Human Health Risks Associated with Formalin Treatments Used in Aquaculture: Initial Study

No studies exist that address the health risks to humans resulting from environmental exposure to formaldehyde used to treat fish diseases. This study monitored formaldehyde exposure during two treatment scenarios to better ascertain the health risk. When a single 110-L tank was treated as an indefinite bath treatment at 250 mg/L formaldehyde, mean short-term exposure limit (STEL) averaged 0.76 ± 0.73 mg/L and permissible exposure limit (PEL) was 0.152 ± 0.10 mg/L, 10 cm from the source. One meter from the source, mean STEL and PEL were 0.45 ± 0.35 mg/L and 0.070 mg/ L ± 0.013 mg/L, respectively. The second scenario involved a 530-L flow-through tank treated at 250 mg/L as a 1-h flow-through treatment. Mean STEL averaged 1.61 ± 0.344 mg/L and mean PEL averaged 0.14 ± 0.012 mg/L, 10 cm from the source. One meter from the source, mean STEL and PEL were 0.97 ± 0.744 mg/L and 0.172 ± 0.0495 mg/L, respectively. For both scenarios, STEL and PEL were below the recommended exposure limits set by the U.S. Department of Labor, Occupational Safety and Health Administration (OSHA). However, factors such as water temperature, room air exchange rates, and the number of tanks treated per area must be considered when evaluating human health risk.