Decontamination Best Practices

Aug. 11, 2009
The main purpose of decontamination at a hazardous materials emergency is to limit the spread of contaminants from the release area, or "hot zone," to include the cleaning of responders and their equipment. Decon even includes cleaning contaminated victims from a wide spectrum of events, such as industrial emergencies, along with mass-casualty incidents, whether accidental or intended. Almost always, decon is conducted as an afterthought or on the back end of an incident.

The main purpose of decontamination at a hazardous materials emergency is to limit the spread of contaminants from the release area, or "hot zone," to include the cleaning of responders and their equipment. Decon even includes cleaning contaminated victims from a wide spectrum of events, such as industrial emergencies, along with mass-casualty incidents, whether accidental or intended. Almost always, decon is conducted as an afterthought or on the back end of an incident. In other words, decon is most likely carried out after all the excitement is over and done with and the emergency phase is wrapping up.

Because decon is conducted in the declining stages of an incident, it may sometimes be dismissed as not an integral and important part of a quality response. A good example of this mindset can be observed at numerous hazmat exercises. Frequently, responders focus on the decision-making and task completion of the exercise and decon becomes something that is done to merely complete the event. Then, the decon personnel doff their personal protective equipment (PPE), the decon corridor is torn down, the contaminated water in the decon kiddie pools is dumped and they go home.

It shouldn't be this way. Proper and effective decontamination should occur at all hazmat events and responders should be vigilant in carrying out good decon operations, even at exercises. Consequently, the intention of this column is to point out how responders can employ decontamination best practices.

The Mundane Is Important

Decontamination is a very mundane assignment and it is just not very "sexy"! In fact, it can be downright boring. There are long periods of inactivity and short periods of actual work. But, it is nevertheless very important because everything needs to be properly cleaned before it leaves the decontamination corridor. This we all know. Yet, it is difficult to be enthusiastic when the limelight is elsewhere. After all, the excitement is in the "hot zone" and not upwind in the "warm zone." Because decon is anti-climactic, common pitfalls can be observed from incidents across the country such as:

  • Overusing structural fire protective clothing (SFPC) as decon worker apparel. SFPC is not designed for hazmat events, so why is it used for decon activities? The answer is because it is habit, it is easily available and it is easy to don. The downside is the contamination, or cross-contamination, issue when SFPC is used to decontaminate contaminated personnel. There is a dangerous assumption that the SFPC remains clean afterwards. Maybe SFPC is allowed for decon worker apparel because "we are just using it for decon."
  • Overlooking contaminated spray and runoff from decontamination. The Environmental Protection Agency (EPA) does pardon decontamination runoff in times of emergency when lives are in peril, but responders must try to retain contaminated water runoff as soon as possible. This pardon does not apply to the everyday decon activities that should be prudently completed at hazmat events. Maybe a quick, down-and-dirty decon is acceptable because "it is just a splash of water we are using that can't hurt anything, even if we just allow it to go into the environment."
  • The over-the-top practice of dumping decon pools indiscriminately after the emergency. A countless number of events have seen the wastewater in decon pools merely dumped into the environment or storm sewers without being properly checked. Why is this practice allowed? Maybe this happens because "it is how it is done after training sessions."

From a best-practices standpoint, all of the above can be corrected by taking the task of decontamination seriously, following standard operating guidelines (SOGs) strictly and avoiding cutting corners. Specifically, decon workers should be dressed appropriately in Level A, B or C apparel, depending on the contaminant, the entry team's level of protection and even a consideration of National Fire Protection Association (NFPA) 1991 or 1992 approved attire. Additionally, decon activities should be conducted in a decon corridor per SOGs with disposable plastic tarps and wastewater basins for runoff control. Lastly, before wastewater is handled, environmental authorities should be consulted and wastewater should be tested and disposed of through licensed contractors.

Another practice is to avoid the use of water for decontamination in the first place. For instance, for materials with low boiling points — that is, materials that evaporate at low temperatures, such as chlorine and ammonia — the simple act of letting the materials evaporate off of protective equipment can be effective. Enhancing the evaporation process with positive pressure blowers is a very effective technique. Another technique that has been used by hazmat teams in the Great White North for years is "dry decon." This technique merely entails having entry personnel simply doff their PPE without using water but with careful movements. It takes practice, but it is a great alternative when the ambient temperature is -30 degrees Fahrenheit! (For more information on these two decontamination techniques, see

"Clean" Is Not Necessarily Clean

There is an assumption with nearly all decontamination activities that everything that endured the decon process comes out "clean." While it can be argued that if no one contracts an illness or affliction after being decontaminated, then the decon process was effective and adequate. The problem is that this practice relies on a "wait-and-see" approach. What if everyone who was decontaminated became ill several hours later because the decon was ineffective and inadequate? This result does not seem to happen often, or at least we do not hear of it much, but what if?

We do know that contaminants are absorbed into PPE and can be absorbed into bare skin, and that surface decon efforts can be ineffective. The hope is that contaminants are removed enough, or diluted enough, so that only a small amount is left and that amount cannot possibly cause harm. But is hope enough? Experts say no. How then can responders in the field check whether decon efforts were adequate? The answer, from a best-practice approach, is with appropriate monitoring instruments.

After entry personnel, and even victims, have been decontaminated (and before doffing PPE), a quick scan with monitoring instruments can be accomplished. Instruments such as radiation survey meters and photoionzation detectors (PIDs) can screen adequately for radiation and volatile organic compounds, respectively. If levels are found to be unacceptable according to SOGs, then another round of decon is warranted and anything less than this is merely guesswork. Also, how many hazmat teams check for the adequate decontamination of the decon workers? It is only through proper checks with appropriate monitoring instruments in the field that decon efforts can be determined to be effective. It is only then that "clean" can truly be clean. (For more information, see"How Clean is Clean?: Assuring Decontamination Efforts are Adequate.")

For Mass Decon, You Need the Masses

For over a decade, an accepted practice for decontaminating large numbers of victims has been what is known as the "car-wash" method. This method uses fire engines that discharge wide-angle/low-pressure fog streams in order for large numbers of people to pass by and get showered. The addition of an overhead stream through an elevated ladder truck has also been recommended to enhance effectiveness.

These guidelines are all fine if contaminated people line up and wait for the equipment to be set up and water is activated. However, experts like Joseph Scanlon state that history does not support the theory that mass-decontamination concepts will be effective. (See\hazmat\ "Rethinking Terrorism Response Decontamination Issues" for more information.) The simple question is what would you do if you knew you were contaminated or had a noticeable skin or respiratory irritation along with hundreds or thousands of other people? Would you line-up and wait for the first responders to arrive, set up and staff their mass decon method? It is inconceivable to think that victims would do this — and that is exactly Scanlon's point. Most people will bolt and act in their own best interest.

Best-practice approaches to the mass decon problem may be to install hardware in or near venues where large crowds could be expected such as sporting events, music festivals and shopping malls. Shower units could easily be installed to allow for thousands of people per minute to be decontaminated at these sites. Similar systems could be used at hospitals where the walking wounded will appear. Also, an idea from the Columbus, OH, Division of Fire employs mass-decon hydrant caps around large-attendance buildings such as a stadium. Obviously, the hydrants must be activated, but this may be more effective and less costly than the "car-wash" method. The key is to honestly examine what would work and then act before mass-decon measures are needed.

In conclusion, decontamination is more than rinsing, scrubbing and rinsing. It behooves responders to examine their present decon approach, employ best practices and better prepare through complete exercises to ensure their safety along with effective decontamination.

DAVID F. PETERSON is a lieutenant in the Madison, WI, Fire Department, where he is the lead fire and hazmat training officer. He is in his 30th year as an emergency responder and is the managing member for the Wisconsin FLAME Group LLC. Peterson also operates, a hazardous materials response training website. Please send your comments and questions to him at or [email protected].

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