Document K651z90v4LYxGRJyJyoDdNxO0

FILE NAME Packings and Gaskets PAG DATE 1995 DOC PAG009 DOCUMENT DESCRIPTION Journal Article - Releasability of Asbestos Fibers From Containing Gaskets Releasability of Asbestos Fibers From Containing Gaskets James R. Millette Michael D. Mount and Steve M. Hays MVA Inc. 5500 Oakbrook Pkwy Suite 200 Norcross GA 30093 B Gobbell Hays Partners Inc. 217 Fifth Ave. North Nashville TN 37219 Gaskets must be considered during reinspections under the Asbestos Hazard Emergency Response Act AHERA Maintenance operations on gaskets may release asbestos fibers exceeding 1 cc Therefore precautions should be taken during this type of work 4 aber Ce one CAUTION Asbestos CAUTION Contains fibers Avold .. nder the Asbestos Hazard Emergency Response Act AHERA the Local Educational Agencies LEAs must conduct reinspections every three years of all friable and nonfriable known or assumed ACBM Among the materials that the LEAs are to consider for reinspection are other materials such as boiler fire brick gaskets and caulking which may have been missed If an inspector overlooked a suspect material during the original AHERA inspection there is no specific requirement that it be included in the reinspection reinspection However any missed actual or suspect ACBM present in the school represent a violation of AHERA for which both the LEA and the original inspector could be liable Gaskets represent an containing material ACM which is somewhat different from the surfacing material easily observable in an asbestos survey The term gasket is a general term for a number of sealing materials including sheet gaskets packing and asbestos rope This paper presents information primarily about sheet gasket materials Packing is often found inside valve systems and asbestos rope has been used on boiler and furnace doors Although replacement sheet gaskets may be found in a storage closet in service gaskets of this type are generally located betweenbetween two pipe flanges and are not readily accessible a dust s seriousIlltytwshahrm armhharam rm : Figure 1. Warning Label on piece of containing sheetgasket , material for disturbance The concern over containing gaskets is derived principally from maintenance issues Periodically a pipe connection must be broken at the flanges and the old gasket removed and replaced This effort may require a simple scraping with hand tools or may need the assistance of power tools clean the flange Possible fiber release from both cutting new gasket material and from the removal of after service gasket 10 EIA TECHNICAL JOURNAL FALL 1995 material as well as the debris from these activities must be considered This paper provides information about the release of asbestos from sheet gasketing material referred to as gas- kets in many instances in the remainder of the paper Gasket Materials In buildings sheet gasket materials are used mainly to seal pipe joint connections and prevent leakage of fluids between the solid surfaces of the pipe flanges They are used in steam lines and in some water pipelines Gaskets often consisting of more than 70 percent chrysotile asbestos are used against alkaline neutral or weak acid solutions Crocidolite blue asbestos containing gaskets have been used against harsher acid solutions Sheet gaskets are composed of chrysotile asbes- tos compressed into a 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.In their original state containing sheet gasket materials which are composed of asbestos in an organic binder are not considered friable However gasket material after service may be dry and friable Under 1992 U. S. Environmental Protection Hazard Communications Labels In accordance with OSHA's Hazard Communication Stan- dard labels shall be used to identify asbestos containing material The labels shall contain a warning statement against breathing asbestos fibers However labels are not required when asbestos fibers have been modified by a bonding agent coating binder or other material provided that the manufacturer can demonstrate that during any reasonably foreseeable use handling storage disposal processing or transportation no airborne concentrations of asbestos fibers in excess of the permissible exposure limit and excursion limit will be released While some manufacturers ofgaskets represent that the asbestos is completely bound or encapsulated in their gaskets and therefore need no hazard label others have put warning labels on their gaskets as shown in Figure 1 Agency EPA NESHAP regulations gaskets are in- cluded in Category I nonfriable containing material ACM along with packings resilient floor covering and asphalt roofing products In most cases the asbestos NESHAP does not require their removal prior to demolition Removal prior to demolition would be required if the gaskets or other Category I Fig 2. containing sheet gasket material of the type from nonfriable ACMs became regulated asbestos which gaskets could be cut for sealing pipe flanges ing material RACM because they have been subjected to sanding grinding cutting or abrading Removal would be necessary before demolition if the gaskets Category nonfriable ACM were located in a structure which was to be Sethe view ae eT Fig 3. Close go : age of the surface of the cx demolished by burning 4 gasket material In the Occupational Safety and Health Administration from Fig 2 OSHA regulations containing gaskets are included under Class II asbestos work which acti to av ctii vitt iesiinevos lv- ing the removal of ACM which is not thermal system insulation showing uncoated Bfi chrysotile or surfacing material According to the OSHA rules and regulations when re- moving gaskets containing ACM the employer shall ensure asbestos fibers ei [Se yt, protruding that the following work practices are followed A if gasket is visibly deteriorated and unlikely to removed intact removal shall be undertaken within a glovebag B the gasket shall be thoroughly wetted with amended water prior to its removal C the wet gasket shall be immediately placed in a disposal container D any scraping to remove residue must be per- formed wet Encapsulation or Releasable Fibers The question of whether or not all asbestos fibers are completely bound or encapsulated in gasketing material is one that has been studied by microscopy A close examination of the surfaces of four unused gaskets showed that although most Gaskets would also be covered in Class IV asbestos work of the asbestos is indeed bound within an organic binder Class IV work includes maintenance activities during which uncoated asbestos fibers were present on the surface and on the employees contact ACM and custodial activities in which employees clean up waste and debris containing ACM nder the Class IV activities dry sweeping shoveling or enor dry clean of dust and debris containing ACM is prohibited prohibited regardless of measured levels of asbestos exp edges of the gaskets which would be released released as free fibers with mild abrasion Additional work examining examining gaskets from a number of manufacturers showed similar results A portion of a John Crane Crane Packing Company sheet gasket labeled 2. magnified view of initial exposure assessments in Figure 3. The EIA TECHNICAL JOURNAL FALL 1995 11 Table 1. Summary of Air Sampling Results for Gasket Activities Activity Cutting Hand punching no controls Hand & machine processing controls Cutting with knives power shears wheels Cutting with saber saw power shear and wheel cutter,," PCM cc 3.0-5.0 0.01-1.3 0.001-0.017 0.33-0.49 Installation Installation Installation following removal of old gasket 0.03 0.13-0.19 Removal Removal Hand scraping Dry removal with scraper wire Dry polishing of flange,," Wet removal,," brush 0.049-0.44 up to 0.4 0.11-0.33 1.4 0.06 Cleaning Cleaning of debris following removal no controls Shearing and punching activities with cleanup 0.05 1.2& 1.67 chrysotile fibers are uncoated and protruding from the gasket surface Gasket Fiber Release Studies Reported in the Literature A government sponsored report on the exposures from gasketing operations was compiled by the GCA Corporation in 1982. They summarized their findings on gaskets as follows Secondary processing of compressed sheet gaskets can result in comparatively high workroom fiber concentrations on the order of 3.0 to 5.0 cc during hand and machine punching if control measures are not employed When dust control procedures are implemented which is usually the case fiber concentrations resulting from various hand and machine processing steps and materials handling operations range from less than 0.01 to 1.3 cc Measured airborne fiber concentrations result- ing from the installation of compressed sheet gaskets were less than 0.03 cc as reported by one study Removal of these materials however can result in higher concentrations up to 0.4 cc during hand scraping of material adhering to a bearing surface In this latter case fiber release is related to the physical exertion required to remove the material and to the high asbesOs content equal to or greater than 75 percent of compressed sheet gasket The information in the GCA report is apparently based primarily on a Naval Regional Medical Center report com- monly referred to as the Bremerton study Air samples were collected during gasketing activities including gasket handling installing removal and disposal at the Puget Sound Naval Shipyard In addition to the summary provided by the GCA Corporation data on cleaning of gasket debris showed less than 0.05 cc in one cleanup following removal with no controls and 1.2 cc and 1.67 cc during shearing and punching activities which included cleanup Data published in the scientific literature on asbestos exposures during use and handling of asbestos gaskets in the oil and chemical industries showed a range of fiber levels depending on the activity Longterm samples over 300 minute sampling periods during gasket fabrication with knives power shears and a wheel cutter showed levels ranging from 0.001 to 0.017 cc Short term samples 30-55 minutes collected while the gaskets were cut with a saber saw or power shear and wheel cutter showed concentrations ranging from 0.33 to 0.49 cc Short- term exposures during dry removal ofgaskets varied between 0.11 and 0.33 cc when surface cleaning was done with scraper and with wire brush One air sample collected during dry polishing of pipe flanges with a power sander showed 1.4 cc for the task A work method for the removal of after- service gaskets which called for the spraying of a solvent wetting agent such as an oil to wet the gasket and seating surfaces before removing and cleaning showed workers short asbestos exposures to be below detection detection limit = 0.06 / cc Other published results of simulated gasketing operations showed personal exposure to fiber levels ranging from 0.049 to 0.44 fibers for removal and 0.13 to 0.19 cc for installa- tion TEM analysis of air samples collected during gasket removal and installation showed asbestos fiber levels ranging from 0.86 to 18.44 structures cc for removal and 0.40 to 74.32fs or installation As can be seen in Table 1 the scientific literature shows a range of values describing asbestos fiber release from sheet gasket materials The higher values seem to be related at least in part on whether dust control measures were in place and whether power tools were used Two studies were performed by the authors to study in a more controlled situation the release of asbestos from gasketing activities primarily from operations using power tools without dust controls and to gain information about the possible releases during the clean of debris The latter question had not been studied independently Study : Removal of Gasket Material and Brushing of the Pipe Flange In a controlled area personal and area air samples were collected before and during the removal of asbestos sheet gasket material and brushing ofthe pipe flange Because a maintenance activity often involves the disturbance of more than one material is difficult assess the contribution any 12 EIA TECHNICAL JOURNAL ' FALL 1995 of a particular ACM to the overall airborne asbestos concentra- tion To determine the possible contribution of an asbestos gasket during removal special precautions were taken to iso- late the removal activity from other activities that might have contributed airborne asbestos from other sources 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 by 8 ft was completely contained within a larger containment area The study area had two high efficiency particulate absolute HEPA air filtration devices 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 The study consisted of the collection of air samples before and during a gasket removal activity A valve that had been used in a steam line board 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 steam fitter 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 160 Gaskets were removed from both sides ofthe valve The gaskets were not wetted before removal 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 The air was stirred aggressively with a broom and the drill power wire brush was operated The drill was a Campbell Hausfeld Model TL 1006 air pressure powered drill that has a maximum speed rating of 2500 RPMs The area sampling cassettes were located on the walls at the breathing zone five feet from the floor During the gasket removal activity personal air samples were collected on the person doing the gasket removal That person was fitted with two personal air sampling devices All personnel inside the study area were protected by respirators and head and body coverings The decontamination system consisted a changing room outside the testing area and a clean suit room The decontamination system was used each time a person exited the study area and the overall containment area The study consisted of four parts In the first part personal air samples were collected while the worker removed the flange and hand scraped the gasket residue from the flange surfaces as shown in Figure 4. In the second part new personal air monitoring cassettes were placed on the worker and he cleaned the flange face with power brushing equipment as shown in Figure 5. In the third part the worker wearing a new set of air monitoring cassettes removed the flange on the other side of the pipe valve and removed the old gasket by hand scraping and then power brushed the flanges In the fourth part the worker again wearing a new set of air monitoring cassettes swept the floor in the containment with a broom Air samples were analyzed by the standard phase contrust microscopy PCM method NIOSH 7400 using the A count ing rules Although the phase contrast microscope enhances the EIA TECHNICAL JOURNAL FALL 1995 TabTabllee 2. Summary of Personal Air Air SampliSampling ng Results | far Gasket Removal Study 1 Activity Background PCM cc 0.004 TEM cc 0.02 | Hand scraping Power wire brushing 0.14 6.8 3.9 i 62 Hand scraping and power wire brushing 2.1 \ 20 | Broom sweeping of area after removal 5.5 44 in * Phase Contrast Microscopy counts and than 0.25 in diameter greater pm fibers greater than 5 um in length identifies Electron Microscopy counts ** Transmission identifies and asbestos structures containing fibers greater than 0.5 m in length and ; greater than 0.02 min diameter Fig 4 top Removing an after service asbes- containing gasket from a pipe flange by scraping Fig 5 left Power wire brushofipnipge flange after removal of the gasket during Study 1 13 4 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 may 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 and ray elemental analysis All asbestos fibers longer than 0.5 ...mwere counted by TEM so that total asbestos concentration could be determined Both personal samples were analyzed by both PCM and TEM 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 Results The results of the personal air monitoring are shown in Table 1. Chrysotile fibers were identified as the primary type of fiber The TEM fiber counts include structures containing asbestos fibers of any width above 0.5 ...min length Polarized light microscopic analysis showed the sheet gasket to be approximately 80 percent chrysotile by volume The gasket materials removed from the valve flanges were friable Study 2. Asbestos Fiber Levels Caused by Sweeping of Gasket Debris After Cutting This study consisted of the collection of air samples during a cleanup of asbestos dust and debris following a cutting of a gasket material with a band saw Although a saber saw has been reported to be used in the cutting of gasket material a band saw was used in this case to produce the dust and debris that would be swept up for the study Air samples were also collected before and during the cutting of the gasket material The study was conducted in a warehouse area in Norcross GA in an enclosure as described in Study . Priotro starting the activity three 3 area air samples were collected to determine the background level of asbestos in the air of the study area The band saw was operated and the area swept with a broom during the background air sampling A dry piece of John Crane Crane Packing Co. sheet gasket labeled 333 heavy duty was cut with a Craftsman in band saw for approximately 10 minutes The air samples for this activity were collected for 18 minutes The band saw was equipped with a in wide blade which ran at a speed of 1725 RPM The blade was described as one for finished straight and curved cuts in material such as wood plywood veneer and plastic Airborne dust particles were allowed to settle for a period of an hour Then air samples were collected to establish the air level before clean Samples were collected while the worker swept the containment area with a broom Weekly listings of environmental contract opportunities Find out who owns the work who's bidding it and who's winning it Each report has hundreds of contract opportunities to pursue Call TODAY for a complimentary and current issue 527 800 5 - 2204 Covering the Northeast Atlantic Mid Southeast West California vest ae2s Mid aaee Central ieeSeet fetSeasteaiS eEOe Roeeose ra it EIA TECHNICAL JOURNAL FALL 1995 During the activities the person doing the cutting and sweeping was fitted with two personal air sampling devices All samples were analyzed by phase contrast microscopy PCM nd some by transmission electron microscopy TEM Analytical Methods Personal air samples were analyzed by the standard phase contrast microscopy PCM method NIOSH 7400 using the A counting rules 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 and counting procedure This TEM analysis method identifies asbestos fibers the basis of morphology crystal structure and ray elemental analysis In this study only asbestos fibers longer than 5 jun were counted by TEM Polarized light microscopy PLM was used to determine the type and amount of asbestos in the gasket material A friability test was performed on the sample of gasket material before cutting and on the residue after the activity Results Polarized light microscopy PLM analysis showed the John Crane Gasket to contain approximately 80 percent chrysotile asbestos As received the gasket material was not friable However it produced dust when scratched The residue materials from cutting contained dust The results of the air monitoring are summarized in Table 3. During cutting with band saw the asbestos fiber level for the operator was 11 fibers as measured by PCM TEM analyses of the airborne fiber concentration during band sawing showed a high level of chrysotile asbestos of all widths over 5.0 ...min length The high number oflong thin asbestos fibers prevented an accurate TEM count It was estimated that the concentration was over 30 cc for asbestos fibers of all widths over 5.0 um in length During sweeping with a broom the airborne fiber level in the vicinity of the breathing zone of the person sweeping was 1.7 fibers TEM analyses ofthe airborne fiber concentration during sweeping showed a level of 5.9 cc for asbestos fibers of all widths over 5.0 ...min length Conclusions Asbestos sheet gasket although not considered friable in original unused condition can release asbestos fibers into the air during various operations when hand methods are used and especially when power tools are involved Clean following cutting of new gaskets and the removal ofservice gaskets may resuspend dust containing asbestos into the air . Recommendations In considering containing gaskets during an in- spection reinspection or other survey an inspector should begin by checking storage areas for gasket materials labeled with asbestos warnings The inspector should be aware that not all containing sheet gaskets are labeled Because inservice gaskets cannot be sampled without potentially damaging the piping seal they should be considered as ACM in the Table 3. Summary of Average Personal Air Sampling Results For Cutting and Sweeping of Sheet Gasket Material Study 2 Activity Background Before Cutting PCM cc 0.005 TEM f 5um cc BDL 0.004 During Cutting of the Gasket 11 30 Background Before Sweeping 0.13 0.37 During Sweeping of Dust & Debris 1.7 5.9 * Estimated Sample too heavily loaded with thin chrysotile fibers absence of information to the contrary The results of various tests suggest that asbestos sheet gasket material although not considered as a friable ACM when new may become friable Proper precautions should be taken especially during removal activities The data presented here emphasize the importance of wetting gasket material before removing or cutting it as well as the need to avoid sweepingof dry dust and debris Sweeping dry containing dust and debris following cutting or removal of gaskets can cause significant levels of asbestos fibers in the air REFERENCES 1 U.S. EPA A Guide to Performing Reinspections under the Asbestos Hazard Emergency Response Act AHERA Office of Pollution Prevention and Toxics EPA 700 1992 2 Bowler W.J. Hows and Whys ofPacking and Gaskets Paper Trade Journal Oct. 11 1965 3 U.S. EPA Asbestos Publication of Identifying Information Notice CFR 5153 Feb. 13 1990 4 U.S. EPA A Guide to Normal Demolition Practices Under the Asbestos NESHAP 1-92-013 Sept. 1992 5 U.S. Department of Labor Occupational Safety and Health Divi- sion Asbestos standard for the construction industry 29 CFR part 1926 FR vol 59 No. 153 Rules and Regulations Aug. 10 1994. p 41080 6 U.S. Department of Labor Occupational Safety and Health Divi- sion Asbestos standard for construction industry 29 CFR part 1926 FR vol 59 No. 153 Rules and Regulations Aug. 10 1994 p 41089 7 Millette R.S. Brown close examination of the surfaces of asbestos gasket materials Microscope 131-135 1992 8 AndePr .Hs . o Grannt M.A. McInnes R.G. Anal W.Jy . As nai lyss is of Fiber Release from Certain Asbestos Products Draft Final Report GCA CorporatiRopntNo. 82-53 developed under U.S. EPA Contract No. 68-01-5960 Dec. 1982 9 Liukonen L.R. Still K.R. and Beckett R.R. Asbestos Exposure from Gasket Operations Report by the Industrial Hygiene Branch Occupational and Environmental Health Service Naval Regional Medical Center Bremerton Washington May 1978 10 Cheng R.T. and H. J. McDermott Exposure to Asbestos from Asbestos Gaskets Appl Occup Environ Hyg 6. 588-591 1991 11 McKinnery W.N. and Moore R.W. Evaluation of airborne asbestos fiber levels during removal and installation of valve gaskets and packing Am Ind Hyg Assoc J. 53 531-532 1992 EIA TECHNICAL JOURNAL FALL 1995 15