Japan's Toray Industries has developed a new type of polyamide 4 (PA4) spherical particles, which the company says have been proven to biodegrade in the marine environment.

The company will provide samples and evaluate fine particles as cosmetic ingredients to replace traditional, non-biodegradable particles long used in cosmetics such as foundation and eyeshadow. Toray plans to promote technology development for mass production and sales, aiming to achieve commercialization by the end of March 2025.

Unlike the PA12 spherical particles Toray has produced so far, the new PA4 spherical particle products are biodegradable, with bacteria, fungi and other microorganisms breaking down organic compounds into simpler inorganic substances, including water and carbon dioxide. Biodegradation in the ocean is generally slower because the microorganisms in the ocean are not as abundant as in the soil.

Microplastic particles in cosmetics and facial cleansers pass through domestic sewage treatment and filtration systems and eventually enter the ocean. This undermines environmental biodiversity and marine pollution prevention efforts, prompting regulatory agencies around the world to begin restricting these materials. In September 2023, the European Chemicals Agency introduced new restrictions on microplastics in the annex to the REACH regulation. The use of intentionally added synthetic polymer particles smaller than 5 mm will be gradually restricted, with a total ban beginning in 2035.

Biodegradable PA4 offers a way to overcome these environmental and regulatory challenges.