Registration Dossier

Diss Factsheets

Administrative data

Hazard for aquatic organisms

Hazard for air

Hazard for terrestrial organisms

Hazard for predators

Additional information

Environmental fate and pathways:

No biodegradation studies were conducted with 1,3-Dioxole, 2,2,4-trifluoro-5-(trifluoromethoxy). However, based on the molecular structure, no significant biodegradation is expected in the environment because of fluorinated structure. Fluorochemical products can resist degradation by bases, oxidising and reducing agents, photolytic processes, microbial and metabolic processes (Shultz et al. 2003), as the carbon-fluorine bond is the strongest covalent bond existing (450 kJ/mol) in organic chemistry (O'Hagan, 2008).

(Schultz M.M., Barofsky D.F., and Field J.A., 2004. Fluorinated Alkyl surfactants. O'Hagan D., 2008. Understanding organofluorine chemistry. An introduction to the C-F bond.)

Aquatic toxicity:

The toxicity of the test item on aquatic algae was not determined. The substance is highly volatile (84 kPa) and highly insoluble in water. According to Annex VII, section 9.1.2., column 2 of Regulation No. 1907/2006, the study of growth inhibition of aquatic plant study does not need to be conducted as the substance is highly insoluble. In conclusion, no growth inhibition study on aquatic plants could be performed due to the physico-chemical properties of the substance.

One key study (Migchielsen, 2017) is available to assess the short-term toxicity of the registered substance to aquatic invertebrates, Daphnia magna. This study was performed according to OECD Guideline 202, under semi-static conditions for 48 hours.

A test limit at 150 mg/L (nominal concentration) was performed. The initial measured concentration of test substance was only 1.95 mg/L. All the daphnids exposed to this concentration of test substance were immobile after 24 hours of exposure, whereas all the daphnids exposed to the control were still mobile. Microscopic observation revealed that the immobilised daphnids had deceased. The experiment was consequently stopped but effect concentrations could not be determined due to analytical issues. In conclusion, due to the technical difficulties it was not possible to generate reliable results to calculate the effect concentration. It was however concluded that it is highly likely that the 24h-EC50 is below 1.95 mg/L according to the values of the measured concentrations over the first 24 hours of the test, that caused 100% immobilisation of daphnids.

Conclusion on classification

Only an estimation of the short-term toxicity of the test item on aquatic invertebrates is available. Thanks to the available study, it was concluded that it is highly likely that the 24h-EC50 is below 1.95 mg/L regarding the values of the measured concentrations over the first 24 hours of the test, that caused 100% immobilisation of daphnids.

- Lowest EC50 between 1 and 10 mg/L for daphnia

- Log Kow is between 3.0 and 3.6

- Test item is considered as not ready biodegradable due to the chemical structure of the substance

Based on the above data, the substance is classified as Aquatic Chronic 2 according to the Regulation (EC) No 1272/2008 (as amended) (CLP).