Document 5LxY6pgq37NVbZmJ2qpED0bM0

FILE NAME: Foseco (FOS) DATE: 1974 Sept 26 DOC#: FOS038 DOCUMENT DESCRIPTION: Unpublished Inspection Report - .** _ TH O M A S A, B O Z iC H 40 3 GATLIN R O A D CLEVELAND. OHIO 4 4143 6c A S S O C . bUiirifiltNIIAL 216*602-1674 IC.WRU) 2W*30Qr2906 Mr, li&tfjtt.'/ September 26, 19IX Hr, David B. Woodbury Foseco Incorporated 20200 Sheldon Road Brook Park, Ohio 44142 Dear Mr. Woodbury: RECEIVED OCT 4- 197-1 PERSONNEL The following is a report of an industrial hygiene survey performed at your Me. Braddock Plant on August 2?, 1974. You were present during the survey, along with Hr. G, D. Brandt and Mr. T. Whalen. t. PURPOSE ADD SCOPE; The purpose of this survey was to measure the prevailing concentra tions of airborne asbestos and silica dust at selected plant loca tions where asbestos or silica materials were being handled. Tire results were reviewed in order to determine if the concentrations were below the OSHA standard, and if not, to determine the location, and extent of any problem. Previous studies by your insurance carrier suggested that a high silica dust concentration bad been measured at one of two locations, while no measurable concentrations of asbestos fibers could be found in three locations sampled. Vi Operations selected for sampling during this survey were those be lieved to have the greatest potential for asbestos or silica dust generation at this time, and in most cases do not necessarily coin cide with those of the insurance carrier. For some operations, only observations and/or ventilation measurements were made due to the fact they were not operating at the time or because of time limita tions. Some discussion and recommendations regarding control mea sures are also included. II. FINDINGS: The raw materials of primary concern for this evaluation are omosite asbestos (RM 265A), chrysotile asbestos (XM 319, 319A), silica flour {RM 131B), silica sand {RM 3182, 3183, OOF, O O E ) , amorphous silica (RM 3553) and diatomsceous earth (KM 544). At the time of the sur vey, little or no wollastonite was being used. The asbestos counts noted in this report exclude any fiber glass and possible Wollas ton!te found on the filters used to collect the air samples. i Battery operated personal air samplers were used in accordance with OSHA methods to collect breathing zone (B.Z.) samples. The asbestos samples were examined microscopically under phase contrast illumina tion. The silica dust samples were analyzed gravimetrically and subsequently for free crystalline silica. The free crystalline allies Fas-00-0000000sa7 EXHIBIT : "b f) 1 , p- i ?3>;$73oflCL_| Mr. David B. Woodbury 2 974 II. FINDINGS: Ccont'd) analysis results are used to calculate 6lllca dust Threshold Limit Value* (TLV'e) for each respective silica dust sample. Attached Is a summary of the sampling performed and the results of the analysis. . At the Pre-Mix Operation, two operators work together. Approxi mately 7 mixes or cycles are accomplished each day. During the survey, one complete cycle of 49 minutes was evaluated. For the first 8 minutes of the cycle, silica flour and dlatomaceous earth, among other materials, were loaded at a downdraft grill hopper which feeds to the mixer elevator. For the next 13 minutes, amoslte and fiber glass were loaded into the hammermill hopper (downdraft) which conveys the materiel to the mixer. Previously chrysotlle was also used in the mix. A dust separator which is located next to the mixer removes the dust from the exhaust system. For the next 8 min utes, water was a'dded to the batch and the mixer turned on, materials were weighed for the next batch and the dust collector chute was hammered to shake down the dust. A wall fan was operating near the collector chute. For the last 20 minutes,, the product containers were loaded and weighed. Both loading hoppers have a face velocity of approximately 400 fom. On this basis, the hammermill hopper air flow would be approximately 1600 cfm. while that for the mixer grill hopper would be approxi mately 2300 cfm. While the face velocity for both hoppers is quite good, the height of the hammermill hopper places It directly in the B.Z., resulting In some probable operator exposure. A personal' sampler was worn by each operator during the one cycle of the PreMix Operation. One was used to collect an asbestos sample, the Other, the silica dust sample. Results of these two samples (No. 1 and A) are shown on the attached summary. The OSHA TLV for free silica containing dust is calculated from a formula and varies with the various forms and types of silica con tained in a sample. The TLV varies inversely with the free silica content. The free crystalline silica analysis of sample A revealed it contained 23.27. quartz, le6s than 0.5% of tridymlte and 0.8% of cristoballte. Based upon this analysis, the calculated TLV for sample A is 1.2 rng/ra^. The "upper limit" for the TLV for dust con taining less than 1% free crystalline silica is 10 mg/m . which is also the American Conference of Governmental Industrial Hygienists nuisance dust TLV. The current OSHA nuisance dust level Is 15 mg Am*, but 10 mg/nr Is the more commonly accepted value. The current OSHA permissible 8-hour time-weighted overage concentra tion for asbestos fibers Is 5 flbers/ml of air. Only fibers longer than 5 microns are to be counted. The celling concentration is 10 flbers/ml of air. On July 1, 1976, the 8-hour time-weighted overage concentration will be reduced to 2 flbers/ml of air. The ceiling limit will remain the same. T Mr. David B. Woodbury -3 - iff iiPU'i aun&* September 26, 1974 . FINDINGS: (cont'd) At the Sawing Operation, one operator cute flat board product. Two radial saws are provided with hooded exhaust enclosures. A band saw which la reportedly seldom used Is not provided with any exhaust ventilation. A considerable amount of residual dust was apparent In the general area on surfaces, etc. The operator cuts the boards with a radial saw for 4 to 6 hours per day, approximately once per week. The face velocity of each hood was determined to vary from spproximately 250 fpm near the top to 150 fpm near the bottom. Total air flow from each hood would be approximately 600 cfm. The hoods were exhausted outside of the building and were not, it Is believed, pro vided with any dust removal system. The hoods appeared to be effec tive in controlling dust produced by the radial saw. At the time of the survey, the operator simulated the normal sawing operation by cutting scrap pieces of board product with a radial saw. A personal sampler was used to collect two consecutive B.2. samples, one for asbestos, the second for. silica dust. Results are shown on the attached summary (samples Ho. 2 and B). Analysis of sample R for free crystalline silica revealed It contained 35.2Z quartz and less than 17. of crldymlte or cristobalite. Based upon, this analysis, the calculated TLV for sample B Is 0.8 mg/ro^. At the Pulping Platform, one operator loads two mixers, one for Kalmaoex and One for Profax. Only the Kalmanex mixer was being loaded at the time of the survey. The operator normally handles and measures the related materials and loads the mixers 8 hours per day. TWO types of asbestos, but no silica were being handled or.loaded. Ball-mill dust was poured into a loading container In a ventilated enclosure. The exhaust ventilation was provided by a drum-type ex hauster with a bag filter which exhausted to the room. Total air flow through the system wae measured and found to be approximately 80 cfm. Assuming an "average" face opening during pouring of approximately 2 ft , this would provide a face velocity Of approxi mately 40 fpm. It was not effective In controlling the duBt, The asbestos and other RM's were weighed in a canopy type hood with partial sides which was mounted against a wall. Total air flow was measured and found to be approximately 700 cfm. Because of the height of the hood, the effectiveness was poor. The capture velocity at the level of the scale was negligible. The cross-draft at the time wa6 100 to 150 fpm from the large open door. A personal sampler was used to collect a B.Z. sample while the operotor performed one complete cycle for the Kalmanex mixer, ex cept that four batches of material were weighed under the canopy hood. Since no silica-type RM'e were being handled, only one sample was collected for asbestos. Results are shown on the attached summary (sample Ho. 3). F D S -0 0 - 0 0 0 0 0 0 0 q q <3 I lTtl jury September 26, 1974 (cont'd) H e peretlon was reviewed but not sampled, as it was not . Two mixers ara provided with a cover to rduce the ,ixe and are exhausted by means q a drum-type exhauster jg filter. It did not appear to be operating properly blocked, etc.), as the total air flow was determined to approximately 5 cfm. This would provide a face velocity of an 1 fpm. Two types of amorphous silica and 157 of the site and possibly some chrysotlle are loaded. her operations noted, but not sampled,were the Oven Area, it Booth and the Sand Hold Operation. The product is sanded lly in the hood in question. It is exhausted by means of a type exhauster with a bag filter. Silica eand is used in the Mold area. If the silica dust concentration in the area is mined to be excessive, it would appear to only be a problem re it is handled initially, before it is dampened, --sjCLUS XOKS AND RECOMMENDATIONS Pre-Mix Operation: The prevailing B.Z. concentrations of 6.6 fibers/ml of asbestos sod 16.8-mar/nr Of silica dust are considered good approximations of their respective 8-hour time weighted average concentrations. While they sre both in excess of their TLV's, the silica dust is excessive to a much greater degree. In fact, it even exceeds the nuisance dust TLV (less than 17. free crystalline silica) of 10 mg/m3 . The dust exposures appear to be most significant during the ataosite handling and loading, during dust collector shake-down, during final product loading through open door of mixer, and when handling accumulated empty RH bags. In view of the above, the following is recommendeds a. The cutting and opening of the amosite bags should be performed under local exhaust ventilation conditions. If feasible, consideration should be given to cutting the bags on the downdraft grill hopper located next to the mixer. If too much material would be drawn through the grill, It could possibly be temporarily partially covered. The alternative would be to provide a separate exhaust enclosure for the operation, preferably in conjunction with the hammer mill hopper. A platform or other method is needed so the B.Z. would not be so close to the hopper opening. b. Either better dust control ventilation should be pro vided for the collector shake-down or a dust ask should be worn during that operation. The mixer door which ia left open should'be kept closed. If it is necessary for the operator to see through the opening, plastic sheet could be used to cover it. One of the i\x David 8. Woodbury -5 September 26, 1974 H I . CONCLUSIONS AND RECOMMENDATIONSi (cont'd) occurs when Che operator picks up and carries stacks of empty RM bags. Another procedure should be adopted, or a dust mask also worn for that operation. 2 Sawing Operation: * . The prevailing B.Z. concentrations of 56.2 fibers/ml of asbestos and 13.3 mg/nw of silica dust would not be considered 8-hour averages. Since the operation Is performed for 4 to 6 hours per day, the average concentration# could be 1/2 to 3/4 of that reported. The adjusted concentrations would still be well In excess of their TLV'S. The first sample collected for asbestos may be atypical, however, as some dust contamination from the operator's shirt pocket was suspected because of the filter holder position. It was repositioned for the second sample which was collected for silica dust. For this reason, it Ib felt the asbestos result should be discounted. The higher than expected result for the silica dust, however, is believed to be a result of the dust residual in the room, on cut product board surfaces, etc.; the hoods appeared to be quite effective In controlling the dust from the saw. Another possible factor could be recirculation of the exhausted dust back into the building or general area. It is recommended that the residual dust be reduced through use of a dust vacuum or other method and that the hood exhaust system be provided with a dust collector. 3. Pulping Platform: The prevailing B.Z. concentration of 13.3 fibers/ml of asbestos is considered an approximation of the 8 -hour overage when only the one mixer is loaded. If both were loaded, however, the 8-hour average would be expected to be somewhat lower. Most of the asbestos and other types of dust exposure appeared to be most significant during the pouring-of bailTiiIll dust into the loading container, when loading the mixer, and when weighing materials under the hood. In view of the above, the following is recommended: a. The hall-raill enclosure exhaust system should be checked to see if it is operating at capacity. A total s ir flow of at le a s t 200 cfm would be needed to be effective. b. Each mixer (tank) should be provided with exhaust ventilation so as to produce a face velocity at the tank opening of at least 100 fpm. This would require approximately 1400 cfm for each mixer. If the openings were reduced, the required air flow would, of course, be reduced proportionally. (Note: This approach Is similar to that depicted in the upper right of' the enclosed data sheet VS-304.) FOS-00--0000000Q9| Mr. David B. Woodbury -6- M ^ LP^iioWArUj, B9t'*tU- c. The weighing hood should be converted to conform to a lateral-exhaust type of hood with back draft ventilation with a face velocity of 100 fpm. 4. Other: a. To provide an effective face velocity (100 fpm) on the Moldcote mixers, approximately 400 cfnr would be needed for each mixer (with partial cover)* Sampling would be necessary to assess the asbestos and silica dust exposure levels. b. From a general standpoint, additional procedures should be considered to reduce the level of general floor and surface dust in the plant. Wherever asbestos or silica 'dust levels were found excessive, dust respirators should be provided and worn until measures are taken to reduce the concentrations and campling confirms they are at safe levels. Sin/'nrtlv urtitv att. Summary (2p) VS -304 Thomas A. Bozich Industrial Hygiene Consultant FQs-00-0000000aoe T