Perfluamine

Sediment toxicity

Administrative data

Endpoint:

sediment toxicity: long-term

Data waiving:

exposure considerations

Justification for data waiving:

other:

Justification for type of information:

We propose waiving testing of long-term toxicity to sediment organisms on PTPA in consideration of column 2 of Annex X of the REACH Regulation and with regard to section 3 of Annex XI (regarding substance-tailored exposure-driven testing). Per column 2, Long-term toxicity testing shall be proposed by the registrant if the results of the chemical safety assessment indicates the need to investigate further the effects of the substance and/or relevant degradation products on sediment organisms. The choice of the appropriate tests depends on the outcome of the chemical safety assessment. A consideration of physicochemical properties and use and disposal shows that sediment exposure is unlikely. PTPA is a liquid at room temperature with low water solubility (0.381 µg/L), vapor pressure (3.87 mm Hg at 20°C), and a high Henry's Law constant range (read across from analogous compounds of similar water solubility) of 3400 - 4020 atm•m³/mol. Releases are expected to be atmospheric emissions based upon its intended uses. During routine use, there is no anticipated release to aquatic systems or sewage treatment plants that would result in a sediment exposure. The vapor pressure, low water solubility and the extremely high Henry’s law constant combine to rapidly move PTPA from the marine and freshwater sediment compartments into the atmosphere. Once in the atmospheric compartment, this compound will not partition to sediments based on the same properties. Therefore, this compound will partition to and remain in the atmosphere when released from intended uses. Toxicity was not observed for PTPA or any other category members in short-term testing in the aquatic compartment, nor in a freshwater green algae test, nor in a chronic aquatic invertebrate test of category member PTBA. For purposes of evaluating the need for sediment testing, PNECs were defined for the aquatic compartment based on solubility limit in biological media. Freshwater and marine sediment PNECs of 0.131 and 0.0131 mg/kg dw, respectively, were then derived using the Equilibrium Partitioning Method and the aquatic PNEC. Exposure modeling was conducted using EUSES v.2.1.2 in order to evaluate the significance of environmental exposure in soils. The worst-case predicted environmental concentrations (PECs) were PECfreshwater sediment, 0.078 mg/kg dw, and PECmarine sediment, 0.0079 mg/kg dw. The resulting PEC/PNEC ratios for sediment compartments, 0.595 and 0.603, are clearly below 1, indicating that exposures are always well below the PNEC. Because the PNECs were defined using medium solubility data from the toxicity studies, and no actual toxicity had been observed, the PNECs provide a very conservative estimate of hazard. Based on the physicochemical properties and use pattern, PTPA is not expected to attain significant sediment concentrations even in the steady state. Therefore, long-term testing of sediment toxicity would not provide useful information for the environmental risk assessment of PTPA. Direct and indirect exposure of the sediment compartment is very unlikely.