A default PECsurface water of 0.13 µg/L has been calculated, which is above the threshold for conducting
a Phase II assessment. The results of toxicity tests with microorganisms, algae, Daphnia and fish were
used to calculate PNECs. The PEC/PNEC ratios for surface water and ground water are well below 1 and
the PEC/PNEC for microorganisms is well below 0.1, hence no further evaluation is needed in Tier B.
Based on the adsorption coefficient to sludge, a risk assessment in the terrestrial compartment is not
required. The degradation study of naloxegol in aquatic sediment systems indicates that naloxegol is
rapidly shifted from water to sediment and is likely to become irreversibly bound to sediment.
Consequently, the effects on the sediment dwelling organism Chironomus riparius have been investigated
in Tier B. The PEC/PNEC ratio for sediment dwelling organisms was below 1. Naloxegol is not considered
as PBT nor vPvB.
Considering the above data, Naloxegol is not expected to pose a risk to the environment