Hazardous Materials, MCIs, and Incident Management

Zones & EMT responsibilities

A hazardous materials scene is divided into three zones, and which one you may stand in depends on your level of training. The table below describes them.

Table 39.1Zones & EMT responsibilities

EMTs are typically trained to the Awareness level and sometimes to the Operations level, but not to the Technician level; it is the Technician-level responders who actually plug and patch a release. Your responsibilities are to recognize that an incident involves hazardous materials, to call for the resources it will take, to control the scene, and to identify the substance safely from a distance. Treat every patient who leaves the site as contaminated until it is proven otherwise.

Identifying the substance

Identify the substance only by methods that keep you away from it. Read placards through binoculars rather than approaching them, and use the National Fire Protection Association (NFPA) 704 numeric and color coding, the Department of Transportation (DOT) placards, the shipping papers and the Safety Data Sheets (SDS). No one source can be trusted on its own: studies show that 25 to 50% of placards can be incorrect, so always cross-confirm the substance against several sources.

Several references are available to you. The Emergency Response Guidebook (ERG) is the first of them, CHEMTREC can be reached at 800-424-9300, and poison control centers, which are often overlooked at these incidents, can give useful guidance on decontamination and treatment.

Decontamination

Patients at a hazardous materials incident sort into 4 types: those who are uninjured and not contaminated, those who are injured and not contaminated, those who are uninjured and contaminated, and those who are both injured and contaminated.

Decontamination itself happens in phases. Gross decontamination removes the majority of the material, secondary decontamination removes most of what remains, and tertiary decontamination is carried out at the hospital. Throughout, keep hold of one principle: water dilutes, it does not neutralize most substances.

Some parts of the body hold residual contamination and are easily missed. Pay particular attention to the scalp and hair, the groin, the buttocks, the armpits, the spaces between the fingers and toes, the ear canals and the navel.

MCI definition & disaster plans

A multiple-casualty incident (MCI) is not defined by any fixed number of patients. What defines it is that the patients challenge or hamper the ability of the EMS system to respond to them, so the same number of casualties may be an MCI in one system and routine in another.

The response to such an incident rests on a disaster plan, and a plan is worth having only if it meets four conditions. It must be written for the events that are conceivable locally, it must be well publicized, it must be realistic, and it must be rehearsed.

Incident Command System (ICS)

The Incident Command System (ICS) is a subset of the National Incident Management System (NIMS). It divides an incident into Command, Operations, Logistics, Planning and Finance, and it keeps span of control, the number of people reporting to any one supervisor, to between 3 and 7.

Command takes one of two forms. Under single incident command, one agency controls everything. Under unified command, several agencies cooperate while each keeps control of its own resources, and that arrangement works best at a large or complex incident.

Communication follows the same discipline. Only Command speaks to dispatch and only Command requests resources; everyone else speaks to their own direct supervisor. The alternative is freelancing, meaning uncoordinated activity by people acting on their own, and freelancing is a leading cause of injury and death on scene. Organizing early and aggressively is what prevents it.

Triage — priority categories

Triage sorts patients by how urgently they need care, and each patient is tagged with a color that tells everyone who reaches them where they stand. The table below gives the priorities and what puts a patient in each.

Table 39.2Triage — priority categories

The priorities depend on the resources available. A patient in cardiac arrest is tagged Priority 4, black, while resources are limited, and can become Priority 1 if resources later become available.

START triage — RPM

START triage is meant to be fast: about 30 seconds with each patient. What you assess is captured by the mnemonic RPM, for Respiration, Pulse and Mental status. Only 3 treatments are permitted while triaging: opening the airway and inserting an oropharyngeal airway (OPA), controlling bleeding, and elevating an extremity.

The table below gives the criteria that place a patient in each category.

Table 39.3START triage — RPM

Patients who can walk are assigned Priority 3, green, at the outset, but they must be triaged again, since they can deteriorate.

Transportation & staging logistics

No ambulance transports a patient until the transportation supervisor approves the move. It is the transportation officer, and not the individual EMTs, who communicates with the hospitals. Routing it all through one person keeps radio traffic to a minimum and stops any single hospital from being sent more patients than its surge capacity can absorb.