History of California Microplastics Legislation

California has a long history of leadership in trash management – a consequence of California’s population density and the ecological and economic importance of the state’s natural resources. Though previous efforts have been focused on the mitigation of large trash items, microplastics have recently come to the forefront as researchers have consistently found microplastics in almost every environmental compartment, including drinking water.

California’s first piece of legislation that specifically applied to microplastics was passed in 2008, when strict regulations were placed on the manufacture, handling and transport of pre-production plastic pellets. Then, in fall 2015, Assembly Bill 888 prohibited the sale of personal care products containing plastic microbeads – only a few months prior to enactment of a similar federal ban.

Most recently, in 2018, the California Legislature adopted a pair of bills that require the State to begin building microplastics management strategies for both drinking water and California’s coastal ocean and estuaries. Senate Bill 1422 requires the California State Water Resources Control Board to develop plans for measuring microplastic particles in drinking water by 2021. Senate Bill 1263 requires the California Ocean Protection Council to adopt and implement a statewide strategy for lessening the ecological risks of microplastics to coastal marine ecosystems.

Efforts to meet the requirements of Senate Bills 1422 and 1263 are ongoing, and SCCWRP has taken a leadership role in facilitating the completion of each of these mandates. Specifically, SCCWRP hosted a Microplastics Measurement Methods Workshop in spring 2019, where microplastics experts from around the world came together to begin discussing appropriate methods and best practices for measuring microplastics in the environment. This workshop culminated in an intercalibration study, launched in fall 2019, to evaluate the various proposed measurement methods; more than 35 research groups are participating. The results of this study will directly inform which methods are selected by the State to monitor microplastics in drinking water and the environment.

In fall 2020, SCCWRP is launching a multi-component Microplastics Health Effects Workshop in which an international group of experts will convene to identify the primary pathways by which microplastics affect biota, prioritize the microplastics characteristics (e.g., size, shape, polymer) that are of greatest biological concern, and identify critical thresholds for each at which those biological effects become pronounced.

The first part of the Microplastics Health Effects Workshop involves a webinar series during which internationally-renowned microplastics experts will summarize current knowledge and discuss the latest findings regarding microplastics toxicity. Representatives from the State Water Resources Control Board and the Ocean Protection Council will also share their perspectives about how such science will be used in meeting the legislative mandates.