Cleaning Mold-Contaminated Contents

Cleaning Contents from Mold-Contaminated Environments

By Michael A. Pinto, CSP, CMP

Mold growth and associated contamination in buildings continues to garner public attention. While the insurance industry is struggling to define payment restrictions, the need for professional, competent mold remediation continues to grow. Fortunately, the remediation industry is advancing to meet the evolving needs related to mold.

Every mold clean-up project has two components, one of which has received considerably less attention than the other. All knowledgeable contractors and consultants understand the need for remediation of visible mold from building components, but often these same people are less educated about the assessment and control of contents in mold-contaminated environments. An increasing awareness of the potential problems that are created when clothes and furnishings are not properly addressed as part of a mold remediation effort is forcing the industry to broaden its approach to mold cases.

Two Bad Examples

A short time ago, our laboratory received a lampshade from a woman who was in the middle of a mold remediation project. The fungal growth in her residence was severe enough that she had been advised to find an alternate living space until the remediation project was completed. Unfortunately, nobody warned her about cross contamination issues related to moving contents that had not been properly cleaned. Her continuing health problems, even after moving, led her to send a lampshade to us for analysis. Although there was no visible mold growth on the shade, or even visible dust or dirt, a microvacuum sample revealed a high concentration of spores associated with water-damaged buildings, including Stachybotrys.

An even more contentious case involved a contractor who conducted a mold remediation project that involved transferring all moveable items out of the house. Evaluation, cleaning, handling and documentation of the process were so poor that after the contents had been moved to a storage facility we were asked to assess their condition. Evaluation of the “cleaned” materials confirmed the presence of excessive levels of spores and fungal fragments of the types that were targeted for removal from the house. This improper handling of contents resulted in a five-figure settlement.

Guidelines Codify Field Experience

Although there is no mandatory national standard for dealing with mold, there is a standard of care that can be understood by focusing on the points where various guidance documents intersect. Currently, six of the most important documents related to mold all confirm that mold-contaminated contents should be subject to specialized cleaning.

Most of the guidance documents favor the disposal of contents made of porous materials (e.g., drapes, clothes, upholstered furniture) that have visible mold growth. Several recent studies confirm the difficulty of removing the spores and growth structures from fabrics and other porous materials after growth is visible.

Contents that are contaminated by deposition of spores from adjacent growth can be cleaned. The IICRC’s S520 document refers to such contamination as Condition 2. The dust from impacted items does not reflect a normal fungal ecology.

It Starts With Assessment and Categorization

Since proper handling of contents from a mold-impacted environment is based on the type of material and the type of contamination, an initial assessment and categorization is the first step of the cleaning process, using a tool similar to Table 1 below. The key is to segregate items with actual mold growth from those impacted only by spore deposition.

Once the initial segregation is completed a determination can be made on how the content cleaning will proceed. Thinking through answers to key questions will assist in the development of an effective plan.

• What amount of contents is impacted?
• What is the overall condition of the structure?
• Are there security concerns at the site?
• What cleaning techniques will be used?
• Is there adequate space on-site to set up a decontamination work area?
• Will a substantial portion of the items be processed off-site (e.g., laundry or dry cleaning)?
• Is a general pack-out part of the overall job?
• How long is the structural remediation expected to take?

Determining If Content Cleaning Was Successful

Perhaps the most vexing aspect of mold remediation projects in general, and content cleaning in particular, is determining an endpoint. What is clean enough? Does it depend on the situation and the occupants? The size of the project budget?

Most knowledgeable industry professionals believe that it is crucial to evaluate and document the cleaning effectiveness. But without an accepted standard endorsed by a regulatory agency or national standards group, the suggestions for post-cleaning criteria range from the thoughtful to the ridiculous. Some evaluation methods that have been suggested or used include:

• Sensory verification – The owner conducts a visual and odor check.
• Canine sensory verification – A trained mold inspection dog is brought in to sniff the contents and react to any mold.
• Mycotoxin testing – Samples are collected and analyzed to determine if any residual poisonous chemicals are present.
• Viable spore testing – Samples are collected and analyzed by culturing, which identifies residual spores capable of growing on a specific nutrient agar.
• Total spore and fragment testing – Samples are collected by tape lift, microvacuum or air collection methods and fungal residue is identified under the microscope.

Regardless of which method is employed, a comparison criteria needs to be established at the beginning of the project, as well as the number of samples that will be collected and their timing.

At Wonder Makers Environmental we achieve content cleaning verification through a combination of visual inspection and total spore/fragment testing. Since visible growth on dust or contents signals improper cleaning, our first step in verifying content cleanliness is a visual inspection. We normally have the remediation contractor group cleaned items into batches. If a single item in a batch fails the visual inspection, the entire batch is recleaned. Once a batch of contents has passed the visual inspection, a representative number of samples are collected. Since the actual number of spores in the dust on an object is influenced by both the concentration of spores in the air and the time it has taken for the dust to collect, we began reviewing microvacuum samples to determine the percentage of spores. By recording the data as a relative number rather than an absolute count of spores, we were able to correlate analytical results with field conditions and, ultimately, with customer satisfaction.

After years and hundreds of projects we have seen that fungal spore concentrations of one percent or less of the total sample constituents (absent target fungal types) are an indication of a normal fungal ecology. Fungal spore concentrations between one and three percent are an indication of an indoor environment contaminated with settled spores, dispersed directly or indirectly (Condition 2). Fungal spores recovered at three percent or more of the total sample constituents indicate an indoor environment contaminated with the presence of actual mold growth and associated spores (Condition 3). Recovery of target fungal spore types (including Memnoniella, Stachybotrys, Trichoderma, Chaetomium, and Fusarium) is further indication of fungal contamination. The total percentage of fungal spores recovered and the identification of target fungal spore types are two pieces of information used to determine if contents or surfaces have been impacted by mold sources in the environment, or whether they have been properly cleaned.

Solving the Contents Conundrum

Dealing with contents from a mold-contaminated building is complicated and fraught with technical and legal pitfalls. But traps can be avoided by following these common-sense guidelines:

1. Appreciate the risk to the occupants, the remediation crew, and the environment posed by mold-contaminated contents.
2. Understand the growing consensus that the ultimate goal is for the contents of a mold-contaminated environment to have mold concentrations at levels consistent with, or less than, a normal environment.
3. Conduct a thorough assessment of contents, addressing fungal growth and spore deposition as well as the porosity of each item.
4. Implement appropriate cleaning practices and protective controls.
5. Select a defensible endpoint at the beginning of the project. This includes both the evaluation method (i.e., type of inspection, number and location of samples, timing of sample collection, etc.) and the comparison criteria.
6. Utilize the percentage of spores criteria described in this article in the absence of other technically supported data as a pre-defined endpoint for determining if contents are clean following a mold remediation project.

Combining these guidelines with common sense and awareness that dealing with contaminated contents is an important aspect of each mold remediation project will protect the contractor and advance the industry as a whole.

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Cleaning #Mold-Contaminated Contents http://t.co/3nilI38hTg (This article offers guidelines!) PLS RT pic.twitter.com/XJlUMp38tb

— Mold Sensitized (@moldsensitized) July 31, 2015