The T-value in the PBT index refers to acute toxicity for the trophic level crustacean 11.1 mg fentanyl/L. This information and the information about P and B are from Fass environmental information for Durogesic (downloaded 2018-05-22). Data from the assessment report, see below, also gives the number 0 for B. The risk "cannot be excluded" is from Goodpoints report.
In Sweden fentanyl has been found in surface waters at very low levels, but because of the expected high potency and expected bioconcentration, risk can not be excluded. Mechanism-based efficacy data is lacking.
Fentanyl has previously been found in purified wastewater in Stockholm County (2005-2012).
Assessment report for Ionsys (fentanyl), 24 September 2015, EMA/801150/2015.
Persistence: No information.
Bioaccumulation: log Kow = 2.96, Conclusion: "Potential PBT (N)".
Chronic toxicity: No information.
"The applicant has provided a suitable review of the environmental risk implications of the use of fentanyl. The estimation of exposure (Phase I) of fentanyl does not raise concern with respect to the PEC action limit for surface water, this is 0.0004 μg/L, and so a Phase II assessment is not required. LogKow is also below 4.5, and so fentanyl is not considered to be a PBT substance. Therefore fentanyl is not expected to pose a risk to the environment. The ERA is acceptable.
Fass environmental information for Durogesic (downloaded 2018-05-22).
Persistence: "Fentanyl is not readily biodegradable in a biodegradability test according to OECD No. 301 F: “Manometric respirometry test”. Within the given test period of 28 days and at the given test conditions fentanyl HCl cannot be regards as readily biodegradable. Consequently, the medicine is potentially persistent."
Bioaccumulation: "The partition coefficient octanol/water was to be log Kow = 3.94 (pH = 3) using unknown internal method. The ChemSpider ACD/Percepta log Kow for Fentanyl = 3.89. The substance therefore has low potential for bioaccumulation."
Toxicity: algae ErC50 72 h (growth rate) = 15.1 mg/L, crustacean EC50 48 h (immobilization) = 12.3 mg fentanyl HCl/L ≈ 11.1 mg fentanyl/L och fish LC50 96 h (survival) = 24.0 mg/L
PEC/PNEC is based on sales data in Sweden in 2016. PEC/PNEC = 0.000145068, i.e.the hazard insignificant, i.e. consideration has not been given to measured levels in the environment.
Note that a consumed patch still contains the active substance and should be returned to the pharmacy for disposal.
Author: The Pharmaceutical unit of Region Stockholm