The T-value in the score for hazard refers to chronic toxicity. Underlying data for P, B, T and risk are from Fass.
Fass environmental information for Propecia (finasteride) (downloaded 2018-10-11).
Persistence: "Biotic degradation: Test results 0% degradation in 7 days based on CO2 evolution (i.e., no biodegradation) (FDA 3.11). Abiotic degradation: Hydrolysis: Test results 0% degradation in 5 days (US FDA 3.09). Photolysis: Test results 0% degradation over 8 days (US FDA 3.10)."
Bioaccumulation: "Log Kow = 3.56, 3.57 and 3.59 at pH 5, 7, 9, respectively (OECD 107)."
Chronic toxicity: There is NOEC for 3 trophic levels, lowest NOEC for fish (Oryzias latipes) 50 microg/L.
PEC/PNEC is based on sales data in Sweden in year 2015. PEC/PNEC = 0.004 which gives the risk insignificant.
Finasteride has been detected in raw water in Stockholm County during the period 2012-2016 and has been detected up to 20 ng/L in purified wastewater nationally.
Author: The Pharmaceutical unit of Region Stockholm