FDA Highlights Critical Challenges in Detecting Microplastics in Food

Analytical limitations, inconsistent measurement methods, and uncertain contamination sources complicate efforts to assess microplastics and nanoplastics in food.

Microplastics and nanoplastics have attracted increasing attention as researchers investigate their presence in food and beverages. However, significant scientific uncertainties continue to limit reliable assessments of their potential effects on human health.

You can also read: Inside the Analytical Challenges of Measuring Microplastics

Plastics Engineering spoke with Dr. Raymond Peter Briñas, Senior Review Chemist in the Human Foods Program (HFP) at the U.S. Food and Drug Administration (FDA), about the scientific gaps preventing more definitive risk assessments, the challenges of detecting nanoplastics in complex food matrices, and the potential contribution of food packaging to particle contamination.

According to Briñas, current scientific evidence does not show that microplastic and nanoplastic levels detected in food pose a risk to human health. However, the FDA continues to monitor emerging research and advance analytical capabilities to address existing uncertainties.

Why Measuring Nanoplastics Remains Difficult

Microplastics and nanoplastics vary widely in size, shape, polymer composition, degradation state, and chemical additives. This diversity makes reliable identification and characterization particularly challenging.  According to the FDA, one of the biggest obstacles is the lack of validated analytical methods for complex food matrices. Food contains organic compounds that can share chemical characteristics with synthetic polymers, complicating particle isolation and identification. The challenge becomes greater at the nanoscale. Many existing microplastic detection techniques lack sufficient sensitivity to identify particles substantially smaller than one micrometer. Consequently, reliable nanoplastic measurements may require fundamental advances in analytical technology.

Why Published Results Are Difficult to Compare

Although numerous studies have reported microplastics in food, differences in sampling procedures, sample preparation, detection limits, and analytical techniques make their findings difficult to compare.

The FDA identified several considerations when interpreting reported concentrations:

• False positives: Some methods may incorrectly classify nonplastic particles as synthetic polymers.
• Unconfirmed particle identities: Certain studies report suspected microplastics without adequately verifying their polymer composition.
• Uncertain contamination sources: Researchers cannot always determine whether detected particles originated from packaging, processing, or environmental exposure.
• Inconsistent reporting metrics: Studies frequently report particle counts, although mass-based or surface-area-based measurements may offer greater toxicological relevance.

These limitations complicate comparisons between studies and prevent researchers from establishing consistent exposure estimates.

Validated Methods Are Essential for Regulatory Decisions

The FDA emphasized that analytical methods must demonstrate acceptable accuracy, precision, selectivity, detection and quantification limits, measurement uncertainty, and robustness under relevant testing conditions.

Researchers must also validate methods for their intended applications and the specific food matrices being analyzed.

Reference materials represent another critical requirement. Without well-characterized standards, laboratories cannot adequately establish whether their methods consistently identify and quantify target particles. The agency also highlighted the need to agree on appropriate concentration metrics before finalizing analytical workflows. The FDA has begun research to identify methods that can accurately and reproducibly detect, quantify, and characterize microplastics in human food.

Is Food Packaging a Source of Microplastics?

The potential contribution of plastic food packaging remains an important research question. According to the FDA, current evidence is insufficient to conclude that microplastics and nanoplastics migrate from plastic packaging into food and beverages.

To investigate this pathway, the agency identified several research priorities:

• Source identification: Distinguish packaging-derived particles from environmental contamination using rigorous experimental controls.
• Migration prevention: Investigate measures to reduce potential particle transfer from packaging and food-processing equipment.
• Nanoplastic detection: Develop methods capable of identifying nanoscale particles specifically associated with packaging materials.

These studies could help researchers determine whether packaging contributes to particle exposure and under which conditions.

What This Means for the Packaging Industry

For food-packaging manufacturers, the FDA’s responses reinforce the importance of reliable analytical evidence before drawing conclusions about contamination pathways or potential health risks. The agency evaluates the broader scientific literature rather than relying on individual studies when developing regulatory policies. It also collaborates with stakeholders, interagency working groups, and international organizations to advance measurement methods and consensus standards. The FDA said it would take regulatory action if scientific evidence shows that microplastics or nanoplastics in food, including packaged products, pose a risk to human health.

Until researchers establish reliable measurement methods and better characterize exposure, significant uncertainties will remain. For the packaging industry, advancing analytical science will be essential to understanding potential contamination pathways, evaluating material performance, and supporting evidence-based food safety decisions.