This subject has taken several different directions, one of which is to look at the PPE itself as a potential source of chemicals that, over time, get into the firefighter’s body and contribute to long-term health problems.
It has been our opinion that the real dangers of fireground exposure occur as a result of:
Having contact with different substances through respiration (not wearing the SCBA all the time it is needed)
Skin contact during emergency itself (problematic when dirty clothing is not removed after use or when showers are not taken after the fire event)
Nevertheless, allegations have been made with respect to certain substances leaching out from clothing components, evaporating from the clothing during use, or otherwise causing firefighter exposure.
Understanding PPE as a chemical exposure threat is murky. While certain substances may or may not be present in turnout clothing, the extent to which they are present and more importantly, the manner in which they may present themselves as a hazard for exposure has not been fully determined.
To date, there have not been any studies that definitively show the quantity of particular substances that comes out of the turnout clothing and gets into firefighters’ bodies by any route of exposure. This does not mean to say that this does not happen – the topic simply has not been studied adequately.
This should not further imply that industry should just wait for all the research to be done just because specific risks have not yet been quantified. Instead, industry should move forward with actions that minimize the potential risks to fire fighters who already operate an ultra-hazardous environments.
EXISTING AND EMERGING REGULATIONS AND THEIR IMPACT
Large parts of the consumer textile and other industries are already addressing potentially hazardous substances that may be used in very small amounts as part of their products through what are called restricted substances lists (RSLs). These are lists of compounds with known adverse health effects that have either been banned or are being closely scrutinized by different jurisdictions whether by regions, countries, states or even cities.
RSLs include a variety of chemicals, such as plasticizers, certain toxic heavy metals, different dyes and other substances that have been discovered to pose particular toxic or carcinogenic effects. Most often, the chemicals on RSLs are subject to certain limits, but these can vary from jurisdiction to jurisdiction.
California Proposition 65 is an example of an RSL that is well-established in the United States. Its main intent is to protect drinking water from contamination by hazardous substances. The list now contains over 800 naturally occurring and synthetic chemicals that are known to cause cancer, birth defects or other forms of reproductive harm. They include additives or ingredients in pesticides, common household products, food, drugs, dyes or solvents. They can also be chemicals used in manufacturing and construction, or byproducts of chemical processes, such as motor vehicle exhaust.
The state regulations establish safe harbor levels for some of these chemicals in terms of a known concentration that does not cause harm or in the form of allowable daily dose. The regulations do not prescribe safe levels for products, but do require manufacturers of products that contain these substances to provide a warning that Proposition 65 substances are present.
A more recent example specific to the fire service and certain chemicals occurred when the State of Washington enacted new state regulations in July 2018 banning the use of Class B firefighting foams that contain perfluoroalkyl substances (PFAs), with certain exceptions. It further required manufacturers of firefighter PPE which contain any PFAs to disclose that information to the departments who purchase the PPE and to indicate the reasons for why PFAs are used in the product. This is a particularly aggressive regulation because PFAs are a very broad class of chemicals for which only a few chemicals are known to have any toxicological properties. According to an FAQ published by the Environmental Protection Agency (“EPA”), PFAS are present in a variety of common consumer goods, such as food packaging, cookware, cleaners, etc.
The fire service PPE industry reacts to these regulations in the respective areas where they apply but the reality is that these requirements do not uniformly pertain to the U.S. fire service. Regulations affecting California or Washington are not addressed elsewhere. Moreover, some areas of the country are in the process of setting different restrictions for specific substances that may vary dramatically. While the intent of these regulations is laudable, the fire service is not gaining the overall benefit. Consequently, industry needs to get ahead of this problem by working with standards organizations to create consistent requirements.
A POSSIBLE SOLUTION FOR FIREFIGHTER PPE MANUFACTURERS
Instead of PPE manufacturers attempting to maintain their own RSLs that cobble requirements of different states or local areas, and deciding when and where to disclose or control constituent parts of their products, a better approach would be to adopt a universally recognized set of criteria that can be applied to the entire industry. There is already comprehensive knowledge on restricted substances in textile and related products but there are no specific requirements for testing and no uniform set of criteria for potentially hazardous components that are determined independently.
Fortunately, there are organizations that exist which offer these services, and which have been in use primarily in the consumer field for indicating that products including the fabrics and other components are either free of or have the lowest safe levels of pertinent restricted substances.
One such organization has created the Oeko-Tex Standard, which is an independent certification system testing textiles for “harmful substances.” When a textile is certified to the Oeko-Tex Standard, it means that it has met certain criteria:
It contains no illegal substances (carcinogenic colorants).
It only has a certain amount of other legally regulated substances (e/g/, formaldehyde, heavy metals, phthalates, etc.).
It only contains a certain amount of substances that are known to be harmful but are not yet regulated at all (e.g., pesticides and allergenic dyes).
The Oeko-Tex Standard is far more strict than legislation in the U.S., and the amounts of these chemicals allowed in certain products depends on the article’s use. There are four product classes, each of which has its own limits for various substances.
Moreover, there is a specific variant of this standard that addresses protective clothing. While the standard originated in Europe, it has been adopted through various well known product outlets, manufacturers and suppliers in the U.S., including some components providers of turnout clothing. The adoption of this or similar practices within the fire service PPE industry would seem to provide broad benefits to the fire service.
It is our recommendation that NFPA PPE product standards consider incorporating systematic ways of regulating restricted substances for new products. By adopting new requirements as part of NFPA involving independent testing and certification of PPE for restricted substances, concerns over one path of potential exposure can be eliminated.
This approach is no different than what is already done for establishing acceptable levels of protective performance by third-party certification. Requirements for restricted substances must be further coupled with investigations of the real hazards from legacy gear so that the science can used to establish if any risks exist. Only in this fashion can confidence be established for the fire service in addressing overall chemical exposure safety.
The views of the author do not necessarily reflect those of the sponsor.
The Continuing Debate on Turnout Gear Service Life
Over the past several years, we have written various columns associated with the care and maintenance of firefighter protective clothing and equipment. One of the perennial issues on this topic has been gear service life. In many cases, this particular topic has been a subject of polarization among the fire service, particularly when it comes to firefighter helmets. In this month’s column, we attempt to shed more light on this topic to allow fire departments and individual firefighters to make better informed choices with respect to their gear service life.
All clothing and equipment have a finite service life. For the most part, turnout gear is designed to be quite durable, made with rugged materials that are intended to repeatedly provide protection under a wide range of varying exposure conditions. By definition, service life is the length of time that clothing and equipment can remain in service while still providing a minimum level of protection. Nevertheless, even brand new gear that is subject to a serious fire event can require immediate retirement. Similarly, gear that is abused or improperly cared for can also lead to a shortened service life.
The interpretation of service life will further depend on an individual organization’s understanding of what factors constitute continued safe usability of clothing and equipment, which can also be influenced by available resources. Yet, since 2008, NFPA 1851: Selection, Care and Maintenance of Structural Firefighting Protective Clothing has imposed a 10-year service life limit based on the element manufacturing date for any structural firefighting ensemble element, including garments, helmets, gloves, footwear and hoods.
The reality of turnout gear service life
Every five years, the NFPA conducts an extensive needs assessment of the fire service. This assessment entails getting answers and information in response to a comprehensive set of questions and inquiries directed to fire departments across the United States. The content covers key issues regarding equipment, operations, training, safety and health issues. Among the areas of inquiry are certain questions related to personal protective equipment (PPE).
According to the information obtained from the most recent NFPA needs assessment published in 2016, 71.7 percent of the departments indicated they had at least some protective clothing at least 10 years old – meaning that the use of this gear would not comply with NFPA 1851. The NFPA further breaks down these statistics by the size of the jurisdiction served by the department, which shows departments over smaller populous areas having larger proportions of older gear with no real shift in the trend over the four needs assessments conducted in 2001, 2005, 2010 and 2015.
A survey of the fire service conducted by the Fire Protection Research Foundation in 2013 further examined care and service issues for firefighter protective clothing. This survey expanded on some of the earlier NFPA needs assessment questions, including determining how long departments were keeping gear in service. Not unsurprisingly, many survey participants reported that gear was generally retired between seven and 10 years of use, but there was an equal number of respondents indicating that gear was not retired until after 10 years of service. Information was provided by individual element – coats, pants, hoods, helmets, gloves and footwear – and the numbers showed that helmets tended to be kept in service the longest.
The primary reasons for continued use of older gear usually boils down to available resources and the relative wear and tear on gear in use. According to the same needs assessment, some fire departments struggle with providing all of their firefighters with full gear. Many departments are unable to provide second sets of gear or regular cleanings. The situation also occurs where departments do not have many structural fires which allows them to extend the life of their gear simply because it does not have the wear and tear that causes any breakdown of performance.
However, there are also circumstances where gear is kept in service well beyond its use, even if worn out and with signs of degradation, which can affect overall protection. Lastly, some firefighters want to keep their gear because of its personal value – a sign of their experience or a preference for old items as compared to newer products available in the marketplace.
The appropriate basis for service life
A common question asked by many in the fire service is “Why did the committee responsible for NFPA 1851 decide to include a requirement for a maximum 10-year service life?” Contrary to the belief of some, it was not because of a conspiracy by manufacturers to sell more gear.
The basic logic that was used was based on a combination of product obsolescence and experience. NFPA standards are generally revised every five years and each new edition of the standard bring changes in response to fire service needs and experience for improvements in their gear. Many of these changes can be minor, but, over the years, they add up.
For example, drag rescue devices are a relatively new feature of protective coats that would not be found in some coats over 10 years old. Moreover, many performance requirements have been updated in response to identified improvements made in protection offered by ensemble elements. Therefore, 10 years represents two cycles of revision so that products can be kept up to date to the latest safety standards. This is not an uncommon practice where newer products are considered safer and more consistent in their performance.
Secondly, there is a vast amount of experience and research to suggest that used gear, even when properly maintained, will eventually wear out. Gear manufacturers and material or component suppliers have monitored the performance of their products in the field and over time, and have found that the combination of physical or thermal exposures, combined with ordinary wear and tear, does lead to breakdown of clothing and equipment. In many cases components can be repaired or replaced, such as a helmet faceshield that becomes heat damaged, but eventually there comes a point at which the number of repairs warrants full replacement of the gear item. Performance properties of clothing items have been tested at various stages during their service life, with some indicating degradation minimum requirements and others remaining relatively unchanged. All in all, turnout gear service life tends to become a judgement call when left to individuals.
The difficulty that arises with determining the continued serviceability of firefighter clothing or equipment is having the evidence at hand to make an informed decision. In reality, most performance properties on which the qualification of the item is based cannot be performed in the field or without destructive testing. Unless there is obvious damage, such as significant charring of an item, a physical breach or the item was subjected to a known consequential incident that brings its future into question, the fire service is confronted with having to make best guesses for gear serviceability. This is part of the reason NFPA 1851 does set a standard 10-year maximum service life for turnout gear.
Moving forward and understanding new trends in turnout gear service life
Until new, nondestructive test methods are made available that allow definitive determinations for gear viability, judgment will always be part of the decision for continued clothing and equipment serviceability. Yet, there are new reasons emerging that are likely to influence retirement decisions. Concerns over clothing and equipment contamination with the increase in cleaning options are likely to add factors that may subtract from gear longevity, rather than extend it. Right now, there are mixed opinions for how well gear will hold up to more frequent launderings. Other items, such as hoods, gloves and footwear, have been cleaned more often, while helmet suspension and ear covers are rarely cleaned. The impact of contamination control practices will certainly make a difference on busier departments and how they view turnout gear service life.
The question of service life is not going to be answered in the immediate future. As with all important matters, there is continuing research on this topic. The CDC is preparing to launch a multi-year project: “Evidence to Inform Standards that Ensure Turnout Gear Remains Protective Throughout its Lifecycle.” The CDC had previously invited the public to comment on the project and plans to provide for future public input.
The most important takeaway is that firefighter protective clothing and equipment must in be a serviceable condition in order for these items to provide the needed protection. When there are doubts, the prudent course of action is to reevaluate the gear and seek expertise for making the best possible decisions for continued use. In the meantime, firefighters will rely on checklists in NFPA 1851 and recommendations from suppliers for judging serviceability. And, while not always popular, the 10-year rule can be regarded as a safeguard for at least keeping up with new technology and perhaps lowering the risk for unseen degradation that takes place until better means of assessment become available.
Fundamental changes needed to address turnout gear contamination
In a recent meeting of the technical committee responsible for revision of NFPA 1851: Standard on Selection, Care, and Maintenance of Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting, extensive discussion revolved around proposing modifications in how turnout clothing should be cleaned and, in particular, verified for removal efficiency of harmful contaminants.
Changes have been recommended for moving forward with more frequent advanced cleaning of turnout clothing (At this stage, the changes have only been proposed. Ratification of the changes does not occur until the committee has formally voted on the overall standard.)
Whereas the current edition of NFPA 1851 prescribes advanced cleaning to be performed at least annually, the new edition, if accepted, will require advanced cleaning at least twice a year. This means that those departments that follow NFPA 1851 will be conducting more frequent cleaning of their gear than in the past several years.
AN EMPHASIS ON FREQUENT FIREFIGHTER GEAR CLEANING
It must be pointed out that the NFPA 1851 standard has always indicated that firefighter clothing and equipment should be cleaned whenever it becomes soiled or contaminated. That requirement exists both in the current edition, as well as in the new edition.
What is changing for the 2019 edition of NFPA 1851 is the fact that more frequent advanced cleaning is being prescribed for turnout clothing in general. Part of this change involves the promotion of language which indicates that exposure to the products of combustion represents contamination. Therefore, whether visibly soiled or not, the standard will be dictating advanced cleaning of clothing that is worn on the fireground.
In addition to the increased frequency of advanced cleaning, new proposed requirements for NFPA 1851 now refer to “preliminary exposure reduction” in replacing routine cleaning. Preliminary exposure reduction encompasses activities on the fireground to begin the decontamination process, including:
Either wet rinse or dry brushing of the clothing exterior while the firefighter is still on air.
Isolation and bagging of the firefighter gear.
Separate transport of the firefighter gear away from the apparatus cab interior or personal areas of the vehicle back to the station or cleaning facility.
Needless to say, these practices impose a serious demand on fire departments for providing both the resources to carry out the preliminary exposure reduction actions as well as the spare gear required to maintain the operational readiness of the specific company involved. It is recognized that such practices will not always be possible or practical, and language has been proposed in the standard to allow for some accommodations for these factors.
Still, the trend is now in place for recognition that cleaning has to be much more thorough and frequent in order to prevent gear from becoming a continuing hazardous substance source to firefighters.
RAMIFICATIONS OF MORE FIREFIGHTER GEAR CLEANING
If frequent cleaning is to become the norm, then implications arise as to the impact on both the gear and the departments that choose to provide this level of cleaning. For years, many departments have struggled to outfit their members with two sets of gear. The push for two sets has been based on the argument that as one set becomes soiled or contaminated, an extra set is needed to prevent taking the unit out of service.
This two-set approach has been instrumental in ramping up the ability to more frequently clean gear and having fire department members in cleaner gear. Yet, for some departments, a two-set approach may not be the solution or even possible within their available resources. This can occur because two sets are simply insufficient for a relatively busy station, or this simply creates a financial burden that a department cannot overcome.
In addition to the availability of clean gear, other questions arise even as to the ability to clean. Generally, the focus has always been on garments and, to a lesser extent more recently, hoods. This is because these items can be cared for much like regular apparel.
Helmets, gloves and footwear are generally more frequently ignored. Typically, these items cannot be machine washed and sometimes are never cleaned after a fire incident. Yet, it is well recognized that these items become just as dirty, if not more so than the full garments.
Thus, the ability to clean these items effectively remains a significant variable as the trend for frequent cleaning is increased. For example, the portions of the helmet suspension that come in contact with the firefighter and the ear covers are probably not cleaned after most fires. The ability to remove these items varies significantly among manufacturers and types of products. For gloves and footwear, there are significant limitations to the ability to clean these ensemble elements uniformly.
CLEANING VERIFICATION AND ENSEMBLE INTEGRITY
Even when it is possible to implement more frequent cleaning, there is still the issue of how cleaning can affect the long-term protective performance of the clothing and equipment. As anyone who washes their own clothing knows, regular cleaning can break down clothing over time. In the case of turnout clothing, only rudimentary controls are built into NFPA 1971: Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting, for making this assessment.
For most performance requirements as a prelude to testing, only five cycles of laundering are applied for garments. For one particular property – moisture barrier effectiveness – that number is increased to only 10 washing and drying cycles. Thus, if the expectation is that clothing is cleaned after every working fire, then some gear can be subjected to up to 25 cycles a year.
Many manufacturers currently indicate that clothing generally has a service life, ranging from five to seven years for moderately busy department. While it is recognized that many components are indeed quite rugged and durable, there remains some uncertainty as to whether frequent cleaning will cause some degradation of clothing and equipment performance.
CHALLENGES IN DECONTAMINATION FIREFIGHTER GEAR
The Fire Protection Research Foundation has conducted a study evaluating how well current procedures remove contaminants. Among the findings is the simple adage that materials that are easy to contaminate may also be the same materials that are easy to decontaminate. Similarly, materials that are hard to contaminate are also hard to decontaminate. This preliminary finding was highlighted by the fact that finishes used on outer shell materials, while relatively outstanding in preventing liquid absorption, actually also may make it difficult to remove some contaminants once absorption does occur.
If you combine the above finding with the established knowledge that most ensembles only partially attenuate the amount of contaminant penetration into the clothing, then the problem of contamination control becomes all the more difficult to address, even with effective cleaning.
In reality, firefighters need to have clean protective equipment whenever they enter a hazardous environment where exposure will occur and further need to remove that gear as soon as they leave the emergency scene to minimize their overall exposure. This type of thinking only reinforces how closely structural firefighting is starting to resemble hazardous materials response.
EMERGING NEW PATHWAYS FOR PPE IN CONTAMINATION CONTROL
If all the information presented in this column is taken collectively, then the current system of PPE design, materials, cleaning and decontamination may not be the best solution for managing firefighter exposure to contaminants. To address this problem more holistically, it may be necessary to think completely outside the box with respect to existing practices.
Turnout clothing availability may be better served by clothing that is maintained by the department and issued as needed, meaning that gear is no longer specific to the individual but to the organization. This approach in and of itself creates significant problems such as ensuring appropriately sized ensemble elements for each firefighter, but it does provide a basis for ensuring that clean items are provided for each incident to the firefighter. Such practices are already being employed for protective hoods, albeit a much simpler item of protective clothing.
There may become a day when the hazards being as significant as they are point towards either disposable protective clothing or disposable covers on existing protective clothing to minimize the impact of contamination. This also introduces as many problems as it does solutions because ease of donning and maintaining comfort are difficult to attain.
What is clear from these issues is that conventional approaches probably will not provide long-term solutions and therefore other forms of technology, perhaps borrowed from other industries and adapted for the fire service, or altogether unique designs and techniques, should be considered to address the minimization of continued firefighter exposure to carcinogenic and other hazardous contaminants.
Firefighter face, eye protection advances stalled
Attitudes, not technology, are what’s holding back significant improvements to firefighter safety
One of the elements of a firefighter’s protective ensemble that often gets neglected is eye and face protection. Most often firefighters rely on their self-contained breathing apparatus facemask, but SCBA are not worn for every type of emergency response.
Manufacturers must provide firefighter helmets with either a set of goggles or a faceshield, which is intended for supplemental eye and face protection. Yet, these items may not be the most effective for emergency response activities other than structural firefighting and also are easily damaged and become a source of contamination.
Perhaps, it is time to rethink how eye and face protection is provided. It’s been a running debate in the fire service and one that NFPA recently looked at.
Without any doubt, the full facepiece of an SCBA is a complete and reliable form of eye and face protection. When properly worn, it protects against physical, thermal, chemical and biological hazards. Current standards dictate a high degree of protective performance including extreme thermal exposures.
The committee that writes standards for SCBA has endeavored to make the SCBA the most survivable part of the firefighter ensemble on the basis that protecting the firefighter’s air supply should be of paramount importance. This philosophy transcends into similarly providing high-quality eye and face protection.
While there are certainly circumstances by which this protection can be compromised, the use of SCBA facepieces during structural fires and similar immediately dangerous to life and health environments is quite appropriate.
If there are any limitations for the SCBA facepiece in terms of eye and face protection, it is that the SCBA are not always used when they should be and there are the ongoing issues of contamination control. The fire service has been steadily moving toward firefighters continuing to wear SCBA during overhaul following structural fires.
This is not always been the case because the burden for wearing SCBA remains high, particularly after the high demands of fire suppression activity. Yet, overhaul is a relatively dangerous activity where significant exposure hazards are present from both an inhalation and physical perspective.
On the other hand, any use of SCBA in a firefighting environment will result in its contamination. It is therefore critically important that the facepiece be fully cleaned to ensure that the firefighter does not continue to expose him or herself to toxic and carcinogenic fireground soils by the direct contact of the facepiece on their skin.
Firefighters wear their protective ensemble in a range of different emergency responses that are not necessarily IDLH. In many cases, severe eye and face exposure hazards are encountered and some form of protection is needed.
For the past two decades, helmets have been required to include either faceshields or goggles. Faceshields must be mounted directly on the helmet and can take a variety of configurations.
The most common form is a full faceshield that are stored above the helmet brim and then brought down when required. Another type is the flip down visor that is stored underneath the helmet brim.
If a faceshield is not provided, then goggles are an alternative. These may have some form of attachment to helmet through clips or are simply provided separately.
GOGGLES AND FACESHIELD SHORTCOMINGS
There is an ongoing debate in the fire service over what is the best helmet-based eye and face protection. Some regard faceshields as the better protection; others contend that goggles provide a more protection.
Many firefighters like faceshields because they tend to stay with the helmet, are easy to use during an emergency and provide broader face protection (at least for some types). Those who choose goggles say they truly provide primary eye protection because goggles completely encompass the eye area, whereas faceshields only provide partial protection.
Less frequent are firefighters who use both types eye and face protection with their helmet depending on the circumstances faced during the response activity. Further, many firefighters carry supplemental goggles or safety glasses.
One of the main problems with eye and face protection provided with helmets is that they are easily damaged and contaminated during a structure fire. Many firefighters complain that during any moderate fire exposure, their faceshield or goggles are thermally damaged.
Certainly by being on the exterior, these helmet components are readily contaminated by fireground soils. This means that when the eye and face protection component is needed, it will not offer adequate visibility and will create unintended exposure to contamination to a vulnerable portion of their body.
Some fire departments and firefighters attempt to get around these issues by keeping their goggles in a coat pocket or by using some device to provide protection to their goggles when worn on the helmet.
There also are helmets where the faceshield is retracted into the helmet interior when not needed. Many of these products are gaining popularity, but they still represent a minority of available protection capability.
There are some helmets of European design with retractable face and eye protection. But these helmets do not resemble the traditional North American design and are not considered acceptable by the large majority of departments and firefighters across the country.
It is clear that current eye and face protection practices are not optimum unless the SCBA facepiece is being worn as part of the protection envelope. The reliance on helmet-based goggles or faceshields may attenuate some hazards. But unless they are kept clean and undamaged, these components do not necessarily work as intended.
Then there is the issue of prolonged contamination. This can be overcome by thorough cleaning, but there is less attention in the fire service on the cleaning of these components then there should be.
As long as parts of the fire service cling to traditional helmet designs, it will be difficult to advance alternative eye and face protection approaches. Yet, there are requirements in the occupational safety and health standards for fire service that dictate the provision of primary eye protection in any emergency event.
There was an attempt to install forward-thinking concepts for alternative eye and face protection during the last revision of NFPA 1971. But alas, many committee members thought that the effort was premature without fully vetted requirements for how different types eye and face protection could be demonstrated.
We believe that in our age of ensuring the lightest, least stressful and contamination-resistant protective ensemble that endeavors should be made to promote more sustainable, efficient and cleanable eye protection.
The technology is available, but changes in attitude are certainly needed to accomplish this goal.
Update: Firefighter PPE cleaning initiative
As previously reported, the Fire Protection Research Foundation, the standards research arm of the National Fire Protection Association, is working toward a project that has the short title, “How Clean is Clean?”
This project is directed toward carrying out the research to understand the levels of contamination in firefighter clothing and how to properly clean that clothing. Here’s an update on where the project is going and some of the initial findings.
To understand the significance of the project, it is necessary to recount the reasons that clothing contamination has become such a concern. For many, cancer in the fire service has reached a problem of epidemic proportions. Statistics clearly show that firefighters have an increased risk of certain cancers above the general population.
Part of that risk is due to structural fires exposing firefighters to combustion products that include myriad of carcinogens. Most fire service organizations have adopted an aggressive posture to address ways to reduce risk through proper hygiene and other practices.
Smoke particulates and fire gases easily penetrate turnout clothing and the clothing picks up and retains many of these contaminants. Thus, one way to mitigate continued exposure of firefighters to carcinogens and other harmful substances is to ensure that clothing is clean, a trend on the increase over the past two decades.
Yet, despite the general improved practices, the industry still lacks any certainty if cleaning is effective and what approaches are the best to ensure that dirty or inadequately cleaned clothing does not become another way of creating firefighter exposure to carcinogens.
Several studies show that firefighters are exposed to a variety of chemicals on the fireground. This has been confirmed by blood and urine samples, skin wipe samples and the analysis of short- and long-term health monitoring.
While this in itself is not a direct link to cancer, it does show that chronic exposures in some cases can accumulate over a firefighter’s career.
Other research shows that different contaminants retained in firefighter clothing can transfer to the apparatus, station and wearer’s body. Thus, examining personal protective equipment as one source of firefighter exposure is both relevant and critical to addressing the broader problem.
Fire departments, manufacturers and service providers have been washing PPE for decades but it is difficult to make a claim that all contaminants are removed. Often people use the “sniff test” or wipe a piece of tissue paper on the exterior of the clothing. But these techniques do not prove that the clothing is clean.
We need a way to determine whether clothing is clean and if a cleaning and decontamination process has removed all contaminants. This is a significant part of the foundation’s effort as it works with government and commercial partners to conduct a thorough investigation. More importantly, it hopes to provide industry guidance and create changes in how the fire service cleans clothing to show effectiveness.
The principal effort is to create a cleaning-validation technique. The idea is that this technique can be applied to any location, cleaning process, detergent, machine or overall technology to determine if contamination is removed.
The research is being directed to first find ways to contaminate samples similar to how the contamination occurs on the fireground. This is important because in order for cleaning efficiency to be determined, you have to know the level of contaminants in the clothing at the start and how much remains or has been removed.
Measuring contaminant levels in the rinse water is insufficient to answer this question. The ability to contaminate clothing with known amount of chemicals and particulates provides the basis for offering a methodology that can create surrogate samples.
Once consistent contaminated samples can be generated, they can be inserted into clothing, subjected to the cleaning process, then removed and analyzed for contaminant levels. The percentage of specific contaminants can be determined by comparing the levels before and after washing.
Separate samples have to be used for this because the technology does not exist to nondestructively evaluate all contaminant levels. This is what makes having a consistent laboratory contamination method so critical — ordinary fireground contaminant is highly variable and cannot be evaluated without cutting out large sections of clothing and subjecting the samples to destructive evaluations.
A complex problem
As simple as the process sounds, the research is exceedingly complex. Turnout clothing consists of a variety of materials that have different affinities for absorbing and retaining contamination. There is vast range of contaminants to which firefighters are exposed; even when priority compounds are selected, the number of different types of chemicals is enormous.
There is no universal extraction or analysis method for this range of contaminants. Various methods have to be used for isolating different groups of chemicals and most contaminants employ unique analytical techniques for determining the presence and quantities of these substances.
Moreover, extraction methods do not mimic how firefighters might be exposed to a substance. In some cases, a strong acid is used to dissolve the material while aggressive solvents also remove normal clothing additives that make analyses difficult. And, interpreting the results of the testing should not require a chemistry degree.
To address these problems, the team is considering a kit that includes a surrogate clothing fabric system contaminated with known amounts of priority chemicals representing a range of hazards. The contaminated sample would then be sent to the cleaning facility in a kit with instructions for placing the sample inside the full clothing and subjecting both to the prescribed washing.
The cleaned sample would be removed, repackaged and sent to the laboratory for analysis where the results would show an index of cleaning in one or more areas. This would show how well cleaning works.
Parallel work is aimed at determining if there are any acceptable levels for certain contaminants if the cleaning is not 100 percent efficient.
Most of the project feedback is that the proposed technique should be applied to the makers of detergents and cleaning equipment to qualify their products and processes. It has also been suggested that this technique also pertain to clothing manufacturers and to verify the cleaning capabilities of independent service providers.
This technique will become the basis for evaluating emerging cleaning technologies and assess practices like gross decontamination as part of field activity. The research group plans to recommend cleaning validation as part of the NFPA 1851 standard.
Another part of the research is focused on developing guidelines for how to set up proper cleaning capabilities and provide recommendations more specific than what is usually offered for how turnout clothing should be cleaned and decontaminated.
For example, NFPA 1851 only indicates not to exceed certain washer and dryer temperatures, to keep the detergent in a certain pH range, minimize the speed at which the machine drum turns and not use bleach. The proposed best practices using the cleaning validation measuring tool will set standard procedures that can be used to generally remove fireground soils and contaminants.
In essence, the guidelines will offer a primer on effective cleaning that is based on validated procedures as well as address other issues such as removing certain forms of contamination, including biological contamination and asbestos.
Overall, the largest challenge is to realize that improvements can be attained in successive steps by not only measuring contamination levels, but also in applying the measurement technique widely to ensure complete cleaning.
The provision of both an industry yardstick and best practices will hopefully lead to the reduced chronic exposure of firefighters resulting from contaminated or inadequately cleaned clothing.
Firefighter PPE contamination: What you need to know
Not all contaminates are equal and neither are cleaning methods; understanding both is necessary for clean PPE
Questions often arise as to how easy clothing becomes contaminated on the fireground and if there are differences in the level of contamination for the same items of a protective ensemble. The issue frequently comes up in distinguishing between rubber and leather footwear, but it is a reasonable inquiry for the overall clothing system.
We have looked at contamination of different materials and can offer some insight to help firefighters determine if they need to be concerned about different exposure events.
Contamination occurs when some unintended substance gets on or in clothing or equipment. It may be minor such as light soiling or intrinsically dangerous like a splash of a strong acid. Contamination implies substances that are unwanted because of their potential health effects.
It is also important to recognize that contamination may be transient, either leaving the clothing on its own with time or through cleaning. The greatest concern is for contamination that is persistent and continues to expose the firefighter to the hazard.
The process of contamination itself varies greatly as does the environments in which the contamination occurs. During a structural fire, much of the contamination is in the form of smoke particulate and fire gases.
This form of contamination envelopes the firefighter, contaming all exterior surfaces of the clothing ensemble. The contamination also penetrates various portions of the ensemble, most notably through joints and gaps between different clothing items or closures such as on the front of the coat or pants fly.
Gases and fine particles easily get into interior spaces, so even underlying clothing can become contaminated. The penetration of contamination in this fashion will be more localized where there are easier pathways for entry.
Ensemble areas such as the hood, pant legs and coat-to-pant overlap are common penetration pathways. Places where there are continuous films of flexible material retard this penetration, but some substances can still get through.
In addition to penetration, there is permeation. This is when contamination moves across a material on a molecular level as opposed to the bulk passage that occurs during penetration. Permeation is more insidious because it goes on unseen, and can occur at relatively high rates causing contamination to spread throughout the clothing.
Large bulk substances such as smoke particles tend to coat surfaces in the form of soot. These products of combustion are particularly hazardous because the individual particles adsorb and retain the chemical gases created by the fire, causing a longer-lasting form of contamination.
The particle sizes in smoke can be a hundredth of a micron, making the particles invisible except in the concentrated aggregate of the smoke cloud. Thus the particles easily penetrate textile materials, but any material with a semi-solid surface, such as rubber or plastic, will generally stop this penetration. On the other hand, leather, which is porous, will allow some penetration.
Gases are more ubiquitous. Given their form at a molecular level, these substances will penetrate textile and leather materials but not plastics and solid films.
Nevertheless, depending on the type of the gas, primarily the size of the chemical molecule and the nature of the material, chemical gases will permeate most materials. Very dense and thick materials will reduce permeation and some materials such as metals will completely resist any chemical permeation.
Firefighters are also exposed to various types liquids of whether through hose spray that has picked up contaminants or broken containers of liquids. Liquids can also penetrate clothing and well as permeate into materials.
The ease of liquid contamination depends greatly on the amount of liquid, the characteristics of the liquid, the force behind that liquid and the characteristics of material. Materials may be able stop a small volumes of liquid, but when in large quantities, many porous materials are likely to become wetted and permit penetration.
Some liquids have greater contamination potential because they move more easily over material surface or degrade material due to corrosiveness or their solubility in the material.
Many textile materials used in firefighter protective clothing are treated with repellent finishes that help. However, some liquids with low surface tensions enable the liquid to easily spread on surfaces (instead of beading like water). This allows the liquid to penetrate small openings.
Unfortunately, already soiled and contaminated surfaces allow easier penetration. If there is pressure behind the liquid such as from kneeling in a puddle or the force of hose spray bouncing off a surface and back onto the individual, that pressure will push the liquid farther into clothing, particularly porous textiles and leather.
As with gases, liquids can also permeate by dissolving in the material, even plastic and rubber materials. In some cases, some of these more solid materials can actually retain the chemical longer than can the porous materials.
A firefighter helmet best represents the full range of materials and illustrates how contamination can occur. The hard surface of the shell can be coated with solid soot. This soot coating will adsorb and hold fireground gases.
The same soot will deposit on all exterior surfaces include the faceshield or goggles, reflective trim, ear flaps and exposed portions of the suspension that include a range of plastic, textile and leather materials.
While fire gases will not penetrate or even permeate a hard thermoplastic shell, the gases will enter the helmet through any opening between the shell and suspension, be absorbed by the textile or leather materials and permeate plastics. Similarly, liquids that contact the helmet will be absorbed by any exposed textile or leather components.
The retention of contaminants in clothing and other protective equipment depends mainly on the type of substance and how the contamination took place. Many fire gases are volatile and, while absorbed by soot or directly into materials, will off gas over time, usually at very low levels.
Thus removing the soot not only gets rid of the solid contaminant, but also takes away some of the trapped gases.
Chemicals that are less volatile are more likely to remain in place, particularly if directly absorbed into materials. The increased affinity of the substance for the material can mean that some contaminants can stay for very long periods unless the item is thoroughly cleaned.
One important factor other than substance volatility is the degree to which the contamination is water-soluble. Not all combustion products dissolve in water and therefore rinsing may not be effective. Using detergents and soaps improves non-water soluble contaminants’ solubility in water, particularly for oil-based chemicals.
Yet the ability of a soapy water to penetration and completely wet the material for removing the contaminant is key for addressing persistent contaminants. In some cases other types of cleaning products have to be used to address contaminant issues.
Many clothing items contain a variety of materials. When exposed to the wide range of contaminants on the fireground, including biological liquids not addressed here, these materials will be contaminated to different extents depending on the how much exposure occurs, the manner in which the exposure occurs, the types of contaminants involved and the nature of the materials.
Thus, it is possible that while some parts of the clothing might be cleaned easily, other parts may not. The less cleanable parts of the clothing can then become repositories where contaminants build up.
Cleaning turnout gear properly takes expertise in removing contaminants. Many independent service providers have gained this experience and have found various solutions for removing both general and specific contaminants.
Other resources include the gear manufacturers that can offer specific recommendations in most cases.
But an important consideration is determining their ability to decontaminate effectively, which may rest in addressing all materials in the gear, not just the principal fabric in the case of clothing or the shell of a helmet.
Full removal of contamination means applying a process that addresses the complete item, including all of its materials and understanding the contamination process.
How firefighter hoods will fight cancer
While no silver bullet for cancer prevention, barrier hoods are a great step in that direction
In February 2014 we wrote that protective hoods are the most vulnerable area of the firefighter’s ensemble. That’s because hoods lack any type of barrier characteristics to keep out the superfine particles that absorb a variety of hazardous chemicals including carcinogens.
This shortcoming was coupled with NIOSH studies and other research showing carcinogen buildup on firefighters’ skin, particularly on the neck and face areas unprotected by the SCBA face piece. Further, that skin absorbs chemicals easily around a person’s jaw line led to the obvious conclusion that current-day hoods have little effectiveness in keeping out soot.
Then in January 2015, we assisted the IAFF with a study to show how much particle penetration takes place throughout the entire structural firefighting ensemble. After that, there could be no doubt that the hood is one of the serious gaps in firefighter protection that needs to be solved.
An overwhelming number of firefighter hoods consist of two layers of knit material fashioned into a sock-like hood that stretches over the firefighter’s head with an opening for the SCBA face piece and bib that is supposed to stay tucked inside under the top of the coat.
The current requirements in NFPA 1971 considers hoods an interface devices for providing thermal protection in areas where other ensemble elements do not always provide complete coverage, such as the SCBA face piece, helmet ear covers and coat collar.
Yet as the firefighter moves, the hood shifts and leaves the interface areas exposed to the hostile environment.
Revising NFPA 1971
When the revision process for the NFPA 1971 standard began, a specific task group was charged to come up with possible ways for minimizing firefighter exposure to the carcinogens and other harmful substances contained in soot.
Through NFPA 1971 public input process, we proposed that a new optional category of protective clothing be added to the standard covering a particle barrier layer added to the hood. We further recommended that the effectiveness of this barrier layer be demonstrated through a standardized particle-filtration efficiency test.
This test was selected to show how the combination of hood materials, including a new barrier layer, would greatly diminish how many particles could pass through the hood to the firefighter’s neck and head. An initial target of 90 percent effectiveness percent was suggested.
One way to achieve complete particle blockage could be to install a moisture barrier as part of the hood composite, similar to the way garments use the same barrier materials.
In this instance, there would be no need to test the moisture barrier since, as a continuous solid layer, it already is fully effective particle-blocking material. Thus, the particle-filtration efficiency test would be applied to those materials that had some level of air permeability.
The increased layering of the hood and the further encapsulation of the firefighter’s head pose additional stress to an already physiologically challenged first responder. We therefore suggested that a total heat-loss test be applied to these newly reinforced portions of the hood at levels far above those required for garment composites.
In this way, the maximum amount of heat stress relief could be provided without compromising the particle holdout capabilities of the new hoods.
Research and development
These proposed requirements will not be adopted in one form or another until mid-2017. Meanwhile, several manufacturers and fabric suppliers have been working on prospective hood products to reduce firefighter exposure to soot and the adsorbed chemicals contained in smoke particles.
These products encompass a variety of new hood designs and combinations of different barrier materials, including both new particle filter layers as well as conventional moisture barriers.
Hood manufacturers have had to develop creative designs to still allow the “one size fits all” without the benefit of the same level of elasticity. In most cases, there is more to a particle-barrier hood than simply inserting a barrier layer between the two knit fabric layers. Each manufacturer has responded with new product designs that transformed their traditional hoods in some fashion.
Those hood suppliers not using established moisture barriers are using different ways to evaluate their barrier layer particulate filtration efficiency. For overall product efficacy, one manufacturer has undertaken the same testing that was performed by the IAFF showing the difference between a non-barrier hood in their barrier-based product in full ensemble testing.
Another company conducted similar testing, but put the hoods on a head form in the same particle laden chamber used for the IAFF test with photographs showing the differences between new and existing products. Each manufacturer has tried a variety of field evaluations, some involving live-fire conditions and others simply determining the relative comfort and ease of use.
All of the new products, many unveiled this past spring, are certified to current requirements in NFPA 1971 as regular hoods. The new particle barrier hood criteria are not finished.
More work to do
It would be nice if we could acknowledge “a job well done” and move on to the next issue. Yet, this avenue of protection is not completely solved.
As would be expected, the new hood products are more complex, use new materials and are consequently more expensive. The fact that these hoods are more costly means that fire departments will expect the hoods to stay in service longer.
This brings into question the hoods’ durability over an extended period with multiple cleanings and how well the particle-blocking capability and relative fit will be maintained. In short, we don’t know how the new products may hold up or how well they can be cleaned and reused.
And since the new hoods incorporate an additional layer, they are also somewhat heavier and will have higher thermal insulation than conventional hoods. The greater levels of heat protection means firefighters will perceive heat to a lesser degree than the already do, which can be good or bad depending on how firefighters are trained to react to heat.
Some new hoods may reduce a firefighter’s ability to hear. Further, not all products have been validated on the full scale dynamic human subject-based particulate environment testing.
The industry still has to work out these issues, particularly as the new version of NFPA 1971 comes to fruition. The fact that there is industry movement in this area should be cause for optimism. Nevertheless, as with all new technologies there are still a lot of details to be worked out.
Remembered, in minimizing exposure to carcinogens, PPE use is only one of several approaches needed to solve this problem. Thus, barrier hoods are an important first step, but not the silver bullet for cancer prevention.
Firefighting gear: Is it time for large changes?
Here’s a hard look at the barriers prohibiting meaningful PPE innovation
“Don’t fix what is not broken” is a common phrase used to impede change or at least to question change for change’s sake. If we look at the turnout clothing industry, we actually see a product range that is relatively mature with continual, gradual improvements.
In essence, gear is pretty much the way it has been for more than two decades. Yes there are the occasional blips where something new comes along like barrier hoods, and novel improvements can bring about an interesting materials or features.
For the most part, the vast majority of the fire service seems to be satisfied with current state of technology for turnout gear. But the reality is that we live in a rapidly changing world, and we are constantly affected by new discoveries and technological developments.
The current situation leads to two questions: why are there not larger changes afoot in the industry, and what types of changes might the fire service be missing out on?
Change comes about usually because of firefighter needs or a new technology becomes available that supplants the old technology. In the early 2000s, SCBA went through a tremendous change when there was a perceived need that there needed to be chemical, biological and radiological protection as part of the SCBA.
This need drove some significant changes in how SCBA were designed and the materials used in their construction. At about the same time, it became possible to incorporate a heads up display that allowed a more effective means for firefighters to monitor their air levels.
These changes occurred for two different reasons. In the first case, there is the perception that firefighters would be the first on scene to a weapons of mass destruction event. The second change came about due to an advancement of technology.
Impediments to change
So why have there not been more dramatic changes in SCBA? Yes, some new technology has recently included different types of air cylinder options. Further, one manufacturer recently introduced a thermal imaging camera as part of its SCBA system.
But what about all the other things that we have often heard about such as liquid-air systems or low-profile SCBA? Some of these technologies made the news many years ago but never came to fruition.
The answer is that the product technology may have matured. It is also that the standards that govern these products have matured to the point that they often constrain new technology rather than encourage further development.
In the case of liquefied air system, the technology offered a weight-efficient air supply with the prospect of providing enhanced cooling technology simultaneously.
Yet, there are several requirements in NFPA 1981 that have prevented the introduction of this technology. Certainly, there were a variety of other significant issues affecting its implementation such as the need for completely different air fill stations and infrastructure changes in how SCBA are maintained.
More recently, an effort to introduce low-profile SCBA failed when it became increasingly clear that the lower profile system was no lighter or less bulky than conventional SCBA. For the low-profile SCBA, the culprit was a Department of Transportation regulation that affected the burst strength of the cylinders, thus negating some of the technological advantages of new materials that were held to pre-1960 technology requirements.
Similar, more obvious impediments exist that discourage potential better-protective products. While NFPA 1981 addresses fire service SCBA, the same SCBA must meet the more industrial based criteria enforced by National Institute of Occupational Safety and Health.
For example, NIOSH has a maximum 35-pound weight requirement on SCBA. Now certainly 35 pounds is a lot of weight and is best that any respiratory system be kept to the lowest possible weight.
Yet, anything that becomes attached to the SCBA, such as a personal alert safety system or a thermal imaging camera, is included within that weight limit. If in the future, manufacturers want to incorporate the facepiece as part of the helmet, the helmet is included in the weight limit.
It does not matter to NIOSH if the item that is part of the respirator is completely independent in its operation and does not contribute to respiratory protection. Or more importantly, if it achieved a better distribution of weight on the firefighter — the regulation is the regulation and NIOSH is currently inflexible in its interpretation.
Another impediment to change has been the fire service culture. We have repeatedly seen how new products that deviate in appearance from what is considered traditional have slow acceptance.
One of these has been the European style helmets, which are generally more streamlined, lighter weight and sometimes offer advantages on integration of eye and face protection more efficiently than their American counterparts.
Tradition dies hard. In some cases it is just a matter of time, like the idea that dirty turnout gear was a badge of honor showing the relative experience the firefighter. Fortunately, firefighter culture is becoming less of an impediment, but it still exists.
So if the fire service is not seeing technology improvements that it can, what is on the forefront that should be sought out and bought into use?
The biggest problem facing the fire service in terms of its protective clothing and equipment is the lack of an integrated approach. Integrated protective approach means that the clothing items and related equipment are designed to work together as a system.
On occasion, we see attempts to integrate products in a fashion that allows for better interoperability and more consistent performance. This has been partly facilitated by some government research programs as well as private endeavors.
Right now, each individual fire department acts as its own integrator by buying separate garments, helmets, SCBA, gloves, footwear and other equipment to be worn together to provide the needed protection.
The industry is focused on the individual elements and materials of the ensemble without considering the overall ensemble itself. This philosophy leads to a breakdown in protection and often over encumbers the firefighter at the expense of emerging technology that could be better implemented.
For example, IAFF showed in its 2015 particle testing of an ensemble just how easily smoke entered the gear primarily through the different interface areas. So far, the industry reaction has been the barrier hood that, while addressing a particular vulnerable area of the body, does not solve the entire problem that can only be addressed by a full system approach.
An integrated approach can address major areas of concern such as ensuring uniform thermal protection and minimizing the stress impact of the clothing and equipment on the firefighter. It could do this by judiciously applying designs for an appropriate level of tradeoffs between protection and physiological stress and comfort created by wearing the clothing system.
As long as the fire service relies on piecemeal standards as exists today, it will be difficult for new technology to emerge. It is our hope that the fire service will move towards systems requirements, testing and a more holistic approach for the promotion of improved personal protection.
It is with deep regret that we report that passing of retired Chief Charles Soros, with the Seattle Fire Department from 1967 through 1994.
We worked with Chuck both when he was with the fire department on a number of protective clothing matters during the 1980s where he chaired a subcommittee on station uniforms and then headed the committee on fire service SCBA.
Chuck was further our alternate on the technical committee on structural fire fighting clothing and equipment for several years in the 2000s. Chuck had a forward way of thinking for the fire service and we will miss him.
Does firefighter PPE need another breathability test?
Over the past two decades, firefighting protective clothing has transformed from being relatively heavy with rubberized layers to being more sleek, form-fitting and lighter.
Some of this transformation came about because years ago stress-related fatalities and injuries were the number one risk facing firefighters. And that partly came about due to the excessive weight and bulk of the gear.
Those involved in the turnout clothing business evolved new materials and gear designs to lessen those burdens without sacrificing protection. In the 1980s and 1990s, turnout gear took the form of multi-layered clothing that consisted of the primary layers of an outer shell, a moisture barrier and a thermal barrier.
The outer shell layer provided the principal physical and flame protection by being rugged and resistant to the effects of moderate duration high-heat exposure.
The moisture barrier actually started out as a vapor barrier. It was intended to prevent water, hot and cold, and lessen steam penetration to the inner thermal barrier, which was the primary insulating layer against heat.
Most fire department buying decisions were based on the newly introduced material composite thermal protective performance (TPP) test that indicated clothing’s overall thermal insulation. The argument was that firefighter protection was improved with increasing TPP values.
However, this had significant penalties in that it created severe burdens on the firefighter. While it provided protection during structural firefighting, it encumbered firefighters on the way to the first scene or in other non-structural firefighting activities.
The extra stress that this heavy clothing imposed created a significant physiological impact on firefighters and became a hazard to their overall health and well-being.
It soon became recognized that the industry needed some balance between TPP and ways to minimizing this stress.
Several firefighters from the Indianapolis Fire Department went through simulated engine and ladder company exercises while their body core temperature, heart rate and skin temperatures were telemetrically recorded. Firefighter sweat rates were also measured and the firefighters answered detailed questionnaires about their perceived comfort and stress.
As a result of this study, IAFF was able to relate a new material composite test method called total heat loss (THL). This test method measures how heat can be removed from the body by the combination of sweating and conduction, the two principal forms of heat loss possible while wearing encumbering clothing.
The study showed that THL could reasonably predict the heat stress produced by wearing heavy clothing. As a consequence, THL testing was introduced into the NFPA 1971 standard on protective clothing and created an upper boundary on preventing overly heavy and bulky clothing.
Thus, fire department purchasing practices focused on tradeoffs between heat loss and thermal protection.
Enter evaporative resistance
There are certainly limitations to any test method, whether TPP or THL, in being able to set universal requirements for some level of performance deemed critical to firefighter health and safety.
For example, TPP is intended to measure the PPE’s thermal insulation when exposed to flashover or backdraft. Yet, most firefighters never experience those circumstances.
However, they can still be burned under a variety of thermal exposures, particularly by being in prolonged radiant heat or making contact with hot surfaces. For this reason, there are supplemental tests such as stored heat energy and conductive/compressive heat resistance that are applied to turnout gear.
For gauging thermal comfort, THL has been the only test in the NFPA 1971 standard since it was introduced as an optional test in 1991. Understanding why evaporative resistance is a concern is based on the same rationale why one test cannot completely characterize needed product performance.
Total heat-loss testing has had a dramatic impact on fire service clothing materials and to a lesser extent clothing design. Many fire departments have learned how to balance thermal insulation with heat stress relief in their clothing choices using TPP and THL values for the material composites.
Yet, there can still be differences in how clothing systems perform and the perception of the firefighters who wear them. Some argue that THL really does not make any difference because in the heat of fire, any system is going to be overwhelmed.
This argument falls short because PPE is worn leading up to the fire and in many non-structural fire events where improved breathability can afford less physiological stress. That means that when the time of greater exertion does occur, their bodies are less apt to be overcome by large increases in core temperature and heart rate that can alter judgment, endurance and overall health status.
If THL is accepted as a bona fide measure for the stress effects of clothing on firefighters as demonstrated by the IAFF study, then it follows that other types of measurements may supplement THL just as other thermal insulation tests must be used to demonstrate protection against heat.
Evaporative resistance is not a new test and has been used in several industries, although primarily outside the United States. As a test property, it can measure the intrinsic breathability — the ability of moisture vapor arising from sweat to be passed through clothing material.
This is important because sweating is one of the primary ways the body sheds heat. If the outside temperature is warmer than body temperature, it can be the only way the body can lose heat. Therefore, this measurement can provide utility for assessing turnout clothing’s impact on firefighter physiology in ways that are not determined by THL testing.
Confusion and clarity
Unfortunately, introducing a new test requires educating the fire service for its usefulness and providing an understanding for how to interpret the results. Although it is an established test, it’s mandatory for firefighter clothing in Europe, some have been trying to spread confusion by misrepresenting information about the test.
For example, one claim is that the IAFF Indianapolis study already looked at the use of evaporative resistance and concluded that it did not correlate with physiological measurements. That of course is untrue. Having run that study and preparing its report, we can definitively vouch for the specific conclusions that were reached.
There has also been an attempt to indicate that evaporative resistance is already part of the THL test. This is misleading since a different form of evaporative resistance is measured in THL testing, as is thermal resistance to create a combined measurement.
The reality is that both tests represent different measurements, which is why they have separate individual procedures.
One problem is that the units of measurement for evaporative resistance are not as intuitive as they are for total heat loss — lower values are better than high values, the reverse of TPP and THL.
Another challenge is that THL is established and evaporative resistance is not, and that nothing is to be gained from adding a new test other than additional expense to already costly turnout clothing.
We encourage you to look at the data that is being presented over the next several months. Judge for yourself whether evaporative resistance ranks clothing material composites differently than THL and if you believe this type of test data allows you to make an informed decision for overall safety and health.
How good are firefighter SCBAs at keeping chemicals out?
Since its full introduction into mainstream firefighting, SCBA have protected firefighters and have led to sustained aggressive, interior-attack fireground tactics under ever-changing and extreme circumstances.
SCBA are further used in a variety of operations potentially involving IDLH conditions such as hazardous-materials response. SCBA must therefore provide resist not only the effects of high heat and physical abuse, but retain their integrity and prevent any hazardous substances from leaking inward and contaminating the breathing air.
It was not long after 9/11 that research was stepped up to examine just how well SCBA prevented the inward leakage of chemicals through the various components, namely the facepiece seal and lens, regulator materials, exhalation valves, high-pressure hoses, and connectors. The research conducted by the National Institute for Occupational Safety and Health and the Edgewood Chemical Biological Center resulted in new standards for defining CBRN (chemical, biological, radiological and nuclear) protective respiratory devices.
This protection focuses on the more insidious threat of exposure to chemical warfare agents. The NIOSH standards created sophisticated test methods using a vapor and liquid involving live chemical warfare agent exposures on sample SCBA mounted on a breathing manikin where the breathing air is monitored for permeation of the chemicals.
In the 2007 revision of the NFPA 1981 standard on SCBA, the CBRN criteria were made permanent for all fire service SCBA. Although the committee responsible for the standard recommended that such requirements be optional, an overwhelming number of firefighters and fire service organizations supported mandatory requirements.
The reasoning was that firefighters were truly the first responders to any terrorism incident and that their equipment should provide a level of protection for the likely hazards they may face in these situations.
Chemical agent testing
The tests results showed that chemical warfare agents could get into SCBA at dangerous levels. The industry had to change its materials and designs for fire service SCBA to conform to the new requirements.
The NIOSH-specified testing that is currently performed at ECBC entails separate evaluations with two chemicals: sarin and distilled mustard. Both are classical chemical warfare agents.
Sarin, a nerve agent, is tested as a vapor at a concentration of 2,000 milligrams per cubic meter (350 parts per million). In contrast since it is a lower volatile blister agent, distilled mustard is tested both as a vapor at a concentration of 300 milligrams per cubic meter (46 parts per million) and as a liquid with the placement of 43 20-microliter liquid droplets distributed over the principal components of the SCBA protecting the breathing air.
These chemicals are the two more common warfare agents; the exposure levels are also set based on research for what would be anticipated during a terrorism event. Testing SCBA in this fashion gives rise to the expectation that the SCBA is adequately designed to protect against exterior environment chemicals permeating through its key materials.
Historically, only limited chemical testing has been carried out on SCBA against more conventional hazardous such as toxic industrial chemicals. These chemicals, such as ammonia, chlorine and hydrogen sulfide, tend to be smaller molecules and thus should more easily permeate as compared to the larger chemical warfare agents.
Yet, this testing is difficult to perform because most material tests — such as those applied for chemical protective clothing — require small flat samples that can be placed in a test cell for measuring permeation. Most SCBA components are either curved or have varying thicknesses that make testing in this way impractical.
Moreover, one consideration for the effectiveness of SCBA in providing the permeation resistance against exterior chemical exposures is that air passing through the system and being continually replenished and exhausted reduces any risk of exposure.
In testing performed by the IAFF in early 2015 evaluating the entire structural firefighting ensemble involving SCBA against a particle-laden environment intended to represent a heavy smoke exposure showed that the SCBA facepiece adequately prevented any particle infiltration. This evidence suggests that the SCBA functions extremely well to prevent most contaminants from getting into the breathing air supply.
Still, there is an increasing use of SCBA on the exterior of protective ensembles for chemical protection. In hazardous materials response, many choose between Level A vapor-protective suits and Level B liquid splash-protective suits, which both use SCBA.
The principal difference is that most Level A ensembles are fully encapsulating, enclosing both the wearer and the SCBA. On the other hand, Level B ensembles have the SCBA on the outside of the clothing system.
The vast majority of hazardous material exposures involve Level B exposures and there are several types of ensembles that meet the NFPA 1994 standard for CBRN that are now popular for hazardous materials responses. Many of these use clothing configurations where the SCBA is worn on the outside of the ensemble primarily to provide a more form fitting and functional design of the clothing.
As the materials used in the clothing are rigorously tested for chemical compatibility and permeation resistance, the same cannot be said for SCBA. Therefore, there are questions concerning how well SCBA hold out chemicals under both these circumstances and other IDLH environments.
These questions are about to be answered in new government-sponsored research. Like the NIOSH/ECBC testing, the plan is to evaluate full SCBA for effectiveness against selected chemical exposures.
These exposures could involve a myriad of different hazardous chemicals, yet it is impractical to evaluate a large number of chemicals given the expense of not only the equipment that the testing itself. Therefore, there is interest in determining which chemicals should be the priorities for any form of respiratory system testing.
The research project extends into the evaluation of other types of respirators that are sometimes used in hazardous materials response such as powered air-purifying respirators and ordinary air-purifying respirators. Thus, the research team is interested in getting any end user feedback through this short on-line survey.
This survey is mainly intended for SCBA end users that have worn hazardous materials protective ensembles, where the SCBA has been positioned on the outside of the ensemble.
It is believed the most fire service SCBA will perform well against the industrial chemicals given the hardening that resulted after CBRN chemical agent testing was added to NFPA 1981 in 2007. Nevertheless, the testing is intended to prove or disprove that SCBA are as good as we believe they are.