Making Good Choices in HAZMAT Response: When Industrial Hygienists Are Essential

This article was written by Bernard L. Fontaine, Jr., D.B.A., M.Sc., CIH, CSP, FAIHA. For more information about his professional experience and the American Industrial Hygiene Association (AIHA), please refer to the biography section at the end of the article.

Introduction

Hazardous materials (HAZMAT) incidents—including chemical fires, industrial explosions, pipeline releases, and transportation accidents—require rapid, high-consequence decision-making under conditions of uncertainty. Incident commanders, emergency managers, firefighters, and HAZMAT technicians are trained to control hazards, stabilize scenes, and protect life and property. However, protecting responder and public health requires more than tactical control; it requires informed evaluation of exposure risk.

Industrial hygienists (IHs) bring expertise in exposure science, toxicology, and occupational health that directly supports these decisions. Their role is not to replace command authority or operational control, but to inform them. Good choices in HAZMAT response are not defined solely by stopping a release or extinguishing a fire—they are defined by whether unnecessary exposures are prevented, health risks are recognized early, and long-term consequences are minimized. This is where industrial hygiene becomes essential.

Keywords: Hazardous materials, emergency response, industrial hygiene, exposure assessment, air monitoring, PPE, ICS

Where Industrial Hygienists Fit in the Response Lifecycle

IHs are most effective when integrated across the full hazard lifecycle—before, during, and after an incident. Extensive industrial facilities, utilities, refineries, laboratories, and research institutions often employ IHs in-house or through either corporate or consulting safety and health functions. In these organizations, IHs are routinely involved in pre-incident activities such as hazard identification, exposure risk assessments, SDS development and interpretation, emergency response planning, training, and pre-incident air monitoring strategies.

During an incident, IHs support Incident Command or Unified Command by evaluating potential and actual exposures, recommending air monitoring strategies, interpreting data, advising on PPE selection, and anticipating secondary or evolving hazards. After the emergency phase, IHs play a critical role in re-entry decisions, contamination assessment, cleanup oversight, exposure documentation, medical surveillance support, and after-action reviews. This continuity helps bridge preparedness, response, and recovery - an often-missing link in emergency management.

HAZMAT Incidents Are Exposure Incidents

Every HAZMAT incident is fundamentally an exposure scenario. Fires, explosions, and releases rarely involve a single, well-defined substance. Responders and nearby communities may be exposed to complex mixtures of gases, vapors, particulates, and combustion byproducts. Heat and fire frequently transform materials into new hazards, including carbon monoxide, hydrogen cyanide, metal fumes, respirable crystalline silica, and polycyclic aromatic hydrocarbons.

Placards, shipping papers, and odor recognition are insufficient for managing these risks. IHs are trained to anticipate what is likely present—even when it cannot be immediately identified or measured—and to guide protective decisions using toxicological principles rather than assumptions. OSHA’s HAZWOPER standard explicitly recognizes this uncertainty, emphasizing that emergency response must address both known and potential hazards, including those generated by fire and decomposition (29 CFR 1910.120).

The Value of Industrial Hygienists in Early Decision-Making

The earliest decisions at a HAZMAT scene often have the most significant impact on health. Isolation distances, evacuation or shelter-in-place orders, PPE selection, and approach strategies all influence exposure outcomes. IHs provide essential input when materials are burning or reacting, multiple or unknown substances are involved, responders face inhalation or dermal risks, or conditions are rapidly changing due to weather or fire behavior.

Common pitfalls—such as underestimating the effects of combustion products, prematurely downgrading respiratory protection, or declaring areas safe based on limited data—are often the result of incomplete exposure evaluation rather than poor intent. Industrial hygiene expertise helps Incident Command make defensible, health-protective decisions under uncertainty.

An on-call IH from the company’s corporate OEHS team was brought into the incident command structure within the first hour. The IH reviewed process chemistry and recent maintenance change, identified the most credible release candidates based on temperature, pressure, and odor threshold, and distinguished between acute irritants and systemic toxicants. Using a photoionization detector (PID), the IH prevented overinterpretation of high total VOC values and avoided escalation based solely on screening data. 

The IH’s training and experience applied exposure banding principles to select appropriate respiratory protection while avoiding the use of Level A suits, which would have increased heat stress and slowed the response time. Additionally, the IH defined safe re-entry criteria using conservative occupational exposure limits, established air-monitoring checkpoints and decision thresholds, and enabled controlled, limited entry rather than a blind shutdown.

Accessing Industrial Hygiene Expertise in Smaller Organizations

Many small and mid-sized organizations, including municipal fire departments and smaller industrial operations, do not employ full-time Industrial Hygienists. In these cases, IH expertise is typically accessed through regional consultants, emergency response contractors, environmental firms, insurers, corporate mutual-aid agreements, or public-sector resources.

The challenge is rarely availability—it is timing. Organizations that pre-identify IH resources and integrate them into emergency response plans are far more likely to receive timely, actionable support during an incident. Without planning, IH involvement often occurs after critical decisions have already been made or exposures have occurred. For emergency managers and safety professionals, planning for access to IH expertise is a practical component of preparedness, not an optional enhancement.

Small companies face the same HAZMAT risks as large organizations but usually without dedicated OEHS staff, emergency response teams, or on-site industrial hygienists. The goal is not to become experts overnight, but to know what resources to use, when to use them, and how to make defensible decisions under pressure. Small companies do not need a full-time IH, but they should pre-identify access to one. Here are a few suggestions to obtain the proper support by hiring a part-time or retainer-based consultant. An insurance workers’ compensation carrier can provide loss-control or IH services as part of the policy or a request for additional support. Good decisions in emergencies depend on relationships built in advance.

Air Monitoring Requires Interpretation, Not Just Instruments

Air monitoring is central to modern HAZMAT response, but instruments alone do not define risk. Real-time monitors have limitations, including cross-sensitivities, detection thresholds, and blind spots for specific compounds. “Non-detect” does not necessarily mean “no hazard.” 

IHs help select appropriate environmental air monitoring strategies, interpret ambiguous or conflicting readings, recognize instrument limitations, and translate data into operational guidance. OSHA and NFPA emphasize that air monitoring results are interpreted appropriately to support protective decisions. Without this specialized expertise, data can provide false reassurance—or drive unnecessary risk-taking.

Industrial Hygienists in Real-Time Emergency Operations

During active incidents, IHs operate under the same constraints as other responders: incomplete data, time pressure, and rapidly changing conditions. Their value lies in informed judgment and professional experience rather than perfect measurement. IHs assist Incident Command by applying toxicology, exposure modeling, and conservative assumptions when uncertainty is high.

In real-time, IHs advise on sampling locations, likely undetected hazards, PPE selection and downgrade timing, and how fire and explosive behavior, suppression activities, or weather may alter exposure pathways. Equally important, they help communicate uncertainty—clarifying when decisions are precautionary rather than definitive—so that responders understand both the risk and the rationale.

Emergency response phone services are often the first point of contact for experts during a hazardous materials incident. Callers are under stress, information is incomplete, and decisions must be made quickly. This is where IHs add critical value either by telephone or onsite. Rather than replacing emergency response specialists, IHs strengthen and support the decision-making process by translating exposure science into clear, actionable guidance.

For example, a plant supervisor calls an emergency response phone service to report a strong chemical odor, eye and throat irritation among workers, or a spill involving an unfamiliar intermediate chemical. The IH on the phone gathers initial facts, such as the route of exposure, symptoms, and what is known about volatility, odor threshold, and acute toxicity. 

The IH can inform the emergency responder about what the instrumentation can and cannot tell us about VOC readings, and how odor perception can occur well below harmful concentrations.

The IH helps the emergency responder communicate measured caution, not panic. IHs can apply exposure banding logic, compare reported conditions to occupational exposure limits, and balance chemical risk against heat stress and physical hazards. They can establish safe re-entry criteria, define monitoring checkpoints, identify when ventilation or isolation is sufficient, and determine when operations can safely resume. This allows the IH to guide the caller through controlled, defensible decisions rather than all-or-nothing actions. Together, they provide credible, calm, and scientifically grounded guidance at the exact moment it is needed most.
When emergency response phone services integrate IH expertise, worker and responder exposures are reduced, unnecessary evacuations are avoided, downtime is minimized, regulatory compliance decisions are more defensible, and trust with authorities and the community is preserved. In many cases, the cost of the call is trivial compared to the losses avoided.

Fire, Re-Entry, and Long-Term Health Protection

When fires are controlled and visible hazards are gone, health risks often remain. Combustion byproducts, settled particulates, contaminated debris, and off-gassing materials can pose ongoing exposure risks during overhaul, cleanup, and re-entry. IHs are essential for evaluating these conditions, establishing clearance criteria, documenting exposures, and supporting long-term health surveillance. 

Delayed occupational and public health effects—including respiratory disease, cancer, and cardiovascular impacts—underscore the importance of documenting exposure and conducting follow-up. IHs help ensure that response decisions protect not only today’s responders, but also their long-term health.

Conclusion

Effective HAZMAT response depends on informed decision-making grounded in exposure science. IHs are essential team members whenever health risks must be evaluated—not just when immediate hazards are controlled.
•    Firefighters suppress hazards.
•    HAZMAT teams contain releases.
•    IHs protect health—during incidents and long after they end.

Integrating IH expertise into emergency management and incident response leads to better and more informed decisions, safer work tasks for responders, healthier communities, and stronger recovery outcomes. In HAZMAT response, that contribution is essential—not optional.

References

1.    Occupational Safety and Health Administration (OSHA). 29 CFR 1910.120 – Hazardous Waste Operations and Emergency Response (HAZWOPER).
2.    Occupational Safety and Health Administration (OSHA). 29 CFR 1910.134 – Respiratory Protection.
3.    National Fire Protection Association (NFPA). NFPA 472 / NFPA 1072: Standard for Competence of Responders to Hazardous Materials/Weapons of Mass Destruction Incidents.
4.    International Labour Organization (ILO). Guidelines on Occupational Safety and Health Management Systems (ILO-OSH 2001).
5.    World Health Organization (WHO). Health Effects of Particulate Matter and Air Pollution from Fires.

About the author

Dr. Fontaine has over 49 years of professional and business experience in regulatory compliance, insurance, national defense, environmental services, and consulting.  He is a board-certified Industrial Hygienist (CIH), board-certified Safety Professional (CSP), and an American Industrial Hygiene (AIHA) Fellow.     
Thank you to all of the IHs who provide technical support for nationwide emergency management and responder services to law enforcement, firefighters, and HAZMAT units. For more details, visit the American Industrial Hygiene Association (AIHA) website at https://www.aiha.org/