Trifluoro(trifluoromethoxy)ethylene

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING

According to Annex XI section 2, testing for a specific endpoint may be omitted if it is technically not possible to conduct the study as a consequence of the properties of the substance.
Long -term aquatic toxicity testing is not proposed by the registrant because, due to the volatile nature of PMVE, the technical feasibility of the experimental test is unlikely.

PMVE is a gas with a limited water solubility (31.5 mg/L) resulting in a very high Henry’s Law Constant (HLC) (32000 Pa m3/mol). The HLC of PMVE indicates that, in a system water-atmosphere, PMVE would tend to rapidly leave the water phase distributing to the air phase, making the generation of a stable concentration in water very challenging from a technical point of view and consequently making the possibility to obtain meaningful results very unlikely.

Additional considerations indicating that the evaluation of the long-term toxicity on aquatic invertebrates is unnecessary are the following:

- No significant exposure of the aquatic compartment is anticipated:
PMVE is only used in industrial installations and all the uses foresee limited environmental emissions, substantially directed to the atmosphere only. The EQC Fugacity III Model indicates that essentially the whole amount of PMVE eventually released to air would tend to remain into this compartment and therefore significant exposure of the aquatic environment can be excluded.

-There are mitigating factors which indicate that aquatic toxicity is unlikely to occur:
Because of the above discussed properties of PMVE (i.e. gaseous substance with a high tendency to rapidly leave the water phase), even in the hypothesis that PMVE was emitted to water, it is expected to not remain in the aqueous compartment the time sufficient to exert toxic effects on aquatic organisms.

Description of key information

Long -term aquatic toxicity testing is not proposed by the registrant because, due to the volatile nature of PMVE, the technical feasibility of the experimental test is unlikely.

Additional information

PMVE is a gas with a limited water solubility (31.5 mg/L) resulting in a very high Henry’s Law Constant (HLC) (32000 Pa m3/mol). The HLC of PMVE indicates that, in a system water-atmosphere, PMVE would tend to rapidly leave the water phase distributing to the air phase, making the generation of a stable concentration in water very challenging from a technical point of view and consequently making the possibility to obtain meaningful results very unlikely.

Additional considerations indicating that the evaluation of the long-term toxicity on aquatic invertebrates is unnecessary are the following:

- No significant exposure of the aquatic compartment is anticipated:
PMVE is only used in industrial installations and all the uses foresee limited environmental emissions, substantially directed to the atmosphere only. The EQC Fugacity III Model indicates that essentially the whole amount of PMVE eventually released to air would tend to remain into this compartment and therefore significant exposure of the aquatic environment can be excluded.

-There are mitigating factors which indicate that aquatic toxicity is unlikely to occur:
Because of the above discussed properties of PMVE (i.e. gaseous substance with a high tendency to rapidly leave the water phase), even in the hypothesis that PMVE was emitted to water, it is expected to not remain in the aqueous compartment the time sufficient to exert toxic effects on aquatic organisms.