Terror-proofing Respirators and Protective Ensembles

March 17, 2003
Much progress has been made on ensembles and respirators, but changes are in the works.

by Alan S. Brown

Within hours of the attacks on the World Trade Center and Pentagon, experts began speculating about whether the terrorists had released chemical or biological weapons as well.

Their concern was not surprising. The first responder community had pushed chem/bio weapons to the top of its priority list six years earlier, after Japanese cult Aum Shinrikyo released sarin nerve agent in a Tokyo subway. The attack killed 12 and injured more than 1,000. Of the 1,364 EMTs dispatched to the scene, 135 were affected by secondary symptoms. At the hospital nearest the scene, 23 percent of the medical staff reported signs of secondary exposure.

The attack prompted the International Association of Firefighters, International Association of Fire Chiefs and others to press for new standards to protect first responders against chemical, biological, radiological and nuclear (CBRN) threats.

Standard-making bodies reacted quickly. By 9/11 the National Fire Protection Association (NFPA) had already published two protective ensemble standards, and the National Institute for Occupational Safety and Health (NIOSH) was nearly finished with its self-contained breathing apparatus (SCBA) standard.

The standards were based in part on military CBR experience. As NFPA senior fire service safety specialist Bruce Teele is quick to point out, although soldiers and first responders may face the same agents, their concentrations and exposure times are likely to differ.

"Military exposure takes place in an open battlefield where a release dissipates fairly quickly," he explains. "The civilian environment tends to be indoors, in large enclosed areas where heating and air conditioning systems could spread any release through stadiums, shopping malls, convention centers, auditoriums and theaters."


NFPA's first CBRN standard appeared as an option in the 2000 edition of its vapor-protective hazmat ensemble standard, NFPA 1991. The standard tests ensembles for both durability and permeation resistance against hazardous industrial gases. The chem/bio option adds nerve gases (sarin, VX), blister agents (distilled mustard, lewisite), and blood toxins (cyanogen chloride) to the list.

Unfortunately, says Teele, vapor-protective ensembles (VPEs) are expensive. "It would be costly for fire departments to have sufficient VPEs for all the personnel who would need high levels of protection at a chem/bio incident." To make CBRN ensembles affordable enough to store in every responder vehicle, NFPA began work on a new standard, NFPA 1994, to address chemical and biological terrorism. It went into effect one month prior to 9/11.

Class 1 Protection

NFPA 1994 defines three classes of ensembles. Class 1 provides the most protection. It is recommended when responders cannot identify the exposure agent or its concentration, and should be coupled with a NIOSH-certified SCBA. It limits 1-hour permeation to no more than 4 micrograms/sq cm even when challenged with undiluted chemical warfare gases and liquid concentrations of 100 g/sq m.

Class 1 ensembles are similar to conventional hazmat suits. They resist industrial chemicals (which could be released as weapons). They have similar burst, puncture, cold temperature and seam strength. They lack equivalent abrasion and flame resistance.

Not surprisingly, many companies plan to modify existing hazmat suits to meet NFPA 1994. "Our suit won't differ much from our hazmat model," says James Zeigler, a research associate at DuPont Personal Protection (Wilmington, Del.). The most noticeable change will be a new hood/SCBA system to meet stringent liquid infiltration requirements.

Protection for Everyone Else

DuPont expects to be one of the first companies to achieve certification. So does Lakeland Industries Inc.(Ronkonkoma, N.Y.), says Carl Brown, a product manager for the company's Chemical Protective Clothing Division. The company already markets an ensemble certified to the NFPA 1991 chem/bio standard. Brown expects it to meet NFPA 1994 Class 1 with no modifications.

Class 1 suits are clearly intended for dedicated hazmat and chem/bio units responding to the worst emergencies. NFPA envisions two additional protective classes for responders who will work near the hot zone.

Class 2 ensembles provide 1-hour protection against liquid concentrations up to 10 g/sq m and vapor concentrations to 1000 ppm. They are designed to accommodate either SCBAs or air-purifying respirators (APRs). Class 3, intended for such peripheral jobs as traffic and crowd control, offers only 10 g/sq m splash protection. Both suits have significantly less mechanical strength than the Class 1 ensemble.

Breathing Easy

NIOSH began looking at chem/bio standards in 1999, and was able to rush SCBA certification procedures into effect by December 2001. It is now moving rapidly forward on criteria for air purifying respirators (APRs).

According to Rich Metzler, director of NIOSH's product testing laboratory, NIOSH chem/bio-certified SCBAs must meet all NIOSH SCBA requirements, plus stand up to the two most aggressive chemical warfare agents, mustard and sarin.

Highly corrosive mustard accumulates on protective clothing as a liquid and permeates it over time. Sarin, a highly volatile gas, penetrates any cracks or crevices in a seal. Both agents degrade many polymers.

In May 2002, Interspiro USA Inc. (Branford, Conn.) became the first manufacturer to certify its SCBA units (Spiromatic 9030, 6630 and 4530) to the new NIOSH standard. This was not a big stretch, because it was already meeting CBRN standards for SCBA masks it sells to U.S. Air Force firefighters.

Scott Health & Safety Division of Scott Technologies Inc. (Monroe, N.C.) recently received certification of its first SCBA. "Basically, we took our standard airpak and changed the materials in the regulator," says fire service marketing manager John Skaryak. Draeger Safety, Inc. (Pittsburgh, Pa.), Mine Safety Appliances Co. (MSA, Pittsburgh), and Survivair Division of Bacou USA Safet, Inc. (Santa Ana, Calif.) are also moving along in the testing process.

NIOSH expects to begin certifying APRs by April 2003. Although it will test against the same nine chemical threats, the procedures will differ. Unlike SCBAs, APRs do not have their own air supplies. "Here the filter cartridge is critical," says Metzler. He plans to test filter ability to screen out biological materials and neutralize chemical warfare agents. NIOSH will also test the fit of APRs on human subjects using aerosolized corn oil as a surrogate for chemical agents.


Because the NFPA and NIOSH standards are so new, issues are bound to occur. DuPont's Zeigler, who helped write NFPA 1994, talks about debugging the standard. "Things pop up that no one even dreamed of," he explains. One example: "We're a garment manufacturer, but if no one is certifying boots or gloves, how do we certify an ensemble?"

Scott's Skaryak also notes that NIOSH and NFPA have entirely different CBRN testing procedures. NIOSH subjects the entire respirator to a test that lasts six hours, far longer than any responder will remain in a hot zone. NFPA uses higher concentrations of chemicals in its permeation tests, but only tests swatches of material. Skaryak would rather see a consistent test of the entire respirator/ensemble system.

Testing is also expensive. Interspiro operations manager Michael Swofford says it costs about $40,000 to test each of his three certified SCBAs. Skaryak puts the cost at $50,000. He expects to spend about $88,000 for APRs.

Safety Equipment Institute director Pat Gleason puts the cost of testing an NFPA 1994 Class 3 ensemble (gloves, footwear, garment and visor) at $90,000. Class 1 and Class 2 testing will cost about $150,000. Only a few military and commercial labs actually test live agents, which are expensive to handle safely.

The very nature of CBRN testing also adds to costs. Ordinarily, companies pretest products and know they will pass before sending them for certification. Unfortunately, no one has developed a way to mimic mustard or sarin without using actual live agents.

As a result, vendors cannot tell beforehand whether their gear will survive a live test. Because products contaminated with live agents must be destroyed, they cannot examine a failed SCBA or ensemble to see where to make improvements. They can only guess and try again.

Because the entire process is so costly, companies are likely to limit the number of products they certify.

The Future

Skaryak worries that some responders may assume their SCBAs will provide more protection than they actually do. "The respiratory tract of a firefighter with a CBRN-approved SCBA might be protected, but if they show up in their normal turnout gear they won't last two minutes. We want to make sure they have the right training."

Zeigler agrees. "There may be certain situations where a garment out of a box is not adequate, but you could say that for any protective piece of equipment. You don't just put this on, you have to be trained to wear it.

"Part of that training is knowing when it is appropriate. The standard includes only minimum performance requirements. There are certain situations – sharp objects, heat and flame, falling objects – where there may be a need for additional protection."

NFPA recognizes the need for a broader standard that will encompass additional threats, says Lakeland's Brown. The latest NFPA 1994 revision discusses five ensemble classes with options for flash fire, high or low physical properties, and high or low liquid splash protection.

Brown sees NFPA 1994 evolving into a "grocery list" standard that could be used for hazmat as well as chem/bio emergencies. Users would simply pick the type of certified garment that meets their most likely hazard scenarios. "If 90 percent of Atlanta's hazmat emergencies involved overturned tanker trucks, then 90 percent of the city's teams would select high liquid-splash ensembles," he explains.

An interesting thought. A standard that began as a way to meet chemical and biological threats may eventually evolve into a standard for meeting any unknown hazmat emergency.

As NFPA's Teele notes, "We're learning as we go."

Sponsored Recommendations

10 Facts About the State of Workplace Safety in the U.S.

July 12, 2024
Workplace safety in the U.S. has improved over the past 50 years, but progress has recently stalled. This report from the AFL-CIO highlights key challenges.

Free Webinar: ISO 45001 – A Commitment to Occupational Health, Safety & Personal Wellness

May 30, 2024
Secure a safer and more productive workplace using proven Management Systems ISO 45001 and ISO 45003.

ISO 45003 – Psychological Health and Safety at Work

May 30, 2024
ISO 45003 offers a comprehensive framework to expand your existing occupational health and safety program, helping you mitigate psychosocial risks and promote overall employee...

Case Study: Improve TRIR from 4+ to 1 with EHS Solution and Safety Training

May 29, 2024
Safety training and EHS solutions improve TRIR for Complete Mechanical Services, leading to increased business. Moving incidents, training, and other EHS procedures into the digital...

Voice your opinion!

To join the conversation, and become an exclusive member of EHS Today, create an account today!