Document 5VvB332m9D88Mbq6MqMn2q9R

FILE NAME Packings and Gaskets PAG DATE 2000 June DOC PAG013 DOCUMENT DESCRIPTION Unpublished Report - Spiral Wound Gasket Removal Work Practice Study ~ Spiral Wound Gasket Removal Work Practice Study Materials Analytical Services Inc. June 2000 Raleigh Office 616 Hutton Street Suite 101 Raleigh NC 27606 919 829-7041 FAX 919 829-5518 Atlanta Office 3945 Lakefield Court Suwanee Georgia 30024 770 866-3200 FAX 770 866-3259 Spiral Wound Gasket Removal Work Practice Study Study Design & Protocol Summary of Data PCM TEM & Fabric Analysis Bulk Sample Analysis & Affidavit 1. M23793 Air Sample Analysis 1. M23791 Fabric Analysis Results 1. M23792 Tools Used in Study Photographs Spiral Wound Gasket Removal Work Practice Study This study was designed and conducted by Richard Hatfield William Longo Ph.D. and Larry R. Newton CIH CSP Study Design and Methodology The study was performed in the exposure characterization lab ECL The size of the ECL is approximately 20 ft x 15 ft x 8 ft and the walls and ceiling is constructed of a painted plastic laminate The ECL is constructed with two viewing windows for video taping purposes and has a ventilation rate of approximately 200 cubic feet per minute with two primary inlet sources and a negative air machine that produces a constant airflow during the study During video taping of the work practice study lighting is utilized inside the ECL to increase the possible observations of dust release during the work practice Previous studies have shown that the use of what is commonly referred to as the Tyndall light phenomena is an effective method of displaying respirable airborne dust generated from workplace activities To minimize light reflection the walls floor and ceiling inside the ECL are painted black MAS received a number of flanges and valves from Dr. Robert Gay Dr. Gay had harvested these flanges and valves from a wood products mill powerhouse located in Oregon Three of these valve and flange assemblies which contained spiral wound gaskets were selected A fourth valve and flange assembly was provided by Patton Warnom & Watkins The four flange assemblies were identified as containing spiral wound gaskets and were partially opened to confirm the presence of these asbestos containing gaskets prior to the work practice study The flanges were reassembled and the outside surfaces were cleaned After cleaning the flange assemblies were sand blasted and painted The cleaning and painting measures were performed to eliminate any contribution of asbestos from previous thermal insulation which may have been present Four flange assemblies were slated for use in this study Each assembly contained two flanges therefore eight spiral wound gaskets were to be removed in this study During the study air samples were collected using 25 mm cassettes containing micron pore size mixed cellulose ester MCE filter on a 5.0 micron backing pad The air sampling pumps were calibrated both before and after the sample collection High volume pumps were used for area air samples during the simulation The pumps were located outside the ECL and connected to the air samples cassettes by Tygon tubing through the walls of the ECL 1 Surgen Commander P.G. Harris The Effects and Control of Disease Associated with Exposure in Devonport Dockyard Doctoral Dissertation 2 C. Dernchi & K.S. Lane Asbestos Toxicology Report Union Carbide Corporation 3 D.T. ECL's Dust Control Development S. Chissick & R. Derricott in Asbestos Volume 2 Properties Applications and Hazards 6 193 1983 41. 41. J. Selikoff Insulation Hygiene Progress Report Volume 3 No. 4 Winter 1971 The four area air samples were located around the work site The area air sampling cassettes were placed approximately five feet from the floor and 6 to 7 feet from the work activity The high volume pumps were calibrated to a flow rate of 10 liters per minute for both background and area samples collected during the study The two investigators performing the work practice were each fitted with two personnel air sampling pumps with connecting tubing and 25 mm MCE air sampling cassettes The air sampling cassettes were attached to each shoulder and within the breathing zone of each investigator The personnel air sampling pumps were calibrated to a flow rate of 2 liters per minute flanges background samples were run inside and outside the ECL Before working on the The air samples were collected in general accordance with NIOSH Method 7400 for measuring airborne asbestos fibers The individuals working inside the ECL wore Tyvekfisuits under polyester 35 / 65 work clothes and were supplied air through face pressure demand respirators equipped with an escape HEPA filter system The ECL design included a decontamination area for clothing removal and a shower to remove residual asbestos contamination before the individuals left the ECL area Gasket Removal and Electric Wire Brushing Four flange assemblies were used for this study for a total of eight spiral wound gaskets to be removed During the study the flange face was opened and the spiral wound gasket was removed In most cases the spiral wound gasket assembly was easily removed from the flange face however it was observed that the spiral wound gasket assembly would generally leave a small amount of gasket residue on the flange surface This residue was removed by using an electric wire brush as described by former machinist and maintenance personnel Analytical Methods All air sample cassette filters were analyzed by NIOSH Method 7400 PCM method using A counting rules A portion of the filter material from the air samples was analyzed by TEM using the indirect method after preparation by the ASTM D5755-95 analytical protocol The spiral wound gaskets were collected from the four flange assemblies that were removed during the study These eight samples were analyzed by PLM to determine the asbestos content Additionally an effort was made to identify the manufacturer of the spiral wound ~ gaskets Results During the work practice the worker was exposed to levels of airborne asbestos fibers between 1.1 to 1.4 fibers as measured by PCM and between 76.5 to 402.2 structures as measured by TEM The assistant's exposure level ranged from 1.0 to 1.2 fibers as measured by PCM and between 7.7 to 50.1 structures as measured by TEM The clothing worn by the worker fabric sample tested resulted was contaminated with in a level of 131.7 million respirable 6 of 6 of of e ome asbestos fibers The one asbestos structures per square foot The PLM analysis showed that each of the spiral wound gaskets contained approximately 60 chrysotile asbestos Four of the gaskets were identified to be manufacturered by Flexitallic and four were manufactured by Parker Conclusion MAS conducted a study to determine if there were any asbestos exposures to asbestos fibers generated by removing and electric wire brushing of spiral wound asbestos containing gasket material from flanges Typically a maintenance operation will first remove the spiral wound gasket from the flange and then polish the flange face with either a pneumatic or electric rotary drill brush equipped with a wire wheel These results show that employees should wear at a minimum powered air purified respirators PAPR to conduct this operation In addition an employee standing near the work activity will also be exposed to significant levels of asbestos fibers This employee will require the same level of respiratory protection The results show that both the employee and the helper brushing the gasket exceeded OSHA's current asbestos excursion limit of 1 fiber throughout the study This work should also be performed in an enclosed room or glove bagged to prevent asbestos fibers from migrating and exposing other personnel On examination of the PCM filters it was observed that all filters taken during the study were overloaded with asbestos particulate This type of overloading will bias the fiber counts to lower concentrations Therefore the PCM fiber counts can only be considered as a minimum exposure The evidence that the PCM counts should have been higher lies in the TEM data Based on the fibers 5...min length and greater than 0.25 min diameter counted in the TEM analyses the PCM counts should have been as much as four to five times higher SPIRAL WOUND GASKET REMOVAL Protocol Work Practice Simulation June 2 2000 Richard Hatfield William E. Longo Ph.D. Larry Newton CIH CSP ECL SET A. Study is to be performed in the exposure characterization lab ECL constructed using negative airflow asbestos abatement technology The size of the ECL is approximately 15 x 20 x 8 Air exchange inside the ECL will be approximately 200 cubic feet per minute as measured Extech Model 451126 at the air exhaust of the filter negative air machine Aramsco Comanche Model 55011 HEPA C. Tyndall lighting setup according to the protocol as described in D.T. Chambers Asbestos John Wiley & Sons 6 193 1979 BACKGROUND AIR SAMPLES A. Adjust and calibrate high volume area pumps to 10 liters per minute B. Setup four area air samples inside the ECL Use 25 mm air cassettes Containing 0.8 micron pore size mixed cellulose ester MCE filters with a 5.0 micron backing pad Locate the area air samples in each quadrant of the ECL at a height of 55 from the floor and a distance of approximately 6 feet from the work activity WORK PRACTICE STUDY Four flange assemblies will be utilized in this study On each assembly there are two flanges therefore eight spiral wound gaskets will be removed in the study The method used will be to first remove the gasket assembly then electric wire brush to remove any residue and polish the flange facings A. During this study the area samples will be calibrated and run at a rate of 10 minute B. The worker and observer will each be fitted with two personnel air pumps and air cassettes located in their breathing zone and calibrated at a flow rate of 2 minute Both the worker and the assistant will wear appropriate protective clothing work apparel and appropriate respiratory protection equipment The work practice will be performed under both ambient and Tyndall lighting The entire procedure will be videotaped with three separate cameras During filming the Tyndall lighting will be turned off and overhead lights turned on at least once during the study Air samples for both the area and personnel will be collected during the entire duration of the study IV LABORATORY ANALYSIS A. All air samples will be analyzed by the NIOSH 7400 PCM method using A counting rules and by TEM analysis For the TEM analysis all samples will be analyzed by the indirect method Samples will be prepared using the ASTM D5755-95 method protocol Fabric samples will be analyzed by the Chatfield method MATERIALS ANALYTICAL SERVICES INC Work Practice Simulation Protocol ) Chamber Setup A The walls ceiling and floor are painted black to diminish light reflection B Arranged lighting for Tyndall effect in general accordance with the method described in by D.T. Chambers Asbestos John Wiley & Sons 6 193 1979 E Background Air Samples A Adjust and calibrate high volume area pump to appropriate flow rate B Set up two or more air samples inside the chamber and one outside air sample in general accordance with the procedure outlined in the NIOSH 7400 method , Work Practice Study,, Review the appropriate information on work practices simulation Acquire all necessary tools and materials required for work practice simulation Calibrate personnel and high volume sampling pumps appropriate to flow rates Set ventilation to 200 cubic feet per minute as measured with the Extech Flow Anemometer Set up two or more inside air samples and one outside air sample in general accordance with the procedure outlined in the NIOSH 7400 Method Participants in the study are to wear protective clothing work apparel and respiratory protection equipment Set up the personnel air samples in general accordance with the : procedure outlined in the NIOSH 7400 method Determine the appropriate time for the length of study Work practice study performed as determined in Section III & Parts of the procedure may be done in advance of chamber set up J If appropriate film the work practice study from start to finish in two directions During filming turn off Tyndall lighting and turn the overhead lights on at least on one occasion IV ANALYSIS Analyze A air samples by NIOSH 7400 PCM methods with A counting rules B) Analyze air samples by either TEM direct or indirect method C Analyze the fabric samples by the Chatfield method D Analyze dust samples by the ASTM 5595 method V. RESULTS A Air Report PCM results as fibers report TEM results all sizes structures and greater than or equal to 5 microns in fibers B Fabric Report TEM results as number of asbestos structures per cmand per square foot of cloth sample C Dust Report TEM results as number of asbestos structures per cmand per square foot of surface area sampled 2 If the air samples are two overloaded for PCM analysis use the indirect method as descrived by ASTM 5595 Spiral Wound Gasket Removal Studoy%n%an Asbestos Air Analysis Results I. BACKGROUND SAMPLES Sample No. A NE A SE C SW A NW Sample Description IWA Background IWA Background IWA Background IWA Background PCM Fibers 0.00 0.00 0.00 0.00 II PERSONNEL SAMPLES WORKER Sample No. A B Sample Description Personnel WLR Personnel WLL PCM Fibers 1.4 1.1 TEM AII Structures 0.00 0.00 0.00 0.00 TEM 5.0...m Fibers A A A A TEM AII Structures 402.2 76.5 TEM 5.0...m Fibers 71.0 19.8 C D Personnel RHR 1.2 Personnel RHL 1.0 50.1 7.7 11.1 1.7 III AREA SAMPLES Sample No. A NE A SE C SW D NW Sample Description IWA Area IWA Area IWA Area IWA Area PCM Fibers 0.29 0.55 0.20 0.18 TEM AII Structures 26.52 21.72 25.51 10.02 TEM 5.0...m Fibers 90.03 3.90 7.21 2.23 IV FABRIC ANALYSIS Sample No. WL WL Sample Description Fabric Control Fabric Area Asbestos Structures 0.00 131.7 million Asbestos Structures 0.00 141.7 thousand