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Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Stability

Phototransformation in air

After evaporation or exposure to the air, isobutyl acrylate will be rapidly degraded by photochemical processes. The calculated half-life for a 24-hr day and 0.5E+06 OH/cm3 is 27.98 hr.

Hydrolysis

The study does not need to be conducted because the subtance is readily biodegradable (study scientifically not necessary). Nevertheless, a QSAR estimate was conducted. Isobutyl acrylate was predicted to hydrolyse slowly if in contact with water. The calculated half-life at pH 7 and 25 °C is 16.5 years.

Biodegradation

Biodegradation in water: screening tests

In a CO2-Headspace test according to ISO 14593 isobutyl acrylate was readily biodegradable (90 - 100 % (TIC/ThIC) after 28 days).

Biodegradation in water and sediment: simulation test

In accordance with column 2 of REACH Annex IX, no simulation tests in water and sediment are required, since isobutyl acrylate is readily biodegradable according to OECD criteria.

Biodegradation in soil

In accordance with column 2 of REACH Annex IX, no simulation tests in soil are required, since isobutyl acrylate is readily biodegradable according to OECD criteria.

Bioaccumulation

Bioaccumulation: aquatic sediment

The study does not need to be conducted because isobutyl acrylate has a low potential for bioaccumulation based on log Kow >= 3. The measured log Kow of 2.38 (25 °C) and the calculated BCF of 17.3 give no indication for a potential for bioaccumulation.

Transport and distribution

Adsorption / desorption

The study does not need to be conducted because the substance has a low octanol water partition coeffiicient and the adsorption potential of this substance is related to this parameter (study scientifically not necessary). However, using QSAR the log Koc of isobutyl acrylate was determined to be 1.53 (Koc = 33.8).

Henry's Law contant

From the water surface, isobutyl acrylate will slowly evaporate into the atmosphere. The Henry's Law constant at 25 °C was calculated to be 21.9 Pa*m3/mol.

Additional information

In contact with water, isobutyl acrylate will hydrolyse slowly. Photodegradation in air will proceed rapildy. In water, sewage treatment plants and soil rapid degradation is expected, since isobutyl acrylate was readily biodegradable in a screening test. Based on an experimental log Pow and calculated BCF, a potential for bioaccumulation is not to be expected. Adsorption of isobutyl acrylate to the solid soil phase is not expected. Fugacity model calculation (Mackay Level I) revealed the atmosphere as the main target compartment for distribution which is also indicated by the substance's physicochemical properties.

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