Abbreviations such as WMD (weapons of mass destruction) and CBRN (chemical, biological, radiological, and nuclear) are becoming more and more pervasive in the emergency response industry.
Firefighters and other first responders are seeing their missions expanded to deal with potential terrorism involving chemical, biological, or radiological agents.
Responses involving hazardous materials were traditionally the responsibility of selectively trained and equipped HazMat teams. But the magnitude of potential events and need for preparedness warrants that all first responders be schooled in techniques for handling the unique hazards associated with WMD-based terrorism incidents.
An important part of their readiness is in having appropriate personal protective equipment. To this end, a series of standards have been created to establish requirements for first responder clothing and equipment.
Standards have been established by two key organizations: the National Institute for Occupational Safety and Health (NIOSH), which has the responsibility for standards in equipment related to respiratory protection, and the National Fire Protection Association (NFPA), which has undertaken the development of several standards for protective ensembles for different emergency response applications.
NIOSH has created a series of standards for different kinds of respirators, including self-contained breathing apparatus (SCBA), air-purifying respirators (APR), powered air-purifying respirators (PAPR), and two types of emergency escape respirators. For each of these standards, specific criteria have been defined to offer respiratory protection against CBRN hazards.
These hazards include exposure to chemical warfare agents (e.g., sarin and mustard gas), toxic industrial chemicals (sometimes referred to as TICs, such as ammonia and phosgene), biological agents (e.g., anthrax), and radiological or nuclear particulates. CBRN protection does not address high energy ionizing radiation such as gamma and X-rays.
To gain CBRN approval, respirators submitted by manufacturers must meet rigorous criteria, with specialized testing by NIOSH above the normal certification requirements for the type of respirator. For example, APRs are evaluated for their service life against specific chemical agents only if they already meet the federally mandated requirements for APRs.
APRs can be used in environments where concentrations of hazardous substances are below immediately dangerous to life and health (IDLH) levels. CBRN SCBA must not only meet federal regulations, but also be certified to NFPA 1981, which sets the fire service requirements for SCBA. However, the NFPA 1981 was revised late last year so that CBRN approval is now a mandatory part of that standard. CBRN SCBA are intended for the highest levels of respiratory threats where CBRN concentrations are at or above IDLH levels.
Protective ensembles, which couple clothing systems with the CBRN-approved respirator, have been developed by the NFPA. The principal CBRN standard is NFPA 1994, Standard on First Responder Protective Ensembles for CBRN Terrorism Incidents.
The standard provides several different classes of ensembles to address varying levels of these hazards. NFPA 1994 went through a significant revision during late 2006.
The new 2007 edition includes a number of significant changes:
• The scope was revised to address the needs of all first responders, including members of the fire service, emergency medical services, and law enforcement, who might called upon during a terrorism incident.
• The Class 1 requirements, which in the 2001 edition of the standard addressed the highest level of protection for trained HazMat responders, have been removed and added to NFPA 1991 as mandatory CBRN requirements for all vapor-protective ensembles.
• Class 2 is the new highest level of first responder ensemble for protection against chemical vapor and liquids, in addition to biological agents and radiological particulates. The requirements for Class 2 are being aligned with SCBA use and conditions that are considered IDLH.
• Class 3 ensembles provide lower levels of protection against chemical vapors/liquids, biological agents, and radiological particulates. Class 3 ensemble requirements are aligned with the use of CBRN APRs or PAPRs, which are used at conditions below IDLH and generally involve longer usage periods. In addition, the materials used in Class 3 ensemble garments must be breathable, with a minimum total heat loss requirement of 200 W/m2.
• A new Class 4 ensemble was introduced for protection against biological and radiological particulates, such as white powder calls, only. While the ensemble does not provide chemical agent or toxic industrial chemical protection, performance criteria were provided to address both biological and radiological particle hazards. Class 4 garment materials will have to demonstrate a total heat loss requirement of 450 W/m2.
• A new overall ensemble integrity test, known as man-in-simulant testing (MIST) will be applied to Class 2 and 3 ensembles.
• The chemical battery for testing Class 2 and 3 ensembles was changed to soman (a nerve agent), distilled mustard (a blister agent), and five toxic industrial chemicals (acrolein, acrylonitrile, ammonia, chlorine, and dimethyl sulfate).
Associated with each class of ensemble are a series of design and performance criteria for garments, gloves, and footwear.
Important design criteria include:
• Ensembles are to be designed to accommodate specific NIOSH-approved CBRN respirators (CBRN SCBA for Class 2 and CBRN APR or PAPR for Classes 3 and 4.
• Ensembles are designed for single use only.
• A different number of minimum sizes apply to each element (garments, gloves, and footwear).
Performance criteria include:
• Overall integrity testing of the ensemble (MIST for Classes 2 and 3; particle testing for Class 4).
• Functionality testing of the entire ensemble (form and fit evaluation).
• Permeation resistance testing of conditioned materials against chemical warfare agents and toxic industrial chemicals (Classes 2 and 3).
• Viral penetration resistance testing of conditioned materials.
• Burst strength, puncture/tear resistance, and cold temperature bending for garment and visor materials.
• Breathability (total heat loss) testing of Class 3 and 4 materials.
• Inward leakage and mounting strength on exhaust values.
• Dexterity of whole gloves.
• Cut resistance, puncture resistance, and cold temperature performance for glove materials.
• Cut resistance, puncture resistance, abrasion resistance, and slip resistance for footwear materials.
The following table shows the intended use and testing of NFPA 1994 ensembles.
|
Class
| Intended Use | Required Respirator | Ensemble Integrity Testing | Ensemble |
| 2 | IDLH* environments; high levels of vapors, liquids, or particulates | CBRN SCBA | MIST** (PF ≥ 360)† | Permeation : Liquids at 10 g/m2 (closed top); vapors at 350 ppm‡ |
| 3 | Non-IDLH environments; low levels of vapors, liquids, or particulates | CBRN APR or PAPR | MIST** (PF ≥ 76)† | Permeation : Liquids at 10 g/m2 (open top); vapors at 40 ppm‡ |
| 4 | Biological and radiological particulates only | CBRN APR or PAPR | Particle inward leakage test | Performance relies on |
* IDLH – Immediately dangerous to life and health
** MIST – Man-in-simulant-testing
† Requirement for overall testing (results in individual sampling areas also apply)
‡ Specific criteria apply to chemical warfare agents and toxic industrial chemicals
The new changes in NFPA 1994 are intended to address a broader responder user base, permit better decisions in deciding which ensemble to use by linking clothing ensemble decisions with the choice of respirator, and address a better balance of protection and the stress-related impact of the ensemble on the wearer.
In part two of this article, new CBRN requirements for structural/proximity and technical rescue ensembles will be addressed.
