The proposed bill, known as the "Microplastics Reduction Act," establishes a new chapter in Title 23 of the General Laws, which includes definitions for key terms such as "microplastics," "manufacturer," and "product." The act mandates that, beginning January 1, 2030, manufacturers are prohibited from selling, offering for sale, or distributing any products containing intentionally added synthetic polymer microparticles. This prohibition does not apply to products that are preempted from regulation by federal law.

Additionally, the bill requires the Department of Environmental Management, in consultation with the Department of Health, to develop a microplastics testing plan to determine if and when to regularly test water, soil, and other environmental media for the presence of microplastics, including those shed from vehicle tires. This testing plan must be made public by July 1, 2029, and updated every twenty-four months thereafter.

Furthermore, by January 1, 2030, the department is tasked with adopting and publishing a statewide microplastics strategy plan. This plan will include the characterization of ambient concentrations of microplastics, an assessment of the environmental and health impacts associated with microplastic contamination, an investigation of significant sources and pathways of microplastics, a summary of existing scientific research on reducing microplastics, and recommendations for policy changes or additional research needed to mitigate their environmental impact. The act will take effect upon passage.