Working hours schemes offshore are characterised by intense and lengthy periods of work, and they differ significantly from normal working hours schemes on land.
The HSE regulations stipulate special requirements for working hours schemes offshore. Work offshore is characterised by lengthy and intensive periods of work and by a relatively large share of the hours worked taking place on night shift. Not uncommonly there will also be overtime, and the stays offshore sometimes get extended.
Little is known about the specific health consequences of working offshore. However, a general insight into shift arrangements will provide a basis for further studies of the offshore schemes. In this respect, people are working to set up research that might give a more exact understanding of how the working hours schemes used in the petroleum activities might affect people’s health and ability to work, in the longer term.
In principle, work on the facilities should be planned so that as much as possible of the work is done during the daytime, and so that the employees are ensured the necessary rest and restitution.
The main working hours schemes for petroleum activities offshore
(Source: Trends in Risk Levels 2005/2006)
- Permanent day shift (about 43 per cent)
- Permanent night shift (2.4 per cent)
- Whole shift– nights for two weeks, days for two weeks on alternate tours (15.5 per cent)
- Swing shift– seven nights, then seven days (12.5 per cent)
- Swing shift– seven days, then seven nights (5.1 per cent)
- Varying schemes (21.6 per cent)
Working hours at the land facilities
For major projects at the land facilities, schemes with more concentrated working hours are being used to an increasing degree. There has been a particular focus on the so-called commuting schemes used for major projects. A commuting scheme may mean that the person works up to 12 hours every day for 14 consecutive days, followed by three weeks off. The PSA has challenged the industry and the relevant parties on whether the schemes that are being set up are appropriate from a health and safety point of view. Compared to offshore, the framework conditions are different on land.
Shift arrangements and night work – importance for health and safety
The PSA’s own statistics on serious personal injuries during the years 2001-2006 show clearly that the serious personal injury rate is higher for night-time than for daytime work – when the level of activity is taken into account.
Several studies from non-petroleum industries have also demonstrated that the risk of incidents increases for night work. Many laboratory studies have shown that tiredness and a disturbed diurnal rhythm reduce a person’s alertness, judgment and ability to react. Switching between night and day causes sleep problems and diurnal disturbances that affect alertness and mental performance:
- Experimental studies show that both night work and a lack of sleep can reduce a person’s reading of a situation and reaction time similar to the effect of a blood alcohol percentage between 0.05 – 0.1.
- Results from other industries show a clear connection between night/shift work and several serious diseases. For instance: the risk of cardiovascular disease is 30-60 per cent higher with night-time than with daytime work. There is a similar risk increase for breast cancer.
- There is also a strong combined effect with shift work and lifestyle factors such as smoking, overweight, too little physical activity and serious disease. This means, for example, that the risk of heart disease for a day worker is about 50-60 per cent higher if he/she smokes, while smoking in combination with shift work gives an increase of nearly 100 per cent compared to a non-smoker. Studies have also shown that shift workers generally have a less healthy lifestyle than others.