Document jgarEO9MNpOR51pbo94pD2yx9

FILE NAME Packings and Gaskets PAG DATE 1999 DOC PAG018 DOCUMENT DESCRIPTION Unpublished Report - Asbestos Fiber Release During the Removal of a Sheet Gasket 20.35bd 20.35bd 0019bbb012 62:10 0002 ET NI Abstract Report for MVA Project No. 0765 Asbestos Fiber Release . During the Removal of a Sheet Gasket James R. Millette Ph.D. Michael D. Mount OHST Asbestos sheet gasket material used between piping flanges is generally considered to be friable material unless cut or tom In a controlled area | personal and area air samples were collected before and during the removal of asbestos sheet gasket material and brushing of the pipe flange The results of this study show asbestos fibers can be released into the air during the procedures for the removal of asbestos sheet gasket material and brushing of the flange Cleaning of the area with a broom after removal also increased airborne fiber concentrations Air concentrations were measured by phase contrast microscopy to be from 0.1 to 6 fibers and by transmission electron microscopy in the range of 3.9 to . 62 fibers for asbestos fibers of all sizes .. Introduction Most piping systems especially in industrial and maritime facilities use gaskets to seal joints The gaskets may contain asbestos fibers as part of their composition Periodically a pipe connection must be broken at the flanges and the old gasket removed This effort may require a simple scraping with hand tools or may need the assistance of power tools to clean the flange Asbestos Sheet Gasket Material According to the U.S. Environmental Protection Agency EPA gaskets are materials used to seal one compartment of a device from another in applications such as engine and exhaust manifolds Asbestos gaskets are used mainly to seal connections and prevent leakage of fluids between solid surfaces Gaskets often consisting of more than 70 chrysotile asbestos are used against alkaline neutral or weak acid solutions Crocidolite containing gaskets have been used against harsher acid solutions Sheet gaskets are composed of chrysotile asbestos compressed into a PROJECTS N 700'd 0019666012 G'OINHO SATVS XTVANATH NILS 87 0007-71 20 35 0019000012 02:10 0002 EI NOS sheet with styrene butadiene rubber or other binder Other organic binders used in making asbestos gaskets include natural rubber buna and buna synthetic rubbers or neoprene Study Design containing materials are common in industrial sites and on ships and because a maintenance activity often involves the disturbance of more than one material it is difficult to assess the contribution if any of a particular ACM to the overall airbome asbestos concentration To determine the possible contribution of an asbestos gasket only during removal special precautions were taken to isolate the removal activity from other activities that might have contributed airborne asbestos from other sources . Study Site The study was conducted in a warehouse in Norcross Georgia An asbestos abatement type enclosure was built for the study to isolate the testing from any other source of asbestos and to prevent any fiber release from contaminating the building The containment barriers in the area consisted of three layers of mil polyethylene plastic sheets on a wooden frame and three layers of mil polyethylene plastic on the floor The containment area 8 ft by 8 ft was completely contained within a larger containment area The study area had a two High Efficiency Particulate Absolute HEPA air filtration device AFD used to clean the area of particulate including asbestos before the gasket removal activity In the outer area the AFD operated . throughout the test Study Procedures The study consisted of the collection of air samples before during and after a gasket removal activity A valve that had been used in a steam line onboard a ship was used for the experiment The valve assembly had two sets of flanges with a gasket between each set of flanges According to the retired steamfitter performing the gasket removal the valve assembly probably carried 40 to 75 pound steam through it The temperature in the valve could have reached about 300 F. Gaskets were removed from both sides of the valve PROJECTS _ Page 2 790/900 790/900 MIZ X FOLAAO SATES XTXAHBAIH NILSAM NILSAM EZ NOW 0007-71 NAC 39bd 0019DDDOIZ 08:10 0002 EI NOS The removal was separated into two activities with separate air samples being collected during each activity The flanges were first scraped with a putty knife or screw driver to remove the majority of the gasket material The flanges were then wire brushed with an air powered drill to remove the residual gasket material adhering to the flanges The drill was a Campbell Hausfeld Model TL1006 drill that has a maximum speed rating of 2500 RPMs Prior to starting the study three 3 area air samples were collected to determine the background level of asbestos in the air of the study area using aggressive sampling and operating the drill for approximately two minutes before starting the air samples The sampling cassettes were located on the walls at the breathing zone five feet from the floor Area air samples were collected during the sheet gasket removal in the same locations as each of the background air samples approximately five feet from the gasket removal activity The person doing the gasket removal was fitted with two personal air sampling devices All personnel inside the study area were protected by air purifying respirators and complete head and body coverings The decontamination system consisted of , changing room outside the testing area and a clear suit room The decontamination system was used each time a person exited the study area and the overall containment area Analytical Methods Air samples were analyzed by the standard phase contrast microscopy PCM method NIOSH 7400 using the A counting rules Although the phase contract microscope enhances the analyst's ability to see fibers over other types of light microscopes the standard procedure involves does not involve identification steps which specifically determine how many of the fibers counted are actually asbestos Because sheet gasket material is known to contain other types of fibers some of the samples were prepared for further study by transmission electron microscopy TEM The samples were prepared and analyzed using the International Standards Organization ISO Direct preparation counting procedure This TEM analysis method identifies asbestos fibers on the basis of morphology crystal structure - PROJECTS Page 3 790/500 790/500 4 00197660 2 XV BOIANO SATVS XTVA NILSAX EZ NOW 0007-71 90 30bd 0019^ ^ ^ 012 02:10 0002 ET NI and ray elemental analysis On one sample during each activity all asbestos fibers longer than 0.5 ...mwere counted by TEM so that a total asbestos concentration could be determined In other samples only those fibers longer than 5 ...mand wider than 0.25 ...mwere counted to provide an asbestos count equivalent to the PCM data Polarized light microscopy PLM was used to determine the type of asbestos in the sheet gasket material A friability test was performed on the samples of gasket material removed from the flanges The EPA friability test is a field test in which an attempt is made to crumble the ACM by hand If the material produces dust when crumbled by hand it is considered friable The EPA distinquishes friable from nonfriable ACM in their regulations on handling asbestos products Friable ACM is considered more of a potential hazard than friable material Results | The results of the air monitoring are shown in Table 1. During the sheet gasket ~ removal activity which lasted approximately 34 minutes the asbestos fiber level for the person removing the packing was 1.86 fibers PCM time weighted for the period of removal It should be noted that only fibers greater than 5.0 ...mare counted using the PCM method The area samples collected in the vicinity of the sheet gasket cutting activity showed levels of fibers elevated over the background levels The TEM analysis results are also shown in Table 1. Chrysotile fibers were identified as the primary type of fiber The TEM fiber counts ranged from 3.9 to 62 fibers per cc for asbestos fibers of all sizes above 0.5 ...min length A list of flow rates and air volumes for the cassettes is given in Table 2 Polarized light microscopic analysis showed the sheet gasket to be approximately 80 chrysotile Appendix C The gasket materials removed from the valve flanges were dry and friable Conclusions Asbestos sheet gasket although not considered friable in original unused condition can release asbestos fibers into the air during removal operations both when PROJECTS Page 4 90 300d 0019 02:10 0002 EI NI hand methods are used and when powered brushing is done Clean following the removal may resuspend dust containing asbestos into the air . Recommendations The results of these tests suggest that asbestos sheet gasket material although not considered as a friable ACM when new should be considered as such during removal activities especially if a powered brushing device is involved PROJECTS Page 5 9 WA BOIANO SETVS XTVAMBATH NILS 61:87 NOM 0007 NOG 30bd 0019DDOIZ TE 0002 SI NAS Table 1 Summary of Air Sampling Results for Gasket Removal MVA Inc. 5500 Oakbrook Parkway Suite 200 Norcross GA 30093 404 662-8509 Activity PCM cc TEM cc Background Hand Scraping Power Wire Brushing Hand Scraping and Power Wire Brushing Broom Sweeping of Area After Removal 0.004 0.14 6.8 2.1 5.5 0.02 3.9 62 . 20 44 Contrast length Phase Microscopy countfsibers greater than 5 min than 0.25 min diameter and greater Transmission Electron Microscopy identifies and counts asbestos fibers greater than 0.5 ...min length and greater than 0.02 pm in diameter PROJECTS N. DEPOSITION EXHIBIT Bayone i Page 700/1001 700/1001 700/1001 001Qbbb017 001Qbbb017 VWA TALLINN CFTbO VINWTTLY Wem 61:97 NOW 0007 NOC Table 2 Summary of Results - PCM Data PAGE.08 MVA Inc. 5500 Oakbrook Parkway Sulte 200 PAGE.08 Norcross GA 30093 404 662-8509 Project Name Gaskel Removal Experiment Project No 0765 Method Filter Area Retc Area 7400mm2 385 . 0.00833 mm 21046 . Average . Concentrallon Sample No Date Sample Location Description Flow Duration Volume Min Min L Fibers Counted Fields Counted Dmenmsity Resull cc D4037 | 12/29/93 | Background in NW corner of work area 9.8 157 1539 19.5 100 21.0 0.005 OFICE | D4038 | 12/29/93 | Background In NE comer of work area 9.8 157 1539 12 100 12.0 0.003 SALES 3-04039 | 12/20/93 | Background In SE corner of work area 98 157 1539 23 100 25.2 0.008 RIVEWALK | D4040 12/29/93 Area in center of work area during 0.9 18 14.4 3 100 7.0 0.18 scrape WESTIN D4041 12/29/93 | Personal left side during scrape 1.2 16 19.2 8.5 100 7.8 0.18 23:19 D4042 | 12/29/93 | Personal right side during scrape 1.2 16 19.2 7.5 100 6.6 0.13 01:31 The average value of the two blank samples 2 fibers flelds was subtracted from the tolal fiber count for calculation of the fiber concentrallons MON 20 0 The number of fibers counted in sample no 4 was less than the estimated Ilmll of detection LOD for the melhod which is a filler loading of 7 mmThe 13 airborne fiber concentration is calculated using the LOD thus the reported value should be considered higher than the true concentration J12-U0N JUN IWA = Inside Work Area OWA = Oulside Work Area O.L. = Loaded Damaged PF = Pump Failure NA Not Applicable Table 2 Summary of Results PCM Data MVA Inc. PAGE.09 5500 Oakbrook Parkway Suite 200 Norcross GA 30093 PAGE.09 404 662-8509 Project Gaskel Removal Experiment Project No 0765 Method Filter Area Retc Area 7400 385 mm 0.00833 mm Sample No. Date Sample Location Description 21046 Average Flow Duration Volume Min MID L Fibers Counted ~ Flelds Counted Concentration Density Result mm : Nicc 7 - D4043 12/29/93 | Area in center of work area during wire 20 fl, 10.8 101.5 100 119.4 4.3 brush OF ICE 8 - D4044 12/29/93 | Personal left side during wire brush 1.2 4 4.8 78 100 88.B 7.1 D4045 12/29/93 Personal right side during wire brush 1.2 4 4.8 70.5 100 82.2 6.8 SALES 10 D4048 12/29/93 | Personal left side during scrape and 112 14 16.B 89.5 100 105.0 2.4 RIVEWALK wire brush . 11-04047 11-04047 | 12/29/93 | Personal right side during scrape and 1.2 ) 14 16.B 68 100 79.2 1.8 WESTIN wire brush 23:19 D4048 | 12/29/93 | Area NW comer of work area during 5 37 185 scrape and wire brush 73 100 85.2 0.18 13 D4049 | 12/29/93 | Area NE comer of work area during 5 32 160 87,5 100 78.8 0.19 01:31 20 0 scrape and wire brush The average value of the two blank samples 2 fibers fields was subtracted from the lola fiber count for calculation of the fiber concentrations 13 Samples 7 8 and 10 through 14 are heavily loaded with particulate which could result in the lack of detection of fibers JUN IWA Inside Work Area OWA = Oulsida Work Area O.L. = Loaded Damaged PF - Pump Failure NA = Not Applicable PROJECTRPTS 0127 Pan A Table 2 Summary of Results PCM Data PAGE.10 MVA Inc. PAGE.10 5500 Oakbrook Parkway Suite 200 Norcross GA 30093 404 662-8509 Project Name Gaskel Removal Experiment 7400 } Project No 0765 Method Filter Area Retc Area 385 mm2 0.00833 mm 21046 Sample Density No. Dale Sample Localion Description Average Flow Duration Volume Min Min L Fibers Counted Fields Counted Concentration Result mm cc D4050 | 12/29/83 } Area on south center wall during scrape 5 37 185 51.5 100 and wire brush 59.4 0.12 . 15 D4051 | 12/29/03 | Area center of work area during 0.9 in 4.5 78.5 100 91.8 7.8 sweeping 16 D4052 | 12/29/93 | Personal left side during sweeping 1.2 5 6 73.5 100 85.8 5.5 17 - D4053 | 12/29/93 Personal right side during sweeping 113 5 8 75 100 87.8 5.8 D4058 | 12/29/93 Blank field NA NA NA 3.5 100 4.2 NA D4059 | 12/29/93 | Blank sealed NA NA NA 0.5 100 0.6 NA The average value of the two blank samples 2 fibers fields was subtracted from the total fiber count for calculallon of the fiber concentrations 01:31 Samples 7 8 and 10 through 14 are heavily loaded with parliculale which could result in the lack of delection of fibers 200 IWA = Inside Work Area OWA = Outside Work Area O.L. = Loaded D Damaged PF = Pump Failure NA = Not Applicable 13 JUN PROJECTS Penn