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Environmental fate & pathways

Henry's Law constant

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Administrative data

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Description of key information

From the water surface the substance will not evaporate into the atmosphere.

Key value for chemical safety assessment

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 TPGDA (CAS 42978-66-5) (Q)SAR results were used for the estimation of the Henry’s Law constant. 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 the Henry’s Law Constant are not provided.

Assessment

 The substance is an UVCB substance. The following four main constituents which concentrations at or above 0.1 % (w/w) were analytically determined:

1.    Constituent 1 (2-{2-[2-(acryloyloxy)-1-methylethoxy]-1-methylethoxy}-1-methylethyl acrylate), ca. 85% (w/w)

2.    Constituent 2 (2-Propenoic acid, 2-[2-(2-hydroxymethylethoxy)methylethoxy]methylethyl ester), ca. 4% (w/w)

3.    Constituent 3 (2-Propenoic acid (1 or 2), (4 or 5), (7 or 8)-trimethyl-10,14-dioxo-3,6,9,13-tetraoxahexadec-15-en-1-yl ester), ca. 3% (w/)

4.    Constituent 4 ((1 or 2)-methyl-2-{(1 or 2)-methyl-2-[(1 or 2)-methyl-2-(2-propenoyloxy)ethoxy]ethoxy}ethyl (5 or 6), (8 or 9), (11 or 12)-trimethyl-14-oxo-4,7,10,13-tetraoxahexadec-15-en-1-oate), ca. 2% (w/w)

The Henry’s Law Constant values were calculated for substances by using the bond estimation method of HENRYWIN v3.20 (EPISuite v 4.11. These estimates refer to the uncharged molecule.

The following table provides results for the constituents of the substance (impurities or additives are not present in concentrations at or above 0.1 % (w/w)):

 

Henry’s Law constant (Pa m3/mol)

Applicability Domain

Constituent 1

8.82E-06

Yes

Constituent 2

2.57E-7

Yes

Constituent 3

2.79E-8

Yes

Constituent 4

2.45E-13

Yes

 

As can be seen from the data compiled above, all of the constituents of the registration item are not expected to evaporate into the atmosphere from the water surface. All substances are within the applicability domain of the estimation model.

The remaining “non-specified constituents” sum up to a typical concentration of approximately 6.0 % (w/w). According to GC analytics, more than 45 peaks contribute to this part of the composition of the registration item. Though it is virtually not possible to identify each single peak and assess the respective substance(s) individually, a generic assessment of the environmentally relevant properties of these ingredients may be applied. Multifunctional acrylates are synthesized from alcohols and acrylic acid. As a consequence, the resulting products – including the “non-specified constituents” – are made of the same, similar chemistry. As shown by the evidence provided above, this chemistry basically is subject to ultimate biotic degradation: in none of the four main constituents, a potential metabolite that may be generated from the degradation of these compounds was identified. Therefore, from a scientific perspective, it is extremely likely that also the degradation of the chemically similar “non-specified constituents” of the registration item will not lead to the formation of a persistent metabolite. The raw materials used as well as the conditions of the reaction chosen during manufacture are targeted to produce 2-{2-[2-(acryloyloxy)-1-methylethoxy]-1-methylethoxy}-1-methylethyl acrylate. Side-products beyond the main constituents discussed above are expected to slightly vary in chain lengths and/or branching, but are not anticipated to significantly differ in terms of structural elements – if at all. Therefore, also these structures are deemed degradable by the same metabolic pathways. Consequently, there is no concern that (part of) the UVCB may persist in the environment.

 Hence, based on the available calculated data for main constituents of the TPGDA is not expected to evaporate into the atmosphere from the water surface.