Additional comments to RAC on the biodegradability exemption proposed in the restriction on intentionally added microplastics

ClientEarth and ECOS submit that the European Chemicals Agency's (ECHA) proposed exemption for 'biodegradable' microplastics lacks sufficient scientific evidence to ensure degradation in real-world environmental conditions. They argue that current laboratory tests at 20°C do not reliably predict biodegradation at lower average temperatures found in nature, such as 12°C in soil and fresh water or 9°C in marine environments. The organizations recommend that no exemption be granted at this stage to maintain incentives for improving testing criteria. Alternatively, they propose a more rigorous framework requiring each polymer and substance in a microplastic mixture to be evaluated separately, with specific ultimate degradation thresholds of ≥ 90% relative to reference materials within defined timeframes for water and soil.

• The proposed biodegradability criteria for microplastic exemptions are insufficient to guarantee degradation across all environmental compartments and real-world conditions, potentially undermining the restriction's goal of reducing environmental risks.
• There is a critical lack of scientific data to support the assumption that biodegradation rates observed at standard laboratory temperatures (20°C) are applicable to lower average environmental temperatures, specifically 12°C for soil and fresh/estuarine water and 9°C for marine water and sediment.
• ClientEarth and ECOS advocate for the complete removal of the 'biodegradable' microplastic exemption at this time to prevent the adoption of inadequate criteria and to encourage the development of better scientific tests.
• If an exemption is maintained, the authors propose a revised 'screening-tier' where each polymer and substance in a mixture must be tested separately, achieving ≥ 90% ultimate degradation relative to a reference material within 60 days for aquatic tests, 6 months for seawater/sediment interface tests, and 24 months for soil.
• For microplastics deliberately applied to soil, such as controlled-release fertilizers, the authors suggest the 24-month soil degradation window could be extended by the application period, provided the total does not exceed 48 months.

APA

ClientEarth (2019). Additional comments to RAC on the biodegradability exemption proposed in the restriction on intentionally added microplastics. https://www.clientearth.org/media/fpanuyzg/additional-comments-to-rac-on-the-biodegradability-exemption-proposed-in-the-restriction-on-intentionally-added-microplastic-coll-en.pdf

Chicago

ClientEarth. Additional comments to RAC on the biodegradability exemption proposed in the restriction on intentionally added microplastics. 2019. https://www.clientearth.org/media/fpanuyzg/additional-comments-to-rac-on-the-biodegradability-exemption-proposed-in-the-restriction-on-intentionally-added-microplastic-coll-en.pdf.

Wikipedia

{{cite press release |author=ClientEarth |title=Additional comments to RAC on the biodegradability exemption proposed in the restriction on intentionally added microplastics |date=September 2019 |url=https://www.clientearth.org/media/fpanuyzg/additional-comments-to-rac-on-the-biodegradability-exemption-proposed-in-the-restriction-on-intentionally-added-microplastic-coll-en.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@misc{clientearth2019additional, author = {{ClientEarth}}, title = {{Additional comments to RAC on the biodegradability exemption proposed in the restriction on intentionally added microplastics}}, publisher = {ClientEarth}, year = {2019}, month = sep, url = {https://www.clientearth.org/media/fpanuyzg/additional-comments-to-rac-on-the-biodegradability-exemption-proposed-in-the-restriction-on-intentionally-added-microplastic-coll-en.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }