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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Butanamine, N,N-dibutyl-, branched and linear, fluorinated (perfluorotributyl amines, or PTBA) is a member of the category Perfluorinated Organic Chemicals, C5-C18. It comprises a mixture of perfluorinated tertiary amines, and is sold as two distinct classes of products, designated FC-40 for a wide-boiling range fraction and FC-43 for a narrow-boiling range fraction. PTBA is a liquid at room temperature with vapor pressures of 0.02 mm Hg at 20 °C for FC-43 and 0.36 mm Hg at 20 °C for FC-40. FC-40 and FC-43 solubilities in distilled water are <0.06 µg/L at 23 °C. The measured Henry’s law constant (expressed as the ratio of vapor phase partial pressure of FC-43 over aqueous phase concentration) is >4020 atm∙m³/mol at 22 °C, and the n-octanol:water partition coefficient for FC-43 is 6.1. Data for FC-43 was used for hazard assessment and exposure-based waiving exposure modeling. The data set is more complete for FC-43. Despite some differences in physicochemical properties between these two products, they are expected to have similar environmental fate properties.

Releases of PTBA are expected to be to the atmosphere based upon its intended uses. Fugitive emissions may occur at transfer points. During routine use, there is no anticipated release to water or wastewater in the EU. The vapor pressure, low water solubility and the extremely high Henry’s law constant combine to move perfluorotributyl amines from any terrestrial compartment into the atmosphere. Further, based on the measured and calculated soil-atmosphere volatilization half-lives of category member perfluoro-N-methylmorpholine, PTBA is expected to volatilize faster than may be initially predicted. Once in the atmospheric compartment, this compound will not partition to terrestrial or aquatic compartments based on the same properties. Therefore, this compound will remain in the atmosphere when released from industrial applications. The molecule contains no hydrolysable groups and is not biodegradable. Degradation in the environment is expected to be by direct photolysis in the upper atmosphere. An additional pathway may be indirect photolysis by singlet atomic oxygen, O(¹D), in the stratosphere. A half-life in the range of 150-300 years is expected by these processes. The ultimate degradation products are hydrofluoric acid (HF, CAS# 7664-39-3), carbon dioxide and oxides of nitrogen. These materials are miscible in water and are completely ionized in rainwater. They are expected to undergo wet deposition with no further significant transformation upon return to the troposphere.

As a perfluorinated substance, global warming and ozone depletion potentials may be of interest for perfluorotributyl amines. USEPA states flatly that hydrofluorocarbons do not deplete ozone because they lack chlorine or bromine. Fluorine radicals do not contribute to ozone depletion because of fast quenching of F* by water or hydrogen donors, slow reaction of FO* radicals with oxygen, and obligate reformation of F* in the pathway (1). F* radicals are rapidly and irreversibly removed from the atmosphere after quenching as HF. Therefore, neither perfluorotributyl amines nor any acidic photodegradation products contribute to ozone depletion. Global warming potential depends on three factors: absorption of infrared radiation, area of the spectrum the absorption occurs and lifetime of the material in the atmosphere. Perfluorotributyl amines have an estimated GWP of 8800 over a 100-year integrated time horizon.

FC-40 and FC-43 solubilities in distilled water are <0.06 µg/L at 23 °C. However, in a short-term Daphnia toxicity test, solubility of FC-43 in abiotic test medium was 0.710 µg/L. For difficult substance such as this, a wide range of test results is considered acceptable. The water solubility limit value is used to describe the chemistry of PTBA and for exposure modeling, while the higher value will be used to describe solubility in biological media and for use in deriving PNECs.

Category member perfluoro-N-methylmorpholine was shown to volatilize from soil several orders of magnitude more rapidly than EUSES software would predict using default parameters. Calculations using a USEPA methodology were used to obtain soil volatilization half-lives for parameterization of EUSES software and exposure modeling.

PTBA is not expected to partition to moist soils or surface waters. Upon accidental, direct release of perfluorotributyl amines to the aquatic compartment, the chemical is expected to volatilize rapidly. In a headspace biodegradation (OECD310) assay of the category member FC-770, no biodegradation was observed, and in general members of the Perfluorinated Organic Chemicals, C5-C18 are resistant to biological metabolism. No biodegradation of perfluorotributyl amines is expected. PTBA is expected to have little potential to bioaccumulate. Given its extremely short half-life due to volatilization, PTBA will not exist in aquatic environments or organisms for a sufficient time to allow partitioning into lipid tissues or testing of bioconcentration meaningfully.

Please see IUCLID section 13 for a full matrix of environmental fate and pathway data for members of the Perfluorinated Organic Chemicals C5-C18 category.

References

1) A.J. Colussi, M.A. Crela. 1994. Rate of the reaction between oxygen monofluoride and ozone. Implications for the atmospheric role of fluorine. Chem. Phys. Lett. Vol. 229, pp. 134-138.