Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

MTDID 22327 is manufactured in the EU for export.  Releases are anticipated to be primarily to the atmospheric compartment. This compound is unlikely to partition to terrestrial or aquatic compartments from the atmosphere based on partition coefficients. The experimental vapor pressure (213 mm Hg at 20 °C) and read across values for Henry’s Law constant (range: 171 - 1021 atm∙m³/mol for other constituents, >1021 – 4020 atm∙m³/mol for tertiary amines, at 22 °C) suggest that MTDID 22327 is expected to partition from wet or dry terrestrial surfaces into the atmosphere.  Only negligible amounts of MTDID 22327 are expected to be present in aquatic systems or soils.

The logarithm of the organic carbon normalized adsorption coefficient (log Koc) is used to describe the tendency for a substance to partition from water to soils or suspended solids. The water solubility of MTDID 22327 is slight (range for predominant constituents, 0.679 μg/L to 758 µg/L at ca. 23 - 24 °C) and the log Koc range was calculated (1) to be 3.6 - 5.1 based on read across log Kow values for predominant constituents. Based on these data MTDID 22327 is anticipated to partition from water to soils and suspended solids for a short period of time. Given the rapid partitioning to the atmosphere from soils and from water, the overall net partitioning will be to the atmosphere.

The logarithm of the octanol air partition (log Koa) coefficient is used to describe the tendency of a substance to partition from air into the lipid rich tissues of air breathing organisms. The calculated log Koa values for MTDID 22327 range from 0.39 to 1.52, based on read across of dimensionless Henry’s Law constant and Kow values. This log Koa range indicates that MTDID 22327 has a low potential to partition from air to the lipid rich tissues of air-breathing organisms.

Unlike most members of the category, MTDID 22327 is a UVCB consisting mostly of perfluoro-N-methylmorpholine, a mixture of C5-C7 perfluorinated tertiary amines, and mixed perfluorohexanes. However, all of the members of this category stem from the same manufacturing process, have similar physicochemical properties including high vapor pressure and low water solubility relative to the hydrocarbon analogs (e. g., hexanes v. perfluorohexanes), and also lack any chemically reactive groups, which forms the technical basis for the category. Members of this category are fully fluorinated, meaning that fluorine, rather than hydrogen, is bonded to all carbon atoms in the molecule. Fluorine is the most electronegative of the elements (fluorine has an electronegativity of 3.98 on the Pauling scale, as compared to 2.55 for carbon or 2.20 for hydrogen). This electronegativity is expected to dominate over all other aspects of substance chemistry and is the underlying basis for similarity of substances in this 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 or indeed any reaction by normal enzymatic processes, they are considered to constitute a chemical category. Data gaps for transport and distribution can therefore be addressed by read-across between category members. Please see IUCLID section 13 for the category justification and a matrix of physicochemical and distribution data for members of the Perfluorinated Organic Chemicals C5-C18 category.

(1) European Chemicals Bureau: Technical Guidance Document of Risk Assessment, Chapter 4.