Reactionmass of dodecan-2-yl prop-2-enoate and dodecan-3-yl prop-2-enoate and dodecan-4-yl prop-2-enoate

Endpoint summary

Additional information

MTDID 44430 is a multi-constituent substance comprising a mixture of secondary alkyl esters of acrylic acid.  The predominant isomers are the 2-, 3-, and 4-dodecyl acylates. Many of the properties of this substance are therefore average measurements, although isomer-specific data are sometimes available.  This material has a vapor pressure of 0.0024 Pa at 18°C and has water solubilities at 23.7 °C of 2.36 mg/L (2-dodecyl acrylate), 0.831 mg/L (3-dodecyl acrylate), and 0.27 mg/L (4-dodecyl acrylate).  Due to limited volatility, distribution to the atmosphere is expected to be a minor fate of MTDID 44430 in the environment.

MTDID 44430 is not readily biodegradable but is inherently biodegradable (not meeting specific criteria).  In the abiotic control of the inherent biodegradation test, the test material could not be detected at the end of the test.  In an abiotic hydrolysis test, somewhat contradictory were obtained.  For example, in the preliminary test at 50 °C, the substance was less than the limit of detection after five days, but in the Tier 2 definitive test the material could still be detected at day 7, and the half-lives determined in the Tier 2 test appeared to be independent of temperature and pH.  The expected hydrolysis products, i.e. the secondary alcohols, were the only hydrolysis products examined, and the mole fraction detected was far less than would be indicated by the amount of MTDID 44430 lost.  It is possible that some degree adsorption is possible in this study, which would make the substance less available for biodegradation.  It is also possible that the hydrolysis products are not amenable to biodegradation.  Secondary alcohols are expected to be converted to ketones.  However, undecan-2-one was not readily biodegradable in a test done at a loading rate four times higher than its measured solubility.

In a shake-flask study of octanol-water partition coefficient, the log Kow of MTDID 44430 was determined to be 6.5 - 6.6 for the two most prevalent isomers. The constituents of MTDID 44430 therefore have partition coefficients in the range of chemicals having a potential to bioaccumulate and further evaluation was needed.  No experimental studies of bioconcentration of MTDID 44430 were available, and a preliminary study showed that a BCF test under semistatic conditions would not be feasible.  In a QSAR analysis using Catalogic software v.5.13.1, BCF values ranging from 32 to 33 were predicted for fish.  This software establishes a baseline BCF based on log Kow and applies factors for metabolism, a conformation-based calculation of molecular size, water solubility, and presence of phenolic or acidic functional groups.  This result is in agreement with well-studied metabolism of acrylate esters in mammals.  It is shown that metabolism is via ester hydrolysis and is nearly complete.  Acrylate esters are rapidly detoxified and eliminated.

The log adsorption coefficient (log Koc) of MTDID 44430 was found to range from 4.27 to 4.41 for two constituents. This indicates that MTDID 44430 would sorb strongly to soil, sediment or activated sludge.