This summary information comes from Fass.
Persistence. Betamethasone is potentially persistent.
Bioaccumulation. Betamethasone has low potential for bioaccumulation.
Toxicity. Betamethasone has very high chronic toxicity.
Risk. The use of betamethasone (sales data Sweden 2018) has been considered to result in high environmental risk.
Betamethasone has different classifications on fass.se. According to Lif (the trade association for the research-based pharmaceutical industry in Sweden) the various pharmaceutical companies compile environmental information for their active substances based on internal studies and published data. Based on data, which may thus differ between different pharmaceutical companies, the companies assess the environmental risk with guidance from “Environmental classification of pharmaceuticals at www.fass.se – Guidance for pharmaceutical companies 2012”. The Swedish Environmental Institute (IVL) reviews the assessment but does not have the task of coordinating/harmonizing environmental information from different pharmaceutical companies for the same active substance.
Persistence: "78% degradation of betamethasone was observed in the OECD 302B/314B study within 14 days but it does not pass the criteria of inherent biodegradability. The phrase “The substance is potentially persistent” is thus chosen."
Bioaccumulation: Log K = 2.11 at pH 7 (OECD 107).
Chronic toxicity: There are data for 3 trophic levels, most sensitive fish (Oryzias latipes) full life cycle toxicity F1 generation NOEC 219 d (growth rate) = 0.007 microg/L.
PEC/PNEC is based on sales data in Sweden in year 2018. PEC/PNEC = 14.6 which gives the risk high.
Persistence: "Inherent degradability: 28% primary degradation in 28 days (OECD 302C) (Reference 5). Abiotic degradation Hydrolysis: 50% degradation (pH 7) = 6.5 days (TAD 3.09). [...] The phrase “betamethasone valerate is potentially persistent” is thus chosen."
Bioaccumulation: Log P = 3,49 (TAD 3.02).
Toxicity: No data.
Risk of environmental impact of betamethasone valerate cannot be excluded, since there is not sufficient
ecotoxicity data available.
Comparative assessment of environmental risk when using the corticosteroids betamethasone, budesonide, hydrocortisone and prednisolone from a Swedish perspective.
The use of both betamethasone and budesonide poses an environmental risk, and exchange with synthetic glucocorticoids with a lower environmental risk is to be advocated in cases where it is possible from a clinical perspective. Hydrocortisone and prednisolone have a lower environmental risk but are rarely medically interchangeable alternatives to betamethasone and budesonide. Note that corresponding environmental risk assessments have not been made for other synthetic glucocorticoids that are available on the Swedish market, and which could possibly constitute exchange alternatives. No actions are recommended with regard to replacement of hydrocortisone and prednisolone as their use poses a low environmental risk given the current state of knowledge.
Author: Health and Medical Care Administration, Region Stockholm