A new study in Environmental Toxicology and Chemistry has found that substances used in antiseptics that replaced high-use antimicrobials appear to have little to no adverse effects at concentrations found in the environment.

There was an intense need for antiseptics during the COVID-19 pandemic, and use of three topical antiseptic compounds—benzalkonium chloride (BAC), benzethonium chloride (BZT), and chloroxylenol (PCMX)—increased before and during the pandemic due to the phase-out of other antimicrobial ingredients (such as triclosan) in soaps and other disinfecting and sanitizing products.

Researchers assessed the environmental safety of BAC, BZT, and PCMX, focusing on aquatic systems receiving effluent from wastewater treatment plants and land-based systems where wastewater biosolids were applied. Neither BZT nor PCMX were likely to cause adverse ecological effects, with high margins of safety in the scenarios assessed. Adverse ecological effects were also unlikely for BAC. 

“The COVID-19 pandemic was happening in real-time as we were doing our research—making the assessment even more relevant but also making it harder to estimate ever-changing environmental concentrations of sanitizer ingredients. The assessment framework we developed provides a sound basis to interpret environmental data for the ingredients we studied, if their concentrations change in the future,” said corresponding author Phyllis Fuchsman, of the consulting engineering group Ramboll.