FDA’s Allowable Level of Aluminum in Vaccines Based on Decades-Old Tests — but the Tests Had Nothing to Do With Safety

A new review of studies underpinning the FDA’s limit on the allowable level of aluminum adjuvant per vaccine dose reveals the level, set decades ago, was determined on the basis of how well the adjuvant generated an immune response — not on whether the aluminum posed a health risk.

by Jeremy R. Hammond

September 17, 2025 Children's Health Defense

In the mid-1900s, U.S. regulatory agencies set the limit for aluminum adjuvant in vaccines at 0.85 milligrams (mg) per dose. Because regulators never changed that limit, the Centers for Disease Control and Prevention (CDC) today claims that aluminum adjuvants “have been used safely in vaccines for more than 70 years.”

But how did regulators determine the 0.85 mg per dose limit in the first place? And what evidence exists today that it is safe to expose children who follow the CDC’s recommended childhood vaccine schedule to amounts of aluminum up to that limit?

Just because aluminum adjuvants have been used in vaccines for decades doesn’t mean it logically follows that this exposure to a known neurotoxin is harmless — especially considering that in addition to individual vaccines, children are exposed to cumulative amounts of aluminum via multiple vaccines on the CDC schedule.

To support its safety claim, the CDC states that “vaccines containing adjuvants are tested for safety and effectiveness in clinical trials before they are licensed for use in the United States.”

The CDC cites a U.S. Food and Drug Administration (FDA) webpage, which similarly states that aluminum-containing vaccines “have a demonstrated safety profile over many decades of use.”

According to the FDA webpage, “When evaluating a vaccine for safety and effectiveness, FDA considers adjuvants as a component of the vaccine; they are not approved separately.”

The problem with this reasoning is that clinical trials for vaccines are not designed to detect long-term harms — for example, later development of allergies, autoimmune diseases or neurodevelopmental disorders — from this aluminum exposure.

The FDA’s statement that adjuvants are not separately approved for safety translates into an admission that there is a dearth of toxicological data to support the claim that injecting children with aluminum-adjuvanted vaccines is harmless.

An article published on Aug. 26 in Environmental Toxicology and Pharmacology highlights this lack of safety studies. The paper, “Regulatory limits of aluminium content of vaccines have not been set based on toxicological studies,” is authored by French researchers Loïc Angrand, Ph.D., Romain K. Gherardi and Guillemette Crépeaux, Ph.D.

As the authors reveal, the 0.85 mg per dose limit, set decades ago, was based on immunological considerations — not on data demonstrating this amount to be non-toxic when injected into children. The limit was never intended to indicate an amount of aluminum that could be considered harmless to children.

Why do vaccine makers use aluminum adjuvants?

An adjuvant is a substance used in vaccines to stimulate a more inflammatory immune response, resulting in a greater downstream production of antibodies.

Vaccine manufacturers have long used aluminum as a preferred adjuvant to meet the regulatory requirements for immunogenicity, or a certain level of antibodies in the blood considered to protect against the virus targeted by the vaccine.

Under the existing regulatory framework, antibody titers commonly serve as a surrogate measure of immunity — even when no antibody level has been scientifically correlated to protection against infection or disease.

For instance, the aluminum-adjuvanted pertussis vaccine produced by GlaxoSmithKline Biologics (GSK) was approved by the FDA based on blood tests designed to measure the antibody response to the pertussis antigens included in the vaccine.

GSK admits in the vaccine’s package insert that this is not a scientifically validated approach. The insert states:

“The role of the different components produced by B. pertussis in either the pathogenesis of, or the immunity to, pertussis is not well understood. There is no well-established serological correlate of protection for pertussis.”

Such disclosures are legally required in package inserts because, although manufacturers were granted broad legal immunity under the 1986 National Childhood Vaccine Injury Act — which shifted the financial burden for vaccine injuries away from the pharmaceutical industry and onto the taxpaying consumers — they could still face lawsuits for making fraudulent claims about their products’ safety and effectiveness.

How did regulators determine the 0.85 mg/dose limit?

As Angrand and his colleagues pointed out in their paper, for many decades, aluminum adjuvants “have been regarded as safe by regulatory agencies” despite accumulating evidence of toxic effects in animals and humans.

This evidence of harm includes consistent observations that aluminum adjuvants can induce autoimmune disease and that the aluminum is biopersistent and translocates from the injection site to other tissues and organs — including the brain, where it accumulates.

In 2019, the Informed Consent Action Network (ICAN) sent Freedom of Information Act (FOIA) requests to the National Institutes of Health (NIH) and the Agency for Toxic Substances and Disease Registry (ATSDR), a subagency of the CDC, requesting studies the agencies used “to establish the safety of injecting infants and children” with aluminum adjuvants.

Both agencies responded to the FOIA request by stating that no such records could be located.

According to the researchers’ review of the documentary record, the maximum level of 0.85 mg of aluminum was set by the NIH in 1968. Regulatory authority over biological products, which includes vaccines, was transferred in 1972 to the FDA, which retained the 0.85 mg limit.

Digging deeper, the researchers obtained via FOIA request two NIH documents, which served as the basis for this upper limit.

The first document, from 1947, related to the manufacture of diphtheria toxoid. The second, from 1952, related to the manufacture of tetanus toxoid.

Those documents revealed that regulators set the 0.85 mg limit based not on any toxicological data but instead on immunogenicity data — the amount of aluminum adjuvant required to induce the intended immune response.

The 1947 document stated, “In all instances, the amount of aluminum used shall be the minimum needed to accomplish the purpose intended.”

A similar statement appears in the 1952 document. Neither document discussed aluminum toxicity.

The only safety references were requirements for the respective toxoid to be tested on mice and guinea pigs, at least two animals of each species, with at least one week of follow-up observation for immediately obvious symptoms or death, plus a “detoxification” test involving “at least 4 animals” observed for one month.

The researchers concluded that it “is difficult to see how these texts [of these documents] could serve as a reliable basis for ensuring the safety” of aluminum-adjuvanted vaccines routinely recommended for children today by the CDC.

The regulatory limit “established more than 60 years ago,” the authors summarized, was “originally based on the immunological efficacy of diphtheria and tetanus toxoids alone, rather than on robust toxicological evaluations” of aluminum adjuvants.

FDA admits safety is not the consideration

The NIH and FDA also explicitly acknowledged the French researchers’ note.

During a workshop on aluminum in vaccines in 2000, Dr. Michael Gerber from the NIH asked the FDA’s Dr. Norman Baylor if he could explain how regulators came up with the 0.85 mg per dose limit.

Baylor answered, “Unfortunately, I could not.”

He explained how they had “been trying to figure that out” from “the historical records,” but “just have been unsuccessful.”

Two years later, Baylor and his colleagues published a paper in the journal Vaccine in which they admitted that the 0.85 mg per dose limit “was selected empirically from data that demonstrated that this amount of aluminum enhanced the antigenicity and effectiveness of the vaccine.”

In other words, it was based on the perceived need to generate a high level of antibodies — not on considerations about the safety of injecting children with a known neurotoxin.

Aluminum adjuvants “have been proven to be safe,” Baylor and his colleagues nevertheless concluded, based on the circular reasoning that “vaccines using aluminum adjuvants have a demonstrated safety profile of more than six decades.”

According to the French researchers, “As it stands, the limit of 0.85 mg of Al [aluminum] per vaccine dose appears to be justified by historical precedent and not by rigorous scientific investigation corresponding to current vaccination schedules.”

In other words, the regulation establishing a limit of 0.85 mg per dose was never intended to indicate an amount of aluminum that could be considered harmless to children.

Neither was it completely arbitrary. It was simply a ceiling that ensured sufficient aluminum to provoke the desired immune response without being so reactogenic that signs of acute toxicity became almost immediately apparent in animal models.

Scientists, media apply double standards when interpreting observational data

In their paper, Angrand and his co-authors raised growing concerns about:

• Increasing aluminum exposure “among newborns, infants, children, teenagers, and pregnant women.”

• Use of aluminum-containing injections in lieu of placebos in clinical trials.

• Variability of measured aluminum content in vaccine vials bearing no relationship to amounts claimed by manufacturers.

• Lack of disclosure about the chemical nature of specific adjuvants.

• Lack of large epidemiological studies to examine long-term health effects.

• 
  

Among the epidemiological studies that have been conducted is a CDC study published in Academic Pediatrics in 2023. The study “revealed a significant association between cumulative vaccine-associated Al exposure before age 24 months and persistent asthma incidence at age 24 through 59 months.”

The release of that study was accompanied by typical reassurances that it is just observational data, a “flawed” study that we shouldn’t put too much weight into due to its methodological limitations.

This contrasts with the nature of reporting on observational studies that find no association between vaccines and harms. Those studies are routinely characterized as being so methodologically sound that we can regard their findings as absolutely conclusive.

Recent Danish study declaring aluminum safe draws fire

Such was the case with a recent study out of Denmark led by Niklas Worm Andersson, M.D., Ph.D., a Danish researcher with the Statens Serum Institut in Copenhagen.

The study examined the effects of aluminum-adjuvanted vaccines and a large number of childhood health outcomes, including atopic and allergic diseases, autoimmunity and neurodevelopmental disorders.

The media hailed the study as conclusive proof that aluminum from vaccines is harmless to children.

But as Angrand and his colleagues noted, “ongoing methodological debates about exposure assessment, exclusion criteria, adjustments used and data consistency from a subsequent erratum warrant cautious interpretation for the moment.”

Public comments on the Danish study, published July 15 in Annals of Internal Medicine, include a broad range of criticisms:

• Lack of an unexposed control cohort.

• Effective exclusion of children at higher risk.

• Biologically implausible findings of a protective effect of aluminum.

• Irreproducibility of their findings due to non-disclosure of data and modeling.

• Failure to control for the tendency of children at higher risk of the outcomes to receive fewer vaccinations (sometimes called “healthy vaccinee bias”).

• A duration of follow-up less than the average age of diagnosis for numerous outcomes.

• A contradiction between the authors’ claim to have found no evidence of harm and statistically significant associations shown in a corrected version of their supplement.

  
  

Danish study was biased, some critics say

Numerous critical analyses of the study have been written. In a critique published the same day as the study, research scientist and author James Lyons-Weiler, Ph.D., highlighted how the Danish researchers “adjusted” their data for number of general practitioner visits before age 2, thus mistakenly treating this number as though it were an independent variable.

This introduces collider bias, which occurs when two variables both influence a third — the “collider.” Treating a collider as a confounder and adjusting for it can conceal real associations between exposures and harms.

In this case, vaccinations can increase doctor visits due to side effects. Early symptoms of vaccine harms can also drive more doctor visits. The number of visits is thus influenced by both the exposure and outcome.

Moreover, the number of visits may in turn influence both factors: more visits can result in more vaccinations and more diagnoses, creating a self-reinforcing feedback loop.

Since it is not an independent variable, “adjusting” their data for the number of visits this way biased the study in favor of finding no association.

This, along with other methodological decisions, might explain why the study found statistically significant negative associations despite the biological implausibility of aluminum exposure being protective against atopic and allergic diseases, autoimmunity and neurodevelopmental disorders.

RFK Jr. calls for retraction of Danish study

In an article published on July 30 by the Brownstone Institute, Czech mathematician Tomas Fürst, Ph.D., and Danish medical researcher Vibeke Manniche, M.D., Ph.D., pointed out, among other problems with the study, how children at higher risk of measured outcomes were effectively excluded.

They also noted how the original supplement was replaced with a corrected version showing “a statistically significant association between certain neurodevelopmental outcomes — particularly autism and ADHD — and aluminum exposure from vaccines.”

U.S. Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. called for the study’s retraction in an article published by Trial Site News on Aug. 1, in which he summarized numerous ways that the study was biased in favor of the null hypothesis.

While the authors of the Danish study claim they “did not find evidence” for an increased risk, Kennedy also noted that their corrected supplementary data show significant associations. As he wrote:

“The data show a statistically significant 67% increased risk of Asperger’s syndrome per 1 mg increase in aluminum exposure among children born between 2007 and 2018.

“Compared to the moderate exposure group, for every 10,000 children in the highest aluminum exposure cohort, there were 9.7 more cases of neurodevelopmental disorder, 4.5 more cases of autistic disorder, and 8.7 more cases of the broader category of autism spectrum disorder.”

This is corroborated by a critique of the study by scientists with Children’s Health Defense (CHD) published on Aug. 5 at Preprints.org, an online server for papers that have not yet undergone peer review.

In that article, Karl Jablonowski, Ph.D., CHD’s senior research scientist, and Brian S. Hooker, Ph.D., CHD’s chief scientific officer, emphasize how, in the study’s original supplemental material, “the neurodevelopmental diagnoses of the sicker kids were deleted,” whereas “with the updated supplemental material, where those diagnoses were included” — and after restoring the omitted children — the data “yielded association between aluminum exposure and devastating neurodevelopmental disease.”

Describing it as “a flawed work with good supporting evidence of fraud,” Jablonowski and Hooker echoed Kennedy’s call for the study to be retracted.

Danish researchers refuse to retract study

The journal editors, however, have refused to retract the study, maintaining in a public comment on Aug. 11 that the study “found no evidence for a clear association” and is free of any “serious errors” that might invalidate their findings or indicate scientific misconduct.

In an article reiterating numerous flaws that together indicate the study was designed to find no association, Lyons-Weiler described the journal as being involved with “narrative curation rather than neutral scientific arbitration.”

In a public comment on their study responding to criticisms, Andersson and colleagues argued that the significant associations shown in their supplementary data could be dismissed because children born before 2002, who received fewer aluminum-containing vaccines, could not belong to the highest-exposure group, and that rerunning the analysis without those children erased the statistical significance.

Yet their primary analysis also compared exposures and outcomes across birth cohorts, including those born before 2002. The study was designed to test whether children with higher aluminum exposure, necessarily dominated by later-born cohorts, had higher risks of the outcomes.

This article was funded by critical thinkers like you.

The Defender is 100% reader-supported. No corporate sponsors. No paywalls. Our writers and editors rely on you to fund stories like this that mainstream media won’t write.

Please Donate Today

CDC relied on outdated, discredited analysis of aluminum-adjuvanted vaccine safety

To further support their conclusion that aluminum-adjuvanted vaccines are harmless, Danish researchers uncritically cited an FDA study by Robert J. Mitkus, Ph.D., et al., which the CDC relies on to support its claim that “the amount of aluminum exposure in people who follow the recommended vaccine schedule is low and not readily absorbed by the body.”

The CDC accompanies that assertion with the usual circular reasoning that aluminum adjuvants “have been used safely in vaccines for decades.”

In their paper revealing the absence of safety data underlying the regulatory limit of 0.85 mg per dose, Angrand and his colleagues allude to that FDA study by stating:

“Furthermore, the outdated and poorly documented theoretical views supporting these claims have been challenged by the increasing understanding of their nanoparticle nature, the unanticipated long-term persistence in immune cells, the ability to spread from the injection site throughout the body including brain, their neurotoxicity in animal models, and by the growing concerns about their potential role in neurodevelopmental and allergic disorders.”

The reference provided is “Critical analysis of reference studies on the toxicokinetics of aluminum-based adjuvants”, by Jean-Daniel Masson, Ph.D., et al., and published in the Journal of Inorganic Biochemistry in 2018.

The authors of that critique, which included Angrand’s associates, Crépeaux and Gherardi, noted how Mitkus and his co-authors inappropriately adopted a “minimal risk level” (MRL) defined for daily oral intake of soluble aluminum in mice — not the insoluble particulate form of aluminum injected into children.

The FDA researchers also made “erroneous calculations of absorption duration” and ignored systemic diffusion of aluminum particles, including into the brain, where it can cause neuroinflammation.

When I asked Crépeaux what the problem is with citing the FDA study by Mitkus as proof that aluminum adjuvants are safe, she said:

“The main problem is that more recent peer-reviewed studies have explained why Mitkus is wrong. The CDC should base its recommendations on up-to-date literature, and Mitkus is mistaken in various ways, as we explained in 2018 — already seven years ago!”

In their new paper examining the origins of the 0.85 mg per dose limit, Crépeaux and her colleagues conclude that there is an “urgent need for independent pharmacokinetic and toxicological studies” relevant to the CDC’s current vaccination schedule.

Ignoring the alarming failures of existing research to explore much less demonstrate safety, the authors remark, “would not make them disappear.”

The views and opinions expressed in this article are those of the authors and do not necessarily reflect the views of Children’s Health Defense.

Jeremy R. Hammond

Jeremy R. Hammond is an independent researcher and journalist focused on exposing deceitful mainstream propaganda serving to manufacture consent for harmful government policies.