2-methylbutyl acrylate

Endpoint summary

Additional information

2-MBA is an intermediate used as a monomer which is further polymerized into various polymer matrices in the manufacture of various coatings, films, tapes and adhesive formulations. It is a very reactive monomer and is rapidly polymerized in its uses. All 3M manufacture of 2-MBA in the EU will be at a location where biological wastewater treatment coupled with carbon treatment is applied to wastewater. The industrial sludge from the manufacturing process is incinerated and therefore direct exposure to soil from application of sewage sludge will not occur.

2-MBA is volatile (vapor pressure of 0.17 kPa at 20 °C) and has an appreciable water solubility (316 mg/L at 23 °C). A Henry's Law constant of 95 Pa*m³/mol at 23 °C, calculated using experimental values, indicates a moderate tendency to volatilize from aquatic systems or moist environments. The vapor pressure indicates that 2-MBA released to the atmospheric compartment will remain in the vapor phase. Vapor-phase 2-MBA is expected to degrade quickly due to indirect photolysis, with a modeled half-life of 1.04 days.

2-MBA is readily biodegradable. Abiotic hydrolysis is not expected to contribute significantly to fate in aquatic systems or wastewater treatment systems. Material released to wastewater treatment systems or surface waters will be rapidly degraded.

2-MBA has an experimentally determined log Kow of 2.90 by a shake-flask method, and therefore by column 2 of Annex IX bioconcentration need not be tested. Furthermore, metabolism of acrylate esters in mammals is well studied. It is shown that metabolism is via ester hydrolysis and is nearly complete. Acrylate esters are rapidly detoxified and eliminated. Therefore, bioaccumulation of 2-MBA is not expected.

The log adsorption coefficient (log Koc) was calculated from log Kow, providing a value of Koc = 2.45. This indicates that 2-MBA would have a medium mobility in soil and a partial tendency to bind to organic materials in soils, soils and sediments. Though readily biodegradable, reduced water availability relative to aquatic systems and sorption of 2-MBA to soil organic matter may to a degree slow the process of removal.

Summary: 2-MBA is quite reactive and will be polymerized rapidly in industrial applications. Most emissions will be to air rather than to water. 2-MBA released to the atmosphere will be rapidly destroyed by indirect photolysis. Any 2-MBA released to water will be rapidly biodegraded. Releases to water are expected to be low, and 2-MBA is not expected to bioconcentrate to levels of concern. 2-MBA will likely partially sorb to soil and sediments and be biodegraded more slowly than in the aquatic compartment. Releases to soil are expected to be low. 2-MBA will be phototransformed in the atmosphere and/or biodegraded in terrestrial and aquatic systems.