Microbiological investigations in textile plants

Status:

completed 12/1999

Aims:

During the processing of natural fibres (plant fibres, animal hairs), impurities adhering to the fibres (moulds, bacteria, endotoxins, i.e. cell wall constituents of gram-negative bacteria) may enter the air breathed by employees, and thus lead to hypersensitization or irritation of the respiratory tracts and the lungs. In accordance with BiostoffV (the German ordinance governing occupational health and safety in relation to activities involving biological agents), employers are obliged to perform a hazard evaluation in cases where employees come into contact with biological agents.

Activities/Methods:

Between 1995 and 1999, the institution for statutory accident insurance and prevention in the textile and clothing industry and the BG Institute for Occupational Safety - BIA together performed microbiological investigations in 35 textile plants of the ambient air at workplaces, in the ventilation and air-conditioning systems, and upon the respective raw materials employed, in order to be able to support their members in hazard evaluation. A range of production processes (spinning mills, fleece production, yarn processing, weaving mills) and different raw materials (natural fibres of plant and animal origin, synthetic fibres, fibre blends) were investigated in the plants. The institution for statutory accident insurance and prevention in the textile and clothing industry recorded the technical data, the details of the production process and raw materials employed, and the condition of the ventilation and air-conditioning systems. At the same time, the BIA measured the concentrations of moulds, bacteria and endotoxins in the ambient air and studied the germ count in the ventilation and air-conditioning systems on the basis of the humidifier water and tape lift samples. The microbiological procedures were employed in accordance with TRBA 430 (technical rules for biological procedures for the measurement of mould concentration in the air at the workplace) or the procedures laid down in the BIA folder (Nos. 9430 and 9450).

Results:

Major variations in germ counts in the ambient air were attributed in certain sectors primarily to differences in the production procedures and the raw materials employed. In companies in which synthetic fibres or fibre blends were processed, the germ count in the workplace atmosphere was often in the same order of magnitude as that in the ambient air. Comparatively low germ counts were also observed where precleaned and dyed wool was used. High concentrations of bacteria and endotoxins were observed in particular during the processing of natural fibres such as cotton, silk or animal hair (depending upon the origin and prior treatment of the materials) or where the ventilation and air-conditioning systems had not been properly maintained. With a few exceptions, the mould fungus levels were in the same order of magnitude as those in the outside air. Tests on the quality of the humidifier water in the ventilation and air-conditioning systems revealed that the organisms present were generally of risk groups 1 and 2, i.e. the germs were of species which either do not provoke illness, or which cause infections for which effective treatment or preventive measures are available. Legionella, for example, was not detected in these studies. Taking the cotton spinning mill as an example, a progressive decrease in the microbial load was demonstrated over the course of the production process, owing to the progressive decontamination of the product. Whereas the processing of synthetic fibres would appear to be safe in terms of biological impact, a range of protective measures are recommended for the processing of natural fibres. Based upon these initial studies, the exposure to germs and endotoxins generally occurring across the sector as a whole and in particular processes is to be measured, and an inventory of exposure data drawn up.

Publications:

Kraus, G.: Luftkeime und Endotoxine in der Textilindustrie. Der Sicherheitsschirm (2000) Nr. 1, S. 24-27

Further informations:

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