Legionnaires Disease | FAQ
What precautions should be taken in working on cooling towers?
Experts recommend wearing a high-efficiency particulate air (HEPA) protective mask while cleaning cooling towers or collecting samples from them (unless the tower fans are shut off), especially if legionellae contamination is suspected or hyperchlorination is in process. Full masks allow less leakage and thus filter more than half masks. A good fit is critical with any mask. Be aware, however, that HEPA filters will not block all bacteria. Gloves, goggles, and other body coverings have also been suggested for cooling tower work.