News from CRIS: Science vs. Sensation - Bisphenol A (BPA)
March 30, 2026
If you’ve been following the BPA conversation over the past decade, you probably have a vague sense that the science kept shifting, regulators kept disagreeing, and at some point, you stopped being sure whether your reusable water bottle was safe.
We’re seeing more sensationalized headlines and conversation about BPA. Let’s take a look at what the current evidence says.
Top Takeaways
- BPA is a widely used chemical in plastics and food packaging that has been studied for decades.
- The CLARITY-BPA study is the most comprehensive research effort to date and helps bridge gaps between academic and regulatory science.
- Large regulatory studies have not found consistent evidence of harm at typical human exposure levels.
- Some academic studies raise questions about low-dose effects, but results are inconsistent and often not reproducible.
What is BPA, and where do we find it?
Bisphenol A (BPA) is a chemical ingredient that’s been used since the 1960s to make polycarbonate plastics and epoxy resins. It is used in a wide range of everyday products like the lining inside metal food cans, reusable plastic containers, bottle caps, water pipes, and even thermal paper receipts.
Because of that widespread use, exposure is widespread as well. Biomonitoring studies in the United States have consistently shown that most people have detectable levels of BPA in their bodies. That’s not inherently alarming because we know that detection doesn’t mean harm. It reflects how widely the material is used.
Why are people worried about BPA exposure?
Due to the widespread use of BPA in plastics, researchers investigated the ingredient to determine whether it harms our health. Some researchers are concerned that, at low doses, BPA can mimic estrogen to an extent that it could interfere with normal hormone signaling.
It’s important to remember that hazard and risk are not the same thing. The fact that a substance can interact with biological systems does not automatically mean it does cause harm at real-world exposure levels.
What was done to investigate BPA safety exposure?
To address years of conflicting research, the National Toxicology Program (NTP), the U.S. Food and Drug Administration (FDA), and the National Institute of Environmental Health Sciences (NIEHS) launched the CLARITY-BPA program.
The CLARITY-BPA program developed one of the largest and most expensive studies ever conducted on a single chemical ingredient, costing roughly $30 million. The program lasted 5 years and was intentionally designed to resolve long-standing disagreements in BPA research.
It combined a large, guideline-compliant regulatory study (the kind typically used for safety decisions) with a series of independent academic laboratory studies exploring specialized endpoints. Uniquely, both sets of researchers worked from the same pool of animals, under the same exposure conditions, and with blinded samples to reduce bias.
Blinded samples were critically important because they ensured that researchers were unaware which animals were exposed to high, low, or no BPA. This means it eliminated many common biases, resulting in a much stronger outcome.
By using shared, blinded samples and identical exposures, the goal was to determine whether differences in findings were due to study design or true biological effects. Ultimately, it aimed to improve how we evaluate chemical safety.
To continue reading this article, please visit: https://cris.msu.edu/news/science-vs-sensation/bisphenol-a-bpa/.