There are not many studies of flunitrazepam, but no existing data suggest environmental risk.
Another benzodiazepine, oxazepam has been shown in studies to produce behavioral changes in perch at concentrations found in Swedish waters. These behavioral changes can cause potential effects on the ecological balance. Further research is ongoing.
Flunitrazepam has not been detected in treated wastewater in Stockholm County in the last five years (2012–2016).
Author: Health and Medical Care Administration, Region Stockholm