Tamarack Environmental Inc. Case Study
Carpet and Indoor Air Quality at Schools
CFR Environmental Cleaning Systems reduce microbial levels in
carpet and help improve Indoor Air Quality at Schools!
Purpose: This case study is designed to show that with the use of proper cleaning equipment and procedures that the microbial loading in carpeted floors can be greatly reduced. One of the leading causes of asthma and allergy problems in building occupants are excessive levels of microbials in buildings.
This will give school districts a more effective tool in the control of microbial loading in carpet. Proper cleaning of carpet will also increase the useful life of the carpet.
The Cleaning Machine: The CFR "ALTRA 400 O-Z, SP" is able to inject cleaning solution into carpet under a pressure of 400 pounds of pressure per square inch (psi). The "ALTRA 400 O-Z, SP" also is able to instantly recover up to 98% of cleaning solution, so carpets dry in about an hour.
The Benefits: The "ALTRA 400 O-Z, SP" which uses ozone to assist in the cleaning process offers several benefits to building owners, managers, and others.
Can result in tremendous savings because carpet lasts much longer and does not need to
be replaced as often.
Makes carpets look like new again and greatly increases its life expectancy
Will effectively remove microbials (mold, fungal) spores from carpet.
Excellent soil removal, quick dry times and cost savings
The Case Study: The case study was conducted with the assistance of Mike Forer, Paul J. Ellringer P.E., CIH and Dr. Chin S. Yang Ph.D.:
Mike Forer - is the Safety and Health Coordinator for Independent School District 742, 737 Osseo Ave. South, St. Cloud, MN 56301, 320-253-9370. ISD 742 has seen a steady increase in the number of students and teachers with asthma and allergy related indoor air quality concerns in the District's 18 schools. It is believed that excessive levels of microbials in carpet are a likely part of this problem. Carpet in several classrooms has been removed because of microbial
concerns.
Paul J. Ellringer P.E., CIH, is a Registered Professional Engineer and Certified Industrial Hygienist, from Tamarack Environmental Inc., 1640 Scheffer Ave., St. Paul, MN 55116, (651) 696-0267. Mr. Ellringer was hired by the school district to assist Mr. Forer in addressing indoor air quality concerns in the various schools. Elevated microbial levels in the carpet have been documented in several of the St. Cloud Schools over the past two years.
Dr. Chin S. Yang, a Ph.D. microbiologist, has been involved in indoor building related microbiological contamination for 12 years. Dr. Yang worked for the U.S. Public Health Service on microbial contamination until April of 1994. He is currently the Director of P & K Microbiology Services. All case study microbial analysis testing was performed under the direction of Dr. Chin S. Yang at:
P & K Microbiology Services
1950 Old Cuthbert Road, Unit #L
Cherry Hill, NJ 0~034
(609)427-4044
Building Characteristics: The building is a single story St. Cloud Minnesota Elementary School with 300 students.
Problem: Some of the students and teachers at this elementary school believe they have an abnonnal amount of respiratory distress while in this school. In July 1997 indoor air quality consultants recommended that the amount of outdoor air supplied to these classrooms be increased. This was accomplished but respiratory distress continued. As a part of the on going indoor air quality investigations in this school in October 1998 micro vacuum carpet dust samples were taken in four of the fifteen classrooms and analyzed for microbials (mold, fungi and bacteria) The microbial level in the carpet in all four classrooms had elevated level of fungi and two of the four had elevated levels of bacteria when compared to other schools which have been tested. The microbials at elevated levels included the fungi Aureobasidium pullulans, Alternaria, and Aspergillus niger. Bacteria at elevated levels included Staphylococcus, Bacillus, and gram negative. Aureobasidium pullulans, Alternaria, and Aspergillus niger have been associated with occupational asthma and hypersensitivity pneumonitis reactions in office occupants. Aspergillus niger and Staphylococcus have also been shown to be opportunistic pathogens and can cause skin infections and upper respiratory infections in immune suppressed people.
According to Mike Forer, Safety and Health Coordinator: "The School District has recently tried several cleaning methods in attempts to lower microbial levels in carpet. Follow up tests conducted after these cleaning methods have shown an increase in microbial levels. With the CFR Ozone assisted method we were able to reduce the microbial levels to normal in the carpet and help provide better indoor air quality."
The three cleaning methods which were not successful were: vacuuming the carpet and then cleaning it using standard hot water extraction techniques used in the school district, second using a cleaning solution which contained quaternary ammonium compounds similar to those used in hospitals to disinfect non porous surfaces, and third HEPA vacuuming of the carpet, using standard hot water extraction techniques, followed by applying a surface treatment of a chemical used in some hospital bandages and surgical garments to inhibit microbial growth.
Based on before and after microbial tests the "ALTRA 400 O-Z, SP" was able to remove 90 plus percent of the viable microbial spores from the carpet. Carpet after being cleaned this way had microbial levels within the normal ranges found in other schools. The "ALTRA 400 O-Z, SP" is a cost-effective way to reduce the microbial loading in carpet and provides the building owner/manager and others with a new option in the fight to improve indoor air quality (IAQ).
Testing Procedure: Determining the microbial loading of carpet has been difficult in the past. Tamarack Environmental Inc. working with Dr. Yang of P&K Microbiology Services and the U.S. EPA has recently developed a test method which works very well. This test method is called microbial micro vacuum carpet dust sampling. The U.S. EPA first starting using a method similar to this about five years ago to test carpet microbial levels. Since then this method has been refined and used extensively to test carpet. Tamarack has collected more than 1,000 samples using this method over the past three years. The State of Minnesota is presently using this method to test carpet microbial levels. Carpet dust samples are collected using a three-piece 37 mm cassette with a 0.8 ,um pore size mixed cellulose ester (MCE) filter. The samples are collected using a vacuum pump at a flow rate of 20-30 liters per minute through the filter. The filter cassette is used open faced. The samples are collected open face (top of filter cassette is removed) with one square foot of the carpet being vacuumed. A vigorous collection method is necessary. The filter cassette needs to be pressed with some force onto the surface of the carpet. The same one square foot of carpet is vacuumed at least three times. The filter cassette needs to be closed and then tapped lightly. If debris rolls around in the cassette and has a volume at least equivalent to two peas, sampling is complete. If enough debris has not been collected, a second square foot of carpet will need to be vacuumed. Filter cassettes need to arrive at the laboratory within 24 hours of sampling or be refrigerated. Under no conditions should the samples arrive at the laboratory more than five days after collection. MCE filters are removed from the cassettes holders and the loose debris weighed, and then suspended in sterile distilled water, diluted serially (three dilutions minimum 100, 1640, & 4100X), and inoculated onto 2% malt extract agar (MEA) plates. The MEA is suitable for general fungal and yeast isolation and growth.
Test Locations: Four classrooms were initial tested. One classroom was cleaned and follow up testing occurred only in this one room.
Initial Tests:
74,000, 76,000, 1.3 million, and 100,000 colony forming units per gram of carpet dust (CFU/g). The microbial levels in the room which was retested were at 76,000 CFU/g. Predominate organisms were Alternaria, Aspergillus niger, Aureobasidium pullulans, Cladosporium, Epicoccum nigrum, Penicillium, Phoma, & yeasts.
Follow Up Tests: Were all taken from the same classroom which had an initial microbial loading of 76,000 CFU/g.
Three follow up samples were collected. The microbial levels were 12,500, 2,034, and 9,016 CFU/g with an average of 7,850 CFU/g - Predominate organisms were Aspergillus sydowii, Aureobasidium pullulans, Cladosporium, Penicillium, Phoma, & yeasts.
Reduction - 90%
Summary: The "ALTRA 400 O-Z, SP" using ozone to assist in the cleaning process was able to remove 90% of the viable microbial spores from this carpet. The "ALTRA 400 O-Z, SP" is a cost-effective way to reduce the microbial loading in carpet and provides the school district and others with a new option in the fight to improve indoor air quality (IAQ), while maintaining clean carpet.
CFR Corporation: The CFR Corporation designs and manufactures patented cleaning systems including The "ALTRA 400 O-Z, SP," "PERFORMA O-Z," and other cleaning equipment and solutions used for fabric, carpet, upholstery, wall coverings, fabric panels and unique hard surfaces.
