Nowadays, the production of synthetic polymers commonly known as “plastic” is estimated around 450 million tons yearly1. The remarkable increase in the production over the last 70 years is due to its beneficial properties such as being a long-lasting, affordable and reusable material. However, this mounting production turned out to be the origin of one of the most critical environmental issues, plastic pollution.
Country strategies for plastic waste management often fall short in effectively recycling or incinerating plastic, leading to an accumulation that can contribute to environmental pollution2. Due to inefficient waste management and littering, a substantial proportion of plastic garbage is introduced in the natural environment, and due to global circulation, it ends up in the oceans. Ocean currents tend to concentrate floating plastic in oceanic central gyres, and hydrodynamics and winter storms accumulate them in exposed coastal areas called “hot spots”.
In the sea, wind, waves, microorganisms and especially sunlight slowly break down the plastics into small particles of less than 5 mm length, called “microplastics” (MPs)3. Large plastics threaten wildlife because of ghost fishing and obstruction of the digestive track, among other consequences4, but MPs also interact with living organisms and produce several deleterious effects whose severity is inversely related to their particle size5. However, the most relevant ecological risk posed by MPs is not related to particles themselves but to the release of chemicals used as functional additives during manufacturing of plastic materials6. Therefore, environmentally friendly plastics must not only degrade but also lack toxic chemical constituents potentially released during degradation. Moreover, some chemicals used in plastics may mimic the effects of natural hormones, acting therefore as endocrine disruptors interfering with hypothalamic-pituitary-thyroid/adrenal/gonadal axes7.
The European Environment Agency (EEA) highlighted that one of the sources of accumulation of MPs in the environment is the wearing and washing of textiles made from synthetic (plastic) fibres that constitutes more than 16% of the MPs found nowadays in marine environment. But they can be also found in drinking water systems and drifting through the air. Actions like implementing sustainable design and production processes, controlling MP emissions during use and improving disposal and end-of-life processing would reduce the release of these particles to the environment8.
At the beginning of the Glaukos project, literature review of previously available methods for the assessment of polymers’ biodegradation in marine environment was performed9,10. The lack of practical methods that can be representative of real marine conditions together with the absence of an ecological perspective in previously proposed analysis pushed us during the project to develop a practical, sensitive and highly standardized assessment scheme in order to identify truly “marine-friendly” polymers.
This integrative assessment scheme in terms of its potential impact on marine ecosystems is presented within the context of this project, which aims to develop sustainable and eco-friendly biopolymers to be used in fishing gears and textiles. However, it holds validity as a standard approach to develop marine-friendly polymers in general.

The aim of this deliverable (D6.4), is to propose a strategy of integrative assessment of novel plastic materials that allow the identification of truly innocuous plastics with regard to the marine environment, and to validate that strategy with polymers and coatings developed within the project. This deliverable is linked to milestone 6.2, “Project-validated methods + report on assessment of Glaukos products”.