Major chemical spills can often result in fatalities and certainly scores of individuals are treated at local hospitals for the effects of exposure when they occur.
The area fire departments are generally the first responders to these incidents, usually in their turnout clothing, but hopefully with qualified hazardous materials teams in support.
Fortunately, the specific targeting of civilians through terrorism releases such as the Sarin subway incident that occurred in Tokyo in 1995 have not been commonplace. Yet firefighters are repeatedly exposed to chemicals in many of their emergency responses.
Perhaps one of the most pivotal cases was the Binghamton, New York State Office Building fire of 1981. PCB-filled transformers located in the basement of the building caught fire; dioxins and other hazardous chemicals from the resulting thick black smoke were carried throughout the building by the ventilation system.
The firefighters who responded to that fire did so in their normal turnout gear, which at the time consisted of full coats and pants, along with a demand-type SCBA. Today, a number of those responding firefighters have succumbed to cancer, and with the enumerable investigations and lawsuits brought forward as a result of this incident, the seriousness of firefighter exposure to highly hazardous chemicals was brought to light.
Despite being nearly encapsulated in their clothing, the firefighters coming out of this fire had their underlying skin covered with black residue. Follow-on medical analyses showed high degrees of persistence of chemical substances in their blood for many months following the fire.
The dangers of today
While it may be obvious for fires at chemical plants or other manufacturing facilities where chemicals are used, highly toxic chemicals are present at nearly all fires nowadays — and it is getting worse.
It is well documented that the burning of synthetic materials produces an innumerable amount of chemicals. The household fires of today all contribute to the "cocktail" of chemicals that firefighters are exposed to.
In this article, based on our presentation at the PPE Symposium in Charlotte, North Carolina, held during the first week of May, we cover how firefighters are exposed to chemicals and what can be done to limit exposure.
Firefighter exposure to chemicals occurs in several different ways. Certainly the most easily perceived way is through direct contact with a liquid that gets onto your clothing.
This type of exposure is localized and depending on where on your body this exposure occurs, the clothing may or may not be effective in preventing contact of the chemical with your skin.
A second and more common fireground exposure is by contact with fire smoke or other vapors at the fire scene. In this situation, your entire body is exposed and because turnout clothing is not vapor-protective, the fire gases and vapors will penetrate interfaces and other portions of your ensemble where it can come in contact with your skin.
Another and more insidious form of exposure is the contamination of your clothing itself. Any liquid contact may leave traces of the chemical in your clothing, while vapors can penetrate clothing and permeate into material.
The persistency of these chemicals will depend on the characteristics of the chemical. For some example, some relatively non-volatile chemicals (chemicals that do not easily evaporate) will tend to stay in the materials.
Similarly, liquids with low surface tensions that easily wet surfaces will tend to absorb into materials more easily. What is less known is that the soot particles that blacken clothing represent one of the more serious contamination hazards to firefighters.
Soot is made of small carbon particles, which act like "sponges" to the chemicals in the air. Chemical gases and vapors are adsorbed by the soot and can stay in the soot for a very long period of time. The retention of chemicals in the clothing can provide a long lasting, chronic-like exposure of firefighters to hazardous chemicals.
Most firefighters believe that the wearing of their self-contained breathing apparatus during emergencies will prevent their exposure to hazardous chemicals, other than any direct liquid contact.
SCBA are effective and since their implementation have served to provide outstanding protection to firefighters in the past several decades. The correct use of SCBA in firefighting including overhaul has dramatically improved respiratory protection.
However, inhalation is but one route of exposure. Skin absorption is also a significant route of exposure to many chemicals. Some chemicals can produce acute or chronic effects through skin exposure alone.
While intact skin is a good barrier to many substances, it can be compromised by being covered, which opens the pores and makes it more susceptible to permitting the penetration of chemicals.
In addition, some parts of the body have skin that is more easily affected by chemicals due to its texture or thickness. Hazardous chemicals may have surface effects, such as causing burns, allergic, or sensitizing reactions, or be toxic.
Depending on the chemical, toxicity can be acute with short-term effects or chronic with longer term consequences. While acute reactions are likely to be noted, the effects for continued exposure that manifest in diseases or later health disorders are harder to connect with specific chemical exposures.
Your ability for keeping chemicals off of your skin is dependent on several protection strategies. First, it is important to wear full personal protective equipment including your complete ensemble and respiratory protective equipment such as your SCBA.
For firefighters, this will be your turnout clothing for which many elements include barrier materials that prevent liquid exposure and retard some vapor exposure. However, as explained above, this clothing is not vapor-protective and some chemicals will indeed reach your skin during the incident if present in sufficient quantities or high enough concentrations.
The second step is to avoid contamination with unknown substances. If you don’t know what that puddle is — and it may not be water from hose spray — try to stay away from it. If outside the fire building, then stand away from the smoke. There are many times that you cannot see or anticipate these exposures, but it is best to avoid contamination when you can. If you can smell smoke or other chemicals, you are being exposed.
The third step you can take is to properly clean and decontaminate your clothing once you have been exposed.
Importance of hygiene
Lastly, and this is a simple and very important step, practice good hygiene. Take off your contaminated clothing as soon as you can, and properly segregate it from "clean" areas until it can be washed. Then, take a shower as soon after the incident as possible. A shower will remove any soot and surface residues and will limit your exposure.
There is a lot more to be said on this topic. Some ongoing work in Australia is looking at evaluating firefighter exposures to specific fireground chemicals in different controlled fires.
This research is showing that while the clothing attenuates the effects of chemical exposure, many chemicals still reach the skin in measurable quantities. Of particular concern are heavy chemicals found in most fires, known as polyaromatic hydrocarbons, which do not evaporate.
These constituents of smoke are known carcinogens and are encountered in many fires. In our analyses of contaminated clothing for fire departments upon request, we have sometimes found levels of these contaminants in unclean turnout clothing.
However, one of the problems with chemical exposure to the skin is that there are no clear exposure guidelines for what quantities or concentrations are hazardous. We have performed some research in this area, but skin exposure limits to different hazardous chemicals are still much harder to define as compared to acceptable respiratory exposure levels.
Understanding that firefighters are routinely exposed to chemicals and the steps that need to be taken to protect their skin is an important realization that can limit the effects of exposure.
The proper wearing of appropriate PPE, keeping it clean, avoiding chemical contact where possible, and taking a shower immediately after incidents are all ways to lower the risk from the effects of chemical exposures.