There is no doubt in the emergency response industry that the true first responders to most terrorism events will be firefighters, police and emergency medical technicians. In many cases, it is unlikely that these responders will even know at first what hazards they are facing.
It is unreasonable to expect that these responders will be able to quickly recognize the hazard, change into the appropriate outfit, and then continue their response efforts. In the specific case of firefighters and other rescue workers that wear protective gear as a normal part of their response efforts, the ideal circumstance is that their existing clothing and equipment can afford at least some protection during such events until better protective resources can be applied.
Following part one on personal protective equipment against chemical, biological, radiological, and nuclear (CBRN) hazards, this final article looks at other alternatives for firefighter protection.
There have already been some studies conducted where assessments have been made as to how well firefighter gear would perform in the event of a CBRN exposure. In a series of investigations carried out by what was then known as the U.S. Army Soldier and Biological Chemical Command, new structural turnout clothing and SCBA were evaluated for the protection provided against specific chemical warfare agents.
It was found that these clothing systems could provide very limited protection for rescue and reconnaissance in the order of 3 minutes if victims at the site were perceived as dead, or 30 minutes if the victims were still alive. Unfortunately, the recommendations that were coined the “3/30 rule” became a principal preparedness strategy for several departments.
Many groups, including the International Association of Fire Fighters (IAFF) openly spoke out against the application of these results because there were several caveats placed on the testing and the application of these results. For example, the projected protection assumed no contact with liquids by the first responder. Moreover, only a limited set of new and conditioned gear was evaluated, and it would be difficult to extend the study results for all gear already in use.
Chemical agents
The fact is that current turnout gear, no matter how encapsulating it might seem to be, offers relatively no protection to certain types of chemical agents.
The concerns for addressing CBRN protection to firefighters surfaced during the last revision of NFPA 1971, the standard that governs turnout gear. Consequently, the committee responsible for the standard undertook a rigorous effort to establish the requirements for a firefighter ensemble that would function for its main intended mission of structural firefighting and other common emergency activities, as well as provide CBRN protection when needed.
The committee quickly dismissed the approach of just simply allowing NFPA 1971 gear to be certified to NFPA 1994, as discussed in part one, because the two standards were not compatible.
First, the 1971 standard addresses individual elements of an ensemble, but not the ensemble itself. On the other hand, NFPA 1994 is predicated on a single use whereas firefighting ensembles are intended to provide service over several years and up to as much as 10 years. Dual certification of gear to both standards would turn out to be a disservice to firefighters.
Instead, the committee in its revision of NFPA 1971 sought criteria that considered the specific needs of firefighters and the protection required to permit safe escape of firefighters from a CBRN event, and allow limited rescue during the escape process.
The approach taken was to establish an option by which complete ensembles could be specified for additional requirements above and beyond the minimum requirements of NFPA 1971 for everyday firefighting.
These requirements were based on the protection levels established in the 1994 standard for IDLH (Class 2) environments, but included rigorous test criteria to assure that the protection remained in place over the intended service life of the ensemble.
Entire ensembles
Under this option, the entire ensemble of garments, helmets (if part of the protective envelope around the firefighter), hoods, gloves, footwear, and respirators must be specified. There is no mix and match of ensemble elements because the whole ensemble must perform to provide full protection of the firefighter.
The key evaluation is known as Man-In-Simulant-Testing (MIST). In this evaluation, test subjects have special adsorbent pads placed on their skin at several locations, and then wear the ensemble in a chamber where they are exposed to a surrogate warfare agent while exercising.
Following the exercise, decontamination, and doffing of the ensemble, the pads are removed and analyzed to determine how much surrogate chemical agent penetrated the ensemble and at what locations on the body.
In the case of the CBRN option for NFPA 1971 structural firefighting protective ensembles, the local area and overall protection factor are set at levels that coincide with the allowable skin exposure limits for chemical warfare agents.
The specific requirement is a protection factor of 360. To put that into perspective, regular turnout gear will achieve overall protection factors ranging from two to 15, with no protection in some local areas.
The MIST evaluation is aimed at improving the many interfaces in the overall firefighting protective ensemble, including junctures of the gloves, footwear, and hoods with the ensemble, as well as open closures in the coat and pants, and how the respirator integrates into the overall ensemble.
The CBRN option permits some design latitude in how a manufacturer would meet these requirements, but overall the ensemble and its individual elements must still meet all of the other requirements in the 1971 standard, including breathability of materials.
There is a delicate trade-off between achieving stress reduction in the ensemble and maintaining a barrier against CBRN agents. A mainstay of the current criteria in NFPA 1971 is the total heat loss test. It is provided as means for stress relief by requiring that moisture barriers be breathable as a balance to the minimum insulation requirements from heat exposure.
Harmful levels
However, to achieve CBRN protection, the same breathable barrier material must also keep out harmful levels of chemical and biological agents during the life of the garment. For the CBRN option in NFPA 1971, this is accomplished using the same testing as specified for Class 2 ensemble in NFPA 1994. However, the material must undergo extensive conditioning in terms of multiple launderings, heat exposures, flexing, and abrasion, to simulate wear life of the barrier material.
The introduction of ensembles meeting the new CBRN option in NFPA 1971 is on the horizon. Two programs sponsored by the U.S. Government’s Technical Support Working Group are working towards products that may be introduced by the end of the year. These include the CB Ready ensemble designed and produced by Globe Fire Fighter Suits in a program led by North Carolina State University.
The second project, Project Heroes, is an undertaking by the IAFF, in conjunction with the International Association of Fire Chiefs and the National Institute for Occupational Safety and Health, with Morning Pride Manufacturing as the design leader and manufacturer of the ensemble.
Both ensemble development programs face significant technical challenges in the design of effective interfaces and incorporation of appropriate material technology to meet the new requirements. As of this writing, the limiting factor has been a barrier material that can meet the rigorous requirements for CBRN protection as specified in the 1971 standard.
Nevertheless, once available, these ensembles will provide an alternative solution for protecting firefighter responders in escaping from CBRN environments without the need for supplemental protective outfits.
A similar philosophy, which has been applied to NFPA 1971, has also been added to the newly released NFPA 1951, Standard on Protective Ensembles for Technical Rescue Operations.
In the new standard, three ensembles are defined, including a CBRN ensemble that provides protection to the Class 3 requirements (non-IDLH) of NFPA 1994. As with NFPA 1971, requirements for MIST evaluation of the ensemble and barrier protection on ensemble materials are applied after rigorous conditioning to ensure protection stays in place for the service life of the garments. These new criteria will permit options for rescuers to have both general protection as well as CBRN protection when needed.
