Ask the Expert: Gary Crawford
Gary Crawford, CIH, FAIHA, a principal with Risk Management Consulting Health Scientists, visited Bloomington on Nov. 8 to host a webinar and answer common questions about mold in residential settings.
Crawford is an independent expert in mold and remediation work and provided answers to several frequently asked questions both via video and text below.
Description of the video:
[Words appear: Mold 101]
[Words appear: Students, their families, and others in the IU Community have important questions about mold concerns some residence halls.]
[Words appear: Gary Crawford, an independent expert in mold and remediation work, came to campus to talk about how to treat mold and avoid reoccurrences.]
[Video: Gary Crawford appears on camera.]
[Words appear: Gary Crawford; Principle RHP Risk Management Corp, Fellow of American Industrial Hygiene Association]
Crawford speaks: Mold is a form of life that is very primitive. It’s been around on the earth for millions of years. It is not a plant and it is not an animal, but it is a living life form. It cannot produce its own food, it reproduces using spores, which are like plant seeds, only much, much smaller. You need a microscope to see a mold spore, whereas plant seeds are much larger and easy to see. Mold spores are dispersed throughout the world. They are everywhere.
[Words appear: What does it mean to “remediate” or “clean” mold?
[Crawford appears on camera.]
Crawford speaks: Mold remediation or mold cleaning is basically a process where mold colonies have developed, you can see them, they are in an indoor environment and you are wanting to get rid of them. Remediation is a procedure, it’s a type of cleaning procedure. Detergents are often used, in certain circumstances you might use a little bleach solution, and you scrub away the mold colony and physically then remove it. Once the area is cleaned, usually than a high-efficiency vacuum cleaner called a HEPA vacuum cleaner is used to round up any loose spores that might be around.
[Words appear: Is mold in residential services becoming more common? Why?]
[Crawford appears on camera.]
Crawford speaks: Mold in indoor environments is probably becoming more common than it was, decades or maybe even centuries ago, because we have conditioned climates in our buildings now. Years and years ago, everything was pretty much open during warm weather, and you didn’t have air conditioning, so things tended to ventilate and dry out. When we have air-conditioned buildings, we are capturing whatever is in there, and we are cooling it, and we are sometimes producing water vapor and when we don’t do a good enough job of dehumidification, that may be enough moisture for some of these little mold spores to take root and start growing. Molds like to be warm. Some can grow cold. Foods that are put in the refrigerator stay mold-free longer than if you left them out on the counter. Mold growth conversely, the warmer it is, the faster it is going to grow. So, as we have more problems with storms and flooding, higher temperatures, higher humidity’s, those are all factors that produce moistures in the environment that will encourage and proliferate mold growth, more than in past times.
[Words appear: How do air purifiers help remove and clean mold?]
[Crawford appears on camera.]
Crawford speaks: The air purifiers themselves, don’t prevent the reoccurrence. What the air purifiers do is remove dust particles and mold spores that are circulating in the air. That makes the air cleaner, more breathable, less allergenic. However, it does not eliminate all mold spores from an indoor environment. That will never happen unless you you’re in a NASA clean room or a pharmaceutical clean room. Just about every indoor/outdoor environment is going to have mold spores present. We track them in on our shoes. They cling to our clothes, they cling to our hair. They come in on the air when you open and close doors and windows. So, there is always going to be mold spores present. The key is to keep things clean as possible, good housekeeping practices, and dry. Keep humidity as low as you can, and if there are any spills or leaks, clean them up right away. Get things dry. Mold cannot grow unless it has moisture and food.The best chances we have from preventing mold from reoccurring is to keep things dry and keep humidity as low as you can.
[Words appear: What are steps all of us can take to help prevent mold in residential settings?]
[Crawford appears on camera.]
Crawford speaks: Good housekeeping is a good first step. Keep it clean. Don’t allow trash or garbage to accumulate. Dust regularly, vacuum regularly. Don’t track in debris from outdoors, and if you do, clean it up right away. Also, is to control the humidity. Don’t let things get too humid. If there are spills… you spill a soft drink or milk or beverage of any kind, clean it up right away. Eliminate moisture. Moisture is your enemy when you’re trying to prevent mold growth. Keep it clean, keep it dry. Use good housekeeping practices and you’ll minimize the potential for mold to grow in your residence.
[Words appear: For a link to Gary Crawford’s full presentation, visit: buildings.iu.edu]
Cleaning supplies and processes
How prevalent is mold in residence halls? Why is it so common?
Mold growth in college residence halls happens occasionally, usually in summer or early autumn when outdoor heat and humidity are high. There are other universities that have had similar problems. Controlling the indoor climate in residence halls is a challenge, particularly in the Midwest which can have arctic type weather in the winter and tropical conditions in summer. Having a heating and air conditioning system in a large residence hall that can cope effectively with this range of climate conditions is difficult, especially in older buildings.
Where does mold grow in residence halls?
There are three categories of causation which relate to where you will find mold growth.
- Liquid causation – leaks and spills that were not promptly and properly cleaned and dried can potentially result in mold growth on the affected surfaces.
- Humidity causation – high indoor humidity is capable of supporting mold growth on any surface that provides a food source such as lint, house dust, paper, cloth, paint etc. Chilled surfaces such as an air conditioning vent or surfaces that are cool are most vulnerable.
- Food/trash causation – mold loves to grow on just about anything that humans consider food so trash cans and any uncleaned surfaces that had food contact are vulnerable.
What types of mold are typically found in residential rooms?
The typical array of airborne mold spore types found in residential rooms are very similar to what is present outdoors but usually in lower concentrations. Actual mold growth found in rooms is more often species of Aspergillus and Penicillium. When these, and some other types, show higher spore concentration indoors, it is reflected in a higher MoldSCORE™.
How can the university prevent mold from traveling from one room to another?
Airborne mold spores are present everywhere both indoors and outdoors and outdoor air enters and moves within a building and its rooms naturally. Mold spores are also in soil and are tracked in on shoes and on clothes. There is no way to stop spores from entering buildings or rooms within them. Actual mold growth, however, can be prevented by controlling moisture and high humidity. Controlling humidity in large, heavily populated buildings is very difficult, especially in hot humid weather. With respect to mold remediation activities, it is understood that polyethylene sheeting is placed over the doorways while work is underway.
We have seen instances where mold affected rooms are not isolated. Most mold remediation websites state “A standard practice of mold remediation is to isolate the affected area, so the mold does not spread to other areas during remediation. If a mold contractor claims that isolation is not necessary, look for a different contractor.” Can you explain why your company felt isolation wasn’t necessary?
RHP Risk Management was not involved with establishing the mold remediation protocol but has reviewed IU’s plan and found it to be consistent with good practices. OSHA and EPA mold remediation guidelines do not require isolation (containment) of rooms or work areas that are classified as small to medium size mold remediation projects. The size of the project is determined by the surface area that is moldy. A small project would have no more than 10 square feet of mold and a medium project would be in the range of 10 to 30 square feet of mold growth. It is understood that the affected residence halls were almost entirely small projects with affected areas being less than 10 square feet.
The IU Remediation protocol covers two situations. The first is “Basic Remediation” which is used in residence halls where only the fan coil unit is being cleaned. In that case, plastic sheeting is placed under the unit during remediation. The second is “Enhanced Remediation” which is used in residence halls where other surfaces such as walls, book cases, etc. are being remediated. In that case, the doorway of the room is covered with polyethylene sheeting even though that is not be required by either OSHA or EPA mold remediation guidelines.
As an occupant, how can I prevent mold in residence halls?
Be a good housekeeper. Take out trash and food wastes frequently. Clean up spills promptly. Report leaks promptly and dry affected surfaces. Don’t leave damp towels or clothing lying around. Dust and vacuum to keep the room clean.
Be aware that high humidity can cause mold growth and refrain from/minimize opening windows when it is humid outdoors. Letting the outdoor humidity into the room can promote mold growth.
Cleaning supplies and processes
What is the role of HEPA air filter?
HEPA is a very high efficiency filter that can capture microscopic mold spores and dust particles making the air you breathe cleaner.
Some professionals have told us that the industry standard is that the air in the space to be tested should be stagnant for a minimum of 12 hours for accurate testing. Why is IU insisting on running air purifiers in the rooms at full speed for days prior to mold spore air testing? Where exactly in each room is the testing device in relevance to the air purifier output itself?
One purpose for air testing following remediation is to help assure that air quality in a room will be acceptable before re-occupancy, and during occupancy. Since a HEPA air filtration device will continue to be present and in operation after the room is reoccupied, then that is the circumstance that should be tested. It answers the question; Is the HEPA device doing a good job of circulating and cleaning the air so that persons re-occupying the room have acceptably clean air to breathe? Stagnant air testing in this situation would not address that question.
The exact location of the HEPA device and the air sampler likely varied from room to room, however, given the size of the residence halls, they would be in a relatively close proximity.
What disinfectant products are commonly used to remediate mold?
Detergents are primarily used to loosen a mold colony from the surface it is growing on and wiping it away. Bleach containing solutions are also used on hard, non-porous surfaces such as tile, painted concrete blocks and painted wood. Some disinfectant products are also used.
What does basic remediation entail? What does enhanced remediation entail?
It is my understanding that the IU program defines “basic remediation” as the disassembly and cleaning of the heating and cooling unit in a residence hall room. Enhanced remediation involves cleaning of other surfaces in a room such as walls, carpet, bookcases, etc.
Are chemical smells post-remediation common and/or harmful?
Cleaning products such as detergents and bleach used in remediation have odors that should dissipate after a relatively short time. If that is the odor type that is present, it should not be harmful. However, if the odor does not dissipate or is irritating, notify the IU call center and have it checked.
Why is the indoor spore count or spore concentration listed on the portal different than the MoldSCORE™ that I was provided?
The laboratory report sets forth the indoor mold spore count by types of mold. To determine the significance of a test result takes experienced professional interpretation. Simply giving out the basic lab report would be confusing to most people. Therefore, a group of scientists developed MoldSCORE™ which consolidates the lab test results into an easily understandable format.
What does my MoldSCORE™ mean, and how do I read the report? Is my room safe if it receives a moderate score?
A MoldSCORE™ is not the sole criteria for deciding whether a room may be occupied. Rather, MoldSCORE™ gives results of air testing in three categories. The green category essentially indicates that the result was low, or normal/typical for indoors, and is what you would expect to see in a space unaffected by indoor mold growth. The orange category essentially shows a moderate result that is somewhat above normal but not high enough to conclude there is a significant amount of mold growth present.
What is considered “safe” is a relative term. A normal, healthy young adult probably wouldn’t be affected by being in an orange category room that might have some indoor mold growth. Whereas someone with mold allergies, asthma, or some other medical condition might have a problem. The decision to stay in an orange category room is up to the individual. A red category MoldSCORE™ shows a high probability of a mold condition in a room that needs remediation and additional evaluation may result in a recommendation that the room should not be occupied.
What could cause a room’s MoldSCORE™ to increase after remediation has been completed?
Airborne mold spore counts, and types are in a constant state of flux outdoors and outdoor air infiltrates into buildings, so variations in test results up and down from time to time are normal. However if the MoldSCORE™ goes up dramatically following remediation then the room should be re-inspected, have additional remediation performed if necessary, and re-tested.
How can we, as parents, independently verify the information told to us by the university (i.e. the effectiveness of the cleaning strategy, the effectiveness of the air purifiers, the air testing, etc.). We need to re-establish trust.
The effectiveness of the cleaning strategy can be evaluated by the visual absence of mold growth where it had been previously identified and on any other surfaces in the room. Air testing results are also a way to assess cleaning effectiveness.
In order for a device to be sold as a “HEPA” air filter it must be capable of removing 99.97% of all particles 0.3 microns, or larger, in diameter. Mold spores are typically 3 to 100 microns in diameter and therefore very effectively captured by the HEPA filter. The HEPA filtration devices being used in IU residence halls are manufactured by Honeywell, a well-known company.
Air testing samples are/were analyzed by an independent, accredited laboratory. The original reports from this laboratory are posted on buildings.iu.edu.