Document 6w2Or2v0wgK08xpORLNXBDDjd

i ue i4a.s INTERNAL CORRESPONDENCE zr <f, r MINING AND METALS DIVISION ToiNa*)Dr. H. B. Rhodes Division Mining & Metals Div. location Niagara Falls, NY P. 0. SOX 579, NIAGARA FALLS. NEW YORK 14302 Dot. July 16, 1974 originating Dopt. "Calidria" Asbestos PLAINTIFFS EXHIBIT UC-238 Aiwworiitg latter dot* coprto e. j. Kleber File Gloria Faulring J. L. Mversv*' W. C. Thurber P. McDaniel Subject Fiber Loss on Mi Hi pore Filters Due To Handling As you know, we have heard from time to time conflicting stories on the Mi Hi pore filter's ability to retain fibers after handling, recent trip to King City appeared to be a good opportunity to check loss due to handling since the filters were to be read at King City and then returned to Niagara. One group was sent back via UPS, one via Parcel Post and the remainder was carrier back in the case that is normally used to transport the personal sampling pumps and filter cartridges. In all cases, the only handling they had prior to shipment was the normal cutting of a wedge for microscopic examination. The remaining portion of the filter was immediately replaced in the cartridge. Another wedge was cut out and examined upon their arrival at Niagara. The results of these fiber counts are as follows: Sample No. F-7 E-l F-13 E-17 Fiber Count Performed At King City (fibers/cc 5 ) 3.2 3.3 4.3 0.1 Method Of Transportation Hand-Carried II II II II II II Fiber Count Performed At Niagara (fibers/cc 5 ) 2.7 3.2 4.3 0.2 Gain or Fibers/ci -0.5 -0.1 0 +0.1 E-23 E-18 F-7 4.9 2.7 3.2 UPS 4.8 -0.1 II 2.6 II 2.9 -0.3 o 1 E-4 F-l E-6 E-16 1.7 4.2 7.9 6.5 Parcel Post II II II 1.8 3.7 7.1 6.9 +0.1 -0.5 -0.8 +0.4 k/ ( 'l Lr O U o O "7 / *7 / -2- 7-16-74 Although the losses outnumber the gains,,, it doesn't appear to be a definite trend. Gloria Faulring reported significant losses when sample cartridges were "rolled" down a hallway. I can't help wondering whether her samples were handled more than mine and if so, does more handling tend to reduce the electro-static charge on the filter, causing fibers to fall off easier. If you wish to pursue this any further., please let me know. EJK/ml v hw,.O(>On --/ c-