The Food and Drug Administration (FDA) developed an oral cadmium (Cd) toxicological reference value (TRV) range of 0.21-0.36 μg/kg bw/day, based on similar points of departure (POD) for the bone and kidney (urinary Cd 0.5 μg/g creatinine) and 50 μg/g in the kidney cortex. Increasing evidence suggests that Cd exposure also affects the cardiovascular system. We conducted a systematic review through mid-September 2025 to determine if the current TRV is protective of cardiovascular events. We screened the title and abstract of 1354 references and conducted a full text review for 123 manuscripts. Fifty-three studies were excluded based on inclusion and exclusion criteria and 12 additional studies were included from the 2022 FDA systematic review for a total of 82 references. Animal studies indicated that Cd concentrations of 1-5 mg/L in drinking water resulted in elevated blood pressure in rats. For the epidemiological data, moderate evidence supports that atherosclerosis, myocardial infarction, cardiovascular mortality and blood pressure are presumed hazards to human health. Blood and urinary Cd levels for these effects are reported at ≥0.5 μg/g creatinine, respectively, the same POD used for the current TRV. Therefore, the current TRV of 0.21-0.36 μg/kg bw/day is protective of cardiovascular effects.

The FDA monitors deoxynivalenol in the food supply, with an advisory level of 1,000 ng/g established for finished wheat products. To better understand the presence of deoxynivalenol and related type B trichothecenes─nivalenol, 3- and 15-acetyl-deoxynivalenol, and deoxynivalenol-3-glucoside─in food products available in the United States market, we developed and validated a liquid chromatography-tandem mass spectrometry method for their determination. Using this method, we analyzed a convenience sampling of 61 infant/toddler products and 35 grain-based food products. The overall detection rate for the five type B trichothecenes was 24% (23/96), with deoxynivalenol being the most frequently detected mycotoxin (15-312 ng/g) in 14 infant/toddler and 8 grain-based food products. Neither 3- nor 15-acetyl-deoxynivalenol was detected in any samples. Co-occurrence of deoxynivalenol-3-glucoside and deoxynivalenol was found in 8 of the 14 infant/toddler products with positive detects, with concentration ratios ranging from 0.1 to 0.7.

Mycotoxins are naturally occurring toxins produced by certain fungi. Exposure to mycotoxins may occur through the consumption of contaminated foods or from animals that are fed contaminated feed. To safeguard the nation's food supply, the U.S. Food and Drug Administration (FDA) utilizes a comprehensive mycotoxin program which samples and analyzes foods for surveillance and compliance purposes, including enforcing action levels. Mycotoxin analysis is at the center of the mycotoxin program, as concentration data are needed for data analysis, scientific assessments, and risk management. This review focuses on the Agency's continuous efforts to develop and incorporate fit-for-purpose analytical tools for mycotoxin analysis with particular focus on the relationship between analytical methodologies and scientific assessments. The discussion further highlights challenges and advancements in analytical methods and discusses future possibilities to develop analytical tools and preventative risk management approaches to meet the evolving regulatory needs.

IntroductionIdentification of chemical toxins from complex or highly processed foods can present ‘needle in the haystack’ challenges for chemists. Metagenomic data can be used to guide chemical toxicity evaluations by providing DNA-based description of the wholistic composition (eukaryotic, bacterial, protozoal, viral, and antimicrobial resistance) of foods suspected to harbor toxins, allergens, or pathogens. This type of information can focus chemistry-based diagnostics, improve hazard characterization and risk assessment, and address data gaps. Additionally, there is increasing recognition that simultaneously co-occurring mycotoxins, either from single or multiple species, can impact dietary toxicity exposure. Metagenomic data provides a way to address data gaps related to co-occurrence of multiple fungal species.MethodsPaired metagenomic and chemical data were used to evaluate aflatoxin-contaminated kibble with known levels of specific mycotoxins. Kibble was ground to a fine powder for both chemical and molecular analyses. Chemical analyses were performed with Liquid Chromatography Mass Spectrometry (LCMS) and according to the AOAC Official method 2005.08: Aflatoxins in Corn, Raw Peanuts, and Peanut Butter using Liquid Chromatography with Post-Column Photochemical Derivatization. Metagenomes were created from DNA extracted from ground kibble and sequenced on an Illumina NextSeq 2000 with an average sequence depth of 180 million reads per replicate.Results and discussionMetagenomic data demonstrated that the abundance of DNA from putative aflatoxigenic Aspergillus spp. correlated with the levels of aflatoxin quantified by LCMS. Metagenomic data also identified an expansive range of co-occurring fungal taxa which may produce additional mycotoxins. DNA data paired with chemical data provides a novel modality to address current data gaps surrounding dietary mycotoxin exposure, toxigenic fungal taxonomy, and mycotoxins of emerging concern.

Mycotoxins are naturally occurring toxins produced by certain fungi. Exposure to mycotoxins may occur through the consumption of contaminated foods or from animals that are fed contaminated feed. To safeguard the nation's food supply, the U.S. Food and Drug Administration (FDA) utilizes a comprehensive mycotoxin program which samples and analyzes foods for surveillance and compliance purposes, including enforcing action levels. Mycotoxin analysis is at the center of the mycotoxin program, as concentration data are needed for data analysis, scientific assessments, and risk management. This review focuses on the Agency's continuous efforts to develop and incorporate fit-for-purpose analytical tools for mycotoxin analysis with particular focus on the relationship between analytical methodologies and scientific assessments. The discussion further highlights challenges and advancements in analytical methods and discusses future possibilities to develop analytical tools and preventative risk management approaches to meet the evolving regulatory needs.

As part of the US FDA CFSAN's efforts to explore alternatives to animal testing, we retrospectively analyzed a sample of food additive (FAP) and color additive petitions (CAP) submitted to the FDA for the utility of dog study data in safety assessment. FAPs and CAPs containing dog studies (161 petitions) were classified as decisive (38%), supportive (27%), supplemental (29%) or undermined (6%) based on the impact the dog study data had on the final safety decision. Petitions classified as decisive were further categorized based on if the dog study data were used to a) address a safety concern (35/61); b) calculate an acceptable daily intake (ADI) (11/61); c) withdraw a petition (4/61); d) the effect was unique to the dog (2/61); or e) unclear (9/61). Of 11 petitions where the dog study was used to set an ADI, 7 contained studies where the points of departure (POD) from the dog studies were within an 8-fold range of the rodent with differences in study design likely contributing to the difference in PODs. Future research should include the development and use of qualified alternative studies to replace the use of animal testing for food and color additive safety assessment while ensuring human safety.

The U.S. Food and Drug Administration (FDA) developed an oral toxicological reference value (TRV) for characterizing potential health concerns from dietary exposure to cadmium (Cd). The development of the TRV leveraged the FDA's previously published research including (1) a systematic review for adverse health effects associated with oral Cd exposure and (2) a human physiological based pharmacokinetic (PBPK) model adapted from Kjellstrom and Nordberg (1978) for use in reverse dosimetry applied to the U.S. population. Adverse effects of Cd on the bone and kidney are associated with similar points of departure (PODs) of approximately 0.50 mu g Cd/g creatinine for females aged 50-60 based on available epidemiologic data. We also used the upper bound estimate of the renal cortical concentration (50 mu g/g Cd) occurring in the U.S. population at 50 years of age as a POD. Based on the output from our reverse dosimetry PBPK Model, a range of 0.21-0.36 mu g/kg bw/day was developed for the TRV. The animal data used for the animal TRV derivation (0.63-1.8 mu g/kg bw/day) confirms biological plausibility for both the bone and kidney endpoints.

Historically, allergic contact dermatitis (ACD) to chemicals encouraged hazard identification improvements, more sophisticated risk assessment and implementation of regulatory strategies, including banning of specific sensitising substances. The validation process applied to hazard identification methods demonstrates their accuracy; their use to characterise sensitiser potency facilitates quantitative and transparent risk assessment. Diagnostic patch testing at dermatology clinics worldwide delivers feedback showing where risk assessment/management has been insufficient or did not target the exposure of concern, thereby facilitating improvements. When urgent action to protect human health was required, regulations limited/banned, specific skin sensitisers. This can be seen in practice with the fragrance industry, a known source of ACD, thus requiring risk management, usually restrictions to limit allergy induction, and very rarely specific bans on ingredients. Experience and development of more sophisticated tools, e.g. to assess aggregate exposure from multitude of consumer product types, has led to repeated adaptation of risk assessment and promulgation of updated fragrance use limits. Although targeted control may not always lead to rapid change in the overall clinical picture, it is preferable to a blanket undifferentiated regulatory control of all sensitisers, resulting in unwarranted restrictions for many uses of no health concern, with consequent substantial socio-economic impacts.

The U.S. FDA initiative, Closer to Zero, identifies actions the agency will take to reduce toxic element exposure from foods eaten by babies and young children with the goal for exposure to be as low as possible. In support of these efforts, this scoping review sought to characterize the available data for primarily dietary cadmium (Cd) exposure and adverse health effects in infants and children. Based on pre-determined inclusion and exclusion criteria, data were extracted from 59 epidemiology studies, and organ systems/anthropometric data supported by > 3 studies were discussed further. For children, most data available were categorized into the nervous (fullscale IQ and attention), cardiovascular (blood pressure) and urinary systems. Studies identified a negative association between urinary Cd and full-scale IQ, though this was dependent on age and sex. More data are needed to support the associations between Cd exposure and adverse nervous system effects. Studies suggested no association between Cd exposure and blood pressure. Data on renal effects in children were too few and diverse to draw conclusions. For infants, anthropometric measurements and birth timing were studied the most. Some studies found a negative relationship between Cd exposure and birthweight, particularly in females. This finding needs further investigation.

Scientific data characterizing the adverse health effects associated with dietary cadmium (Cd) exposure were identified in order to make informed decisions about the most appropriate toxicological reference value (TRV) for use in assessing dietary Cd exposure. Several TRVs are available for Cd and regulatory organizations have used epidemiologic studies to derive these reference values; however, risk of bias (RoB) evaluations were not included in the assessments. We performed a systematic review by conducting a thorough literature search (through January 4, 2020). There were 1714 references identified by the search strings and 328 studies identified in regulatory assessments. After applying the specific inclusion and exclusion criteria, 208 studies (Human: 105, Animal: 103) were considered eligible for further review and data extraction. For the epidemiologic and animal studies, the critical effects identified for oral Cd exposure from the eligible studies were a decrease in bone mineral density (BMD) and renal tubular degeneration. A RoB analysis was completed for 49 studies (30 epidemiological and 19 animal) investigating these endpoints. The studies identified through the SR that were considered high quality and low RoB (2 human and 5 animal) can be used to characterize dose-response relationships and inform the derivation of a Cd TRV.

The Centers for Disease Control and Prevention (CDC) utilizes a blood lead reference value (BLRV) to identify children with elevated blood lead levels (BLLs). At or above the BLRV, the CDC recommends actions be taken to reduce children's BLLs. In 2021, the CDC updated its BLRV to 3.5 μg/dL. To align with the CDC's updated BLRV, the FDA is updating its interim reference levels (IRLs) for lead from food to 2.2 μg/day for children and 8.8 μg/day for females of childbearing age. The updated FDA IRLs for lead will serve as a benchmark to evaluate whether lead exposure from food is a potential concern. The children's BLL associated with the updated IRL is less than those predicted by other agencies to result in 1 intelligence quotient point loss. Dietary lead exposure estimates for children in the U.S. suggest exposures greater than the mean may exceed the updated FDA IRL for children, indicating a need for additional efforts to reduce lead in foods consumed by young children. The US FDA is addressing this need by implementing its Closer to Zero action plan to reduce babies' and children's dietary exposure to toxic elements (e.g., lead, cadmium, arsenic, mercury) over time.

The goal of this study was to assess a cadmium (Cd) physiologically based pharmacokinetic (PBPK) model to evaluate Cd toxicological reference values (e.g. reference dose, tolerable intake, minimum risk level) adapted to the U.S. population. We reviewed and evaluated previously published Cd PBPK models and developed further adaptations to the 1978 Kjellström and Nordberg (KN) model. Specifically, we propose adaptations with updated U.S.-specific bodyweight, kidney weight and creatinine excretion models by using NHANES data as well as a stochastic PBPK model that provides credible intervals of uncertainty around mean populational estimates. We provide our model review and adaptations as well as present estimates from the newly adapted models using observed U.S. urinary Cd values as a function of gender and age and given dietary exposure as evaluated from NHANES/WWEIA and U.S. Total Diet Study data. Results show all newly adapted models provide acceptable mean estimates of urinary Cd in the U.S. The stochastic model provides credible intervals to further inform regulatory decision making. Validation of the estimated K-Cd concentration values was not possible as data for a representative population was not available. We developed a web-based tool implementing these models and other potential adaptations to facilitate PBPK model estimate comparisons.

In food safety, process pathway risk assessments usually estimate the risk of illness from a single hazard and a single food and can inform food safety decisions and consumer advice. To evaluate the health impact of a potential change in diet, we need to understand not only the risk posed by the considered hazard and food but also the risk posed by the substitution food and other potential hazards. We developed a framework to provide decision-makers with a multi-faceted evaluation of the impact of dietary shifts on risk of illness. Our case study explored exposure to inorganic arsenic (iAs) and aflatoxins through consumption of infant cereals and the risk of developing lung, bladder and liver cancer over a lifetime. The estimated additional Disability-Adjusted Life Year (DALY) in the U.S. from exposure to iAs and aflatoxin based on available contamination and consumption patterns of infant rice and oat cereal is 4,921 (CI 90% 414; 9,071). If all infant cereal consumers shift intake (maintaining equivalent serving size and frequency) to only consuming infant rice cereal, the predicted DALY increases to 6,942 (CI 90% 326; 12,931). If all infant cereal consumers shift intake to only consuming infant oat cereal, the predicted DALY decreases to 1,513 (CI 90% 312; 3,356). Changes in contaminant concentrations or percent consumers, that could occur in the future, also significantly impact the predicted risk. Uncertainty in these risk predictions is primarily driven by the dose-response models. A risk-risk analysis framework provides decision-makers with a nuanced understanding of the public health impact of dietary changes and can be applied to other food safety and nutrition questions.

3-chloro-1,2-propanediol (3-MCPD) and 3-MCPD esters are contaminants present in a variety of processed foods, including infant formulas. Toxicological data are unavailable in humans, but rodent studies have demonstrated renal and testicular toxicity from 3-MCPD and 3-MCPD esters. There is evidence that 3-MCPD esters are hydrolyzed in the digestive system, releasing 3-MCPD that would be absorbed and induce damage. We assessed absorption and metabolism of 3-MCPD and three 3-MCPD monoesters, 1-oleoyl (1-Ol), 1-linoleoyl (1-Li) and 1-palmitoyl (1-Pa) commonly found in U.S. infant formula using differentiated Caco-2 cells. After 1-hour incubation, all three monoesters released free 3-MCPD and free fatty acids (FFA) into Caco-2 cell supernatants. Free 3-MCPD had a high apparent permeability (P-app = 30.36 +/- 1.31 cm/s x 10(-6)) suggesting that it is freely diffusible and highly absorbed by intestinal epithelium. 1-Li released 3-4-fold more 3-MCPD than 1-Ol and 1-Pa over 1 h, suggesting that this variable release rates might contribute to the overall in vivo exposure to 3-MCPD. None of the monoesters or FFA were detected in basolateral supernatants, suggesting that these compounds do not cross the intestinal wall without further transformation. In summary, this study provides relevant data to advance knowledge of in vivo intestinal absorption and metabolism of 3-MCPD monoesters.

Current medical countermeasures for organophosphate (OP)-induced status epilepticus (SE) are not effective in preventing long-term morbidity and there is an urgent need for improved therapies. Rat models of acute intoxication with the OP, diisopropylfluorophosphate (DFP), are increasingly being used to evaluate therapeutic candidates for efficacy in mitigating the long-term neurologic effects associated with OP-induced SE. Many of these therapeutic candidates target neuroinflammation and oxidative stress because of their implication in the pathogenesis of persistent neurologic deficits associated with OP-induced SE. Critical to these efforts is the rigorous characterization of the rat DFP model with respect to outcomes associated with acute OP intoxication in humans, which include long-term electroencephalographic, neurobehavioral, and neuropathologic effects, and their temporal relationship to neuroinflammation and oxidative stress. To address these needs, we examined a range of outcomes at later times post-exposure than have previously been reported for this model. Adult male Sprague-Dawley rats were given pyridostigmine bromide (0.1 mg/kg, im) 30 min prior to administration of DFP (4 mg/kg, sc), which was immediately followed by atropine sulfate (2 mg/kg, im) and pralidoxime (25 mg/kg, im). This exposure paradigm triggered robust electroencephalographic and behavioral seizures that rapidly progressed to SE lasting several hours in 90% of exposed animals. Animals that survived DFP-induced SE (~70%) exhibited spontaneous recurrent seizures and hyperreactive responses to tactile stimuli over the first 2 months post-exposure. Performance in the elevated plus maze, open field, and Pavlovian fear conditioning tests indicated that acute DFP intoxication reduced anxiety-like behavior and impaired learning and memory at 1 and 2 months post-exposure in the absence of effects on general locomotor behavior. Immunohistochemical analyses revealed significantly increased expression of biomarkers of reactive astrogliosis, microglial activation and oxidative stress in multiple brain regions at 1 and 2 months post-DFP, although there was significant spatiotemporal heterogeneity across these endpoints. Collectively, these data largely support the relevance of the rat model of acute DFP intoxication as a model for acute OP intoxication in the human, and support the hypothesis that neuroinflammation and/or oxidative stress represent potential therapeutic targets for mitigating the long-term neurologic sequelae of acute OP intoxication.

Read-across (RAx) translates available information from well-characterized chemicals to a substance for which there is a toxicological data gap. The OECD is working on case studies to probe general applicability of RAx, and several regulations (e.g., EU-REACH) already allow this procedure to be used to waive new in vivo tests. The decision to prepare a review on the state of the art of RAx as a tool for risk assessment for regulatory purposes was taken during a workshop with international experts in Ranco, Italy in July 2018. Three major issues were identified that need optimization to allow a higher regulatory acceptance rate of the RAx procedure: (i) the definition of similarity of source and target, (ii) the translation of biological/toxicological activity of source to target in the RAx procedure, and (iii) how to deal with issues of ADME that may differ between source and target. The use of new approach methodologies (NAM) was discussed as one of the most important innovations to improve the acceptability of RAx. At present, NAM data may be used to confirm chemical and toxicological similarity. In the future, the use of NAM may be broadened to fully characterize the hazard and toxicokinetic properties of RAx compounds. Concerning available guidance, documents on Good Read-Across Practice (GRAP) and on best practices to perform and evaluate the RAx process were identified. Here, in particular, the RAx guidance, being worked out by the European Commission’s H2020 project EU-ToxRisk together with many external partners with regulatory experience, is given.

3-Monochloropropa-1,2-diol (3-MCPD) is a food processing contaminant in the U.S. food supply, detected in infant formula. In vivo rodent model studies have identified a variety of possible adverse outcomes from 3-MCPD exposure including renal effects like increased kidney weights, tubular hyperplasia kidney tubular necrosis, and chronic progressive nephropathy. Given the lack of available in vivo toxicological assessments of 3-MCPD in humans and the limited availability of in vitro human cell studies, the health effects of 3-MCPD remain unclear. We used in vitro human proximal tubule cells represented by the HK-2 cell line to compare short- and long-term consequences to continuous exposure to this compound. After periodic lengths of exposure (0-100 mM) ranging from 1 to 16 days, we evaluated cell viability, mitochondrial integrity, oxidative stress, and a specific biomarker of proximal tubule injury, Kidney Injury Molecule-1 (KIM-1). Overall, we found that free 3-MCPD was generally more toxic at high concentrations or extended durations of exposure, but that its overall ability to induce cell injury was limited in this in vitro system. Further experiments will be needed to conduct a comprehensive safety assessment in infants who may be exposed to 3-MCPD through consumption of infant formula, as human renal physiology changes significantly during development.

FDA developed the interim reference level (IRL) for lead of 3 μg/day in children and 12.5 μg/day in women of childbearing age (WOCBA) to better protect the fetus from lead toxicity. These IRLs correspond to a blood lead level (BLL) of 0.5 μg/dL in both populations. The current investigation was performed to determine if the IRL for WOCBA should apply to the general population of adults. A literature review of epidemiological studies was conducted to determine whether a BLL of 0.5 μg/dL is associated with adverse effects in adults. Some studies reported adverse effects over a wide range of BLLs that included 0.5 μg/dL adding uncertainty to conclusions about effects at 0.5 μg/dL; however, no studies clearly identified this BLL as an adverse effect level. Results also showed that the previously developed PTTDI for adults of 75 μg/day lead may not be health protective, supporting use of a lower reference value for lead toxicity in this population group. Use of the 12.5 μg/day IRL as a benchmark for dietary lead intake is one way FDA will ensure that dietary lead intake in adults is reduced.

This work was carried out under official duties or contract with U.S. FDA.