Acceptance and tolerance concentrations of carcinogenic substances
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After more than 10 years since the last revision, an amendment to the Ordinance on Hazardous Substances (GefStoffV) [1] is due this year. I have already dealt with this topic in another blog post. Among other things, the focus is on carcinogenic hazardous substances. Here, acceptance and tolerance concentrations are gaining in importance. Today, I would like to discuss what these values are all about.
Acceptance and tolerance risk
If you work with substances that have a carcinogenic effect in your everyday life, the risk of developing cancer in your lifetime increases. This risk is a statistical, measurable quantity. The acceptance and tolerance risk each reflect a certain probability. At a probability of 4:10,000 (this value is to be further reduced to 4:100,000 in the future), one speaks of the acceptance risk. Up to this value, the risk of contracting cancer from daily exposure is low and tolerable. If this value is exceeded up to a probability of 4:1,000, one assumes a medium risk. The probability of 4:1,000 marks the tolerance risk – if exceeded, it is a high risk of contracting cancer. This is not tolerable. Of course, the goal should always be to be in a low or medium risk range when working with carcinogenic hazardous substances. [2]
Acceptance and tolerance concentrations
The risk values just described are substance-independent, statistical values. When working with a carcinogenic substance, however, it is important at which concentration the acceptance or tolerance risk is reached or exceeded. For this reason, substance-specific values are required and determined: the acceptance or tolerance concentration. Here, the concentration of a substance in the air at the workplace is measured. If the substance-specific acceptance concentration is adhered to, the risk of contracting cancer is low. Between the acceptance and tolerance concentrations, the risk is in the medium range, and above that in the high risk range. These values are thus comparable to occupational exposure limits for substances. But since there are hardly any OELs for carcinogenic substances, the acceptance and tolerance concentrations were introduced. The values are listed in TRGS 910 [2] and must be taken into account in the risk assessment.
What to do if the limit is exceeded?
If the tolerance concentration cannot be complied with during an activity with carcinogenic hazardous substances, the competent authority must be informed. The exposure determined must be stated. In addition, a plan of action must be enclosed, showing which undertakings have already been carried out.
Conclusion
If you work with carcinogenic substances in your company, you should pay particular attention in future to whether there are acceptance or tolerance concentrations for the substances used. You should try to stay below the acceptance concentration. You can achieve this by taking suitable measures, such as using an extraction system or a closed system. If you use hazardous substance software, for example our GefStoff-Profi, you will be supported here in that the values can be identified and queried automatically.
[1] Ordinance on Hazardous Substances (GefStoffV), as of 07/2021
[2] Technical Rules for Hazardous Substances, TRGS 910, as of 01.07.2022, BAuA website.