Abstract

Traditional degreasing solvents must be replaced with other products due to their flammability and toxicity and the risk of environmental damage.

“Green” degreasers have come onto the market which contain tensioactives and aqueous-phase bacteria, but not solvents. They are primarily used in biological fountains (biofountains) for degreasing parts in industrial environments and in mechanical maintenance. The manufacturers claim that these products contain only group 1 bacteria, which are non-pathogenic for humans.

Researchers at the INRS, in France, have studied the bacterial flora of biofountain degreasing fluids. They found bacterial contamination of biofountain degreasing fluid by infectious risk group 2 strains, which are pathogenic for humans with a low risk of contagion. These studies provide no data on worker respiratory exposure, but reported that workers were not using skin or respiratory protection.

The authors hypothesized that workers could be exposed to biological aerosols (bioaerosols) when cleaning parts. Biofountains are used in Québec workplaces. Université de Montréal and IRSST researchers who have written a monograph on risks associated with bacterial and enzymatic preparations for degreasing and cleaning also observed that blow guns are used to dry parts. They say that this practice could result in respiratory exposure to bioaerosols in workers using biofountains. The current scientific and technical literature provides no metrological data on respiratory exposure to bioaerosols in biofountain users.

This study aims to fill this gap by methodically evaluating two parameters: 1) the nature of bacteria contained in biofountain fluids used in Québec, and 2) respiratory exposure to bioaerosols in workers using biofountains and blow guns for drying.