Disinfectants containing chlorine: an occupational hazard?

The Belgian national guidelines to prevent transmission of Clostridium difficile in hospitals state that it is justified to use a disinfectant containing 1,000 or 5,000 ppm free chlorine to disinfect the rooms of patients with C. difficile–associated disease (CDAD). Concern has risen about the occupational safety of the cleaning employees using the disinfectant at this concentration. We conducted a small test to evaluate the concentration of chlorine in the air while the cleaning employees disinfected a patient’s room according to our standard procedure (furniture, door, bathroom, and floor). The chlorine-containing disinfectant in our hospital is made from 3 tablets of sodium dichloroisocyanurate dihydrate dissolved in 1 L of water to obtain a concentration of 4,500 ppm free chlorine. During the test, the door and windows were closed. Air samples were taken in the neighborhood of the cleaning employees (distance, approximately 1 m) during the decontamination procedure. The samples were analyzed according to method P&CAM 209 in the NIOSH Manual of Analytical Methods. During an 18-minute decontamination with a solution containing 4,500 ppm free chlorine, we sampled 18.3 L of air and found traces of chlorine that were not quantifiable. During a 15-minute decontamination with a solution containing 1,500 ppm free chlorine, we sampled 15.2 L of air and could not detect chlorine at all. On the basis of these results, we concluded that there is no occupational hazard for the cleaning employees while performing a decontamination procedure with a solution containing 4,500 ppm free chlorine made from sodium dichloroisocyanurate dihydrate tablets.