Persistence. Ondansetron is potentially persistent.
Bioaccumulation. Ondansetron low potential for bioaccumulation.
Toxicity. Ondansetron has moderate chronic toxicity.
Risk. The use of ondansetron (sales data Sweden 2018) has been considered to result in insignificant environmental risk.
This summary information comes from Fass.
Fass environmental information
Fass environmental information for Zofran munlöslig (ondansetron) from Novartis (downloaded 2023-02-06).
Persistence: "Inherent degradability: 19% degradation in 28 days (OECD 302). Soil Metabolism: 20-99.9% degradation in 64 days (TAD 3.12). Hydrolysis: 50% degradation (pH 7) > 1 year (TAD 3.09). Ondansetron is not readily degradable nor inherently biodegradable. The phrase “Ondansetron is potentially persistent” is thus chosen."
Bioaccumulation: "Log Dow at pH 5 = 0.23, Log Dow at pH 7 = 1.00, Log Dow at pH 9 = 1.26."
Toxicity: There are data for 3 trophic levels, most sensitive crustacean (Ceriodaphnia dubia) NOEC chronic toxicity 320 microg/L.
PEC/PNEC is based on sales data in Sweden in year 2015. "PNEC (μg/L) = lowest NOEC/100, where 100 is the assessment factor applied for two long-term NOECs when such results have not been generated from that showing the lowest L(E)C50 of the short-term tests. The lowest NOEC for water flea (= 320 μg/L) has been used for this calculation since it is the most sensitive of the two tested species." PEC/PNEC = 0,0007 which gives the risk insignificant. ECHA's guidelines state that AF 50 should be used for data for two long-term studies. If AF 50 is used, the risk is also insignificant (PEC/PNEC = 0.00034).
Author: Health and Medical Care Administration, Region Stockholm