Document v27GG6eYgJKEb6V5DOOjbkXY

Technical Facts Asbestos Products Asbestos-contain i ng Flooring Products CTD033056 t FOREWORD One of the main objectives of the Canadian Asbestos Information Centre is to make available to all interested parties the most factual and up-to-date information possible on all scientific, medical, technical, regulatory or commercial aspects of asbestos. The Centre's Technical Facts aim to assemble in a single document the various data existing on asbestos products -- and often originating from multiple sources -- from the technical and technological standpoint as well as that of health and safety. The documents cover a variety of aspects such as manu facturing processes, usage, physi cal characteristics, performance assessment. The purpose of these documents is to provide a maximum of facts on asbestos-containing products so as to promote enlightened decisions on the uses of asbestos. The present document was com piled to answer the many queries received by the Centre, especially from the United States, about asbestos-containing floor coverings. In view of the particular interest manifested in the United States, most of the data referred to in this brochure have been gathered from U.S. sources. CANADIAN ASBESTOS INFORMATION CENTRE CTD033057 i INTRODUCTION This brochure explains the use of asbestos in vinyl-asbestos floor tile and vinyl sheet flooring. The test data gathered in this brochure are aimed at providing update informa tion on the functions and safety of these products. Health Concerns in Perspective Because of the potential health problems associated with occupa tionally-related exposure to asbes tos, there continues to be some question regarding its safe use in modern products. When discussing asbestos health concerns related to asbestos-containing flooring prod ucts, it is important to keep several facts in mind. 1. In the manufacture of flooring products containing asbestos fibre, advances in packaging materials for asbestos and adherence to proper work procedures and industrial hygiene practices are meant to pre vent potentially hazardous expo sures in occupational and related environments. 2. In vinyl sheet flooring, asbestos is only incorporated in the backing felt, where it is encapsulated by the latex binder. No asbestos is used in the wearing surface of sheet floor ing and thus traffic wear will not cause release of fibre. Asbestos in vinyl-asbestos tile is mixed through out the tile, but is encapsulated by the plastic binder. In-use monitor ing tests have been performed on floor tile in an effort to evaluate potential fibre release. To our knowledge, all tests have failed to demonstrate any detectable fibre release from heavy pedestrian traf fic or floor maintenance operations. A similar conclusion can be found in a U.S. Navy report on a study of asbestos-containing flooring mat erials. They reported no reason to be concerned about adverse health effects in using such products. "Materials which contain asbestos encapsulated in a pliable or malle able organic binder (vinyl-asbestos floor tile or asphalt-asbestos roof tile) are not likely to release asbes tos fibres even under the most severe conditions and consequent ly need not be substituted except when specifically directed." (1) 3. During the removal of asbestoscontaining flooring products, adherence to recommended work procedures, published by flooring manufacturers or, in the U.S., by the Resilient Floor Covering Insti tute, has been shown to prevent hazardous exposures. The recom mended procedures stress the importance of not sanding an existing resilient floor covering. However it is considered com pletely acceptable to buff an exist ing resilient floor covering. -.i: :' : CTD033058 SECTION I Vinyl Sheet Flooring Why Asbestos? The asbestos fibre in vinyl sheet flooring contributes many valuable characteristics to the finished prod uct. The asbestos/latex backing makes the flooring resistant to rot, which is especially important in high humidity environments or when the flooring is laid in base ments or on concrete slab floors. Asbestos also contributes to the dimensional stability of the flooring in these environments. Another advantage of asbestos/latex felt backed flooring resides in its stretch recovery characteristic, resulting in a product that, after installation, I retains its shape even as the sub! floor expands.and contracts with \ temperature change. Asbestos pro- , vides a cost-effective means of building thickness in the flooring, ensuring warmth and comfort together with strength and durability. I ! Aside from its characteristics in the finished product, asbestos/latex felt plays a key role in facilitating the manufacturing process, permitting the felt to withstand the high temp eratures required for the finishing 1 and curing operations and adding the strength needed to endure the rolling and pulling effect of man ufacturing machinery. Manufacturing Asbestos/latex backing is produced on a paper machine. Asbestos fibre used in the process is supplied in pulpable paper bags that need not be opened. Mixing is done in a hydropulper with water. Latex is added to the asbestos slurry in a chemical chest before being pumped into the paper machine head box. On the most commonly used paper machine, the fibre suspension will flow out of the head box onto a traveling wire mesh cloth. Water drains through the wire assisted by table rolls and/or suction boxes. The sheet, with the fibre encapsu lated by the latex, then passes through rollers and is dried on a series of steam-heated cylinders. In a final step, the sheet is passed through a stack of calendar rolls to control thickness and smoothness. The asbestos/latex felt is converted to a finished flooring product in a variety of operations, which may include addition of a foam cushion layer to the felt, followed by roto gravure printing or embossing of a decorative pattern. In the final step a vinyl or urethane coating is applied, which serves as the wear ing surface of the flooring. Substitutes Since a vast wealth of knowledge on potential exposures and safe work procedures is available to those manufacturing asbestos/latex vinyl flooring, it is, in a very practical sense, probably safer to use asbes tos than many other materials about which little is known. Among the substitutes developed for asbestos in the backing of vinyl sheet flooring is a composite ma terial based on cellulose and fillers such as calcium carbonate. This product, according to experts in the field, lacks the dimensional stability and rot resistance of the asbestos/ latex backing. In addition, the com posite material does not have the tensile strength and heat resistance of asbestos that is important in manufacturing. The evaluation of other substitute materials, such as polyesters and fibrous glass, also tends to show that asbestos still is the most costeffective material for sheet flooring. At present, competitive products for asbestos-containing vinyl floor ing are carpeting and hardwoods. While the choice of products often is conditioned by price, other fac tors also are important. Both car peting and hardwoods normally require greater amounts of mainte nance than vinyl sheet flooring and may not be suitable for high-traffic commercial areas.'In addition, most carpeting and hardwoods will not provide the same rot protection that is inherent in asbestos. CTD033059 3 SECTION II Vinyl-Asbestos Floor Tile Why Asbestos? When used in the manufacture of floor tiles, asbestos fibre imparts abrasion and indentation resistance, as well as reinforcement and dimensional stability. The result is a durable, long-lasting floor tile that is especially suitable for commercial installations where heavy wear can be expected. The reinforcing characteristic of asbestos in floor tiles is especially important, and is demonstrated by the fact that tiles not manufac tured with asbestos have a greater tendency to indent or become brittle and crack. This attribute is important when heavy wear can be expected from pedestrian traffic, mobile equipment or when heavy furniture or appliances will be resting on the flooring. The tensile strength of asbestos and its ability to withstand high tem peratures also are important in the manufacturing process. Manufacturing In the manufacture of vinyl-asbestos floor tiles, unopened bags of asbes tos can be fed directly into the mix ers since the polyethylene bags will melt at the high temperatures used in the process. A cohesive mass is formed after being mixed with resin, plasticizers, fillers and pigments. This hot mate rial is fed to a two-roll mill where it is blanketed out to a desired thickness. The slab then is passed through a series of calendar rolls to bring the product to a uniform, finished thickness. Embossing or pigmenting is done before cutting, while the mate rial still is soft. Cooling usually is accomplished by water sprays, although air cooling is necessary before die cutting in order to minimize shrinkage. Substitutes The search for cost effective sub stitutes for asbestos in vinyl floor tiles has been difficult. The flooring industry considers that by and large asbestos remains the most efficient, reliable and cost-effective material for this use. One substitute for asbestos that has been evaluated is a product that uses more limestone in place of the asbestos. Tests, however, show that this mixture lacks the hot strength of asbestos, and also tends to be brittle and more likely to crack. manufacturing process, that would necessitate a change in equipment for most floor tile manufacturers. In addition, the mixture was diffi cult to stabilize thermally under the high temperatures used in manu facturing, often resulting in degra dation of the vinyl itself. When a combination of fibrous glass and ball clay was tested, the end product proved to be brittle and to pose the need for costly changes in the manufacturing process. Some man-made organic materials, such as polyethylene and polypro pylene, also have been evaluated as substitutes for asbestos in vinyl floor tiles. These materials tend to melt or degrade at the high temper atures necessary in the manufac turing process, resulting in quality problems in the final product. Another substitute for vinyl-asbestos floor tiles is vinyl tile, without asbestos. This product costs con siderably more. Carpeting and hardwoods also can be considered for most of the same uses as vinyl-asbestos floor tiles; however, they may not be as suita ble for heavy wear applications. It is generally agreed that vinyl-asbestos tiles will outlast even the best car peting and hardwoods in heavy commercial usage. Fibrous glass also has been evalu ated as a substitute. This material tended to cause problems in the CTD033060 SECTION III Exposure Studies: Sheet Flooring Monitoring In 1979, Stanford Research Institute (SRI) International, in the U.S., undertook a study of sheet vinyl flooring to monitor for asbestos during installation and removal operations. In-use and maintenance tests were not performed since there is no asbestos in the wear layers. (2) All monitoring and analysis was conducted according to methods prescribed by the U.S. National Institute for Occupational Safety and Health (NIOSH). The NIOSH asbestos monitoring technique has a minimum sensitivity of 0.1 fibre per cubic centimeter. Results are given to hundredths of a fibre per cubic centimeter for illustrative purposes only. Installation: Personal, area and high volume samples were taken during this operation in a private home. Background level samples also were taken prior to and after installation for comparison purposes. The results of this test showed asbestos fibre concentrations ranging from 0.008 to 0.012 fibre/cc, compared with a permissible federal limit of 2.0 fibres/cc. The researchers con cluded that the "airborne asbestos concentrations are very low and well below the OSHA allowable limit when recommended proce dures are followed." All of the findings were within the ranges normally found in background levels. (Tables 1 through 5). Removal: A variety of removal tests were conducted -- unadhered, adhered and partially adhered removal. Personal, area and back ground air samples were taken, and in all cases, the detectable concen trations of asbestos fibre were well below the recommended OSHA limit. When proper work procedures were followed, the ranges were comparable to natural background levels. (Tables 6 through 8). Comparison Testing SRI International also conducted a study aimed at monitoring asbes tos fibre levels during the removal of sheet flooring using different methods -- wet versus dry, and different scraping instruments. (3) (The industry recommends wet scraping methods). Results of this study showed that wet scraping methods resulted in very low concentrations of asbestos fibre well below permissible occu pational exposure levels. Dry scraping methods resulted in an increase in the level of airborne asbestos although even these ranges still were at or below per missible limits. They concluded by recommending the wet scraping procedures. (Table 9) CTD033061 5 SECTION IV Exposure Studies: Floor Tiles Monitoring A study was undertaken in 1979 by Stanford Research Institute (SRI) International to monitor for asbestos fibres that might be present during conditions of use, maintenance, installation and removal of vinylasbestos floor tiles. (4) All monitoring and analysis was conducted according to methods prescribed by the U.S. National Institute for Occupational Safety and Health (NIOSH). The NIOSH asbestos monitoring technique has a minimum sensitivity of 0.1 fibre per cubic centimeter. Results are given to hundredths of a fibre per cubic centimeter for illustrative purposes only. In-Use Test: The researchers simu lated the worst conditions by strip ping all wax from vinyl-asbestos floor tiles in an office building, and then monitoring for emission of fibre during heavy pedestrian traf fic. Since no detectable traces of asbestos fibre were found during this test, the researchers concluded that the asbestos constituent of floor tiles does not pose a health threat. (See Table 10) Installation Test: Personal samples of workers and general environment samples were taken during the installation of a vinyl-asbestos floor in a private home. The researchers concluded: "The number of asbes tos fibres on the filters was very small, all well below 0.1 fibre/cc. Compared to the OSHA limit of 2.0 fibres/cc, the concentrations measured when recommended work procedures are followed, 0.0046 f/cc to 0.0027 f/cc, are insig nificant." (See Tables 12 and 13) Removal Test: Monitoring for asbes tos fibres was conducted during the complete removal of a vinylasbestos floor in a private home. Both personal and area samples were taken during this operation. Results of the study showed that, "the number of asbestos fibres on the filters was very small, all well below 0.1 fibre/cc. Compared to the OSHA limit of 2.0 fibres/cc, the concentrations measured when re commended work procedures were followed, 0.006 f/cc to 0.015 f/cc, are insignificant." (See Table 14) Maintenance Test: Monitoring was conducted during maintenance of a vinyl-asbestos floor -- damp mopping, floor stripping, etc. No detectable amounts of asbestos fibres were found and the resear chers concluded that such opera tions present no hazard to mainte nance workers. (See Table 11) Consumer Union Study The Consumers Union, in a study of a variety of floor tiles, also con ducted tests on vinyl-asbestos floor tiles. Its researchers saw no rea son to discontinue the use of vinylasbestos floor tiles, concluding: "The asbestos fibres in tiles that have them are securely bonded into the vinyl. They are not likely to be released -- except perhaps by sand ing -- a practice that should be avoided." (5) IRDA Study The Institut de Recherche et de Developpement sur PAmiante (IRDA), in Sherbrooke, Quebec, conduct ed tests to examine the possible environmental burden which may result from normal handling and from wearing of vinyl-asbestos tile flooring. (6) Simulation of "normal" work prac tices for laying vinyl-asbestos tiles showed that this operation results in no detectable exposure to air borne asbestos fibres. Simulation of heavy misuse by continuous, prolonged sanding yielded an average of 1.2 fibres/cc, counting fibres according to the NIOSH method. (See Table 15) CTD033062 SECTION V Work Practices CONCLUSION A number of studies have verified the fact that adherence to generally accepted housekeeping practices and recommended work procedures will provide protection from any health risk. As noted, recommended work pro cedures for the installation and removal of asbestos-containing floor coverings are available from manu facturers, or the Resilient Floor Covering Institute. (7) Standards for exposure to asbestos dust and for emissions of asbes tos to the atmosphere are available from governmental regulatory agencies or departments. (8) As noted in this brochure, vinyl sheet flooring backed with asbes tos/latex and vinyl-asbestos floor tiles offer special characteristics which make them highly suitable, in comparison with other materials, for use in heavy traffic or commer cial areas. In the manufacturing process of both products, the tensile strength of asbestos and its ability to with stand high temperatures constitute important advantages. From the health and safety stand point, a number of studies of both ; vinyl-asbestos floor tiles and vinyl i sheet flooring have shown that, with proper work procedures, the ! possibility of exposure to asbestos 1 dust in all stages of use, mainte! nance, installation and removal is 1 not significant and presents no evi! dence of threat to human health. When such practices are carried out, modern flooring products are safe to use, and appear to be the most cost-effective materials presently available. CTD033063 7 / BIBLIOGRAPHY ; 1. ARENTZEN, W. P., Dept, of the Navy, Bur. of Medicine and Surgery. International Corre spondence, August 9,1979. i 2. WALCOTT, R. and WARRICK, ]., ; SRI International, Monitoring for ! Airborne Asbestos Fibers: Sheet Vinyl Floor Covering, for Resilient Floor Covering Institute (1979). i ! 3. WALCOTT, R. and WARRICK, J., SRI International, Comparison Testing Monitoring for Airborne ! Asbestos Fibers: Sheet Vinyl Floor Covering, Wet Versus Dry Scraping, for Resilient Floor Covering Institute (1979). 4. WALCOTT, R. and WARRICK, ]., SRI International, Monitoring for Airborne Asbestos Fibers: VinylAsbestos Floor Tile, for Resilient Floor Covering Institute (1979). 5. Consumers Report, Self-Stick Floor Tiles, p. 635 (October 1980). 6. DUNNICAN, J. and LEBEL, J., Institut de Recherche et de Developpement sur I'Amiante (IRDA), Measurement of Chrysotile Fibre Emission from AsbestosVinyl Tile Laying and Sanding Operations (June 1982). 7. Resilient Floor Covering Insti tute, Inc., Recommended Work Procedures for Resilient Floor Coverings (1980). 8. In the U.S., references are: CRF 29,1910.1001 -- OSHA, Standard for Exposure to Asbestos Dust. CFR 40, Title 46, Ch. 1 -- EPA, National Emission Standards for Hazardous Air Pollutants -- Asbestos and Mercury. In Canada, Air Pollution Control Directorate, Environmental Protection Service (EPS-3-AP-76-6). Also relevant pro vincial agencies and departments. / TABLE 1 SRI International Test Results Sheet Vinyl Flooring -- Adhered Installation -- Site No. 1: Model home kitchen in a new housing development in Northern Virginia Description Filter No. Outside Air XX-1 Area-Bedroom C-1069 High-Volume Sample XX-1 Head Mechanic C-1071 Assist. Mechanic XX-003 Air Vol. (Liters) 660 876 782.6 354 350 Time (Min.) 330 438 78.2 177 175 Fibres/ Sq. mm* 4.7 111.7 99.5 133.7 105.8 Total Fibres/cc 0.002 0.1 0.18 0.31 0.246 Asbestos** Fibres/cc 0.0001 0.0052 0.009 0.0155 0.0123 8-Hr. TWA 0.0155 0.0123 *Fibres/sq. mm of filter surface area. 'Analyst estimated that 5% of the total number of fibres were asbestos. CTD033064 8 TABLE 2 SRI International Test Results Sheet Vinyl Flooring -- Adhered Installation -- Site No. 2: Kitchen of a six-year-old home in a suburban Maryland community Description Outside Air Outside Air Kitchen Background Mechanic 1 Mechanic 2 Filter No. AB-9 C-1089 XX009 MWC0620 MWC-1097 Air Vol. (Liters) 760 766 748 200 200 Time (Min.) 380 383 374 100 100 Fibres/ Sq. mm* 2.5 0 4.5 0 0 Total Fibres/cc 0.0026 0 0.005 0 0 Asbestos** Fibres/cc 0 0 0 0 0 8-Hr. TWA 0 0 *Fibres/sq. mm of total filter surface area. `Analyst estimated that none of the fibres were asbestos. TABLE 3 SRI International Test Results Sheet Vinyl Flooring -- Adhered Installation -- Site No. 3: Kitchen of a private home in Woodstown, New Jersey Description Background Background Kitchen Area Mechanic JW Mechanic JP Filter No. RFCI #1 RFCI #2 MWCO 681 MWCO 690 MWCO 698 Air Vol. (Liters) 264 321 462 104 120 Time (Min.) 120 169 231 58 60 Fibres/ Sq. mm* 0 0 92 77 92 Total Fibres/cc 0 0 0.17 0.633 0.655 Asbestos** Fibres/cc 0 0 0.017 0.063 0.066 Wet bulb temperature -- 61F (16*0; dry bulb temperature -- 72F (22C). Fibres/sq. mm of total filter surface area. Analyst estimated that 10% of the fibres were asbestos. Note: All measurements with the CCA Respirable Dust Monitor were less than the detection limit (0.1 mg/m2) of the instrument. 8-Hr. TWA 0.063 0.066 CTD033065 TABLE 4 SRI International Test Results Sheet Vinyl Flooring -- Adhered Installation -- Site No. 4: lower-level foyer of split-level home in Pennsville, New Jersey Description Background Background Family Room Area Steps-Area Mechanic JW Mechanic JP Filter No. MWCO 693 MWCO 677 MWCO 688 RFCI #4 MWCO 674 MWCO 679 Air Vol. (Liters) 336 675 678 650 304 283 Time (Min.) 168 355 357 342 179 177 Fibres/ Sq. mm* 0 0 62 70 197 25 Total Fibres/cc 0 0 0.078 0.092 0.554 0.075 Asbestos** Fibres/cc 0 0 0.0008 0.009 0.055 0.008 Wet bulb temperature -- 63F (17); dry bulb temperature -- 73F (23C). *Fibres/sq. mm of total filter surface area. "Analyst estimated that 10% of the fibres were asbestos. Note: All measurements with the CCA Respirable Dust Monitor were less than the detection limit (0.1 mg/m2) of the instrument. 8-Hr. TWA 0.055 0.008 TABLE 5 SRI International Test Results Sheet Vinyl Flooring -- Unadhered Installation -- Site No. 5: Kitchen of private home in Salem, New Jersey Description Background Background Area-Living Room Area-Kitchen Mechanic jP Mechanic JW Filter No. MWCO 699 RFCI #6 MWCO 661 MWCO 697 MWCO 694 MWCO 680 Air Vol. (Liters) 327 241 238 216 84 90 Time (Min.) 172 127 119 108 44 45 Fibres/ Sq. mm* 30 17 0 100 32 107 Total Fibres/cc 0.078 0.060 0 0.395 0.325 'l.OI Fibres/sq. mm of filter surface area. "Analyst estimated that 10% of the fibres were asbestos. Asbestos** Fibres/cc 0.008 0.006 0 0.040 0.033 0.102 8-Hr. TWA 0.033 0.102 CTD033066 TABLE 6 SRI International Test Results Sheet Vinyl Flooring -- Unadhered Complete Removal -- Site No. 5: Kitchen of private home in Salem, New Jersey Description Background Background Area-Living Room Area-Kitchen Mechanic jW Mechanic JP Filter No. MWCO 699 RFCI #6 MWCO 661 MWCO 697 RFCI #7 MWCO 689 Air Vol. (Liters) 327 241 238 216 144 148 Time (Min.) 172 127 119 108 76 74 Fibres/ Sq. mm* 30 17 0 100 17 12 Total Fibres/cc 0.078 0.060 0 0.395 0.100 0.069 Asbestos** Fibres/cc 0.008 0.006 0 0.040 0.010 0.007 Fibres/sq. mm of filter surface area. 'Analyst estimated that 10% of the fibres were asbestos. 8-Hr. TWA 0.010 0.007 TABLE 7 SRI International Test Results Sheet Vinyl Flooring -- Adhered Complete Removal -- Site No. 4: lower-level foyer of split-level home in Pennsville, New Jersey D ascription Background Background Area-Family Room Area-Steps Mechanic JW Mechanic JP Filter No. MWCO 693 MWCO 677 MWCO 688 RFCI #4 MWCO 696 MWCO 691 Air Vol. (Liters) 336 675 678 650 206 197 Time (Min.) 168 355 357 342 121 123 Fibres/ Sq. mm* 0 0 62 70 97 85 Total Fibres/cc 0 0 0.078 0.092 0.402 0.368 Asbestos** Fibres/cc 0 0 0.008 0.009 0.040 0.037 8-Hr. TWA 0.040 0.037 *Fibres/sq. mm of filter surface area. "Analyst estimated that 10% of the fibres were asbestos. CTD033067 11 TABLE 8 SRI International Test Results Sheet Vinyl Flooring -- Adhered Partial Removal -- Site No. 3: Kitchen of a private home in Woodstown, New Jersey Description Background Background Area-Kitchen Mechanic JW Mechanic JP Filter No. RFCI #1 RFCI #2 MWCO 681 RFCI #3 MWCO 678 Air Vol. (Liters) 264 321 462 88 112 Time (Min.) 120 169 231 44 62 Fibres/ Sq. mm* 0 0 92 42 25 Total Fibres/cc 0 0 0.170 0.408 0.190 Asbestos** Fibres/cc 0 0 0.017 0.041 0.019 'Fibres/sq. mm of filter surface area. "Analyst estimated that 10% of the fibres were asbestos. 8-Hr. TWA 0.041 0.019 TABLE 9 SRI International Test Restults Sheet Vinyl Flooring -- Unadhered Comparison Testing Complete Removal -- Site: Kitchen of six-year-old home in a suburban Maryland community Description Background Samples Outside Outside Kitchen Wear Layer Removal Mechanic 1 Mechanic 2 Wet Scrape Mechanic 1 Dry Scrape Mechanic 1 Mechanic 1 Mechanic 2 Mechanic 2 Filter No. AB-9 C-1089 XX009 AB-12 AB-2 AB-14 AB-13 AB-11 AB-10 AB-15 Air Vol. (Liters) 760 766 748 150 140 110 126 80 126 90 Time (Min.) 380 383 374 75 70 55 63 40 63 45 Fibres/ Sq. mm* Total Fibres/cc 00 00 00 39 0.218 14 0.0844 96 0.4837 327 2.168 96 1.0035 191 1.2669 121 1.1259 Asbestos** Fibres/cc 0 0 0 0.1637 0.0844 0.4093 2.0248 0.8279 1.1207 1.0583 8-Hr. TWA 0.1637 0.0844 0.4093 2.0248 0.8279 1.1207 1.0583 Fibres/sq. mm of filter surface area. Analyst estimated that about 90% of the fibres were asbestos. 12 CTD033068 TABLE 10 SRI International Test Results Vinyl-Asbestos Floor Tiles In-Use -- Site No. 2: Office building in Alexandria, Virginia Description Filter No. Background samples Air Vent C-1066 Hallway XX005 Copy Centre XJB Outside XXI02 Outside XX031 Outside XX006 Copy Centre 1 ft high XX015 3 ft high XX008 5 ft high XX016 Snack Shop C-1051 In-use samples -- Copy Centre -- Table 1 ft high XX027 3 ft high XX030 ! 5 ft high XX011 Copy Centre -- Middle Room 1 ft high C 1078 3 ft high C 1096 5 ft high C 1083 ' Snack Shop 1 Bookcase -- 1 ft XX017 j Bookcase -- 3 ft XX022 S Bookcase -- 5 ft XX002 i Storage Door -- 1 ft XX023 | Storage Door -- 3 ft XX019 Storage Door -- 5 ft XX029 Air Vol. (Liters) 588 556 590 616 834 840 594 594 594 284 838 838 838 822 822 822 260 260 260 266 266 266 Time (Min.) 294 278 295 308 417 420 297 297 297 142 419 419 419 411 411 411 130 130 130 133 133 133 Fibres/ Sq. mm* 4.7 4.7 0 0 0 0 2.5 0 0 0 4.4 0 11.1 2.3 4.5 4.6 0 0 2.5 4.5 2.4 0 Fibres/sq. mm of filler surface area. Analyst estimated that none of the fibres were asbestos. Total Fibres/cc 0.0067 0.007 0 0 0 0 0.0035 0 0 0 0.0044 0 0.011 0.0023 0.0046 0.0047 0 0 0.0079 0.0618 0.0088 0 Asbestos** Fibres/cc 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C7D033069 13 TABLE 11 SRI International Test Results Vinyl-Asbestos Floor Tiles Maintenance -- Site No. 2: Office building in Alexandria, Virginia Description Background samples Air Vent Hallway Copy Centre Outside Outside Outside Snack Shop Maintenance samples Mopping-Copy Centre Buffing-Copy Centre Mopping-Snack Shop Buffing-Snack Shop Buffing-Copy Centre Buffing-Copy Centre High Volume Sample (Mopping) Floor Area Filter No. Cl 066 XX005 XJB XXI02 XX031 XX006 Cl 051 XX026 XX001 XXOOO XX025 KGB-1 XX QTH-1 XX-014 Air Vol. (Liters) 588 556 590 616 834 840 284 30 30 42 42 22 60 537 30 Time (Min.) 294 278 295 308 417 420 142 15 15 21 21 11 30 54 15 Fibres/ Sq. mm* 4.7 4.7 0 0 0 0 0 4.9 4.3 9.8 0 2.4 0 4.9 2.5 Fibres/sq. mm of filter surface area. 'Analyst estimated that none of the fibres were asbestos. Total Fibres/cc 0.0067 0.007 0 0 0 0 0 0.1351 0.1210 0.1949 0 0.0921 0 0.0075 0.682 Asbestos* Fibres/cc 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CTD033070 TABLE 12 SRI International Test Results Vinyl-Asbestos Floor Tiles Installation -- Site No. 3: Private home in Newark, Delaware Description Background Background Area-Breezeway Area-Laundry Area-Powder Room Mechanic JS Mechanic TD Filter No. RFCI #8 MWCO 700 MWCO 692 MWCO 686 MWCO 685 MWCO 682 MWCO 684 Air Vol. (Liters) 587 ' 594 537 739 725 464 418 Time (Min.) 326 297 316 389 372 232 220 Fibres/ Sq. mm* 0 10 70 140 75 145 40 Fibres/sq. mm of total filter surface area. 'Analyst estimated that 10% of the fibres were asbestos. Total Fibres/cc 0 0.014 0.0111 0.161 0.088 0.267 0.081 Asbestos** Fibres/cc 0 0.001 0.0011 0.016 0.009 0.027 0.008 8-Hr. TWA 0.027 0.008 // TABLE 13 SRI International Test Results Vinyl-Asbestos Floor Tiles Installation -- Site No. 1: Model home in new housing development in Northern Virginia Description Indoor Background Outdoors High-Volume Sample Head Mechanic Assistant Mechanic Filter No. Cl 069 XX-1 XXII Cl 02 Cl 062 Air Vol. (Liters) 876 660 1710 228 226 Time (Min.) 438 330 90 114 113 Fibres/ Sq. mm* 111.7 4.7 38.1 27 52.3 Total Fibres/cc 0.104 0.003 0.28 0.092 0.184 Asbestos** Fibres/cc 0.0052 0.003 0.0014 0.0046 0.0092 *Fibres/sq. mm of filter surface area. "Analyst estimated that about 5% of the fibres were asbestos except for filter XX-1. 8-Hr. TWA 0.0046 0.0092 CTD033071 15 TABLE 14 SRI International Test Results Vinyl-Asbestos Floor Tiles Complete Removal -- Site No. 3: Private home in Newark, Delaware Description Background Background Area-Breezeway Area-Laundry Room Area-Powder Room Mechanic JS Mechanic TD Filter No. RFC1 #8 MWCO 700 MWCO 692 MWCO 686 MWCO 685 MWCO 662 MWCO 687 Air Vol. (Liters) 587 594 537 739 725 246 255 Time (Min.) 326 297 316 389 372 123 134 Fibres/ Sq. mm* 0 10 70 140 75 18 44 Total Fibres/cc 0 0.014 0.111 0.161 0.088 0.062 0.147 Fibres/sq. mm of filter surface area. `Analyst estimated that 10% of the fibres were asbestos. Asbestos** Fibres/cc 0 0.001 0.011 0.016 0.009 0.006 0.015 8-Hr. TWA 0.006 0.015 TABLE 15 IRDA Test Results Fibre Concentration Resulting from Various Handling Operations of Vinyl-Asbestos Tiles Sampling Data Duration Flow Rate Fibre concentration (f/cc > 5) Average Tile Laying 30 min. 2 liters/min. Samplers Fixed Personal B.D.L. B.D.L. -- -- -- B.D.L. Operations Tile Laying; Sanding; Vacuuming; Installation of Second Layer 40 min. 2 liters/min. Samplers Fixed Personal 0.53 0.45 0.51 0.56 0.52 0.48 0.5 Continuous Sanding 23 min. 2 liters/min. Samplers Fixed Personal 1.15 1.23 1.12 1.30 1.14 1.27 1.2 B.D.L.: Below detectable limit of 0.06 f/cc CTD033072 CTD033073