Linda S. Birnbaum, Ph.D., is a scientist emeritus and former director at the National Institute of Environmental Health Sciences and National Toxicology Program, and a scholar in residence at the Nicholas School of the Environment, Duke University.


The U.S. Food and Drug Administration (FDA) is responsible for protecting the public’s health and ensuring the safety of our nation’s food supply.

Sadly, as Politico reported this month, the agency “has repeatedly failed to take timely action on a wide range of safety and health issues the agency has been aware of for several years, including dangerous pathogens found in water used to grow produce and heavy metal contamination in baby foods.”

Here, I focus on another critical agency mandate: To protect the public from harmful chemicals in food and cosmetics. Here too the agency is failing to protect consumers.

Chemicals in food and cosmetics—whether present as additives or contaminants—usually do not cause immediate or obvious health effects, but they pose a significant longer-term risk to public health. Consumers want to know that their food and products they use every day are safe and that neither individual chemicals nor their cumulative impacts will harm their health. Congress directed the FDA to do this more than 60 years ago.

FDA’s 2013 review—a commitment unfulfilled

In the midst of growing external scrutiny and skepticism over scientific decisions about the safety of additives and contaminants like bisphenol A (BPA) and synthetic dyes, the FDA initiated a review of its chemical safety assessment program in its Center for Food Safety and Applied Nutrition. The review’s purpose was “to ensure that the agency is making the most effective and efficient use of its chemical safety resources” and was focused on the program’s scientific capacity and management.

The review included interviews with FDA scientists, as well as senior managers from other federal agencies who were experienced in chemical safety. Outside experts in the field commented on a final draft of the report and provided recommendations.

The interviewees’ responses to the science-related questions had a common theme: FDA’s guidance and methods to evaluate chemicals’ toxicities were outdated.

The agency staff and the external experts brought forward a number of issues, including that the FDA:

  • Lacks processes for identifying and managing risks of endocrine-disrupting chemicals;
  • Needs better data on effects of chemicals at low doses;
  • Lacks understanding of chronic toxicological effects;
  • Lacks adequate assessment of sensitive populations who may be at greater risk, like infants and those living in underserved communities; and
  • Needs to consider exposure to mixtures and related chemicals.

The review led to “the development of a process for updating FDA’s Toxicological Principles for the Safety Assessment of Food Ingredients” widely-known as the Redbook.

In 2014, the FDA took a step in that direction by posting the results of the review on its webpage and inviting public comment. Disappointingly, any subsequent action was put on hold, and remains so.

One of the problems highlighted by experts within and outside of the agency is that when it comes to chemical assessments at the FDA, regulatory science is too static and has evolved little since the 1980s, despite a tremendous growth in our understanding of chemicals and their effects on the body. The FDA has maintained its predilection to adhere to precedent regardless of whether scientific advances render that precedent misguided or irrelevant.

And with the agency’s “glacial pace of decisions,” there are few high quality precedents; FDA is in no rush to create new ones.

FDA’s inconsistent use of modern science

In many cases, the FDA fails to make its studies or scientific decisions on additives and contaminants readily available to the public. (Credit: FDA)


New in vitro, [e.g., cells in culture] and other short-term testing methods and epidemiological data have become available as scientific understanding of chemical hazards has evolved. The FDA is beginning to incorporate some of these newer approaches in its assessments and other processes. For example, the FDA used human data to support its decision to remove artificial trans fats from processed foods, and the agency’s evaluation of the persistence of per- or polyfluorinated alkyl substances (PFAS) demonstrated that residues of this class of chemicals in food were unsafe. While these examples are encouraging, the FDA has yet to make the systemic changes needed to modernize the scientific process for chemicals across the board.

Also, when the FDA has conducted a post-market review of a chemical that properly employs modern regulatory science to identify a significant public health risk, the management of such risks has too often been delayed, attenuated, or indefinitely postponed. For example, after scientists concluded that short-chain PFAS needed to be removed from the food supply as soon as possible because of bioaccumulation in humans, the agency gave companies five years to phase them out. Even worse, for cosmetics, actions on chemicals have often completely contradicted FDA’s science assessments. For example, the agency decided not to ban carcinogenic formaldehyde in hair treatments and it took several years to resolve industry’s objections to FDA’s decision to ban lead acetate in hair dye.

The FDA’s lack of transparency doesn’t build trust.

The FDA’s Center for Food Safety and Applied Nutrition has been described as “an incredibly insular and hard to understand place” and critics have said that the agency “sets a high bar for alerting the public of food chemical safety issues.”

Transparency in the Center’s scientific process and decision-making is an essential component that allows for improvements. During the 2012-2013 review, FDA scientists identified lack of transparency and communication about the agency’s activities and decision-making process as a barrier to building trust and credibility with the public, even while its scientists made valuable contributions to the advancement of science.

In many cases, the FDA fails to make its studies or scientific decisions on additives and contaminants readily available to the public, meaning Freedom of Information Act (FOIA) requests are often the only way the public can obtain important information. Additionally, slow responses to FOIA requests erodes trust further, does not promote transparency and review by independent scientists, and wastes agency resources responding to multiple requests for the same information.

Recommendations for the FDA

Dr. Robert Califf, the newly appointed FDA Commissioner, has the opportunity to reset the agency’s approach to chemicals safety, both in food and cosmetics. Here are recommendations on how to tackle six important challenges:

  1. Take steps to immediately update and modernize the scientific principles underpinning FDA’s chemical risk assessment process to consider long term effects of low-level chemical exposures, especially during fetal and childhood development. The agency must act when credible epidemiological evidence arises of effects on neurological, immune, reproductive, and endocrine systems, among others. This involves updating the Redbook and other regulatory science procedures.
  2. Where relevant, assess chemicals as a class/category and account for aggregate and cumulative exposures and health effects in assessing and managing chemical risks. This would reduce regrettable substitution of one chemical of concern for another to which it is closely related and lower health risks to consumers.
  3. Establish a group of agency experts dedicated solely to conducting post-market reassessments since these are a distinct effort from pre-market reviews. This group would develop a strategy, tools, and procedures to prioritize reassessment of prior decisions and take actions when needed. This expert group should systematically monitor the Adverse Event Reporting System, other agencies’ hazard determinations (e.g., carcinogens), post-market actions, and the scientific literature (e.g., epidemiology, new hazard information).
  4. Increase transparency of all CFSAN regulatory activities; any document that would be available to the public under FOIA should be immediately accessible without the need for a FOIA request.
  5. Coordinate closely with other federal and state agencies that conduct human health assessments on chemicals that contaminate and/or are added legally to food (e.g., hazard identification, exposure assessment, dose response assessment) to assure that FDA assessments include a complete set of up-to-date and rigorously-assessed toxicological, exposure, and epidemiological data.

In short, the FDA needs to take advantage of the opportunity to modernize its scientific approach to evaluating the safety of food and cosmetics chemicals, both prospectively and retrospectively, and to take stronger actions to protect the public’s health. Dr. Califf should seize the opportunity of his return to the agency to take on this public health challenge. The scientific, medical, and public health communities are ready to help him succeed.


*Original article online at https://www.ehn.org/fda-chemical-regulation-2657184101/fdas-inconsistent-use-of-modern-science