Is it possible that the metalworking fluids in your shop are a breeding pool for Legionella pneumophila?  According to a recent study by HSE, the answer is “highly unlikely.”  In fact, the levels detected in the limited study suggests that levels of Legionella DNA in used MWF samples are comparable to drinking water supplies.  So, there is no need for you to evacuate the factory right now, but there is a significant asterisk to the report.  Risks arising from the association of Legionella with biofilm were not examined in the HSE study.  Read how and why you should manage these risks by properly maintaining your MWF system to keep levels of bacteria to a minimal level and to avoid the likelihood of biofilm formation.  If biofilm is disturbed during deep cleaning work, potential exposure to Legionella needs to be considered in the risk assessment.