A-dust
In the Technical Rules for Hazardous Substances ( TRGS ), A-dust is the mass fraction of the dust, the particles of which are so small that they are absorbed through the airways when inhaled and can penetrate into the alveoli and bronchioles of the lungs ( alveoli ). The terms respirable fraction , A-fraction , respirable fraction or respirable dust fraction are also used synonymously instead of A-dust . As a short form, A-dust is also u. a. used by government agencies such as BAuA , the statutory accident insurance DGUV , occupational safety institutions such as IFA and professional associations such as BGBau . The A-dust is essentially identical to the previous term fine dust . In Switzerland, the term respirable dust is used instead of A-dust .
Measurement of A-dust at the workplace
The measurement and assessment of a possible dust exposure at a workplace, including the A dust fraction, is regulated by TRGS 402. First of all, it is considered whether inhalation exposure can occur, ie whether hazardous substances such as dusts are present in the breathing area of the employee and in what period they can occur. If it is not possible to safely avoid hazardous dusts in the breathing air, the dust exposure must be determined using suitable measuring devices which, among other things, must comply with the requirements of the EN 481 and EN 482 standards. The respirable dust is determined based on the EN 481 standard as the respirable fraction , which should come as close as possible to the fraction that "gets into the various areas of the respiratory tract under average conditions".
Limit values
The individual occupational exposure limit values (shift average for a daily working time of 8 hours and a 5-day week over the working life) for substances or substances are regulated in TRGS 900. The limit values specified there reflect the current state of knowledge about their hazard potential. Unless explicitly stated otherwise for a substance or substance, the general dust limit value for granular bio-persistent dusts specified there has been in effect since February 14, 2014 . For the A dust fraction this is 0.5 ppm (based on an average density of 2.5 g / cm³, this corresponds to a concentration of 1.25 mg / m 3 ). It is permissible that the exposure peak during a shift for a period of up to 15 minutes is exceeded by up to two times (excursion factor of 2) as long as the shift average complies with the limit value.
literature
- DIN EN 481: 1993-09 workplace atmosphere; Determination of the particle size distribution for the measurement of airborne particles (German version EN 481: 1993), Beuth Verlag, Berlin.
- DIN EN 482: 2012-06 Exposure at work - General requirements for the performance of methods for measuring chemical agents; German version EN 482: 2012, Beuth Verlag, Berlin.
Individual evidence
- ↑ a b German statutory accident insurance: Definition of A dust
- ↑ a b c Federal Institute for Occupational Safety and Health: TRGS 900 Occupational Exposure Limits (PDF)
- ↑ a b c Technical rule for hazardous substances 559 Mineral dust. (pdf) Federal Institute for Occupational Safety and Health, March 3, 2015, p. 2 , accessed on April 10, 2015 .
- ↑ a b Justification for the general dust limit value (2014/2001) in TRGS 900. (pdf) Federal Institute for Occupational Safety and Health, November 2013, pp. 4.12-22 , accessed on April 10, 2015 .
- ↑ a b Federal Institute for Occupational Safety and Health: TRGS 402 Determination and assessment of the risks involved in activities involving hazardous substances: Inhalation exposure (PDF)
- ↑ Search results for inhalable dust fraction on the IFA website
- ↑ a b Dr. med. Sascha Plackov: Competence center: Training for entrepreneurs - Topic: Beware of dust! (PDF) BG Bau, January 2010, accessed on July 24, 2019 .
- ↑ Limit values at the workplace: MAK / BAT values (explanations), physical effects, physical stress. Retrieved July 25, 2019 .
- ↑ a b German statutory accident insurance: limit values for dust