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Inclusion of chronic harm in risk assessments: New consequence scale available

2021-05-03 09:41 | Anonymous

Successful implementation of Health and Safety (H&S) systems requires an effective mechanism to assess risk. Existing methods focus primarily on measuring the safety aspect. The health component, i.e., chronic harm, is more difficult to assess. Partly this is due to both consequences and the likelihood being indeterminate. There is a need for better representation for chronic health issues. This paper shows how this may be achieved.

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The idea was developed at the University of Canterbury by Dr Zuzhen (Sean) Ji, Dr Dirk Pons (CPEng, FEngNZ), and Dr John Pearse. 

'We approached this from a different direction, by adopting a public health perspective of quality of life from the World Health Organisation (WHO) disability index (WHODAS). The WHODAS is a simple questionnaire that gets people to rate how their future quality of life, e.g. in retirement, might be adversely affected by hearing loss and other chronic conditions.

'We have then changed the risk assessment process to accommodate this, by creating two consequence scales. One is for safety (e.g. immediate accident outcomes), and the other is for health (e.g. chronic or future harm outcomes). We harmonised the scales, hence that word in the title. As a result, the new risk assessment can accommodate both types of occupational harm.

'A visual summary follows. Note the two scales below for consequence. You will note that the consequence values range from [2...500] - this is key. Also we found inconsistencies in the commonly used likelihood scale, and now propose that [0.1, 1, 2, 4, 6, 10] is better. 


Figure: Risk matrix for combined safety and accident scales.

'We also address the question of RISK APPETITE, which is the organisational response to hazards. In practical terms, these are represented by the colours [green, yellow, red, purple, grey] in the risk matrix. We propose a specific allocation as shown above. We recommend that consistent scales and colours be used within any one organisation. This is necessary so that risks can be compared.

'We also recommend the following organisational actions for the risk appetite colours.

DQL score

(C x L)

Severity of harm (Color in risk matrix, see Figure 8)

Description of treatment


Authority for continued operation


DQL> 1000



Immediate intermission must be undertaken. Ensure preventions and recoveries are adequate and can manage the risk in the future operations.

Board members

CEO must report and advise solutions to Board members under urgency.

120 < DQL < 1000


Unacceptable risk.

Cease operations immediately until risk has been minimized. Ensure preventions and recoveries are sufficient and it is possible to manage the risk in the future operations.

Board, and CEO

CEO need to report and advice solutions to Board as soon as practicable.

60 <


< 120


Urgent treatment.

Urgent treatment required. Operations proceed with caution and ongoing monitoring of risk

Technical manager

Technical manager to advise CEO as soon as possible, and report regularly on status of the risk and its treatment.

10 <


< 60


Consider treatment.

Implement treatment in a reasonable time period. Continue the operations with caution. Monitor the risk in case it becomes worse.

Team leader

Team leader to report regularly to Technical manager on the risk and the progress of the treatment plan.

0 <


< 10


Not necessary to have special treatment.

No special treatment required. Continue the operations with ongoing monitoring of the efficacy of existing preventions.


Staff to report regularly to Team leader on the state of this risk.


'When we applied this new method to a case study (bakery operations),  merely including the chronic harm scale appeared to be sufficient to elicit a more detailed consideration of hazards for chronic harm. This suggests that people are not insensitive to chronic harm hazards, but benefit from having a framework in which to communicate them.'

What has been achieved? The result is a comprehensive risk assessment method with consideration of safety accidents and chronic health issues. This has the potential to benefit industry by making chronic harm more visible and hence more preventable.

Implications for practitioners: Practitioners will be familiar with hearing loss and other long-term health outcomes of their place of work. In applying the method proposed here, practitioners are recommended to give regard to any widely accepted thresholds and heuristics for safe levels and durations for the various occupational hazards. This type of information is commonly available from the national H&S regulator or safety institutions.

Download the paper:

The paper is *open access* which means it is free to download, copy, use, and adapt.

This  paper has been made open access by funding provided by the University of Canterbury, in the interests of disseminating research findings into our communities. 

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