The Safety Impacts of Night & Shift Work

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n the past, shift work was traditionally associated with industries where 24-hour operation was either necessary (e.g. essential public services like hospitals, the police, the fire brigade and utilities) or practical (e.g. transportation, chemical, mining and other process and manufacturing industries). The recent upward trend in the percentage of people employed in shift work reflects an adoption of shift work beyond the traditional sectors. For example supermarkets, petrol stations and call centres now commonly employ shift workers.

This trend has developed because of changes in society, supported by workers who are prepared to do shift work. There may be several reasons for this, such as the recent shift towards a 24-hour society, lack of employment options or a preference for compensatory factors such as flexible working, better pay or time off in lieu.

As shift work may affect the health and safety of your employees and the public, it is important for you to control risks effectively and prevent harm to people, as required by the Occupational Health and Safety Act 85 of 1993. What are the possible effects of night- or shift work?

Studies in the United Kingdom have shown that night- and shift work may cause or contribute to the following effects:

1. Biological Effects: – Cardiovascular disorders – Gastrointestinal disorders – Circadian dysrhythmia 2. Psychosocial Effects: – sleep loss/fatigue – lowered performance – increased accidents – Stress

What does your ‘circadian rhythm’ mean?

The human body follows a daily rhythm, which involves the fluctuation of over 100 body functions, with regular peaks and troughs, in a 24-hour cycle. These daily cycles are called circadian rhythms. The word ‘circadian’ comes from the Latin ‘circa dies’, meaning ‘about a day’.

Circadian rhythms regulate body functions such as temperature, metabolism, digestion, blood pressure, secretion of adrenalin, sleeping and waking. These rhythmical processes form the body’s internal clock and are co-ordinated so as to allow for high activity (peaks) during the day and low activity (troughs) at night. Hence, this is one reason why people often feel most active and alert around 4-6pm, and sleepiest around 4-6am.

Financial Viability:

For shift working to be financially viable, you need to maintain a satisfactory level of productivity and safety. Fatigued shift workers may perform less well than those working standard daytime hours, especially during periods of low alertness. The consequences of this could range from relatively minor events to serious accidents.

Take both ends of this spectrum into account when you are assessing the cost effectiveness of shift working as the social and financial costs of frequent minor events.

The risk of errors, accidents and injuries has been found:

– To be higher on the night shift; – To rise with increasing shift length over eight hours; – To increase over successive shifts, especially if they are night shifts; – To increase when there are not enough breaks.

Rotating shift schedules reduce the number of nights a worker has to work as night work is shared among all workers. However, the constantly changing shift pattern means workers may have difficulty adapting to the rotating schedule.

Duty under law:

The Basic Conditions of Employment Act and the Code of Good Practice on the Arrangement of Working Time lay down the minimum legal requirements on how to manage night- and shift work.

How to effectively manage shift work:

1. Consider the risks of shift work and the benefits of effective management: – What are the undesirable effects of shift work? – Consider the costs and benefits of effective management of shift-working arrangements. 2. Establish systems to manage the risks of shift work: – Seek management commitment to control the risks of shift work. – Identify individuals responsible for shift-working arrangements. – Involve safety representatives and workers. 3. Assess the risks associated with shift work in your workplace: – Consider the risks that workers may be exposed to. – Establish who might be harmed by shift work. – Consult workers and their safety representatives. 4. Take action to reduce these risks: – Assess how severe the risks are and identify where improvements need to be made. – Improve the shift-work schedule. – Improve the workplace environment. – Apply good practice guidelines. 5. Check and review your shift-work arrangements regularly: – Implement a system for early reporting of problems associated with shift work. – Monitor alterations to shift-work schedules and/or work conditions. – Periodically review the effectiveness of your shift working arrangements.


By assessing the risks in regards to night and shift work, good planning and clear communication between all stakeholders, the benefits will include; reducing sickness and absenteeism; decreasing lost-time incidents; reducing the risk of fatigue-related accidents; reducing the likelihood of compensation claims; increasing work efficiency; improving product quality and reducing staff turnover. In LabourNet, we assist companies with Health & Safety management because we believe –

Everyone goes home healthy and safe …And that includes, employees, customers, and the general public.

For more information on Night shifts, please contact the LabourNet Helpdesk at

0861 LABNET (0861 522638).

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