Document qdVxzoQx7aqV5XZ1Lw44OKvJx

FILE NAME: Union Carbide (UC) DATE: 1977 Aug DOC#: UC079 DOCUMENT DESCRIPTION: Internal Report - Airborne Asbestos Fiber Counts during Consumer Installation of Drywall in a Large Room AIRBORNE ASBESTOS FIBER COUNTS during CONSUMER INSTALLATION OF DRYWALL IN A LARGE ROOM Dates Sampled: August 3-11& 1977 Date Reported: August 29, 1977 Samples Collected By: B,, L. Ingalls Union Carbide Corporation Samples Analyzed By: B. L. Ingalls A G. J. Spencer Union Carbide Corporation Reported By: H. B. Rhodes Union Carbide Corporation Union Carbide Corporation Metals Division Niagara Falls, New York SUMMARY AND CONCLUSIONS Asbestos exposure during and after consumer installation of drywall for the finishing of a 12' x 24' basement recreation room was measured. Nineteen panels of wallboard, each 4' x 8*, were-required to cover three walls and the ceiling of this room. About 80 pounds of ready-mix taping compound, containing 1.75% by weight asbestos as manufactured and 2.6% by weight when dry, was used. > . Personal and area samples were collected throughout the installation, using 0.8y porosity Millipore filter and precalibrated MSA pumps. The filters were mounted and counted by optical phase contrast microscopy in accordance with the latest, March 30, 1977, draft of the NIOSH method (P&CAM 239). The maximum ceiling exposure for any of the operators was 1.3 f / c c ^ which occurred during cleanup after sanding. Eight-hour, time-weighted average operator exposures ranged from 0.1 to 0.2 f/cc with an overall average of 0.2 f/cc. General area weighted average basis A general house survey values were well below present installation. ambient background. exposure levels did not exceed 0.1 f/cc on an 8-hour, timein the work area (cellar) or 0.02 f/cc in the living room. on the day after the job was completed showed that all 0.01 f/cc and had not been changed appreciably by the It is questionable whether this is different from the . (1) f/cc means asbestos fibers having an L/D >3, and >5 micrometers in length, per cubic centimeter of air. TABLE OF CONTENTS Section OBJECTIVES TEST LOCATION AND GENERAL PROCEDURE . SAMPLE COLLECTION AND FIBER COUNTING PROCEDURES PRESENTATION AND DISCUSSION OF RESULTS Completion of Studding, Hanging Drywall, and Start of Taping (8/3-8/5/77) First Sanding, Cleanup, and Application of Finish Coat of Compound (8/6/77) Second (Final) Sanding and Cleanup (8/10/77) Residual Exposure After Completion of Installation (8/11/77) Summary of Results During Drywall Installation CONCLUSIONS .?a9e. 1 1 2 4 5 6 6 7 7 LIST OF FIGURES No. Title 1 Sample Locations - Prior to Drywall Installation 2 Installation of Drywall Paneling 3 Application of Tape and Joint Compound 4 Firsthand Sanding of Tape Joint Compound 5 Sanding of Finish Coat 6 Cleanup After Final Sanding Pase 8 9 10 11 12 13 LIST OF TABLES No. Title I Summary of Airborne Fiber Concentrations-Consumer Drywall 14-15 Installation -1- QBJECTIVES This study had the following objectives: 1. To measure asbestos exposure during the consumer installation of 19 panels (4* x 8') of drywall. - ` 2. To measure residual household exposure to asbestos after completion of the drywall installation. TEST LOCATION AND GENERAL PROCEDURE The tests were run at a one story, wood and brick, single family dwelling located in Lewiston, New York. The house was approximately 20 years old and accommodates'''2000 ft.*- of living area. The original construction utilized plaster walls and no known subsequent consumer or professional use of materials capable of releasing substantial quantities of free-form asbestos fiber had occurred. . In this test, studding was installed over three walls (east, south, and west) and the ceiling of a 12' x 241 basement recreation room. Nineteen 4' x 8' panels of 3/8" gypsum board were then fitted and nailed into place. The joints were finished by the following procedure: . . 1. Compound was hand trowelled over all of the joints and the tape was embedded and covered. The nail holes v/ere filled in at the same time. 2. When the initial taping had dried, a second coat of compound was added and sanded when completely dry. 3. Following the sanding, a finish coat of compound was applied. 4. When completely dry, the finish coat was sanded. About 1-1/2 cans (62.5 lbs. each) of compound (mud) were used in this installation. The mud was a ready-mix obtained from Florida Rolling Mills, Inc. of Ft. Lauderdale, Florida. It contained 1.75% asbestos by weight as received and dried to 2.6% by weight. The drywall finishing was done by a couple whose previous experience with drywall had been limited to the patching of a single seam in a prior residence. They received intermittent instruction over a period of aboutJ-1/2 hours at the start of the taping from another consumer with limited experience, and completed the job on their own. The work was done in a manner that wasconsidered to be reasonably representative of "middle-of-the-road consumer use. All joints were sanded to give a good smooth finish. No specific precautions were taken to avoid dust during sanding and cleanup but deliberate efforts to create airborne dust were also not made. The installation divided naturally into five steps and both area and personal air samples were collected to monitor any significant generation of airborne asbestos fiber as follows: \ -2- 1. The completion of the studding, the hanging of drywall panels, and start of taping. 2. Completion of the taping and application of the second coat of compound. (No samples taken.) 3. First sanding, cleanup and application of the finish coat of compound. 4. Second sanding and cleanup. 5. Residual exposure after completion of installation. SAMPLE COLLECTION AND FIBER COUNTING PROCEDURES The latest draft of the NIOSH sample collection and counting procedure, P and CAM #239, dated March 30, 1977, was used as the general basis for this test. Samples were collected on Millipore filters of 0.8y porosity using M.S.A. pumps precalibrated at 2 liters per minute.. The counting procedure specified in this draft differs significantly from earlier editions in that: 1. Substantial changes have been made in the selection rule covering which fibers encountered by the reticle are to be included in the count. This largely eliminates systematic bias due to fiber size distribution. 2. The total coefficient of variation is expressed as a function of the total number of fibers counted instead of a single value applicable to all situations. A minimum total count of ten fibers is also required. These are clearly substantial improvements but the method still has some serious shortcomings particularly when applied to situations where airborne fiber concentrations are low and/or where non-asbestos particulate material is present.OJ Both of these situations exist in the present study and certain refinements in the procedure have been necessary in order to present the results in the most understandable and meaningful fashion. It should be emphasized that these are additions to the procedure and are not in conflict with it. The legal basis for refinements to be described is found in the following quotation from P & CAM 239: "3. Interferences In an atmosphere known to contain asbestos, all particulates with a length to diameter ratio of 3 to 1 or greater, and a length greater than 5y should, in the absence of other information, be considered as asbestos fibers and counted as such." (Emphasis added.) See for example, "A Report on the Fiber Content of Eighty Industrial Talc Samples Obtained From, and Using the Procedures of, the Occupational Safety and Health Administration. NBS, May 1977." This report is one of the principle reasons for an international confernece on the problem sponsored by NBS and scheduled for duly 18-20, 1977. -3- The approach here emphasizes the development and use of "other infor mation" to obtain the most intelligent assessment of what is seen through the microscope. In this connection it is important to realize that optical fiber counting is not an exact science but an art. It requires a unique blend of tal ent, training, and concentration. An experienced counter develops both an "eye" and a counting rhythm, which permit him to recognize "fibers," decide which fibers are of the appropriate type and dimensions to be counted, and to move rapidly from field-to-field so the counts do not take an inordinate amount of time. The objective is to provide the experienced operator with a set of ground rules to judge between the various types of fiber and put them in certain classes. Under phase-contrast illumination, chrysotile asbestos has some very distinctive characteristics. It is typically dark appearing, composed of random sized bundles and flexible hair-like threads with curvature. When chrysotile fibers are short, however, i.e., 5-10y, they often appear as perfectly straight, dark rod-like particles. Fibers of amphibole asbestos are usually larger in diameter than chrysotile and more rigid and rod-like in appearance. They can, however, break down into very fine needle'-like material. With the exception of crocidolite, _ the amphiboles also can contain prismatic crystals which usually have the ' appearance of chips. The amphiboles normally refract light differently than chrysotile under phase contrast and appear brighter. As particle size decreases, however, light refraction and contrast are diminished and the particle will appear darker and less definitive. At this size it cannot be distinguished from chrysotile fibers of similar dimensions. In addition to the three kinds of "fiber" just described, i.e., _ chrysotile, amphibole fibers and chips and material that looks like the amphi boles, particles are frequently encountered that meet the NIOSH fiber defin ition of L/D _>3, L >5y, but are obviously not asbestos in any form. These include such things as fiberglass "poles," some clay and mica particles, organic fibers, and linear agglomerates of nonfibrous material. On the basis of the optical characteristics discussed tempered with broad operator experience with a wide variety of known particulate materials, fiber counts at this laboratory are made and reported in the categories de scribed below. Material which i^ obviously not asbestos is_ not counted even though it meets the L/D >3, L >5y criteria. 1. Chrysotile asbestos - Any fiber having an L/D >3 and a length >5y that is, in the operator's judgment, chrysotile. In the event of doubt, any fiber having the proper dimensions and dark appearance wil1 be included as chrysotile. On this basis, the short, dark amphibole fibers, where present, would be reported as chrysotile. 2. Possible amphibole - Any fiber of the appropriate dimensions that is not judged to be chrysotile and is not obviously material other than asbestos. This would include all amphi boles and materials similar in appearance. In this approach, all doubts are resolved in favor of including particles as chrysotile or amphibole so it is biased to give a high count for all possible "asbestos" particles without masking results by including -4- Darticulate that is neither asbestos nor fibrous. It is backed by counter experience gained in approximately 250 on-site sample collections and the counting of over 1500 filters. A photo library and a reference sample collection of a wide variety of known materials which contain amphibole or amphibole-1 ike materials are maintained. It falls within the other infor mation" allowed in the NIOSH procedure. ' ; The other counting problem encountered relates to the very low air borne asbestos concentrations found in most of the samples. The NIOSH procedure sets an optimum fiber density on the filter of 50 to 100 fibers per 100 viewing fields and states a minimum density of 10 fibers/100 fields. Within these limi the method is claimed to be applicable t o a concentration range of 0.1 to 60 fibers/cc with a total coefficient of variation of 0.24 - u.db. The validity of these claims, particularly with regard to accuracy, is a subject of considerable controversy at this time. The discussion o is question is well beyond the scope of this study. For the present work sample times were adjusted, within the limits set by the nature of the operation, to S s i t theprop" density of fiber on the filter. Where this was not possible, additional fields were counted in increments of 100 fields, u n M th| nf 10 fibers was achieved or a minimum of 500 fields were countea. rLults f?r chrysotile and possible amphibole are reported at values rounded to the nearest significant figure. Fibers/100 fields and the total number of fields counted arl also shown in all cases to provide more complete information. PRESENTATION AND DISCUSSION OF RESULTS^ ' A detailed listing of all samples taken 1nc!"dy ? ?!rtisn tested collection time, and counting results is provided in Table I. In this section theseairborne fiber counts will be related to the corresponding drywall Installation s t r The ceiling and eight-hour, time-weighted average exposures for the consumers involved are described. romnletion of studding. Hanging Drywall, and Start of Taping (8/3/77, 8/4/77,,. 8/5/77) ~ ~ Fiqures 1(b)(c) and 2 show various stages in the hanging of the 19 sheets of oypsum board. Seven of the 19 sheets used -m the ceiling and four If the sheets used in the walls required cutting and trimm,ns in 7 "9 amnimtc tn achieve proper fit. Figires 3(a), (b), and [c) continue une juu through the application of the tape and the second coat of compound over both the tape and the nail heads. ' Area air samples were collected on 8/3/77 in the living room (see &K i & M op'ratars* urng t L ftartif t h e t a p i n g A n area and a personal sample were collected in the lelar on the tallowing day (8/4/77) while a single operator completed the first installation of compound. Ho samples were taken on 8/5/7/ when tne second coat of compound was applied. The fiber count results are summarized in Table I and include samples ,, 7, N ro R o l o n -53, and N-70. The upstairs area sample showed a N-73, N-52, ' nrior to the use of the compound. The highest 0 % c c for Operator II during taping. -5- Both operators were in the area about 11-1/2 hours on 8/3/77 but timeweighted average (TWA) exposures have been based on 8 hours (480 minutes) in accordance with NIOSH procedures as follows: Operator #1 WA = (6071(0.08) + (87)(0.28) = 015 f / a ; Operator #2 TWA = C607)(0.08) +' (84)(0-1081 = 0.12 f/cc The completion of the initial taping on 8/4/77 took Operator #2 a little over four hours. At that point he left the house. Both the personal and area samples during this step were 0.02 f/cc so that his actua_ exposure would be: TWA = ^ 480 = 0.01 f/cc If he had elected to remain the rest of the day in the work area in the cellar, his TWA would not have exceeded 0.02 f/cc. No samples were taken while the second coat of compound was applied on 8/5/77. The completed job is shown in Figure 3(d). Note that the joints are covered with compound for a width of a foot or more. First Sanding, Cleanup, and Application of Finish Coat of Compound, 8/6/77 After the second coat of compound was dry, the joints and the covered nail heads were hand sanded smooth using 150 grit paper mounted on a sanding block. This operation is shown in Figure 4(a), (b), and(c). After comp!etion of sanding, the dust on the floor was swept into piles with a broom and transferre with a dust pan to a bag and deposited with the trash The sweeping is shown " Figure 4(d). A finish coat of compound was then applied to all joints and n heads. Personal samples were collected in the breathing zone of both operators during the sanding and subsequent cleanup. Separate area ere als obtained during sanding and during cleanup. Area samples were obtained in both rooms (cellar and first floor living room) for the remainder of the day during the installation of the finishing coat of compound. Relevant samples here are N-76, N-89, B-14, N-94, B-18, N~75' B-30 B--31 and B-10 (Table I). Personal exposures during sanding ranged from 0 5 to 0 9 f/ic and were 0.7 and 1.3 f/cc for operators 2 and 3, respectively, durinq cleanup The cellar area samples showed 0.2 f/cc during sanding, 0.7 f/cc during cleanup, and dropped to an average of 0.03_f/cc over the remainder of the day. The living room sample was 0.013 f/cc during the applicati the compound. Operator #2 was present in the house for about 5-1/2 hours. On this basis his actual 8-hour TWA exposure would be: (441(0.9l + (28)(0.52) + (12)(1.3) + (237)(0.033j _ n _162 f/cc TWA = J o --- 1 48Cf -6- If it is assumed he remained in the cellar at an exposure of 0.033 f/cc for the remainder of the day, the TWA would be 0.172 while the remainder of the day in the living room at 0.013 f/cc would yield 0.166 f/cc. It is realistic to round all these values to 0.2 f/cc. In this same sequence, Operator #3 had 415 minutes accounted for and was largely in the upstairs area or out of the house for the 65 minutes needed to complete 8 hours. Using the 0.013 f/cc level found for the living room, a TWA of 0.19 f/cc results (round to 0.2 f/cc). Second (Final) Sanding and Cleanup (8/10/77) After the finish coat of compound was completely dry, it was sanded in the same manner as just described. This operation is shown in Figure 5 and the corresponding cleanup is shown in Figure 6. The large amount of dust generated is clearly evident. This cleanup differs from the previous one in that after the dust had been swept into piles, it was taken up with a shop vacuum cleaner instead of a dust pan. The 17 samples relevant to this operation are too numerous to list individually but appear in Table I [SECOND SANDING AND CLEANUP (8/10/77)]. Personal samples during sanding ranged from 0.2 to 0.9 f/cc and a level of 1.2 f/cc was found during cleanup. This latter value is not significantly different from the 1.3 f/cc found in the previous cleanup. The area samples in the cellar ranged from 0.1 to 0.5 f/cc during sanding and cleanup and dropped to an average of 0.04 f/cc for -he remainder o the day. The living room showed a level of 0.02 f/cc throughout the entire day. Operator #2 was present for about two hours during this operation. On this basis, his actual 8-hour TWA exposure would be 0.16 f/cc. If it is assumed he remained in the cellar or in the living room for the remainder of the day, his TWA's would be 0.19 and 0.17 f/cc, respectively. These all round off to 0.2 f/cc. Operator #3 had 382 minutes of personal sampling accounted for and was in the general area of the living room for the remainder of the 8 hours. A TWA of 0.17 (round to 0.2) results. Residual Exposure After Completion of Installation (8/11/77) On the day following the completion of the drywall installation, the first floor rooms adjacent to the cellar entrance were cleaned with a household vacuum cleaner. A personal sample was obtained on the operator during the cleaning and area samples were taken for the remainder of the day in the living room, kitchen, stairwell to the cellar, and in the completed recreation room. The results are listed in Table I as samples A-72, A-76, Z-4, A-70, and P-56. The results ranged from 0.001 to 0.006 f/cc and averaged 0.003 f/cc. Within the limitations of the method, this is not different from Jhe value of 0 004 f/cc -Cor sample N-73. It is also in the range of the general background exposure and the household is not beina subjected t o c o n t i ^ exOS^ to asbestos as a result of this consumer drywall installation. -7- Summary of Results During Drywall Installation The ceiling and eight-hour TWA values so far described for the operators during the various steps in the installation are summarized below. The correspond ing TWA values for the cellar and the living room are also shown. Personal Operator #1 Operator (2 Operator #3 Area Cellar (Work Area) Living Room 8/3/77 Completion of Studding. Hanging Drywal Start Tapinq Celling*1) TWA*1) 8/4/77 Completion of Tap Installation Ceiling TWA 0.3 0.2 0.1 O.l 0.02 0.01-0.02 - - - - 0.08 - 0.02 - 0.004 * - - 8/5/77 Second Coat of Compound 3OC tn .P3 -1 P* 79C 8/6/77 8/10/77 First Sanding, Cleanup Finish Coat of Compound Ceiling TWA Sanding of Finish Coat Cleanup Ceiling TWA 1.3 0.2 0.7 0.2 0.9 0.2 1.2 0.2 0.1 0.1 - 0.01 * 0.02 8/11/77 House Cleanup After Installation Ceiling TWA 0.004 0.004 - 0.004 - 0.006 (1) All results expressed as fibers/cc >5p. The highest ceiling exposure for any of the operators was 1.3 f/cc which occurred during cleanup. For the three days when asbestos-containing dust generating operations were in progress, the TWA's for the operators involved ranged from 0.1 to 0.2 f/cc and averaged 0.2 f/cc. The sanding and cleanup operations with two people working took 2-3 hours The area TWA's in the cellar where the work was being done ranged from 0.08 to 0.1 f/cc during operations but was measured at 0.004 f/cc for the day after the installation was completed. The living room showed the highest value of only 0.02 f/cc during sanding but recorded only 0.004 f/cc before and 0.006 f/cc after the project. It is clear that there was no significant contamination of the rest of the house during the operation nor any residual contamination after it was completed. CONCLUSIONS The data, as obtained and reported herein, support the following conclusions: . 1. Consumer installation of full-room drywall panelling with tapejoint compound containing approximately 2.5% asbestos (dry weight) gives asbestos exposures substantially less than both the present 0SHA standard of 10 f/cc ceiling and 2 f/cc for an' eight-hour, time-weighted average and the proposed standard of 5 f/cc ceiling and 0.5 fibers TWA. These standards are designed to protect the v/orker for daily exposure for an entire working lifetime. 2. Household exposures after the installation were substantially below 0.01 f/cc and had not been changed appreciably by the present activities. It is questionable whether this is different from natural background. -8SAMPLE LOCATIONS - PRIOR TO DRYWALL INSTALLATION 1 (a) First Floor Living Room - Monitor Located over Fireplace mantle 1 (b) Cellar Recreation Room with with studding in place. South and East walls 1 (c) Cellar Recreation Room with studding in place. North and East walls FIGURE 1 INSTALLATION OF DRYWALL PANELING 2 (c) Westwall and ceiling 2 (d) East wall and ceiling FIGURE 2 APPLICATION OF TAPE & JOINT COMPOUND 3 (a) Covering nail holes with tape ioint compound 3 (b) Applying tape & joint compound between drywall seams 3 (c) Applying tape & joint compound to ceiling drywall 3 (d) After taping and second appli cation of tape joint compound FIGURE 3 FIRST HAND-SANDING OF TAPE-JOINT COMPOUND 4 (a) Sanding wall tape-joints 4 (b) Sanding ceiling tape-joints 4 (c) Dust accumulation after initial sanding 4 (d) Sweeping after first sanding. FIGURE 4 12 SANDING OF FINISH COAT 5 (a) Sanding ceiling joints 5 (b) Sanding wall and ceiling joints 5 (c) Sanding wall joints FIGURE 5 CLEANUP AFTER FINAL SANDINGS 6 (a) Dust accumulation after final sanding 6.(bl Sweeping after final ' sanding 6 (c) Vacuuming after initial sweeping with broom FIGURE 6 TALEJ. or SUMMARY AIRBORNE fi li!R '.INCENTRAI IOUS " .....CONSUiii.K..OJIYWAI L_ IHSJW.IAT.!OH COMPIEI ION OF STUnOIfia - H A M [fit; DRYUALL - STAR F OF TAPING (3/3/77) Sample No. N-73 Date 8/3/77 N-52 8/3 B-3 8/3 J-2 8/3 On 8:30A 8:20A 7:4 3P 7:46P Air Sample______ 6:3QP 600 6:27P 607 9:1 OP 87 9:10P 84 Area-Before handling compound, located in Jivin'- room 1st floor ~6' above floor on nwntel of fireplace. Area-Refore handling of asbestos, located in construction area ~6' above floor on north wall ** center of room. Persona! (Operator #1) Taping joints with ready mix. Personal (Operator H Z ) with ready mix. Taping joints No. of Fields Counted 500 No. of Fil ter Sections Used 5 100 i 100 i . 100 1 COMPLETION OF INSTALLATION ANO COVERING OF TAPE (8/4/77) N-53 8/4 9:3GA 1 :48P 252 Personal (Operator H Z ) Taping joints 200 2 w 'th ready n.iix. N-70 8/4 9:3SA 1: 4BP 253 Area - During taping. Located -6' 200 1 above floor area near center of north celldr wall. AP P U C A T I O H OF SECOND COAT OFJ^0t^UN0_jA/5/2Zjt ---- - No air samples taken. ---- FIRST SANDIN'! CLEANUP AND APPLICATION OF r m r s n c o a t o f COMPOUND (8/0/77) N-76 8/6 10:00A 10:44A 44 Personal (Operator H Z ) . Hand sanding. 100 Tape joint compound. N-89 8/6 11:00A < CSOJ 28 Personal (Operator H ? ). Hand sanding. 100 Tape joint compound B-14 8/6 1 1 :58A 12:10P 12 Personal (Operator H Z ) . Sweep up after 100 first sanding. N-94 ' 8/8 10:01A 10:97a 46 Personal (Operator 03). Hand sanding. 100 Tope joiit compound. 8-18 8/6 IO:55A 1 1 :29A 34 1 Personal (Operator #3), Hand sanding. 100 Tape .join>t compound. N-7S 8/6 1 1 :57A 12:11A 14 Personal (Operator i'3). Sweeping up 100 after first sanding. N-71 8/6 9:59A 1 1 :23P 84 Area. Doming first sanding of tape 100 joint compound. Located W ) 1 above floor . near center of north wall (cellar). 8-30 0/6 1 1 :57A 12:12P 15 Area - During sweep up after first sanding 100 Located -- 6' above floor near center of north wnl 1 cellar. 8-31 8/6 12:39P 4 :46P 237 Area. After sanding and sweep up. During 100 final application of tape joint. Located near center of north wall (cellar). 8-10 8/6 12:23P 4:39P 256 Area. After sanding and sweep up. During 300 final application of tape joint compound. Located first floor upstairs. Living room on mantle, of fireplace. 1 ' 1 1 1 1 1 1 1 1 3 u- Chrysotilc Fibers/lOU Fields 3 ,1 !T 3 V1 is ;o Airborne Fiber Concentrations Eiber/cc ,5U Amphibole Fibe rs /i O Field:s M b e r / c c >5, 0.004 0 0 63.5 0.08 0 0 25.5 0.2 16 0.1 10.5 1 0.08 0.008 7.25 0.02 0 0 5.5 0.02 0 0 53 5 21.6 17.5 43 35 15 25-5 14,5 10 8.5 0.8 6.5 0.5 1 1.0 4.5 0.7 2.5 ' 0.7 * 5 0.7 " 0 0.2 0 0.7 0 0.03 1 0.01 2 0.1 0.02 0.3 0.04 0.1 0 0 0 0.003 0.003 TABl.r ! (CONTJJillOJ. SUMMAttY 01 A II'IW W I !!il M CONU.IilRAT IONS ..............i.eriVnMiK' i w ^ u iN :> i.\u A !to f(' * ' Sample No. B-17 N-36 P-60 fl-4 N-7 B-8 B-20 P-65 M-3 N- 10 A - 75 M-85 N-55 A- 74 N-6 A - 77 A - 71 Date C/10//7 8/10 8/10 8/10 8/10 8/10 8 / 1U 8/10 8/10 8/10 8/10' Air Sai:m! e ""On Of" 9:27A 10:01A 10:02A I0:?HA 10 :?9A 10:46A 10:4t!A 11 :09A 11:18A 1 ! :43A 0:7 5A 1O :OOA 10:01A 10:30A 10:31A U :12A 1 1 : 13A ! 1:43A 1 1 :52A ! ? :13P 12 :4/P 4 : 33P Minutes 34 76 17 21 25 35 29 41 30 21 226 8/10 8/10 8/1 O' 8/10 8/10 8/10 9:24 A 1 7 : 18P 174 9:2/A 10: 15A 48 10: 17A 11 :44A 8/ 11:67A i?:14P 22 1?:19P 12:17P 5:6QP 339 5 :59P 342 Description of Operation______ Personal - Operator ff.?. Sandinq TJC Personal - Operator #?.. Sanding Personal - Operator !!?.. Sanding (ceiling). Personal - Operator H 2 . Sanding (cci 1 ing). rersondl - Operator i?. Sanding (coiling). Personal - Operator #3. Sanding Personal - Operator -;3. Sandinq Personal - Operator O . Sanding Personal - Operator #3. Sanding Personal - Operator <'3. During sweep up and vacuuming alter sanding. Personal - Operator if3. After final sanding and cleanup. Performing normal household duties including laundering of work clothes used during taping and sanding. ' Area. During second sanding and cleanup, located first floor living room ^ 6 * above floor on mantle of fireplace. Area. During second sanding of TJC. Located <-6' above fleer near center of north wa l 1 cellar. Area. Durino second sanding of TJC. Located ^6' above floor near center of north wall cellar. 'Are.i. During swoop up and vacuuming after sanding. Located ^6' above floor on north wall. Area. After final sanding and cleanup. Located first floor 1ivino room -/6` above floor on mantel of fireplace. Area. After final sanding and cleanup. Located ~ 6* above floor in north wall of cellar. Fields Counted 100 100 100 100 100 200 200 100 100 100 100 300 200 100 100 100 100 No. of Filter Sect ions Used i 1 1 1 1 1 1 1 1 ' 1 i 3 2 1 1 i 1 KLS iOtjAL EXPOSbP^ AFTER .COWM _FTJO_N Of INS1 ALLAT lON _(8/1 1/1.0. 4 A-72 8/11/77 0:53A 9:10A 17 PfeirrssotnaMlo o(rOpelriavfionqr r//o3o)m., Vkaictucuhmeinng and 500 den after final sanding and cleanup. A - 76 0/11 9 : 12A 5: OOP 468 Area. Day followinn completion of ' 500 3 work in basement.. Located in kitchen area ^ G* above floor. Z-4 8/11 9 : 1 3A 5: OOP 467 Area. Day followinn completion of work 5C0 4 in basement, located on mantle of fire place -6' above floor. A - 70 8/11 8:45P 5:01P 496 Area. Day followinn completion of work 500 3 in basement, located in stairway of cellar W above cellar floor. P-66 3:42P 6 :Q1 P Aro.i, Day followinn completion of work 500 4 in basement. Located on north wall of Airborne Fiber Concentrations Chr/sotile Possible Amphibole FilTers/TOO f ic-Tds Fiber/cc >5. r i b c r s / I O O T T c T J s M b e r / c c >b. 22.5 0.5 2 0.04 13.5 0.4 0 0 23 0.9 1 0.04 20.5 0.7 0 0 22.5 0.6 0 0 8 0.2 0 0 8.75 0.2 0.5 0.01 20 0.3 0 0 23 0.5 0 0 ' 35-5 . 1.2 0.5 0.02 17 0.05 0 0 h 9.75 29 15.5 10.5 18 0.02 0 .1 0.2 0.5 0.02 0.04 0 0 0.5 0.007 2 . 0.02 0 0 0 0 0 0 0.1 0.004 0 0.001 3.7 0.006 0 1.0 0.001 0 2.6 0.004 ' 0 0 0 . 0 0