reaction mass of 1,1,1,2,2,3,3,4,4,5,5,6,6,6-tetradecafluoro-hexane and 1,1,1,2,2,3,3,4,5,5,5-undecafluoro-4-(trifluoromethyl)pentane

Short-term toxicity to fish

Description of key information

FC-72 is not expected to be toxic to fish at the limit of solubility (84.1 µg/L) by readacross from category members.  No mortality was observed for FC-72 at a loading rate of 1000 mg/L.  When other category members were tested, no toxicity was observed to fish in tests conducted with nominal concentrations ranging from 100 to 2700 mg/L.  This categorical result  is considered applicable to FC-72.

Additional information

FC-72 is a member of the Perfluorinated Organic Chemicals, C5-C18 category. Because these substances exhibit similarity in their physicochemical properties and toxicological properties in mammals, and because available data indicates that parent molecules are not reactive toward biological molecules and cannot undergo bioactivation by normal enzymatic processes, they can be considered members of a chemical category. Data gaps for ecological toxicity can therefore be addressed by read-across and/or trend analysis between category members. Two toxicity studies are available for FC-72. In a static test of P. promelas, no mortality was observed at a nominal concentration of 1000 mg/L, with undissolved material present in the test aquarium throughout the entire exposure period. Another test was considered unreliable since presence of FC-72 in the test chambers was not confirmed analytically or by visual inspection. In addition, two reliable studies are available for other category members. Perfluoro-N-C1,3-alkyl morpholines (FC-770) was tested using D. rerio. After 96-hours, no toxicity was observed from a water-soluble fraction prepared at 100 mg/L. The mean measured concentration during the test was 0.096 mg/L. Perfluoro-C6,8-furans, pyrans and acyclic ethers (FC-77) was tested using P. promelas. In this case, test chambers were prepared at an initial loading rate of 1000 mg/L. Exposure concentrations were not measured, however, the test material could not be entirely dissolved and was observed in the test chambers throughout the experiment. No toxicity was observed. Other category members had study reports which were less detailed but were suitable for weight of evidence in the aggregate. These category members were not toxic to fish in limit tests with nominal concentrations up to 2700 mg/L. Lack of toxicity at the limit of solubility is read across qualitatively to FC-72. The water solubility limit of FC-72 was determined to be 84.1 µg/L, which is accepted as the basis for estimating the highest possible exposure concentration of FC-72 in order to define the LC50.

Please see IUCLID section 13 for the category justification and a matrix of aquatic toxicity data for members of the Perfluorinated Organic Chemicals C5-C18 category.