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Environmental fate & pathways

Phototransformation in air

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Description of key information

After evaporation or exposure to the air, the substance and its hydrolysis product CAS 147 -57 -5 will be slowly degraded by photochemical processes.

This estimation refers to dry air. In mist, rain, droplets and aerosols, hydrolysis will be the major fate process of the acid chloride due to the short half-life in aqueous solution. Therefore this estimate may be of low relevance for 2 -ethylhexanoyl chloride.

Key value for chemical safety assessment

Half-life in air:
47 h
Degradation rate constant with OH radicals:
0 cm³ molecule-1 s-1

Additional information

QSAR-disclaimer:

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met.

According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

For the assessment of the substance and its hydrolysis product (Q)SAR results were used for phototransformation in air.

The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.

Therefore, further experimental studies on phototransformation in air are not provided.

Assessment:

Parent combound CAS 760 -67 -8: The photodegradation was calculated for 2 -ethylhexanoyl chloride (CAS 760 -67 -8) with AOPWIN v1.92, implemented in EPISuite v4.11.

Based on an estimated OH radical rate constant of 11.21E-12 cm3/molecule-sec, the half-life was calculated to be 34.3 hours; for this calculation a 24 -hour day as well as a sensitizer-concentration (OH-radicals) of 5E+06 molecules/cm³ were assumed (BASF SE, 2021). The substance is within the applicability domain of the model. Based on the EPI Suite calculation the substance will be slowly degraded by photochemical processes after evaporation or exposure to air.

This estimation refers to dry air. In mist, rain, droplets and aerosols, hydrolysis will be the major fate process of the acid chloride due to the short half-life in aqueous solution. Therefore this estimate may be of low relevance.

Thus, the assessment of the environmental fate of the substance is also based on the available experimental data for the hydrolytic product: CAS 149 -57 -5.

Hydrolysis product (CAS 149 -57 -5):

The photodegradation was calculated for CAS 149 -57 -5 with AOPWIN v1.92, implemented in EPISuite v4.11.

Based on an estimated OH radical rate constant of 8.18E-12 cm3/molecule-sec, the half-life was calculated to be 47 hours; for this calculation a 24 -hour day as well as a sensitizer-concentration (OH-radicals) of 5E+06 molecules/cm³ were assumed (BASF SE, 2021). The substance is within the applicability domain of the model. Based on the EPI Suite calculation the substance will be slowly degraded by photochemical processes after evaporation or exposure to air.