Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability

Parent compound: 2 -Ethylhexanoyl chloride is expected to hydrolyse in less than 12 hours.

Hydrolysis product: 2 -Ethylhexanoic acid is considered as hydrolytically stable.

In air, 2 - is expected to be photodegraded by OH-radicals with a half-life of 26.6 h (BASF AG, 2008).

Hydrolysis product: 2-ethylhexanoic acid: A half-life of 47 h was calculated for the degradation in the atmosphere by OH-radicals (BASF SE, 2009).

 

Biodegradation

Parent compound: no reliable data are available.However, the test substance is expected to hydrolyse rapidly (t1/2 < 10 min) to form 2 -ethylhexanoic acid. Therefore data on the biodegradation of 2 -ethylhexanoic acid are presented.

The hydrolysis product 2-ethylhexanoic acid is readily biodegradable according to OECD criteria (EKO LAB, 1998).

Regarding the hydrolysis products HCl and CO2, biodegradation is not applicable due to the inorganic character of these molecules. Regarding biodegradation in soil or sediment there are no data available.

 

Bioaccumulation

Based on the log Pow of 2.4 calculated for 2-ethylhexanoyl chloride bioaccumulation is not to be expected in aquatic organisms. However the test substance rapidly hydrolyses and forms 2-ethylhexanoic acid which has a log Pow of 2.9 (BASF SE, 2009). This value refers to the uncharged molecule, however, 2-ethylhexanoic acid has log D values between 2.8 and -1.3 in a pH range from 4 to 9. Therefore, bioaccumulation is not expected in aquatic organisms.

 

Transport and distribution

Based on its calculated log Koc of 1.45 to 2.02 (Koc = 28 to 105; BASF SE, 2009), adsorption of 2 -ethylhexanoyl chloride to soil and sediment is not expected. However, 2 -ethylhexanoyl chloride is expected to hydrolyse rapidly and form 2 -ethylhexanoic acid.

The hydrolysis product 2 -ethylhexanoic acid has a calculated log Koc of 2.69 (value refers to the charged molecule at pH 7.00; BASF SE, 2010). Therefore, adsorption to solid soil phase is not expected.

A high Henry's Law Constant (HLC) of 369 Pa m³/mol was estimated for 2-ethylhexanoyl chloride, indicating rapid volatilization from surface waters (BASF SE, 2009). However, it is hydrolysed to 2-ethylhexanoic acid, CO2and HCl. The HLC for 2-ethylhexanoic acid was determined experimentally to be 0.289 Pa m³/mol, indicating slow volatilization from surface waters (BASF SE, 2009).

Following Mackay Level I calculations, the parent compound will preferentially distribute into the compartment air (73 %) (BASF SE, 2009). Following Mackay Level I calculations for the hydrolysis product 2-ethylhexanic acid, the substance is expected to preferentially distribute into the compartments water (85%) (BASF SE, 2009).