Assessing Directives and Outcomes of Microplastic Study Bills in the U.S.

What if one of the most widespread pollutants on Earth was already in your body? You may
have consumed microplastics today without realizing it. They could have been in your bottled
water, floating through the air, or shed from the clothes on your back. Once considered a distant
ocean pollution issue, microplastics are now found in Antarctic ice, deep ocean trenches,
mountain peaks, and even in human blood and brain tissue.

While scientists race to understand the risks, lawmakers across the United States are still trying
to answer a more basic question: How do we regulate something so widespread and yet so
difficult to monitor, define, and measure?

This question became the foundation of our policy clinic project with Ocean Conservancy. Our
team analyzed nine state and federal laws focused on researching microplastics. Our goal was
to understand what these laws accomplished, what gaps in policy remain, and what future
lawmakers can learn from them.

Our Approach to Assessing Early Microplastics Policy

Microplastics are an emerging issue. A common first step legislators can take when regulating a
novel pollutant is to pass a law requiring an agency or entity to assess the existing scientific
landscape and provide policy recommendations; these are often known as “study bills.” Ocean
Conservancy tasked us with learning more about these efforts to date on microplastics.

In 2025, Ocean Conservancy released a “United States of Plastics” report, which assessed
state-level efforts to address plastic pollution. Study bills relating to microplastics were one of
several policy approaches reviewed in their report. Building on that work, we produced a report
that analyzed eight study bills identified in the United States of Plastics report and one additional
federal law, as shown in Figure 1. The purpose of our report is to communicate insights to
legislators, NGOs, and governmental agencies interested in addressing microplastic pollution.
Rather than treating study bills as the only next step, our report helps legislators, NGOs, and
government agencies see where existing studies already provide enough direction for more
targeted action.

Figure 1. U.S. states and federal microplastics study laws analyzed in our report, enacted between 2018 and 2024.

Methods for Preparing the Report

In producing this report, we started by conducting research on the laws of interest. This phase
of the project involved identifying legislative directives embedded in each law. From there, we
collected data on the outcomes of each directive by reading and analyzing publicly-available
reports. These reports helped us identify whether the requirements of the laws were met, not
met, or if the agency/entity needed additional support to comply with the legislation. We then
sorted the bills into thematic categories: comprehensive strategies, drinking water, microfibers,
and food systems to compare different legislative approaches.

During the final stages of developing our report, we presented our preliminary findings to Ocean
Conservancy staff and received feedback, which we incorporated into our conclusions.

Completing the Project: Takeaways From Our Report

● Upstream action is a commonly recommended solution: Nearly all of the reports that
we reviewed identified source reduction as a solution to pollution. In these solutions,
producers and consumers aim to reduce plastic contamination before it enters the
environment, including the ocean and freshwater systems. Such source reduction
approaches can range from reducing plastic production to adding filters to washing
machines.

● Clear reporting deadlines may increase accountability: Legislation that included
clear benchmarks and due dates appeared to increase likelihood of implementation. For
instance, In California, clear implementation deadlines for a statewide microplastics
strategy offered more accountability over a long time period. ..

● While study bills can be a first step, they are not a prerequisite: Although some
study bills have led to the development of microplastics policy, it may not be the best
approach for every state. Some states may be able to bypass the step by looking at
existing reports and assessments to determine what policies are priorities to directly
regulate microplastics.

● Reports identified that a lack of standardized testing can be a bottleneck: Several
agencies identified that the lack of standardized methods for testing, monitoring, and risk
assessment — especially at the national level — made it challenging to adopt
microplastic policies and regulations. While this was true across many of the reports, it’s
important to note that at least one of the laws we reviewed (SB 1422, California 2018)
resulted in a standardized definition and methodology for monitoring microplastics in
drinking water.

Why Our Project Matters

Microplastics are a widespread contaminant and require a suite of policy solutions to prevent
further pollution and harm. Our report delivers three crucial functions to facilitate future
regulation of microplastics pollution:

1. Streamlining information: A major goal of this report was to produce a resource that
compiled and streamlined scattered information about state-level microplastic policy
efforts.
2. Informing future legislation: Understanding the dynamics of existing efforts to address
microplastics could help future lawmakers craft stronger policy around this issue.
3. Highlighting efforts: State-level environmental policy often builds upon sustained
momentum in other states. By communicating and analyzing existing laws, our report
could encourage and inspire future action.

How EPM Prepared Us

The Policy Clinic experience helped us practice what we learned in the classroom and prepare
for our next steps as environmental decision-makers. In addition to coursework geared toward
completing this report, we participated in a prep seminar last fall that helped us develop project
management skills, navigate client relationships in a consultant capacity, and collaborate as a
team. We hope that the report reflects the team skills we have developed and applies our
technical knowledge and analytical tools in a way that addresses emerging environmental
policy.