Frequently Asked Questions
Can NFPA protection standards be compared to OSHA/EPA levels?
Yes. The OSHA levels were first established in the 1980s by the U.S.
Environmental Protection Agency and then codified into OSHA 1910.120 for
both hazardous waste site operation and emergency response. These
levels describe how ensembles look in relation to the threats to both skin
and the respiratory system but did not define performance. NFPA standards
for hazardous materials protective clothing were introduced in the early
1990s to define minimum levels of protection and performance. The NFPA
standards have evolved to keep up with current and emerging threats and
the table below shows how ensembles certified to NFPA standards compare
to the OSHA and EPA levels.
Does OSHA require the use of Level A ensembles for response to
unknown materials?
No. OSHA designates Level B PPE as the appropriate ensemble for initial entry.
Title 29, part 1910, subpart 120 (29 CFR 1910.120), states “If the preliminary
site evaluation does not produce sufficient information to identify the hazards
or suspected hazards of the site, an ensemble providing protection equivalent
to Level B PPE shall be provided as minimum protection, and direct reading
instruments shall be used as appropriate for identifying IDLH conditions.”
Do Level A suits need to encapsulate the SCBA in addition to the wearer?
No. Level A ensembles differ from Level B ensembles by providing a higher
level of skin protection for preventing absorption of hazardous materials
as defined in OSHA 29 CFR 1910.120. The protection of responder’s skin
from exposure to hazardous materials is the key attribute that defines Level
A performance, not total encapsulation or inflation testing. Suits certified to
NFPA 1994 for Class 1 are considered Level A regardless of whether they are
totally encapsulating. OSHA 29 CFR 1910.120 requires totally encapsulating
suits to be capable of maintaining positive pressure (typically demonstrated
by inflation or pressure testing suits) and preventing inward vapor leakage of
more than 0.5%.
Are there better tests for qualifying the performance of protective
ensembles other than inflation testing?
Yes. While inflation testing of totally encapsulating ensembles is a relatively
easy test to perform, it is only a suggested test within the non-mandatory
Annex A of the OSHA 1910.120 regulations. While inflation testing is
sensitive to small leaks, it is performed statically with the suit exhaust
valves closed off and is not sufficient by itself to determine if the ensemble
is safe. The Man-in-Simulant Test (MIST) used in NFPA 1994 provides a
dynamic, human subject assessment for whether a surrogate chemical
will leak through ensemble closures and interfaces into the suit. MIST
combined with a rigorous manikin-based liquid inward leakage test provides
a comprehensive evaluation of protective ensembles to fully qualify the
ensembles for needed levels of overall integrity to prevent exposure to
hazardous materials.
Are totally encapsulating Level A suits being used more frequently
than the risk assessment or hazard might dictate?
Yes. The purpose of PPE in emergency response is to provide sufficient
protection from potential exposures identified in the initial risk assessment
at the emergency scene and allow first responders to safely carry out their
respective tasks or mission. All PPE causes restrictions in wearer functionality
that generally worsen as protective performance is increased. If protective
performance is set too high based on unrealistic levels of chemical exposure,
then the ensemble is generally over-designed for its intended use, which
results in decreased wearer functionality. Over-designed PPE creates hazards
just as under-designed PPE does and can lead to issues such as increased
likelihood of heat stress or entrapment of first responders.
Are there situations where a total encapsulating NFPA 1991 suit is
still needed for protection?
Yes. Totally encapsulating NFPA 1991 certified suits have utility in responses
involving direct contact with pressurized liquids and pressurized vapors,
particularly as may occur at chest level or higher, such as might occur in
the mitigation of broken chemical lines. However, there are many more
situations where a non-encapsulating suit certified to NFPA 1994 Class 1
offers appropriate protection. This is particularly true for missions not
involving direct contact with pressurized hazardous materials and where
there is the need for greater maneuverability and physical challenges present
in non-line of site rescue for chlorine or ammonia gas environments and
during urban search and rescue missions.
Is there substantial value for more form-fitting, greater functional
high-end protective ensembles?
Yes. Physical restrictions in movement, hand function, vision, hearing,
and loss of comfort all limit first responders during hazardous chemical
responses. In most cases, these limitations create more likely risks to first
responders than exposure to hazardous materials. In some types of missions,
first responders require a high level of functionality in order to carry out
specific tasks and missions. The balance of protective performance
with functionality and other human factors (e.g., thermal comfort) is a key
consideration in the selection of appropriate PPE for hazardous materials
responses.
Has research been performed on the effects of chemicals on the
SCBA and its components?
Yes. Intertek Testing Services, one of the independent organizations that
evaluates and certifies SCBA systems against the NFPA standards, has
performed extensive evaluations of the SCBA and its components in
chemical environments at high gas/vapor exposure or liquid splash levels.
This work, funded by the Department of Defense, has demonstrated that
SCBAs and their components maintain their performance capabilities
during and after chemical exposure with negligible chemical in the breathing
zone. It is also important to note that decontamination of the SCBA should
be done as soon as possible to minimize any effects of chemicals on
exposed SCBA components.
Are hazardous materials protective ensemble tests set at appropriate
levels to define the barrier performance of ensemble materials?
Yes and No. It depends on the standard being applied. For NFPA 1994
protective ensembles, testing is carried out for the individual classes under
different conditions, which are matched appropriately with the protection
offered by an SCBA or other respiratory protective equipment. These classes
are based on the high end of realistic exposure concentrations. Industry
often tests PPE clothing materials against chemicals at 100% concentration
for relatively long periods of time (8 hours). This results in garments with
outstanding barrier performance, but it often creates serious trade offs such
as material flexibility that affects mobility and other attributes important for
the operational and functional effectiveness of the wearer.
Is it possible to use test data based on a limited number of chemicals
to qualify the barrier performance of ensemble materials?
Yes. It is impossible to have permeation test data on every possible
chemical. Moreover, chemical exposures may involve other factors,
including their concentrations, exposure times, temperature, and
combinations in mixtures. For this reason, groups of selected chemicals
are used as part of NFPA standards, which generally use smaller molecule
chemicals (which permeate faster and are a greater exposure hazard) to
represent entire classes of chemicals and thus broaden the use of data. In
addition, NFPA standards apply these groups of chemicals to qualify not
only the base garment or suit material, but also the gloves, footwear,
seams, and other components of the ensemble. Reliance on garment/suit
material test data only is considered a dangerous practice in the selection
of protective ensembles.
Can issues of field testability and confidence in gross decontamination
affect perceptions of protection?
Yes and No. Detailed inspections are needed to assure that PPE remains
viable for its intended use, but field testing may not provide a “full” picture of
protective capabilities. It is essential that information be offered that shows
contaminants can be removed, but there are often circumstances in which
chemical exposure occur where disposal of the ensemble will be the result
of a post-incident review. What is important is the ability to perform gross
decontamination to allow the safe doffing of ensembles without contaminant
transfer to first responders or those assisting them.
Are there other forms of evidence that are important for demonstrating
the use of non-encapsulating ensembles for high end protection?
Yes. NFPA 1994 sets a framework of minimum design, protective
performance and labeling requirements for certified ensembles used
both in hazardous materials emergency and CBRN terrorism incidents.
Additional demonstrations of ensemble performance are necessary to
show how the ensemble can protect against accidental flash fires or other
short-duration high heat/flame sources; ease of decontaminating
ensembles and limiting contaminant transfer during doffing.
