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Frequently Asked
Questions
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Biohazard
Control Damage
Analysis
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In this section we have placed some of the more frequent questions posed to our consultant staff. Browse down and see if a question you have has been answered here, or if not (or if you would like more detail), e-mail us and we'll be happy to answer you promptly. What is sick building syndrome (SBS)? When is a building labeled as having a building related illness (BRI)? Why do newer buildings seem to have more IAQ problems than older ones? Is there a routine recommended IAQ test? What are the current IAQ standards? I've heard about a CO2 test, but what is it for? My CO2 levels go above 1000 ppm which means people will start getting sick, right? How do I know if my air ducts need cleaning? Can you test my indoor air quality? I have an odor in my house, what is it? There are black particles deposited on supply air diffusers - what is it and is it harmful? I have allergic type symptoms when in my home. Can you test for molds and mildew? The cause of occupant illness in buildings is frequently multi-factorial and difficult to quantify. Modern office equipment, furnishings and interior finishes, outdoor air pollution, energy efficient building materials and energy saving operational procedures all contribute to discomfort in a significant portion of the occupants - when at work. The symptoms reported by occupants often are non-specific and make diagnosis difficult without a concomitant investigation. Symptoms may be rooted from factors such as physical comfort, microorganisms, chemicals, pathogens, or psychological mechanisms. When occupants leave the building, the symptoms typically dissipate. Also, as the cause may often be multi-factorial, so likewise is the solution. What is sick building syndrome (SBS)? A term sometimes used to describe conditions when occupants experience acute health or comfort effects that appear to be linked to time spent indoors in a particular building. Complaints may be localized to a time of day, a specific location or the entire building. When is a building labeled as having a building related illness (BRI)? Diagnosable illnesses in occupants whose symptoms can be identified and whose cause can be directly attributed to a building. In contrast to "sick buildings", when affected occupants leave the building, their symptoms typically do not dissipate. Why do newer buildings seem to have more IAQ problems than older ones? While this is not necessarily true, newer buildings (post 1970's) are built with energy conservation in mind. There are many ways to minimize energy cost due to cooling and heating losses, however, one common way is reduce the building leakage factor. Through better construction and insulation techniques, this action, in effect, makes the building tighter or better sealed against natural air exchanges between indoor and outdoor air through the process known as infiltration. Additionally, some buildings practice reduced outdoor air ventilation policies. These conditions and more work to reduce the dilution of indoor air from infiltration (that older buildings may have) allowing ambient concentrations of indoor contaminants to rise. Normal sources of indoor contaminants include office equipment, furnishings, construction materials, occupants, etc. Is there a routine recommended IAQ test? No. There is no routine "litmus" test for good/bad IAQ in environments where there is no known specific contaminant. This is due to the diversity of possible contaminants and the fact that analysis of individual contaminants in air samples may not reveal significant concentrations while combinations of several contaminant or conditions may have adverse effects. For these reasons, the preferential method of approaching any IAQ investigation where the symptoms are non-specific and potentially related contaminants are unknown is to perform an initial observational site survey. The purpose of this survey is to develop an initial hypothesis and recommendations. What are the current IAQ standards? While there are many guidelines and recommended practices in the United States for maintaining good IAQ and comfort, two standards are most referenced in IAQ studies: The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 62-1999, Ventilation for Acceptable Indoor Air Quality and the ASHRAE Standard 55-1992, 55a, Thermal Environmental Conditions for Human Occupancy. I've heard about a CO2 test, but what is it for? Carbon dioxide (CO2) is used to aid in the control of indoor odors by dilution with outdoor air. CO2 is used to aid in the control of indoor odors by dilution with outdoor air. CO2 , a normal product of human respiration, is used as a surrogate ventilation indicator. Many studies have been done (originally in Europe) that demonstrated a relationship between noticeable odors indoors and dilution of indoor air with outdoor air (OA). The relationship is inversely proportional. The more OA is introduced, the less odors are noticed. Additionally, it was demonstrated in several studies, that by using conditioned, acceptable OA, other contaminants which may be present indoors may also be diluted. My CO2 levels go above 1000 ppm which means people will start getting sick, right? Wrong. The 1000 ppm level is not a health exposure limit. There are no documented adverse health effects to exposure to CO2 levels under 5000 ppm. The 1000 ppm indoor maximum level has been recommended by ASHRAE for indoor office spaces to provide ventilation for acceptable indoor air quality (comfort as opposed to health). In a like manner, CO2 levels below 1000 ppm may not accurately indicate acceptable indoor air quality if contaminants are present in the space which may adversely affect occupants. How do I know if my air ducts need cleaning? Air duct cleaning, as discussed by the National Air Duct Cleaners Association (NADCA), Standard 1992-01, may help improve the air quality as a part of a comprehensive IAQ maintenance program. "At the present time there is no consensus of opinion of the recommended frequency of ACS (air duct) cleaning, nor any governmental or code requirements for mandatory cleaning" (NADCA 1992-01). We recommend you contact your local NADCA certified Air Duct Cleaner for a professional evaluation. Can you test my indoor air quality? Unfortunately there is not a "silver bullet" test to qualify and quantify, "assess the air quality," all the contaminants in the indoor air. Testing is specific to the type of contaminant suspected to be present in the space and a sample strategy is not typically designed until after information has been gathered regarding conditions near the site, processes occurring in the space, possible environmental influences, etc. I have an odor in my house, what is it? Odor diagnostics involves much more than performing a single test. Due to personal and environmental factors, odor perception can vary from person-to-person. Before any testing is performed, information must be gathered as to probable or possible sources of the odor. Even if a sample strategy is implemented, the sensitivity of the human nose makes odor detection possible for humans at concentrations well below those of most test instruments. Also keep in mind that when there are indoor contaminants that have odors, humans can usually detect the contaminants odor at concentrations well below those levels that would threaten your health. There are black particles deposited on supply air diffusers - what is it and is it harmful? These black particles are typically from normal airborne particulates (e.g. carbon black and dust) found in room air, which, when entrained into the discharge air from the diffusers, impinges upon the diffuser. Also keep in mind that if you can see the particles, they are too large to be respired down into the lungs - rather, they become lodged in the nasal passages of the upper respiratory system. I have allergic type symptoms when in my home. Can you test for molds and mildew? Moist (wet) materials provide an excellent environment for microbial growth and can act as reservoirs even after the water source is no longer active. Many times, the most cost effective solution, if you've had water damage, is to remove and replace all damaged materials. Testing may not be necessary at this point, especially if you are noticing allergy symptoms that were not present prior to the water damage. |
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