Diphenhydramine
Summary
Persistence. It cannot be excluded that diphenhydramine is persistent, as data are lacking.
Bioaccumulation. Diphenhydramine has low potential for bioaccumulation.
Toxicity. It cannot be excluded that diphenhydramine is toxic, as data are lacking.
Risk. Risk of environmental impact of diphenhydramine cannot be excluded, due to the lack of environmental toxicity data.
This summary information comes from fass.se.
Detailed information
Fass environmental information
Fass environmental information for Desentol (diphenhydramine) (retrieved on 2025-07-18).
Hazard
Persistence: No data.
Bioaccumulation: Log P of 3.27.
Toxicity: No data.
Risk
Sales data for Sweden is available for 2023. "According to the European Medicines Agency guideline on environmental risk assessment of medicinal products (EMA/CHMP/SWP/4447/00), use of diphenhydramine is unlikely to represent a risk for the environment, because the predicted environmental concentration (PEC) is below the action limit 0,01 μg/L."
Pharmaceutical residues in the aquatic environment
Diphenhydramine has been found and detected in the aquatic environment in Sweden.
Pharmaceutical residues in animals
Pharmaceutical concentrations of diphenhydramine have been detected in caddisfly larvae.
References
- Fass.se för vårdpersonal.
- Provtagningar av läkemedelsrester i vatten, sediment och fisk för Region Stockholm.
- IVL Swedish Environmental Research Institute Ltd Fick J, Lindberg RH, Fång J, Magnér J, Kaj L, Brorström-Lundén E. Screening 2014. Analysis of pharmaceuticals and hormones in samples from WWTPs and receiving waters. Rapport C 135.
- Richmond EK, Rosi EJ, et al. A diverse suite of pharmaceuticals contaminates stream and riparian food webs. Nat Commun. 2018 Nov 6;9(1):4491. doi: 10.1038/s41467-018-06822-w.
Author: Health and Medical Care Administration, Region Stockholm