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 Avodart (dutasteride) (downloaded 2019-02-15).
Persistence: "Biotic degradation. Ready degradability: <1% degradation in 28 days (OECD 301B). Inherent degradability: <2.3% degradation in 64 days (OECD 304). Dutasteride is not readily biodegradable nor inherently biodegradable. The phrase “Dutasteride is potentially persistent” is thus chosen."
Bioaccumulation: Log Kow = 3.87 (OECD 117). "Since log Pow < 4, the substance has low potential for bioaccumulation."
Toxicity: There are data for 2 trophic levels, most sensitive fish (Juvenile Pimephales promelas) NOEC 21 microg/L.
PEC/PNEC is based on sales data in Sweden in year 2015. PEC/PNEC = 0.0000238 which gives the risk insignificant.
"PNEC (μg/L) = lowest NOEC/50, where 50 is the assessment factor applied for one long-term NOECs but where there is a high degree of confidence that the dataset includes the most sensitive species (fish). On this basis the NOEC for fish has been used in the calculation. An extended Fish ELS study was conducted to investigate the potential of dutasteride, as a 5-alpha-reductase inhibitor, to indirectly act as an endocrine disruptor. This modified extended fish early life stage toxicity test (OECD 210) examined the dose-effect relationship between aquatic dutasteride concentration and the development of secondary sexual characteristics and effects on gonad development in fish. Appropriate LOEC and NOEC values have been generated. Due to the mode of action of dutasteride and the potential receptor-mediated effects there is a high degree of confidence that the fish is the most sensitive species from the species base set and on that basis there is a strong justification for applying an AF of 50."
Author: Department of Strategic Careers, Stockholm County Council.