What is a threshold limit value?
It is the average concentration of a certain chemical substance in the air. For most substances Sweden and many countries have two values:
- The Threshold limit value that is an average exposure based on a 8h/day, 40h/week work schedule
- The Short-term exposure limit is the peak exposure for only a few minutes/day.
The unit used for measuring the threshold limit value is often milligram/cubic meter (mg/m3). For oil mist and oil smoke, Sweden has set the threshold limit value to 1 mg/m3, which as been valid since 1990. In other countries where there are no restrictions, or the acceptable exposure level is 5mg/m3, Sweden’s threshold limit must be considered as low. Probably one of the lowest in the world
A Review resulted in a new directive
Recently, the Swedish Occupational Health Authority reviewed the hygienic limit values. After having remitted the results to different authorities, a decision was made on August 21, 2018 to implement a new directive named AFS 2018:1. It will replace the previous AFS 2015:7. You will find the directive here, but unfortunately it is only available in Swedish.
In the associated Consequence Report, the health risks connected to high levels of oil mist and oil smoke from metal working fluids are discussed. For example, it is pointed at several ”breakouts” of respiratory health issues, mainly within metal working industry both in Sweden and internationally.
In order to protect workers from these health risks, the Swedish Occupational Health Authority suggests to reduce the recommended target value for the total exposure of metal working fluids during 8 hours to 0,2 mg/m3. If you want to know more, please click on the link here. Unfortunately, this too is only available in Swedish.