When a manufacturing deviation, product defect, or adverse event pattern raises questions about consumer or patient safety, companies need a structured, scientifically defensible way to assess the risk. A Health Hazard Evaluation (HHE) provides that framework.
An HHE is a formal, evidence-based assessment that evaluates and characterizes the risk of a product quality issue or inherent safety concern to cause harm. The FDA relies on HHEs to help classify recalls. Manufacturers use them to guide regulatory responses, defend against product liability claims, and make informed decisions about product corrective actions.
SafetyCall conducts HHEs across both human health and animal health product categories, drawing on a multidisciplinary team of physicians, pharmacists, and board-certified veterinary toxicologists. This article explains what an HHE involves, the scenarios that typically trigger one, and what to expect from the process.
What Is a Health Hazard Evaluation?
A Health Hazard Evaluation is a systematic scientific assessment of the potential health risk posed by a product defect, manufacturing deviation, or safety issue. It considers the nature and severity of the hazard, the likelihood that harm could occur, and the populations that could be affected.
Under 21 CFR 7.41, the FDA defines the health hazard evaluation process as an assessment conducted by an ad hoc committee of scientists that takes into account several factors: whether any illnesses or injuries have already been associated with the product, whether existing conditions could expose consumers or animals to a health hazard, which populations are at risk (including children, immunocompromised individuals, surgical patients, companion animals, or livestock), the seriousness of the potential hazard, the likelihood that the hazard will occur, and the consequences of the hazard both immediate and long-term. Based on an HHE, if a recall is indicated, the FDA assigns one of three recall classifications: Class I (reasonable probability of serious adverse health consequences or death), Class II (may cause temporary or medically reversible adverse health consequences), or Class III (not likely to cause adverse health consequences). Understanding where a deviation falls on that spectrum helps companies respond proportionately and document their reasoning.
Note for Readers
You may have encountered the term "health hazard evaluation" in connection with NIOSH, the National Institute for Occupational Safety and Health, which runs a separate federal program focused on workplace exposure concerns. This article addresses HHEs in the context of product safety for FDA-regulated products and their equivalents in other jurisdictions. Companies with products regulated by other agencies, including the CPSC, may also find the frameworks discussed here applicable to their safety assessment needs.When Is a Health Hazard Evaluation Needed?
Several situations commonly trigger the need for an HHE. Not every product quality concern rises to this level, but when one of the following scenarios occurs, a formal assessment is often necessary.
Manufacturing deviations. Out-of-specification ingredients, contamination, formulation errors, foreign material inclusion, stability failures, or pH deviations can all raise questions about whether a product is safe to remain on the market. An HHE provides the documented scientific rationale for the company's response.
Recall or regulatory action decisions. When a quality deviation is identified, companies and the FDA need to determine whether a recall is warranted and, if so, what classification applies. An HHE is central to that determination. It supports and facilitates communication with the FDA and provides the evidentiary basis for recall decisions.
Adverse event pattern recognition. A cluster of adverse event reports associated with a specific lot, formulation, or product line can indicate a safety signal worth investigating. In some cases, that investigation may lead to an HHE, particularly when the pattern raises questions about whether a product defect or quality issue is contributing to the reported events. More often, signal validation is the first step, and an HHE follows only if the investigation points to a specific product quality concern that warrants a formal risk determination.
Product liability and litigation support. When a product-related harm claim is made, companies need defensible documentation of their safety assessment process. An HHE conducted by credentialed medical and toxicology professionals provides the expert basis for evaluating the merit of claims and supporting litigation defense.
HHEs for Human and Animal Products
Although many HHE service providers focus exclusively on human health products, SafetyCall conducts HHEs across both human and animal product categories, which matters because toxicological considerations differ significantly between species.
Animal health products, including veterinary drugs, biologics, pesticides, pet supplements, and animal feed additives, carry their own regulatory requirements and safety considerations. Exposure levels that are tolerable in one species may be harmful in another. Food-producing animals introduce an additional layer of complexity because safety concerns may extend to the human food supply.
SafetyCall's team includes board-certified veterinary toxicologists who assess animal exposures, evaluate species-specific impacts, and support regulatory submissions to FDA's Center for Veterinary Medicine (CVM), EPA, and USDA's Center for Veterinary Biologics alongside the clinical toxicology team handling human health assessments. For products sold in Canada, SafetyCall also supports submissions to Health Canada's Veterinary Drugs Directorate (VDD), the Canadian Food Inspection Agency (CFIA), and Health Canada's Pesticides Regulatory Directorate (PRD), formerly called the Pest Management Regulatory Agency (PMRA). This dual capability reflects SafetyCall's position as the only adverse event management practice triple-licensed in medicine, pharmacy, and veterinary medicine.
What the HHE Process Involves
While every HHE is tailored to the specific situation, the process generally follows a structured sequence.
Information gathering. A chronological history of events, product quality investigations, relevant product data, adverse event reports, root cause analysis, product distribution channels and status, and applicable regulatory requirements are reviewed.
Hazard characterization. The nature and severity of the potential hazard is assessed based on available evidence, including toxicological data and clinical outcomes.
Population risk assessment. The likely affected population is identified, along with any subgroups at elevated risk. Risk analysis. The probability and mechanism of harm is evaluated, drawing on toxicological principles and clinical evidence.
Written report. The assessment is documented in a structured report that supports regulatory communication, internal decision-making, and, where applicable, litigation defense.
Who Conducts a Health Hazard Evaluation
The credibility of an HHE depends heavily on the qualifications of the team conducting it. Because the assessment may be reviewed by regulatory authorities, used in legal proceedings, or inform a public product recall, it needs to be defensible from both a scientific and regulatory standpoint.
SafetyCall's HHE consulting team includes board certified physicians, pharmacists, veterinary toxicologists, and basic scientists. Team members are academically affiliated and maintain active engagement with regulatory agencies and professional organizations. SafetyCall also draws on a network of credentialed external specialists when a case involves a specific area of expertise.
SafetyCall is licensed by the boards of medicine, pharmacy and veterinary medicine making it the only toxicology focused, triple licensed medical practice in the United States. This allows SafetyCall to conduct clinical assessments rather than regulatory guidance alone. That distinction matters when HHE findings need to hold up to scrutiny.
Common Questions About Health Hazard Evaluations
What triggers an FDA recall classification?
When a company is alerted to a product issue, they are expected to investigate. If they determine the product is violative, generally meaning it presents a risk of illness or injury, gross consumer deception or is in violation of a statute or product specific regulations, the company completes the HHE (or HRA for medical devices.) This is used to inform the company’s recall strategy, which includes the depth of the recall or recall classification. The recall strategy is then submitted to the FDA. The FDA completes its own HHE and reviews the recall strategy proposed by the company.
Can a company commission its own HHE, or does the FDA conduct it?
Companies are required to conduct their own HHE and routinely engage independent, authoritative and qualified experts concurrent with any regulatory action. An independent HHE conducted by qualified experts can support a company's position in discussions with the FDA, provide documentation for recall decisions, and establish a defensible record. The FDA conducts its own evaluations as part of the recall process, but they also rely on information provided by the manufacturer’s HHE.
How quickly can an HHE be completed?
The need for an HHE is often urgent, arising from a critical manufacturing finding or quality deviation that requires immediate attention. SafetyCall is prepared to respond quickly: in most cases, we can meet with a client and provide an initial verbal assessment within 24 hours. For relatively straight forward issues, a written report can typically be delivered within 2 to 5 business days when a rapid turnaround is required (depending on the required response time and complexity of the issue, expedited consulting fees may apply).
That said, timelines vary considerably depending on the complexity of the situation. Some cases are resolved quickly once the available data is reviewed. Others, such as those involving unusual laboratory findings that require additional studies before a safety determination can be made, may extend over days or weeks. In those situations, SafetyCall works alongside the client throughout the process, helping them evaluate new information as it becomes available and supporting decisions about next steps. Every case is different, and we work with each client to meet their specific needs and timeline.
Do HHEs apply to dietary supplements and cosmetics? Yes. The underlying principles apply across product categories whenever a safety assessment is needed to evaluate the risk posed by a quality deviation or adverse event pattern. SafetyCall conducts HHEs across dietary supplements, cosmetics, consumer products, animal health products, and other regulated categories.
Working with SafetyCall on a Health Hazard Evaluation
A Health Hazard Evaluation is most useful when it is conducted by a team with both the clinical credentials and the regulatory experience to make the assessment meaningful. That combination is not always easy to find, particularly for companies that need coverage across both human and animal products.
SafetyCall works with companies across 12 industries to conduct HHEs and related product safety assessments. Whether you are responding to a manufacturing deviation or evaluating an adverse event pattern, we can discuss what an assessment would involve for your specific situation.
To learn more or discuss a specific situation, contact us or visit safetycall.com/consulting.