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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Administrative data

Link to relevant study record(s)

Description of key information

Key value for chemical safety assessment

Additional information

ABSORPTION

Based on physicochemical considerations (log Pow, water solubility), uptake of the substance from the gastrointestinal tract may occur after ingestion. Experimental data indicate that the extent of this absorption will be inversely related to carbon number, with negligible uptake for C29 and above. Applying this information to the proportions of i-alkane and n-alkane species present in the substance leads to a calculated gastrointestinal uptake of approximately 60%.

Based on physicochemical considerations (log Pow, water solubility), uptake of the substance across skin will be low.

Based on physicochemical considerations (log Pow, water solubility), uptake of the substance by the lung may occur following inhalation exposure. Experimental results indicate that tissue concentrations of three i-alkanes (C8, C9, C10) increased with increasing carbon number in rats exposed by inhalation (greatest for C10). Taken together this information supports potential uptake of the alkane species present in the substance vapour by the lung.

DISTRIBUTION

Experimental data demonstrate systemic distribution of C8, C9 and C10 i-alkanes in the rat following inhalation exposure, with internal concentrations being greatest in fat and lowest in blood (relative tissue concentrations: fat>>kidney, brain, liver>>blood). The results suggest that i-alkane components present in the substance will also be distributed within the body after inhalation exposure.

METABOLISM

Michaelis-Menten constants (Km, Vmax) for a series of C6-C10 iso- and normal alkanes were generally greater for n-alkanes relative to the corresponding i-alkanes when determined in vitro using a rat liver slice head-space technique. Other data indicate that metabolic clearance by rat liver microsomes (as predicted by Vmax) was inversely related to carbon number as follows: C9>C10>>>C14 (no detectable removal of n-tetradecane under the conditions of the study). By analogy, the C9 to C18 i-alkane species that predominate in the substance (accounting for greater than approx. 80% of the total) are expected to undergo negligible hepatic metabolism.

EXCRETION

Experimental data demonstrate removal of C8, C9 and C10 i-alkanes from rat kidney, brain, liver and blood 12 hours after inhalation exposure ceased, with detectable (but greatly reduced) levels present in fat only.