Are cigarette butts biodegradable?
Cigarette butts do not biodegrade under typical environmental conditions. Cigarette butts often contain filters, made of non-biodegradable cellulose acetate. These filters degrade into microplastics over years or decades. These microplastics pollute soil and waterways, harm ecosystems, and introduce toxic chemicals into the food chain. As one of the most common plastic pollutants, cigarette butts pose a persistent environmental threat.
A report by the National Institute for Standards and Technology (NIST; U.S. Department of Commerce) explains:
“Filters typically contain plasticized cellulose acetate fibers that are slow to degrade (Puls et al. 2011). Cellulose can be degraded by organisms with cellulose enzymes, but the acetyl groups in cellulose acetate first need to be removed to a certain extent (via the action of esterases or by chemical hydrolysis) for biodegradation of the cellulose backbone to initiate. Cellulose acetate can be photochemically degraded by UV wavelengths shorter than 280 nm, but has limited photo-degradability in sunlight due to the lack of chromophores for absorbing UV light (Puls et al. 2011). Cellulose acetate cigarette butts tend to linger in the environment for extended periods of time for these reasons. After two years of outdoor decomposition, 13C -cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy analysis indicated minimal microbial degradation of cigarette filters (Bonanomi et al. 2015). This stability may be due to the nitrogen limitations in the butts.”
This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.IR.8147
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