Our thoughts and prayers are with the victims of the recent fires and their communities. We hope you will find this information on smoke remediation useful when the time is appropriate.
Wildfires – Overview
Extreme heat occurring across much of the western United States following a winter of significantly increased rain and snowfall creating the perfect condition for increased numbers, size and duration of wildfires. News sources have indicated that the wildland fire season of 2017 may yet be the worst fire season in recent history. This fire season is significant for the number of wildfires and the associated harm to an increasing number of humans living and recreating in wooded areas, as well as to many wildlife, timbers and structures. Whole communities have been severely impacted.
In a 2013 Senate Committee hearing, Thomas Tidwell, head of the U.S. Forest Service, testified before a committee on energy and natural resources that the fire season now lasts two months longer and destroys twice as much land as it did four decades ago. Fires now, he said, burn the same amount of land much faster. This year’s fire season may even exceed the trend Tidwell noted in 2013. Through July 9, 2017, California alone has experienced 2940 fires and over 68,000 acres burned. This is a torrid 28% increase over last year. More significantly, the accompanying number of acres burned has more than doubled.
With this increased potential of wildland fires, health concerns for certain individuals raise significantly. Forest fire smoke is made up of small particles, gases and water vapor. Water vapor actually constitutes the majority of smoke. However, what remains is significant in terms of health effects. The remainder includes carbon monoxide, carbon dioxide, nitrogen oxide, irritant volatile organic compounds (VOCs), air toxics and fine particles. Although smoke can be harmful to all individuals, it may be dangerous to certain populations, especially those already at risk for heart and lung diseases. Individuals with congestive heart failure, COPD, emphysema or asthma are at greater risk. Additionally, children and the elderly are more susceptible to harm from smoke.
Wildwood fires that occur in more populated areas, such as the 2013 occurrence of the Black Forest fire in Colorado, have increased health concerns when structural components become fuel. When structural fires are a part of the wildfire, the types of fuel increase and include all of the building materials – paint, carpet, floor coverings, wall coverings, insulation, manufactured materials, plastics, electronics, furniture, clothing, etc. Chemicals, such as pesticides, cleaning agents, and aerosols also become fuels. Many of these household chemicals are known carcinogens. Others can be damaging to structural components because of their corrosive nature. All of these are the effects from what we refer to as “smoke”.
Smoke Contamination in Structures
Particles are classified by their size. In a wildfire, hundreds of thousands of tons of respirable particulate matter is released. The vast majority of this particulate is smaller than 0.3 micron. To get a sense of size, a human hair will range from 30 to 120 microns. Because of the small size of this particulate, it is easy to see how smoke will infiltrate your house, even though you may have had doors and windows tightly sealed. Smoke damage is a common occurrence in structures near wildland fires. Generally, what we notice after a nearby wildfire is the presence of “soot” and the odor of smoke. Soot, or carbon black, is a relatively small component of the complex elements of smoke; however, it is the most easily recognized or observed.
It is difficult to assess the level of smoke contamination in a structure. Certainly there are tests that can be conducted. One such test is ASTM D6602-03b test method “Standard Practice for Sampling and Testing of Possible Carbon Black Fugitive Emissions or Other Environmental Particulate”. This method requires a wipe sample and a specific analytic protocol. It will provide you with an assessment of the presence of both char material and carbon black in particle sizes of 1 micron and larger. Other tests may be used to determine the presence of specific chemicals. All of these tests are complex and must be determined and conducted by a qualified consultant. If it is necessary to determine and quantify the presence of smoke contamination, a qualified environmental professional should be used.
Smoke Odors in Structures
Practically, contamination will be determined by odor. The presence of smoke in the structure will provide a recognizable odor. Odor brings awareness to the human olfactory system of the presence of airborne chemicals. Awareness of odors can also be from stimulus, triggering unwanted irritation to eyes, nose, and throat.
Smoke can affect anyone, not just those at increased health risk. “The odors from smoke can leave you feeling nauseous or with headaches, as well as an overall sense of annoyance at the constant smoke irritation,” said Janie Harris, Texas AgriLife Extension Service housing and environment specialist. “The smoke infiltrates homes and the lingering odor persists.”
Harris said the odor persists, even after a good scrubbing, due to tiny microscopic particles that cling to walls, furniture, floors and clothing inside the home. “Removing the smell of smoke can be a difficult job involving time, effort and money,” she said.
The most effective way to eliminate odor is to remove the source. Other methods are often attempted, such as masking the odor or altering it to a less offensive chemical, but source removal is the preferred method.
The Federal Emergency Management Agency (FEMA) provides wildfire smoke remediation guidelines in a pamphlet titled “Tips from State and FEMA on Smoke Removal and Fire Cleanup”. This guideline provides some tips on steps that should be taken. Their course of action includes the following:
- Pressure wash, scrub or disinfect all exterior surfaces including walls, walks, drives, decks, window and deck screens, etc.
- Wash and disinfect all interior walls and hard surfaces with mild soap or other appropriate cleaning solutions or products, and rinse thoroughly. Don’t forget inside cabinets, drawers and closets.
- Launder or dry clean all clothing.
- Wash, dust or otherwise clean all household items, including knick-knacks.
- Disinfect and deodorize all carpets, window coverings, upholstered furniture and mattresses with steam or other appropriate equipment.
Following these tips will most likely reduce the surface particulate to acceptable levels. However, it may not reach all areas and it may not eliminate the odor.
Structural Pasteurization as Odor Remediation
The process of structural pasteurization can be used to finish the job and have odor reduced or even eliminated. Structural pasteurization, a process used by ThermaPure® licensees, increases the temperature of a structure with the goal of reducing a targeted chemical(s) or organism to an acceptable level. This technology has been used for chemical reduction processes as well as in mold remediation, bacterial disinfection, and pest eradication.
With regard to chemical reduction, the temperature in the structure is elevated to 105ᴼ-120ᴼF, increasing the vapor pressure of the various volatile chemicals to speed up the process of off gassing. This temperature will be maintained for varying periods of time, from hours to a few days, depending on the complexity and severity of the smoke odor. A ThermaPureHeat® application is an engineered process; which typically includes air filtration, temperature control and monitoring, and air pressure control which will provide appropriate air and temperature distribution to the structure. This allows a more rapid off-gassing of chemicals while maximizing protection to the structural components and furnishings. Air filtration will use HEPA filters to capture much of the particulate and may use carbon filters to capture vapors. In many situations the structure, or portions of the structure, may be heated under negative pressure, allowing both ultrafine and fine particulate to be exhausted along with the target vapors.
Case Study – Fire in Structure with Smoke Damage Throughout
The case study project is a high-end, multi-story single family residential structure. The exterior consists of stucco/plaster over wood framing. The interior walls and ceilings are constructed of gypsum drywall and/or thin coat plaster over wood framing. The flooring is a combination of carpet, tile and wooden materials. The residence is located on a hillside with beach access in Malibu, CA.
The garage and primary entry is located at street level. The residence is approximately six stories from the entry area to the beach. The residence has approximately five levels which would be considered livable floors. The fire loss occurred in the kitchen of the residence. This area is located on the third level from the beach.
The insurance adjuster retained the services of Environmental Testing Associates (ETA), a southern California environmental consulting firm, to provide fire damage assessment and recommendations. The purpose of the requested work was to determine the amount of char material and/or ash/fugitive dust, if any, that may have contaminated the subject property and to gather information necessary to assist in the planned services necessary for the successful cleaning and restoration following the loss. This information would be used in conjunction with the accepted standards of care for treating, cleaning and the decontamination of the impacted areas.
ETA concluded that several areas had been contaminated by char materials and remediation/cleaning was necessary. Smoke-like odors were also noted within the subject property on all floors.
ETA’s recommendations were specific to each floor and included cleaning, removal of materials that could not be cleaned, and removal of loose items and either cleaning or replacement. An all encompassing recommendation was the use of filtration. Here are ETA’s filtration recommendations:
All areas of the residence: HEPA filtered air filtration units should be equipped with charcoal filters. Equipment should be placed generously throughout the residence and must be allowed to run during the entire restoration process. The filters within these units should be frequently/aggressively replaced.
A local restoration company was used to provide the cleaning restoration services. Once cleaning was completed, there was still a significant smoke odor remaining. The homeowner’s wife was chemically sensitive and although low VOC cleaning compounds had been used, there was still a concern that any additional use of chemical cleaners may not be effective and also may be harmful to the client. ETA recommended the use of a non-chemical remediation process, ThermaPureHeat® to complete the off-gassing of smoke-related chemicals and reduce or eliminate the odor.
A southern California based ThermaPure® licensee, was retained to provide the heat services. Because of the magnitude of the smoke odor and the size and complexity of the structure, it was determined that the target temperature would be between 110ᴼF and 120ᴼF for a duration of 10 to 15 days. Multiple types of heating equipment were used, dependent on access, ingress, size and complexity of the area. Electric heaters were used in some areas, hydronic heaters with heat exchangers were used on several floors and some direct-fired propane heaters were used nearer to ground level. In addition to heaters, fans and negative air machines (HEPA), moisture was introduced to the ambient air to reduce the potential damage effect of long term drying. The air exchanges were significant with approximately 3000 cubic feet of air per minute (CFM) exhausted. Particulate that had not been accessible to hand cleaning was aerosolized and either captured by the HEPA/carbon filtration or exhausted along with the bulk of the chemical vapor.
It is extremely difficult to eliminate smoke odor, but on the final walk through the client indicated that he did not detect any odor. This was a very successful smoke odor reduction project. Client and adjuster were extremely satisfied with the outcome. The alternative to this process would have been the expensive removal of many high priced decorative and structural elements and additional chemical application.
July 10, 2017