Methacrylate Fate and Degradation

The basic methacrylates are not persistent in the environment. They degrade mainly via biodegradation and photodegradation.  

In water they biodegrade quickly with substances rapidly broken down by bacteria in water and sewage treatment plants. Laboratory test data show ready biodegradation of methacrylates with complete mineralization. While the products are not intentionally released during manufacturing processes and use, trace amounts present in waste water streams would rapidly disappear by biological degradation and evaporation.

Due to rapid degradation of any amounts in the environment, the possibility of uptake in aquatic organisms is very low and furthermore, any quantities taken up would be rapidly metabolised in organisms, resulting in an overall very low bioaccumulation potential.

In air, methacrylates react with photo-chemically produced hydroxyl radicals and also with ozone. Half-lives for these reactions have been estimated with the EPI Suite™ program as provided by US EPA. Estimated atmospheric half-lives range from 4.4 to 7.0 hours, with shorter half-lives for higher molecular weights (6.9 h (MAA), 7.0 h (MMA), 6.5 h (EMA), 5.7 h (n-/i-BMA) and 4.4 h (2-EHMA)). They have no relevant ozone-depleting potential and do not add to global warming.

References:

OECD, 2001, OECD SIDS/SIAP/SIAR Methacrylic acid, CAS no. 79-41-4

OECD, 2001, OECD SIDS/SIAP/SIAR Methyl Methacrylate, CAS no. 80-62-6

OECD, 2009, SIDS/SIAP/SIAR Category Short-chain Alkyl Methacrylates (Rem.: assessment referring to ethyl methacrylate, n- and iso-butyl methacrylate and 2-ethylhexyl methacrylate)

Staples, C. A., Farr, C., Hunt, E. K., McLaughlin, J. E., Müllerschön, H., & Pemberton, M. A. (2009). Using Quantitative Structure–Activity Relationships to Support the Assessment of the Environmental Fate and Aquatic Toxicity of a Series of Methacrylic Acid Esters. Human and Ecological Risk Assessment: An International Journal, 15(3), 503–525. https://doi.org/10.1080/10807030902892497