the work is organised or "done" (include experience and age of people doing the work, systems being used, etc).
  • Look at foreseeable unusual conditions (for example: possible impact on hazard control procedures that may be unavailable in an emergency situation, power outage, etc.).
  • Examine risks to visitors or the public.
  • Include an assessment of groups that may have a different level of risk such as young or inexperienced workers, persons with disabilities, or new or expectant mothers.

It may help to create a chart or table such as the following:

Table 1
Example of Risk Assessment
Task Hazard Risk Priority Control
Delivering product to customers Drivers work alone May be unable to call for help if needed    
Drivers have to occasionally work long hours Fatigue, short rest time between shifts    
Drivers are often in very congested traffic Increased chance of collision    
Longer working hours    
Drivers have to lift boxes when delivering product Injury to back from lifting, reaching, carrying, etc.    

How do you know if the hazard is serious (poses a risk)?

Each hazard should be studied to determine its' level of risk. To research the hazard, you can look at:

  • Product information / manufacturer documentation.
  • Past experience (workers, etc).
  • Legislated requirements and/or applicable standards.
  • Industry codes of practice / best practices.
  • Health and safety material about the hazard such as material safety data sheets (MSDSs), or other manufacturer information.
  • Information from reputable organizations.
  • Results of testing (atmospheric, air sampling of workplace, biological, etc).
  • The expertise of a occupational health and safety professional.
  • Information about previous injuries, illnesses, "near misses", accident reports, etc.

Remember to include factors that contribute to the level of risk such as:

  • The work environment (layout, condition, etc.).
  • The capability, skill, experience of workers who do the work.
  • The systems of work being used.
  • The range of foreseeable conditions.

How do you rank or prioritize the risks?

Ranking or prioritizing hazards is one way to help determine which hazard is the most serious and thus which hazard to control first. Priority is usually established by taking into account the employee exposure and the potential for accident, injury or illness. By assigning a priority to the hazards, you are creating a ranking or an action list. The following factors play an important role:

  • Percentage of workforce exposed.
  • Frequency of exposure.
  • Degree of harm likely to result from the exposure.
  • Probability of occurrence.

There is no one simple or single way to determine the level of risk. Ranking hazards requires the knowledge of the workplace activities, urgency of situations, and most importantly, objective judgement.

What options exist to rank or prioritize risks?

One option is to use a table similar to the following as established by the British Standards Organization:

Table 2
Risk Assessment by the British Standards Organization
Likelihood of Harm Severity of Harm
Slight Harm Moderate Harm Extreme Harm
Very unlikely Very low risk Very low risk High risk
Unlikely Very low risk Medium risk Very high risk
Likely Low risk High risk Very high risk
Very likely Low risk Very high risk Very high risk

Note: These categorizations and the resulting asymmetry of the matrix arise from the examples of harm and likelihood illustrated within the British Standard. Organizations should adjust the design and size of the matrix to suit their needs.

Definitions for Likelihood of Harm

Very Likely – Typically experienced at least once every six months by an individual.

Likely – Typically experienced once every five years by an individual.

Unlikely – Typically experienced once during the working lifetime of an individual.

Very unlikely – Less than 1% chance of being experienced by an individual during their working lifetime.

Definitions for Severity of Harm

Potential severity of harm – When establishing potential severity of harm, information about the relevant work activity should be considered, together with:

a) Part(s) of the body likely to be affected.

b) Nature of the harm, ranging from slight to extremely harmful:

1. slightly harmful (e.g., superficial injuries; minor cuts and bruises; eye irritation from dust; nuisance and irritation; ill-health leading to temporary discomfort)

2. harmful (e.g., lacerations; burns; concussion; serious sprains; minor fractures; deafness; dermatitis; asthma; work-related upper limb disorders; ill-health)

3. extremely harmful (e.g., amputations; major fractures; poisonings; multiple injuries; fatal injuries; occupational cancer; other severely life shortening diseases; acute fatal diseases)

Definition for Risk Level

Tolerability Guidance on necessary action and timescale :

Very low – These risks are considered acceptable. No further action is necessary other than to ensure that the controls are maintained.

Low – No additional controls are required unless they can be implemented at very low cost (in terms of time, money, and effort). Actions to further reduce these risks are assigned low priority. Arrangements should be made to ensure that the controls are maintained.

Medium – Consideration should be as to whether the risks can be lowered, where applicable, to a tolerable level and preferably to an acceptable level, but the costs of additional risk reduction measures should be taken into account. The risk reduction measures should be implemented within a defined time period. Arrangements should be made to ensure that controls are maintained, particularly if the risk levels area associated with harmful consequences.

High – Substantial efforts should be made to reduce the risk. Risk reduction measures should be implemented urgently within a defined time period and it might be necessary to consider suspending or restricting the activity, or to apply interim risk control measures, until this has been completed. Considerable resources might have to be allocated to additional control measures. Arrangements should be made to ensure that controls are maintained, particularly if the risk levels are associated with extremely harmful consequences and very harmful consequences.

Very high – These risk are unacceptable. Substantial improvements in risk control measures are necessary so that the risk is reduced to a tolerable or acceptable level. The work activity should be halted until risk controls are implemented that reduces the risk so that it is no longer very high. If it is not possible to reduce the risk, the work should remain prohibited.

Note: Where the risk is associated with extremely harmful consequences, further assessment is necessary to increase confidence in the likelihood of harm.

Adapted From:

Occupational health and safety management systems - Guide: British Standard, BS 8800, BSI 2004; and Managing Safety the Systems Way: Implementing OHSAS 18001 using BS 8800, BSI 2004.

Other options include using tables such as Table 3 below.

Table 3
Hazard Control Strategy: A Sample Worksheet
Hazard % Employees Affected Frequency of Occurrence Hazard Potential Priority Priority Rank
Ergonomics 60 H H 60-HH 1 (?)
Back pain 80 H H 80-HH 2 (?)
Noise 30 L H 30-LH 3
Heat 50 L L 50-LL 5
Lasers 2 L H 2-HL 4

H = High, L = Low

* From: Health and Safety Committees Reference Guide, CCOHS

Or, Table 4, where 1 = extremely important to do something as soon as possible, 6 = hazard may not need immediate attention.

Table 4
Example of Hazard Priority Setting
  Very likely - could happen at any time Likely - could happen sometime Unlikely - could happen but very rarely Very unlikely - could happen but probably never will>
Kill or cause permanent disability or ill health 1 1 2 3
Long term illness or serious injury 1 2 3 4
Medical attention and several days off work 2 3 4 5
First aid needed 3 4 5 6

From: Hazpak: Making your workplace safer. A practical guide to basic risk management by WorkCover New South Wales, Australia.[n.d.].

What are methods of hazard control?

Once you have established your top priorities, you can decide on ways to control each specific hazard. Hazard control methods are often grouped into the following categories:

  • Elimination (including substitution).
  • Engineering controls.
  • Administrative controls.
  • Personal protective equipment.

For more details, please see the OSH Answers Hazard Control.

Why is it important to review and monitor your assessment?

It is important to know if your risk assessment was complete and accurate. It is also essential to be sure that changes in the workplace have not introduced new hazards or changed hazards that were once ranked as lower priority to a higher priority.

It is good practice to review your assessment on a regular basis to be sure that nothing has changed and that your control methods are effective. Triggers for a review can also include:

  • The start of a new project.
  • A change in the work process or flow.
  • A change or addition to tools, equipment, machinery (including locations or the way they are used).
  • New employees.
  • Moving to a new building or work area.
  • Introduction of new chemicals or substances.
  • When new information becomes available about a current product.

What documentation should be done for a risk assessment?

Keeping records of your assessment and any control actions taken is very important. You may be required to store assessments for a specific number of years. Check for local requirements in your jurisdiction.

The level of documentation or record keeping will depend on:

  • Level of risk involved.
  • Legislated requirements.
  • Requirements of any management systems that may be in place.

Your records should show that you:

  • Conducted a good hazard review.
  • Determined the risks of those hazards.
  • Implemented control measures suitable for the risk.
  • Reviewed and monitored all hazards in the workplace.

Document last updated on June 19, 2006
Document confirmed current on February 2, 2009


Although every effort is made to ensure the accuracy, currency and completeness of the information, CCOHS does not guarantee, warrant, represent or undertake that the information provided is correct, accurate or current. CCOHS is not liable for any loss, claim, or demand arising directly or indirectly from any use or reliance upon the information.