A recent study published by IRSST examined workers’ exposure to microorganisms when using biological degreasing stations. These stations use a degreasing agent containing bacteria that break down fats, oils, and greases by mineralization. According to IRSST, manufacturers of the agents used in biological degreasing stations claim that the microorganisms they contain are harmless because they are classified as Risk Group 1 under the four-group infection risk ranking system used in most countries (information on risk groups is available from the U.S. Department of Health and Human Services). The Public Health Agency of Canada describes Risk Group 1 microorganisms as posing a low risk to the health of individuals and to public health. However, previous research identified a number of Risk Group 2 bacteria such as Pseudomonas aeruginosa and Klebsiella pneumoniae in biological degreasing station solutions. Risk Group 2 bacteria represent moderate risk to the health of individuals and low risk to the community. The purpose of IRSST’s recent study was to assess occupational risk of exposure to these microorganisms through inhalation. IRSST researchers who monitored the fluids in five biological degreasing stations over one year identified 60 bacterial species from both Risk Group 1 and Risk Group 2. The study found that the biological degreasing stations were rapidly colonized by exogenous microorganisms such as Pseudomonas aeruginosa and that the main risk with skin contact is wound infection or accidental ingestion. According to the authors, strict personal hygiene measures—wearing gloves and handwashing, for example—are necessary before and after using biological degreasing stations. The results also showed that workers using these stations have very low exposure to bioaerosols.  Based on these findings, the authors of the study do not recommend respiratory protection during biological degreasing station use. IRSST’s full report is available online.