Document JJR1VxRGQodr6bKDbYK720nqK

PLAINTIFF'S EXHIBIT DUP-2448 RESPIRATOR WORKPLACE PROTECTION FACTORS FOR ASBgSTOS SUMMARY.AMD BACKGROUND Workplace protection factors for slastomsric and single use half-mask respirators were measured during asbestos reaoval operations. The operations consisted of asbestos removal from a ceiling (fire proofing) and reaoval of pipe insulation. Tbe use of vater/surfactant solutions to spray fire proofing and insulation resulted in conditions of hign humidity for in-doors operations. Out-of-doors operations were also under high humidity conditions since light rain occurred on two of four days of out-of-doors sampling. Temperatures for both operations were in the 65-85*F range. The respirators were used in the context f a respirator program that followed tbe guidance in 29 CTl 1910.134 and ANSI zas.2 (1910) including proper respirator selection and fit testing. A total of seventeen volunteers participated in the study, one or two workplace protection factors were determined for each respirator for which4'the fit test had been passed. The respirators tested were: e- one successfully fitted elastomerie facepiece respirator chosen for comfort from six respirators (MSA Comfo II and Survivair 2000 brands - small, medium or large sizes). These respirators were tested using a dust, fume and mist type filter and a high efficiency filter. DUP 0907355 DU 028456 2 Each of chrte disposable respirators successfully fitted (3K 9910, 3M 8710 and American Optical R1050). A successfully fitted North 7700 elastomeric facepiece respirator, chosen from the small, medium or large size facepieces. In addition two workplace protection factor measurements were made for a self-contained breathing apparatus operated in the pressure-demand mode. Results shoved that, with the exception of the American optical (AO) R1050. all respirators tested reliably provided workplace protection factors of ten or greater based on estimates of the lover Sth percentile. The AO R1050 reliably provided a protection factor of five or greater. These results are consistent with information supplied to the record by Los Alamos National Lat-ratory which reported on the penetration of asbestos through respirator filter medi/. ^ Results for the self-contained breathing apparatus sygest that it may not provide appreciably better protection than the two better disposable respirators and the elastomeric faeepiece respirators, though it creates significantly greater hazard of falling because of the weight and awkwardness of the tanks. Xyhre et al.(2) and Ravn{3) have shown that pressure-demand type respirators -- not maintain positive pressure inside the facepiece when workloads are increased from DU? 0907356 DU 028457 3 r*t condition*. This mar explain in part why no significant difference exists between half facepiece negative pressure and pressure-demand respirators. PROCEDURE Prior to testing, each person was trained in the selection and fit testing of respirators using the National Paint and Coatings Association Training Program^4*. Each was then fit tested using the saccharin fit ttst*4*. Respirators selected for use by participants ace listed above and in Table I. Two individuals were also trained in use of a pressure-demand self-contained breathing apparatus. Fit testing was not done, as it is not required for pressure-demand equipment in the ANSI 2*1.2 (19*0) standard. During sample collection, each participant was o-.erved continually to ensure that the sample train remained intact and did not interfere with the respirator sel on the face, and to note occurences which might have affected respirator performance, such as movement of the respirator on the face. The participants were very busy with their wort activities and soon ignored the presence of the researchers. AIB SAMPLING AND ANALYSIS To determine the workplace protection factors, concurrent samples were taken from inside the respirator (in-mask) at nose level and outside the respirator at the DUP 0907357 DU 028458 liiMii&lUlilHJ z&mammmmsmm -41*9*1 (1*P*1). Closed-face Glasrock (#1505) cassette filttr holders fitttd with half inch extenders and probes developed by NIOSH(S) w*r ua#d for both tu* in-aaak and lapel aamplea. Th# sample probes art p#cially designed to minimize the lose of particular#*. Tha caaaattaa coatainad o.a um, 2Son cellulose #t#r filter*. Th# saapl# traias v#r# calibrated before and after taking each saapl# using a aass flow aster. The aass flow meter was calibrated agaiast a babble flow aster at the beginning and end of the study. A flow rate of 2 Lpn was used for in-aask saaples. Lapel saaples were taken at 0.5-1.0 Lpa to avoid overloading. Saaples were collected for a one to two hour period. Each saapl# represented a single wearing of the respirator. Fiber counts, were done per NIOSH procedure PSCAM 239(phase contrast microscopy). except that the triaeetin/acetone mounting method was used as described in NIOSH method 7400*7*. Counting was don* according to th* "A* counting rules in aethod 7400. Five hundred fields were counted fox ia-aask saapl** to inereas* analytical sensitivity. All analyses were done by one counter who participates successfully in the American Industrial Hygiene Association's Proficiency Analytical Testing quality assurance prograa. Concentrations wsze ealeulatsd froa tht actual nuabsr of fibers counted (even if fever cnan 50 fibers vers counted) per th* foraulaa in th* NlbSH aethod. DUP 0907358 DU 028459 B8KaasBMaii,aiia!iil.i,! NIOSH method PS-CAM 239 reports a coefficient of variation of 0.12 which applies to lapel samples in this study. We estimate that the coefficient of variation for tha in-macIc samples is 0.4 at tha median in-facapiaca concentration and fiber count (table III). SW?.LINC. AKD_mLYS.I.S_.HZTHOtLVSRIFICATION In-aask aampliag required use of closed-face filter cassettes. The Glasscock #1505 25a filter cassettes used have a unique tapered design for the outlet and a half inch extender which improves the deposition patterns^**, to minimize sample loss, the NIOSH{5) probe was used to withdraw ia-mask samples. To eliminate possible bias, the same elosed-face/probed cassette was used for both in-mask and lapel samples. To document whether concentrations determined from closed-face/probe cassette sampling differed from open-face sampling, twelve area samples were taken using b^th methods. Besults are compared in Table II with Student's and Variance latio tests. The two sampling methods were found to give similar results with no significant bias or difference in preeisioa. asawn wa. Transmission electron microscopic analyses were made on four lapel samples to document the distribution of fiber diameters and lengths. Distributions are shown in Figures 1 and 2. Tiber diameters and lengths covered a wide range. DUP 0907359 DU 028460 6 The overall median concentrations of fibers for in-nas)c and lapel samples are given in Table III. The median number of fibers counted for in-mask (500 fields counted) and lapel (<.100 field counted) samples are also given in Table ill. Cumulative distributions, geometric means, geometric standard deviations, best estimates of 5th percentiles and lists of workplace protection factors are given in rigures 3 through 8 for each respirator. The distributions of workplace protection factors were found to be approximately lognormal for all respirators studied. Therefore, logs were used for the plots, geometric means are reported as the proper measure of central tendency and geometric standard deviations are reported as the proper measure of variability. Best estimates of sth percentiles represent the workplace protection factors that most (9S*> respirator users are expected to obtain from each respirator. Distribution plots and geometric standard deviations include variability from the sampling and analytical method as well as from tbe workplace protection factors. The unavoidable inclusion of tbe sampling and analytical variability in the plots results in best estimates of 5th percentile protection faetoss which ate conservative (lower than actual). This should be considered in evaluitiag results. DUP 0907360 DU 028461 -7Workplace protection factors were determined for a self-contained breat&ing apparatus for two individuals. Results are reported in Table IV. Table V gives geometric means and standard deviations for all respirators studied. A Bonferroni(9) test for differences (p0.05) was dose and results are given in Table V. Workplace protection factors for the 3M 9910 were found to be significantly higher than those for the AO R1050. No other significant differences were found. The relatively low results for the AO R1050 are likely due to poorer filter efficiency for asbestos, reported by Dr. Ortiz of Los Alamos National Laboratory.*1* The unexpected comparability of the results from the 3M disposable respirators, and elastomeric facepiece respirators with both dust, mist and fume filters and high efficiency filters may be explained by several factors. First, the limiting factor in performance with the respirators is likely face fit, not filter efficiency (except for the AO S10S0 as noted above). Since the same fit test was used to select good fitting respirators for the study, comparable results would be expected. In addition, the researchers noted a tendency for elastomeric respirators to slip around when some wearers' faces became wet with tbe water/surfaetant spray. This did not occur with the disposable respirators because their fibrous material of construction clung to the skin. OUP Q907361 DU 028462 -aIt is particularly noteworthy that the workplace protection factor* for the self-contained breathing apparatua were not superior to the batter disposable and elastomeric respirators. Myhre^ and Raven^ have shown that at workloads exceeding approximately 35% of maximal aerobic capacity pressure inside the facepiece of pressure-demand type respirators does ".ct remain positive with respect to the surrounding atmosphere. This would provide aa opportunity for asbestos to be drawn into the facepiece. The volunteers who wore the self-contained breathing apparatus complained of stress and discomfort due to its weight and bulk. Movement and balance were difficult and one volunteer almost fall from a step ladder aa s result. Baaed on their observations, the researchers believe that routine use of self-contained breathing apparatus for asbestos removal in the chemical industry would li' tly result in injuries, in visw of the large amoust of climbing involved. Certainly, acceptance will be much poorer than for the other respirators studied, due to discomfort vbieb would discourage respirator use. Transmission electron microscopic analyses were done on in-mask and lapel samples. Besultant workplace protection factors era reported in Table VI. Results for small diameter fibers (<0.2um - the diameter below which fibers cannot be resolved with the standard optical microscopic method) do not appear to differ from those for large diameter (,0.2ua) fibers, for 5 ua or longer lengths. Thus, results for fibers visible DUP 0907362 DU 028463 9 with the phase contrast method (>0.2un diameter) appear to be representative of those foe smaller diameter fibers for the 3M 8710 and 9910, and for elastomeric respirators with a dust, fume and mist filters and hiph efficiency filters. / DUP 0907363 DU 028464 - 10 CONCLUSIONS 1* All respirators tested provided protection against asbestos. lb* American Optical H1050 disposable r*picator reliably provided workplace protactioa factor* of S or greater. The 3M 9910, 3M 8710, and *latoa*ric half-face respirators with both dust, fuse and aist and high efficiency filter* reliable provided workplace protection factor* of 10 or greater. 2. Us* of higher efficiency filters did not appear to improve the workplace protector of the elastomeric respirators. 3. Workplace protection factor measurements for a pressure demand self-contained breathing apparatus verm not significantly higher than those for the better disposable and elastomeric respirators. Comnents from the test volunteers and observations indicate that acceptance of the self-contained breathing apparatus will be poorer lhan that of the other respirators tested. In addition, they present a significant risk of tripping or falling where removal work requires climbing ladders and working from scaffolding. 4. Transmission electron microscopic analyses indicate that overall workplace penetration of small diameter (<2um) fibers (longer than 5 urn) is not discernibly higher than that of larger diameter fibers tor the 3K 1710 and 3M 9910 disposable respirators nor for elastomeric respirators with dust, fume and'aist or high efficiency filters. DUP Q907364 DU 028465 iia--iiiimliiiiih - 11 REFERENCES 1. Octix, L. W. et al: "Interim Report: Penetration of Respirator Filter* by an Asbestos Aaroaol." May 2, 1984 (Los Alamo* National Laboratory). 2. Myhre. L. G., B. d. Holden, F. W. Baumgardner and D. Tucker: Physiological Linit* of Firefighters. Uncla*ified Beport #ESL-TB-79-06. AFESC, Tyndall AFB. Florida (June 1979) . 3. Haven. P. B. et al.: "Physiological Response to Pressura-Demand' Respirator Wear". Am. Ind. Hyg. Assoc, j. 43 (10): 773-781 (1912). 4. "Guide to Respirator Fit Testing" (1981), National Paint and Coating Association. Washington. D.C. 5. Liu, B. Y. U. et al: "In-Mask Aerosol Saapling for Powered Air Purifying Respirators." Aa. Ind. Hyg. Assoc. J. 45(4):278-283 (1984). 6. U.S. Departaent of Health. Education and Welfare: NIOSH Manual of Analytical Methods, Second Edition. Volume I (April 1977). 7. National Institute for Occupational Safety and Health. Method 7400. February IS, 1984. I. Adaas, H. J. et al. "Cassette Extenders: Effects on Chrysotile Fiber Deposition and Concentration Measurements", Presented at the Aaeriean Industrial Conference. May 24, 1983. 9. Snedeeor. G. W. and W. G. Cochran: Statistical Methods. 7th Ed.. Iowa State University Press, Ames, Iowa (1980). UUP 0907365 DU 028466 Respirator Name Survivair 2000 Comfo II 3M 9710 3M 9910 American Optical R1050 North 7700 Scott Air-Pak BL8_1 BtliPUSlLJ5JrBdia tvoe Elactoaarie (silicon! rubber) vita dust, fume and aist and high efficiency filters Elastoaer (neoprene) with dust, fuse and aist and aiga efficiency filters Disposable vita nonadjustable straps Disposable vita adjustable straps Disposable vita nonadjustable straps Elastoaerie (silicon* rubber) vita high efficiency filters Self-contained breathing apparatus, pressure-deaand Vendor U.S.D. Corp. Min* Safety Appliance Co. 3M Company 3M Company American Optical Company North Company Scott Aviation / OOP 0907366 Du 028467 T*Bt.E II COMPARISON OF ASBESTOS SAMPLING METHODS (OPEN-FACE VERSUS CLOSED-FACE WITH PROBE) Mean Parameter Standard Deviation T Statistic* Variance Ratio** Data Open-face cassette: Closed-face cassette: Value 2.2 ibers/aL - open face filter cassette 2.3 fibers/mL - closed face cassette vitb probe 0.264 fibers/aL - open face cassette 0.286 fibers/mL - closed face cassette with probe 1.28 1.17 1.9. 1.9, 2.0, 2.1. 2.1, 2.1. 2.2. 2.2, 2.2, 2.2, 2.3, 2.9 2.0. 2.0, 2.0, 2.2. 2.3, 2.3. 2.3, 2.4. 2.4. 2.4. 2.5. 3.0 / * 1.21 is less tnan a comparison t statistic of 1.71 (p0.05). Therefore, the means do not differ significantly. * 1.17 is less than a comparison T statistic of 2.69 (p>0.0S). Therefore, the variances (precision) of the methods do not differ significantly. DUP 0907 DU 028468 MEDIAN ASBESTOS CONCENTRATIONS AND COUNTS FOR WORKPLACE PROTECTION FACTOR STUDY FOR ALL RESPIRATORS .COMBINED ______________ Concentrations Inside Respirator Outside Respirator 0.006 fibers/mL (8 HR. TWA ~ 0.003)* 2.6 fibers/aL (8 HR. TWA ~ 1.3)* Counts Inside Filter Outside Filter 9 fibers 130 fibers No more than four of eight wocK hours were spent.doing asbestos removal. Therefore, a factor of 0.S (4 HRS/8 HRS) 4as applied to concentrations to estimate HR TWA concentrations. DUp 0907358 DU 028469 ismi**Mflsss table IV WORKPLACE PROTECTION FACTORS FOR SELF-CONTAINED BREATHING APPARATUS (PRESSURE-DEMAND) Workpiece Protection rector*: 400 880 Geometric Mean: 620 / DUP 0907369 DU 028470 flf-iirfli-tiffin'f TABLE V COMPARISON Or WORKPLACE PROTECTION FACTORS FOR SEVEN RES?'IRATORS Numbar of 3M 8710 3M 9910 13 14 Amarican Optical R1050 7 Elaatomarie/Duat. Fuse and Miat Filtar 17 Elaatonaric/High Effieiancy Piltac 14 North 7700 High Effieiancy Filtar 14 Salf-Coatalnad Breathing Apparatus Prassura-Daaand 2 Workplace Protaction Factor Gaoaatric Maan (Geos. S.D.) Significant 310 (5.3) 580 (4.2) Highar than R 1050 52 (4.2) Lovar than 3M 9910 24 j (6.3) Lowar 5th Percantila 20 55 5 12 94 (3.0) 250 (6.9) 16 11 620 / Baaad on a Bonfarroni tast<*) at a 0.09 leval of aigaificanca. only tha 3N 9*10 and AO tioso diffatad. f OUP 0907370 DU 028471 'a?;e vi WORKPLACE PROTECTION FACTORS FROM TRANSMISSION ELECTRON MICROSCOPIC ANALYSES Workplace Protection Factor______________________ __ Respirator Fibers Exceeding 0.2 un Diameter, and 5 um Length- All Diameter Fibers Exceeding 5 um Length 3M S710 330 120 3M 9910 47 41 Survivair 2000 with Dust. Mist and Fume Filter 28 29 Survivair 2000 with High Efficiency Filter 21 19 / Those which would be counted by the standard phase contrast microscopy method. DUP 0907371 DU 028472 Figure 3 - Workplace Protection Factors for 3M 8710 Respirator Cumulative Distribution: (Lognormal) Geometric Mean: 310 Geometric Standard Deviation: 5.3 Best Estimate of 5th Percentile: 20 dup 0907372 Data: 7.4, 15, 61,110, 110, 180, 200, 310, 400, 420, 430, 1000, 1000, 1100,1500, 1600, 1800, 3200 DU 028473 Figure 4 - Workplace Protection Factors for 3M 9910 Respirator Cumulative Distribution: (Lognormal) Geometric Mean: 580 Geometric Standard Deviation: 4.2 Best Estimate of 5th Percentile: 55 Data: 94, 110, 150, 150, 170, 280, 550, 630, 710, 1300, 2400, 3000, 3700, 5600 DU 028474 Figure 5 - Workplace Protection Factors for AO R1050 Respirator Cumulative Distribution: (Lognormal) -<H -- --CD>CD03JTJr Geometric Mean: 52 Geometric Standard Deviation: 42 Best Estimate of 5th Percentile: 5 Data: 9.7, 26, 28, 38, 52, 75, 970 dup 0907374 DU 028475 wSlaaeiat:? v Ml j Figure 6 - Workplace Protection Factors for Survivair 2000 and MSA Comfo Halfmask Respirators with Dust, Fume and Mist Filters Cumulative Distribution: (Lognormal) Geometric Standard Deviation: 6.3 Best Estimate of 5th Percentile: 12 DUP 9073' Data: 15, 24, 45, 46, 47, 74, 88,140,190, 370, 480,1000,1100, 1100, 1800, 4100, 4200 DU 028476 Figure 7 - Workplace Protection Factors for Survivair 2000 and MSA Comfo Halfmask Respirators with High Efficiency Filters Cumulative Distribution: (Lognormal) Geometric Standard Deviation: 3.0 0907376 Best Estimate of 5th Percentile: 16 Data: 12, 28,32,42, 65, 85,110,120,140,160, 160, 220, 220, 780, 7900* Removed from plot analysis, as an outler. DU 028477 Figure 8 - Workplace Protection Factors for North 7700 Haifmask Respirators with High Efficiency Filters Cumulative Distribution: (Lognormal) Geometric Mean: 250 Geometric Standard Deviation: 6.9 Best Estimate of 5th Percentile: 11 DUP Data: 12, 20, 36, 60, 74,110, 260, 350,400,1000,1900, 2000, 2400, 3100 DU 028478