Can better cleaning techniques eliminate fire residues?

A fascinating article entitled, “After a fire, how clean is ‘clean’?” by Sean M. Scott ran last November in Claims magazine. Scott’s premise was that some dangerous residues could remain after the restoration of smoke-damaged textiles.

Based on my knowledge of the subject, the author made a compelling case that traditional laundry methods are inadequate for addressing the dangerous chemical residues that remain in soft goods contaminated by smoke and soot. This is a significant concern given the number of structure fires that occur yearly. In 2017 alone, the National Fire Protection Association (NFPA) estimated there were 1.3 million structure fires, resulting in approximately $23 billion in property damage.

Leaving dangerous chemicals behind

The potentially dangerous fire residue left in soft goods after treatment is well-documented, an issue Scott addressed, both by the by the “practical science” testing he conducted and by previous studies. He included a link at the end of the article to a more extensive paper with additional references that detail some of the other research. Various studies conducted by Wonder Makers Environmental over the past decade have also documented the presence of a large range of “nasty” chemicals in soot and fire residues. Many of these dangerous compounds fall under the general heading of polycyclic aromatic hydrocarbons (PAHs).

Removal of PAHs and other fire residue from soft goods is complicated by the fact that the deposition of these contaminants can be in the form of small particles or vapors, as well as larger, visible particles. The ultra-fine particles and vapor droplets can penetrate deep into multiple layers of soft goods, particularly when driven by the heat of the fire and the difference in temperature of the cooler contents. As such, it was not surprising when Scott’s testing recovered a wide range of chemicals that could be fire residue from items that looked and smelled clean.

Four key questions

Fire residue penetrates deeply and standard cleaning methods likely leave behind some chemicals. This brings to mind four critical questions, one of which was raised in the original article:

1. How much residue is being left behind?
2. How much residue is safe to leave behind?
3. Is leaving any “contamination” a failure to return the contents to a “pre-loss” condition?
4. Are there other cleaning and/or decontamination methods that could do a better job of removing the fire contaminants?

The one question raised in the original article is the second item on the list: How much residue is safe to leave behind? Scott addressed that issue in two important sections when he stated:

“Some are so toxic that the EPA has designated them as having a zero level of permissible exposure limit (PEL).”

He also specified:

“If you send smoke-damaged baby clothes to be treated with ozone and cleaned, is there a possibility that toxic particulates and harmful chemicals could be trapped in the fabric? If so, could these toxic particulates be absorbed by a baby’s skin and cause a reaction, sickness, disease or worse? The answer is a resounding, ‘Yes!’”

Although the emphasis should always be on safety, it is important to remember that we do not live in a risk-free world. Zero tolerance might seem reasonable until additional testing is completed. Without control samples to establish the background levels of specific chemicals in “unaffected” contents, the restoration industry should be cautious of pushing for a standard of clean that might be lower than “normal.” This is especially important since some of the recovered chemicals noted in the earlier article can originate from sources other than a house fire or wildfire (i.e., ethanol from personal sanitizers, acetone from cosmetics, acetic acid in foods, naphthalene in bug repellants).

Obviously, this caution about setting a de facto standard before more detailed testing is done leads directly to the first and third questions. How do we know what the pre-loss condition is for these chemicals found in cleaned clothing until we identify which ones, and how much, are in contents that have not been smoke damaged? Just as importantly, what differences will we find in background levels in contents in a home occupied by people who smoke or vape, buildings heated with gas or oil, or ones with gas stoves or water heaters, as compared to those homes where those conditions are not present?

Understanding the contaminants points the way to proper cleaning

Despite these unknowns, and with the obvious understanding that more testing is necessary, we still can look at question number four from a scientific perspective. To determine if a “non-traditional” cleaning process might yield better results, we first have to understand what is involved with the “traditional” approach to cleaning fire contaminated soft goods. In the article, the general approach was described as: “The theory is that soft goods and fabrics can be completely sanitized and deodorized by placing them in an ozone chamber for a couple of days, using commercial grade laundry detergents, dry cleaning and other cleaning methods.”

This description points out some significant concerns. One of the primary axioms of any cleaning process is to remove the soils first. If fire-impacted soft goods are placed in an ozone chamber before cleaning, then the oxidizing process of the ozone that breaks down the fire odors has to react with all of the soot particles in addition to any chemical vapors absorbed by the fabrics. This greatly increases the potential for creating secondary byproducts that can then be absorbed by the contents. Thorough cleaning prior to any deodorization or oxidation treatments is the smartest approach to eliminating fire residue efficiently. In addition, deodorization/oxidation that happens in a liquid state, as compared to an airborne treatment, reduces the opportunity for reabsorption.

One nontraditional cleaning process that meets these general parameters is the Esporta Wash System. With carefully controlled sampling, past tests have shown that the Esporta cleaning process was five times better at removing soils from garment samples than traditional front-load commercial washing machines. That data is especially relevant in this discussion as the lab tests were conducted at the University of Alberta by an NFPA consultant to address the issue of cleaning fire-contaminated firefighter gear. If soils and particulates are effectively removed prior to other treatments when addressing fire contaminants, it greatly enhances the ability to have cleaned contents reach a “safe” or “background” level.

Oxidizing or deodorizing in a liquid state after soil removal and using chemicals that are not adding to the level of chemicals being tested is a second advantage that the Esporta cleaning process has over traditional content cleaning. Both dry cleaning and standard deodorizing chemicals, which as mentioned in Scott’s article often include fragrances to mask other odors, leave residues that can contain many of the same compounds created by fire. In contrast, the typical Esporta Wash Process uses hydrogen peroxide to oxidize the absorbed chemicals, a chemical that breaks down to water after neutralizing the “bad actors.”

Time to answer these critical questions with science

The concerns raised by Scott in the November article are the sort of serious questions that need to be asked and answered if the remediation industry is going to develop as a professional, respected service provider. His issues regarding the safety of the recipients receiving cleaned contents, and the additional questions raised in this follow-up piece, are straightforward. A well-designed study could build on the existing information and go a step further to include samples that quantify the chemical amounts that remain after different cleaning techniques. It could then compare those results to background levels. This would go a long way to determining whether the restoration industry is putting clients at undue risk when they clean and return fire-damaged contents.

In the meantime, restorers should be aware of the differences in the current cleaning methods and choose the most effective technology available until there is additional evidence to do otherwise. As the science progresses, it is also important to remember that we do not live in a sterile environment. We can take some comfort in the fact that there have been no widely reported cases of cleaned, fire-damaged contents causing serious illness or injury.

Michael A. Pinto is chief executive officer of Wonder Makers Environmental, Inc., a manufacturing and environmental consulting firm that specializes in identification and control of asbestos, lead, IAQ, mold, industrial hygiene and chemical problems. Contact him at map@wondermakers.com.

Related:

After a fire, how clean is ‘clean’?

12 tips to protecting yourself after a wildfire

Playing with fire: Avoiding toxic exposures in structure fires