Emission measurement of airborne endotoxins
Draft VDI guidelines published
The objective of Germany’s Federal Immission Control Act (BImSchG) is to “protect humans, animals and plants, soil, water, the atmosphere as well as cultural and other material goods from harmful environmental effects and to prevent the occurrence of harmful environmental effects”. Plants requiring approval must prevent harmful “environmental effects due to emissions into the air, water and soil, including waste management” and must implement emission-reducing measures.
Bioaerosols and endotoxins can be emitted during the handling and processing of biomass. These include, for example, large animal stables, biomass drying plants, wastewater treatment plants and (bio) waste treatment plants. Work has been carried out for several years on producing VDI Guidelines on recording the emissions of bioaerosols and endotoxins. With these guidelines, results are obtained under standardised conditions, which enable different studies to be compared. The official draft of VDI 4254 Part 2 (April 2020) supplements the existing guidelines to include the recording of endotoxin emissions. Endotoxins are constituents of the cell wall of Gram-negative bacteria, inhalation of increased doses of which can cause health limitations. While many microorganisms in the air are rendered inactivate rapidly, e.g. due to drying stress or sun radiation, some bioaerosol constituents prove to be significantly more resistant under environmental conditions. These also include the bacterial endotoxins. They can therefore be used as a “main parameter or indicator of plant-related emissions of bioaerosols”. bifa worked with others on producing measurement programmes for recording the emissions of airborne endotoxins and for testing the effectiveness of mitigation measures. The several years of work on the guidelines was supported by the practical experience available.