The Nordic Expert Group recommends down-adjustment of occupational exposure limits for employees working long shifts
Occupational exposure limits (OELs) for chemicals are based on 8 hours of work per day, 5 days per week, day time. However, many people have ”unusual” working hours, i.e. work more than 8 hours per shift, more than 40 hours per week, or at night. The Nordic Expert Group (NEG) has reviewed the scientific support for combined effect of unusual working hours (shift work or extended working hours) and chemical exposure.
For extended workhours, NEG recommends down-adjustment according to Haber’s rule. This means, for example, that the OEL for a 12-hour workday should be two thirds (8 hours / 12 hours) of the regular OEL. No adjustment is applied for ceiling values, short-term exposure limits and limit values based on asphyxiation, irritation or malodour. Upward adjustment of the OEL should not be done even if the work schedule is shorter than 8 hours per day or 40 hours per week.
Some animal and human data suggest more pronounced health effects during night shift exposure to chemicals. However, NEG considered the data insufficient to conclude on recommendations in this case.
Link to the document
Occupational chemical exposures in combination with unusual working hours
Kontakt
Prof. Gunnar Johanson
Chairman of NEGInstitute of Environmental Medicine (IMM), Karolinska Institutet