Are biodegradable plastics an environmental rip off?

• Published in: Journal of hazardous materials 2021-08, Vol.416, p.125957-125957, Article 125957
• Main Authors: Viera, João S.C., Marques, Mônica R.C., Nazareth, Monick Cruz, Jimenez, Paula Christine, Sanz-Lázaro, Carlos, Castro, Ítalo Braga
• Format: Article
• Language: English
• Subjects: Bioplastic; Contamination; Marine debris; Pollution; Technical standards
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.125957

While the use of biodegradable polymers is recognized as a global strategy to minimize plastic pollution, the technical standards (TS) used to attest their biodegradability may not be in compliance with most environmental parameters observed aquatic ecosystems. Indeed, through a careful assessment of the TS currently in use, this study evidenced that these guidelines cover only a fraction of the biogeochemical parameters seen in nature and largely disregard those that occur in the deep-sea. Thus, these TS may not be able to ensure the degradation of such polymers in natural environments, where microbial activity, pH, temperature, salinity, UV radiation and pressure are highly variable. This raises environmental concern, since relevant parcel of plastic ends up in the oceans reaching deep zones. Therefore, there is an urgent need to revise these TS, which must consider the actual fate of most plastic debris and include assessments under the challenging conditions found at these types of environment, alongside microplastic formation and ecotoxicology effects. Moreover, the next generation of biodegradability tests must be designed to enable a cost-effective implementation and incorporate accurate analytical techniques to assess polymer transformation. Furthermore, certification should provide information on time scale and degradation rates and, preferably, be globally harmonized. [Display omitted] •Certification of biodegradability do not reflect degradation in natural environments.•Ranges of biogeochemical factors observed on ocean are not covered by any guide.•New biodegradability certification schemes should be globally adopted.•Certification of biodegradable plastics must be tested under real ocean conditions.•Microplastics formation should be monitored in degradation experiments.