Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

n-pentane and 2-methylbutane are considered to be readily biodegradable on the basis of proprietary, GLP compliant, guideline studies (Exxon, 1996 and Givens, 1997).

The substances are expected to have a low potential for bioaccumulation and adsorption to soil and sediment based on the measured log Kow’s ranging from 3 – 3.45 (Lide et al, 2008). Structural analysis of the substances indicates that they are not expected to undergo hydrolysis in the environment due to the lack of hydrolysable functional groups. The physico-chemical properties of the pentanes indicate that the majority of the substances will ultimately be distributed to the atmosphere where they are quickly photooxidised. The photooxidative half lives for 2-methylbutane, cyclopentane and n-pentane are 2.3 (Atkinson, 1985), 3.2 (Droege and Tully, 1987) and 3.95 (Atkinson, 1985) days respectively.

Based on this information the Hydrocarbons, C5, n-alkanes,isoalkane

are not expected to persist in the environment because as they are readily biodegradable, have a low potential for adsorption to organic matter and low potentials for bioaccumulation.