A humidifier disinfectant biocide, polyhexamethylene guanidine phosphate, inhalation exposure during pregnancy induced toxicities in rats.

Biocides are widely used for their effective antiseptic and disinfectant properties, including polyhexamethylene guanidine phosphate (PHMG-P), which is also used as a biocide as it selectively disrupts bacterial cell membrane. It is used to clean humidifiers commonly used in the dry winter season in South Korea, which exposes people to PHMG-P inhalation. However, comprehensive toxicological data on PHMG-P inhalation exposure, including in pregnant women, and the potential occurrence of lung disease is lacking. Therefore, in this study, we investigated PHMG-P inhalation exposure-induced toxicities in pregnant rats and prenatal development of their conceptus. Pregnant rats were exposed to PHMG-P via inhalation at target concentrations of 0, 0.14, 1.60, and 3.20 mg/m3 from implantation to nearly parturition (from gestation day 6-20) and then analyzed for relevant abnormalities. Results showed systemic toxicities in the pregnant rats including respiratory function abnormalities, decreased body weight gain, and decreased food consumption at ≥1.60 mg/m3. Prenatal development toxicities, including decreased fetal weight with ossification retardations of fetal bones, were observed at 3.20 mg/m3. These results will contribute to clarifying the PHMG-P inhalation exposure-induced toxicities during pregnancy and support its risk assessment in humans.