Document JJqzGYVGEG8oZkKR426Q9LkYB

GRACE TO FROM: R. Frohlich J. C. Yang CC: S. H. Ahern R. J. Bettacchl H. C. Duecker R. C. Walsh J. W. Wolter File 1182 DATE: February 10, 1984 SUBJECT: Air Cassette Samples from J. W. Wolter's Office Three air cassette samples collected In J. W. Wolter's office were sent to Arthur D. Little for transmission electron microscopic evaluation of the respirable asbestos fiber content. Dr. E. Peters' report is attached. The results indicated no evidence of any asbestos fibers. / JCY/ph Attachment 10002140 Cambridge, Massachusetts 02140 617 864-5770 Telex 921436 Ah \rthiir 1). Little, Inc. February 9, 1984 Dr. Julie Yang Manager, Research Technologies W.R. Grace & Company 62 Whittemore Avenue Cambridge, MA 02140 Dear Julie: In accordance with your letter of January 4, 1984, we have prepared and analysed the three submitted air cassette samples for the presence and concentration of asbestos by transmission electron microscopy. You also requested that we prepare fiber size distribution histograms. PROCEDURE AND RESULTS Evaluation samples were prepared in two ways: A. Jaffee wick - a portion of the sample was carbon coated after which small 2x2 mm pieces were incised and placed coated side down on 200 mesh electron microscope grids. The filter matter was removed by the Jaffee wick vapor solvent washing method, using acetone, B. Jaffee wick (NIOSH modified) - a 8 mm circle of the sample was taped to a glass slide with a gummed binder ring and briefly exposed to acetone vapors to collapse the membrane filter, producing a smooth, fused*surface. The samples were then carbon coated, incised from the binder rings and placed particle side down on carbon-coated 200 mesh grids. The filter matter was then removed by Jaffee wick washing with acetone. The prepared samples were individually analysed by transmission electron microscopy. Any particles that broadly met the characteristics of a fiber were sized and examined by selected area electron diffraction (SAED). About twenty random pore openings were examined for each sample. The results for the two sets of analysis were the same. Referring to the Group B samples, the following results were obtained: Brussels Houston London Los Angeles Madrid Paris Rio de Janeiro San Francisco Sao Paulo Tokyo Toronto Washington Wiesbaden 10002141 /^Arthur D. Little, Inc. February 9, 1984 2- - Dr. Julie Yang W.R. Grace & Company Sample Fibers Fiber Bundles No. Observed Average Size (pm) LD JW-1 JW-2 JVJ-3 6 1.4 0.20 6 1.3 0.12 5 1.1 0.15 4 7 2 Fiber bundles were actually clumps of material about 5 pm in extent from which numerous (50-100) fibers stuck out, somewhat like a thistle. For every case, the fibers exhibited low contrast and failed to produce a selected area diffraction pattern. It is felt that the fibers (both individual and those in bundles) are organic in origin, probably cellulosic. There was no evidence whatsoever for chrysotile or any other form of asbestos fibers. Please call me if you have any questions or require further information. Very truly yours. Edward T. Peters 10002142