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

ABSTRACT 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 to 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.