According to the HSE, some 3.5 million people are employed as shift-workers in the UK in a wide variety of industries.1 Poorly-designed shift-working arrangements and long working hours, with inadequate rest and recovery periods, can result in fatigue, accidents, injuries, and ill health, so Richard Byrne provides some practical pointers for both employers and employees to help them avoid these problems.
These days many businesses take advantage of the fact that there are 24 hours in the day, and who can blame them? Whether it is for increased plant and equipment usage, to get one over on the competition by being able to respond to customer demands whenever they arise, or simply to take advantage of the relatively quiet motorway network at night — working outside the ‘normal’ hours pays dividends for many employers. And it’s big business, too; people working between the hours of 5pm and 9am add around £180 billion to the economy.2
There are also advantages for employees. Typically, those who work shifts receive an allowance or premium as compensation for working ‘unsociable’ hours. More than 3.5 million people are employed on shift work across all sorts of industries, from those more traditionally associated with it, like health care and the emergency services, manufacturing and transport, to newer areas, like retailing.1
On the face of it then, everyone wins — or do they? Links between shift-working and the development of breast cancer have been identified (see p46), which are described as ‘appreciable but not definitive’,3 and it has also been found to present an increased risk of premature birth.4 These are concerning enough, but when the effects that working shifts play on our ‘body clock’ are taken into account, the toll on our health, as well as our personal life and habits, starts to grow.
Man has evolved over time to be most active during the hours of daylight, and to sleep when it is dark. Changes in the business environment and the advent of shift work have therefore made us go against our natural tendencies.5 The earth spins on its axis once every 24 hours, so we are naturally exposed to highly-regular patterns in terms of things like light and temperature. These patterns are known as the body’s circadian rhythm (‘circadian’ being made up of two Latin words meaning ‘about a day’).
It is widely accepted that the body clock exists, and fascinating studies in the 1960s demonstrated this concept. They showed that despite being kept in isolated conditions for long periods of time, with no external time cues, on average participants continued to wake up and go to sleep regularly. Interestingly, they did so at just over 24-hour periods, hence ‘about a day’.
Bring on the night
Having established that our bodies are happy to be awake during the day and sleep at night, it is unsurprising that some of the biggest occupational health and safety disasters in history have occurred at night, when our bodies want to sleep. For example, the partial core melt-down at the USA’s Three-Mile-Island nuclear power-generation plant in 1979 occurred at around 4am, and the nuclear-reactor explosion at Chernobyl in 1986 occurred at about 1.20am. Chances are, firms that operate a ’24/7′ shift system will also experience an increase in incidents between the hours of 6pm and 8am, with a peak in the middle of the night.
In addition to primary health and safety legislation, the Working Time Regulations (WTR) cover shift work and organisations’ approaches to it. The WTR define night work as that carried out between the hours of 11pm and 6am, unless another seven-hour period has been agreed. (Note that shift work is not just night work, and is generally taken to include working outside of ‘standard’ working hours, 7am — 7pm.)6
To be classed as a night-worker, the individual must work at least three hours of their shift between these times. Special provisions are made by the WTR for night-workers — for example, employers must ensure their health is ‘up to the job’ by providing a free health assessment to help determine their ongoing suitability for such work.
In dreams
From a safety professional’s point of view, the real issue is the effects associated with shift-workers’ sleep disturbance. This problem is not easily overcome. The individual is trying to sleep when the rest of the world is not, and their own body doesn’t want them to. For example, urine output is at its highest during the day, so, if you have worked the night shift, you are likely to wake up frequently to go to the toilet. Daytime sleep also tends to be lighter, of short duration, and more easily disturbed.1
All of this can add up to create a phenomenon known as ‘sleep debt’, or fatigue. This is defined as reduced performance, either mental or physical, brought on by prolonged exertion, sleep deprivation, or disturbances to the body clock.1 In the workplace, therefore, it is obviously a real problem in terms of both performance and safety, as decision-making, reaction time, and ability can all be impaired.
Back in the old routine
Any risk assessment on shift-working should focus heavily on the shift patterns themselves, as these affect the body clock through people’s behaviour. There is a number of different shift patterns companies make use of — from permanent shifts to more complex ones, like advancing and delaying patterns. The fundamental aim in developing a shift pattern should be to devise one that not only fits the business’s need but also reduces the impact on workers’ health, either through maximising the time they have to adjust to it, or minimising the disruption caused to their body clocks.
As anyone who has suffered with jet lag will know, it doesn’t normally kick in until a few days after arriving in a new time zone. Working shifts upsets the body clock just like travelling across time zones, so it is generally accepted that rapid rotating-shift systems are better than slower ones, and that advancing (also known as forward) rotating systems — i.e. morning, afternoon, night — are preferable to delaying ones — night, afternoon, morning.6
It is really important that workers get adequate rest days — again, the Working Time Regulations help here, as they specify certain requirements. As a general rule of thumb, if you employ a rotating shift system then the day following a night shift should be a day off and, wherever possible, people on such shifts should only be asked to work a maximum of two consecutive nights.
However, rotation will not suit everyone; some people prefer to work permanent nights, particularly as these shifts generally attract a pay premium. This is fine providing they choose to work this shift themselves and it is not forced upon them! Some people also like their shift patterns to be as regular and simple as possible, to minimise disturbance to their family/private life.
The right stuff
As already discussed, one of the key things with shift work is the effect on the body, so it is imperative that those working shifts are in good enough health to cope.
According to the Department for Business Enterprise and Regulatory Reform,7 a health assessment for a shift-worker should determine if the person has ever suffered from:
The catch-all ‘any other health factors that may affect your fitness at work’ is also included, and, of course, once they are doing shifts, the workers’ suitability should be regularly reviewed to determine any changes in their health status — for example, if a female shift-worker becomes pregnant.
This assessment is fairly quick and straightforward and can be done in the form of a paper-based survey, which can be easily reviewed by the company ‘in house’, or by external health professionals, should they be required to determine the need for and/or carry out more detailed health assessments.
The individual workers themselves can also do much to mitigate the adverse effects of shift work, and the employer should include such considerations in the risk assessment. Following are some examples of basic advice that can be offered to those working shifts:
Conclusion
In these days of the global economy (parlous as it may be at the moment) the need for 24/7 production will not go away, so shift work will continue to be required. Safety professionals can help reduce the adverse effects associated with it and thus facilitate the growth of their organisation’s business and competitiveness while continuing to safeguard the health and well-being of its employees.
References
1 www.hse.gov.uk/humanfactors/shiftwork
2 www.personneltoday.com/articles/ 2007/05/09/40518/nearly-one-third-of-uk-employees-work-non-standard-hours-research.html
3 HSE (2003): Shift work and breast cancer: A critical review of the epidemiological evidence, HSE Books
4 http://news.bbc.co.uk/go/em/fr/-/1/hi/health/4510804.stm
5 Folkard, S (1996): ‘Body rhythms and shift work’, in Warr, P (ed): Psychology at Work, pp39-77
6 HSE (2006): Managing shift work: health and safety guidance (HSG256), HSE Books
7 www.berr.gov.uk/employment/ employment-legislation/employment-guidance/ page28979.html
Richard Byrne is a chartered member of IOSH.
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