Perfluamine

Toxicity to aquatic algae and cyanobacteria

Description of key information

Perfluorotripropyl amines (PTPA) is not expected to be toxic to algae at the limit of solubility. The cell crude of PTPA was not toxic to P.subcapitata at a loading rate of 100 mg/L. Also, no toxicity was observed to P. subcapitata in OECD201 assays tested at the limit of media solubility for category members FC-770 and PMM. These category member results are considered applicable to PTPA.

Additional information

Perfluorotripropyl amines (PTPA) 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. No studies of toxicity to algae and cyanobacteria are available for PTPA. Reliable OECD201 studies are available for algae toxicity of category members perfluoromethyl morpholine (PMM), and FC-770. In both cases, EC50s (72-h and 48-h, respectively) were in excess of the maximum achievable test substance concentrations. Analytically determined test substance concentrations are not reasonable to use for readacross since the solubilities of PMM and FC-770 are substantially higher than that of PTPA. Lack of toxicity at the limit of solubility is read across qualitatively to PTPA. The solubility of PTPA was determined to be 5.96 µg/L in organism-free Daphnia medium controls during the short-term toxicity test. This value is greater than the measured PTPA solubility in water (0.381 µg/L) but less than the analytically determined concentrations in medium containing live daphnids. The organism-free medium solubility value is understood to be better representative of PTPA solubility in natural waters, and avoids potential impacts on the analytical result by the action of living organisms. Therefore, 5.96 µg/L is accepted as the basis for estimating the highest possible exposure concentration of PTPA in order to define the EC50. In addition, the cell crude of PTPA was tested with P.subcapitata at a loading rate of 100 mg/L. The test material in this study contained 84.2% PTPA and 3.13% of alpha monohydrides. Mean measured concentrations were 5.70 and 0.199 ug/L, respectively. No toxicity was observed at the limit concentration.

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