Chlorhexidine
Summary
Persistence. Chlorhexidine is potentially persistent.
Bioaccumulation. Chlorhexidine has low potential for bioaccumulation.
Toxicity. Chlorhexidine has high chronic toxicity.
Risk. The use of chlorhexidine (interpreted as sales data for Sweden in 2021) has been assessed to pose a moderate environmental risk.
This summary information comes from fass.se.
Detailed information
Fass environmental information
Fass environmental information for Klorhexidin Fresenius Kabi (retrieved on 2025-10-01).
Hazard
Persistence: "Chlorhexidin is not biodegradable in accordance to OECD 301D ... Test results 0 % degradation in 28 days."
Bioaccumulation: The bioconcentration factor (BCF) for chlorhexidine in golden eye (Leuciscus idus melanotus), based on OECD 305 with exposure at 0.05 mg/L for 3 days, is 42. As BCF < 500, the substance has low bioaccumulation potential. Physicochemical data show a partition coefficient (Log P) of 4.51 and a water solubility of 0.0261 mg/mL.
Toxicity: There are data for 3 trophic levels, most sensitive green algae EC50 24 h = 11.6 microg/L.
Risk
PEC/PNEC is based on sales data in Sweden in year 2021, as interpreted.
PEC = 0.317 microg/L.
PNEC = Lowest EC50, 11.6 microg/L/50 (Assessment Factor (AF) for 2 chronic studies) = 0.232 microg/L.
PEC/PNEC = 1.366 which gives the risk moderate.
References
Author: Health and Medical Care Administration, Region Stockholm