Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability

n-Butyl acetate will hydrolyze slowly in contact with water. The hydrolytic half-life was estimated to be 78 d at pH 8 and 2 years at pH 7 (ECT, 2009).

Biodegradation

n-Butyl acetate is readily biodegradable according to OECD criteria in the Closed Bottle test (OECD 301 D: 83 % in 28 d, 10-d window met; Waggy et al., 1994).

In accordance with column 2 of REACH Annex IX, studies on the biodegradation in water and sediment as well as in soil do not need to be conducted as the substance is readily biodegradable.

Bioaccumulation

In accordance with column 2 of Annex IX, the study does not need to be conducted if the substance has a low potential for bioaccumulation. The log Kow of 2.3 for n-butyl acetate (OXEA, 2009; T10198) indicates a low potential for bioaccumulation. In addition, the substance is readily biodegradable (Waggy et al., 1995). Therefore and for reasons of animal welfare, a fish study is not performed.

Based on a measured log Pow of 2.3, the BCF of n-butyl acetate was estimated to be 15 by using the BCFBAF program (v3.00).This estimate refers to the uncharged molecule. According to the BCF, n-butyl acetate has a low potential for bioaccumulation in aquatic organisms.

Transport and Distribution

In accordance with column 2 of REACH Annex VIII, the study does not need to be conducted since n-butyl acetate is readily biodegradable (Waggy et al., 1994) and has a low potential for adsorption due to a low octanol-water partition coefficient (log Kow = 2.3; OXEA, 2009). The adsorption coefficient (log Koc) was estimated to be less than 3 (MCI method: 1.3; Kow method: 1.8) using the KOCWIN (v2.00) program. The estimated Koc indicates that adsorption to soil is not to be expected.

 

The Henry's Law constant (HLC) of n-butyl acetate was experimental determined to be 28.5 Pa*m³/mol (Kieckbusch and King, 1976, as cited in ECT, 2009). The calculated value lies slightly above this value (HENRYWIN v3.20 41.6 Pa*m³/mol at 25 °C). Therefore, slow volatilisation is expected.

 

An experimental Henry's Law Constant (HLC) of 28.5 Pa*m³/mol at 25 °C was reported from the EPI Suite v4.00 database. Taking this value, volatilization half-lives of 3.3 h and 127 h were estimated for a model river and a model lake, respectively.