Types of Occupational Exposure Limit

The Occupational Exposure Limit is a concentration level of a gas, vapour, aerosol, fibre or dust in the air in the workplace. The basic principle is that the health of employees as well as that of their offspring must not be impaired. For substances without a safe threshold, no OEL can be determined which provides this level of safety. These are often carcinogenic and mutagenic substances, as well as substances that can cause respiratory allergies. Mutagenic means that the substance can affect DNA.

Public and private

Employers in the first instance, but also employees, are responsible for the safe handling of substances in the workplace. Employers must set their own OELs, to a level at which there can be no damage to employees’ health. These are called private Occupational Exposure Limits and they form the basis for the current legal system. In addition, the Ministry of Social Affairs and Employment has added public, statutory OELs to the system.

The Ministry of Social Affairs and Employment sets public OELs for substances:

for which the European Union requires an OEL. This requirement results from EU directives.
for which there are special reasons for setting public OELs. Here, the criteria “substances without ownership” and “substances with a high risk of damage to health” are used, possibly supplemented by other substances.

There is an up-to-date list of statutory OELs in the Working Conditions Regulation Annex XIII [Arbeidsomstandighedenregeling bijlage XIII]. Annex XIIIA contains OELs for the non-carcinogenic substances and Annex XIIIB contains OELs for the carcinogenic substances.

Carcinogenic and mutagenic substances

As far as possible, Occupational Exposure Limits (OELs) are also established for carcinogenic and mutagenic substances. Mutagenic means that the substance can affect DNA. Some substances have a safe threshold level, which is therefore the OEL of that substance. There are also carcinogenic substances for which it is not possible to determine a safe threshold level. In that case, a risk of cancer cannot be ruled out. Risk levels are used when setting OELs for these substances. For carcinogenic and mutagenic substances without a threshold level, an OEL corresponding to a specific additional occupational risk was chosen. The OEL for carcinogenic and mutagenic substances is preferably set at what is called the target risk level: as low as possible.

Inhalable allergenic substances

Exposure to inhalable allergenic substances can lead to the development of respiratory allergies. No safe OEL can be determined for this group of substances, so risk levels are also used for them. For allergenic substances, this is an additional 1% chance of developing an allergy throughout a person’s entire working life.