Ethyl 2-methylbutyrate

Phototransformation in air

Link to relevant study record(s)

Reference

Endpoint:

phototransformation in air

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Study period:

Study report date: 15th March 2013

GLP compliance:

no

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No

Estimation method (if used):

Not Applicable

Details on light source:

Not Applicable

Details on test conditions:

Not Applicable

Preliminary study:

Not Applicable

Test performance:

Not Applicable

Results with reference substance:

Not Applicable

The decomposition rate constant of EMB in air following reaction with hydroxyl radicals was calculated to be 3.8848 x 10^-12cm³molecule^-1sec^-1. Assuming that the 12 hour daytime hydroxyl radical concentration is 1.5 x 10⁶molecules.cm^-3, the half-life was calculated to be 2.753 days (12 hour day).

The decomposition rate constant of EMB in air following reaction with ozone was not carried out as this calculation is only applicable to olefins and acetylenes.

Conclusions:

The decomposition rate constant of Ethyl 2-Methylbutyrate (EMB) in air occurring through reaction with hydroxyl radicals was estimated according to the method of Atkinson using the Atmospheric Oxidation Program (AOPWIN version 1.92, US EPA).

The decomposition rate constant of EMB in air following reaction with hydroxyl radicals was calculated to be 3.8848 x 10-12 (0.0000000000038848) cm3 molecule-1sec-1. Assuming that the 12 hour daytime hydroxyl radical concentration is 1.5 x 106 (1500000) molecules.cm-3, the half-life was calculated to be 2.753 days (12 hour day).

Executive summary:

The decomposition rate constant of Ethyl 2-Methylbutyrate(EMB) in air occurring through reaction with hydroxyl radicals was estimated according to the method of Atkinson using the Atmospheric Oxidation Program (AOPWIN version 1.92, US EPA). This method estimates the rate constant for the atmospheric gas-phase reaction between photochemically produced hydroxyl radicals and organic chemicals and between ozone and olefinic/acetylenic compounds.

The decomposition rate constant of EMB in air following reaction with hydroxyl radicals was calculated to be 3.8848 x 10^-12cm³molecule^-1sec^-1. Assuming that the 12 hour daytime hydroxyl radical concentration is 1.5 x 10⁶molecules.cm^-3, the half-life was calculated to be 2.753 days (12 hour day).

 

The decomposition rate constant of EMB in air following reaction with ozone was not calculated since only olefins and acetylenes are calculated.

Description of key information

The decomposition rate constant of Ethyl 2-Methylbutyrate (EMB) in air occurring through reaction with hydroxyl radicals was estimated according to the method of Atkinson using the Atmospheric Oxidation Program (AOPWIN version 1.92, US EPA). This method estimates the rate constant for the atmospheric gas-phase reaction between photochemically produced hydroxyl radicals and organic chemicals and between ozone and olefinic/acetylenic compounds (Aimee Collett 2013).

The decomposition rate constant of EMB in air following reaction with hydroxyl radicals was calculated to be 3.8848 x 10^-12cm³molecule^-1sec^-1. Assuming that the 12 hour daytime hydroxyl radical concentration is 1.5 x 10⁶molecules.cm^-3, the half-life was calculated to be 2.753 days (12 hour day).

The decomposition rate constant of EMB in air following reaction with ozone was not carried out as this calculation is only applicable to olefins and acetylenes.

Key value for chemical safety assessment

Half-life in air:

2.753 d