By Jeffrey O. and Grace G. Stull
Exposure to various forms of hazardous substances seems to be a continuous battle for firefighters. Even structural fires are frequently becoming hazardous materials events as the burning of synthetic materials and the presence of highly toxic liquids produce a variety of chemical exposure hazards.
Let us not forget the responses to industrial sites, where large bulk chemicals can be commonly found at many facilities. The rupture or destruction of containers, transfer lines, or transport vehicles can lead to the spread of chemicals and the subsequent exposure of individual responders.
Clothing and equipment worn by firefighters when responding to such incidents inevitably becomes contaminated — creating the issue of how to manage the contaminated clothing and equipment.
Clothing contamination
Structural firefighting protective clothing is designed and intended to offer some limited protection from chemical exposure but can still become easily contaminated. Outer shell materials are produced with repellent finishes, which help the clothing shed liquids and reduce the potential for contamination. However, it is the use of a moisture barrier and the design of the garment that work together to keep many liquids from reaching the skin.
This does not mean the clothing will not retain some of the liquid it comes into contact with, or more insidiously absorb unknown liquids or gases. Moreover, combustion processes in structural fires create “cocktails” of different byproducts, many of them highly toxic.
These substances latch onto the unburned carbon particles from fires, which act like chemical magnets. Soot and other particles generated during a fire can easily become lodged in textile materials throughout the clothing.
Conventional washing processes that are specified by the garment manufacturers and standardized in NFPA 1851 Selection, Care and Maintenance of Structural and Proximity Fire Fighting Protective Ensembles are intended to remove many fireground soils, but not all chemical contamination. A two-part study (1) the U.S. Fire Administration conducted in the mid to late 1990s showed that many toxic chemicals are not able to be removed by standard laundering and drying.
Generally chemicals that are highly volatile will evaporate from the clothing soon after the exposure. If these same volatile chemicals are trapped in soot, then wash processes that remove the soot particles can also remove the trapped hazardous chemicals. The more serious issues for chemical contamination occur when the chemical is semi-volatile (does not easily evaporate) or non-volatile.
These chemicals tend to remain in the clothing materials unless specifically removed by special decontamination processes. There are also other chemicals that may be generated as gases, liquids, or solid powders, which create contamination of clothing. These substances include asbestos, lead dust, and other heavy metal compounds (such as cadmium and chromium), many of which are known carcinogens.
Firefighters become concerned about contaminated clothing when:
1. They knowingly are exposed to an unusual substance that is either encountered during the response or discovered some time afterwards
2. The continued use of the protective clothing items create rashes or other unexplained health problems issues that may be attributed to some exposure on the fireground.
Certainly, if during the emergency response, firefighters are splashed with a particular substance or it is discovered that some chemical was released, there is good reason to infer that contamination has occurred.
In these events, knowing exactly what substances the firefighters were exposed to aids significantly when handling the contaminated clothing. However, if the fire department merely presumes that some contamination has occurred and has no idea what that contamination is, the problem becomes harder to deal with.
Clothing decontamination
If the clothing is perceptibly contaminated or construed to be contaminated with a particular substance, then the department must collect information to establish if the clothing can be decontaminated. This is a complicated decision process because there is insufficient data in the industry for measuring the effectiveness of cleaning processes in removing different chemical contaminants.
There are numerous factors that will affect this decision including:
- The amount of contamination that occurred
- The type of contaminant and both its chemical and physical characteristics
- The availability of different decontamination agents or processes that are known to be acceptable for use with firefighter protective clothing. Typically, in-house assistance, such as the organization’s or regional hazardous materials team, or even outside expertise, must be contacted for assistance.
Regrettably, garment manufacturers often are not in a position to provide sufficient information for these decisions, because of the extensive variety of chemical contamination that can occur.
Regardless of the approach used, any contaminated clothing must be isolated and further exposure to the contamination in the clothing must be controlled. This practice involves segregating the clothing from normal storage and placing it in a suitable container, such as a lined or plastic drum, where the clothing can be later decontaminated.
As there is no universal decontamination approach that works with all contaminants, some research is necessary to establish the right process for the identified contaminants.
For example, if the clothing is contaminated with a strong acid (such as sulfuric or nitric acid), then standard washing with alkaline detergent and the use of extra rinse cycles may adequately eliminate the acid residue.
There are various chemicals that are so extremely hazardous that the department must make the choice to have the garments condemned. For example, clothing extensively exposed to asbestos fibers should not be reused, since the asbestos poses a known carcinogenic hazard and is not easily removed.
Additionally, exposure substances may be known skin toxic, sensitizing, or carcinogenic chemicals. The risks for reusing the clothing must be weighed, even if the clothing seems to be free of the contamination. In a recent inquiry, one firefighter who had a known severe allergy to peanuts was exposed during a fire involving peanut oil and subsequent wearing of the clothing produced an allergic reaction requiring hospitalization.
In this case, the recommendation was made to condemn the clothing because there may be no satisfactory level of residual peanut oil that would be acceptable since the individual firefighter had become highly sensitized.
Clothing testing
Answering the question as to whether the clothing remains contaminated or if the clothing has been properly decontaminated requires testing. Testing can be performed on clothing to identify and quantify the levels of contaminants, but it is not as easy as it might seem. Certainly, the simplest approach is when the clothing is contaminated with one or more known substances.
The approach for analyzing the clothing can then focus on the specific substances involved. However, even knowing the specific substances, there can still be problems. For example, much of the required testing will require removal and destruction of sample materials from the clothing.
The test methods involved require extraction with solvents or digestion with acid to create solutions that can be evaluated by the appropriate analytical device. There is also no guarantee that the sample(s) removed from the clothing are representative of the clothing’s contamination as a whole. The testing is also expensive with costs ranging from $100 to well over $2,000.
If the department does not know the substance(s) involved, then the laboratory must run a series of tests to identify probable contaminants. This approach is sometimes like looking for a needle in a haystack. The testing usually requires “control” samples (a material that is not contaminated) so a comparison can be made to eliminate common substances that are already in the clothing materials, such as finishes or cleaning agent residue.
Then there is the problem that if a certain contaminant is identified, it is necessary to determine if that level should be considered dangerous. In many clothing analyses, the substance dioctyl phthalate (DOP), a common plasticizer, is often detected. As DOP is a persistent contaminant found throughout the environment, low levels may not be hazardous. DOP contamination may simply be the result of the clothing coming into contact with a plastic bag. Unfortunately, there is little information as to what levels of some chemicals should be considered hazardous.
Only analytical testing directly on clothing materials can determine if contamination has been removed. Sampling of the airspace in a closed container may give some evidence that there is contamination in the clothing but cannot be used to determine decontamination effectiveness.
Likewise, analysis of the waste water from a decontamination process can only verify that some chemical was removed and not assess what contamination may still be present in the clothing.
Significant problem
Known contamination of firefighter protective clothing represents a significant problem that cannot be overlooked. The wearing of contaminated protective clothing can cause extended exposure to hazardous chemicals that may have either acute or long term effects. Specific strategies for decontaminating the clothing to effectively remove the contaminants must be developed and then validated through testing or expert judgment in order to continue the use of the clothing. Otherwise, the clothing must be retired and destroyed.
When the nature of the contamination is not identified, testing may be used to assist in the discovery of the nature and to determine levels of contamination. However, this too is a complex process that may not yield conclusive information. Detailed forensic work is required to link contamination to possible health problems, and usually scant information is available to assist in this process. Any uncertainty in the potential contamination or inability to properly decontaminate clothing warrants its disposal.
References
1) An electronic copy of this study is available from International Personnel Protection. E-mail a request to Gracestull@aol.com for a copy.
