Document peNwKwNR2LbepGyeRgG01XnoE

MATERIALS ANALYTICAL ft/:/. SERVICES m ANALYSIS OF ZONOLITE ATTIC INSULATION Submitted to: J. Conard Metcalf Williams & Trine September 10, 1993 By: Sean Fitzgerald William E. Longo, Ph.D. Raleigh Office: 2418 Blue Ridge Road Suite 105 Raleigh, North Carolina 27607 (919) 881-7708 FAX (919) 881-8227 Atlanta Office: 3597 Parkway Lane Suite 250 Norcross, Georgia 30092 (404) 448-3200 FAX (404) 368-8256 MICROANALYSIS PROJECT REPORT MATERIALS 4% ANALYTICAL SERVICES # CLIENT: J. Conard Metcalf INSTITUTION: Williams & Trine, P.C. PROJECT: Zonolite Product Analysis MAS NO.: M7099-1 DATE: July 26, 1993 PREPARATION BY: Sean Fitzgerald ANALYSIS BY: Sean Fitzgerald P.O. NUMBER: N/A SUMMARY: The objective of this study was to determine the presence or absence of tremolite/actinolite asbestos in Zonolite Attic Insulation that was manufactured by W.R. Grace. DESCRIPTION: In August of 1991, Materials Analytical Services, Inc. (MAS) received one 12 pound bag labeled "Zonolite Attic Insulation, All Mineral Vermiculite", as a known reference material. In July of 1993, the Zonolite Attic Insulation was retrieved from the MAS archive storage room and analyzed by optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). PREPARATION AND ANALYSIS: After removing a random sample of the vermiculite for testing, the zonolite bag was photographed front and back as shown in figures 1 and 2. The Zonolite bag was essentially received in our laboratory in an unopened condition, but due to the deterioration of the plastic over time, the Zonolite bag fell apart during handling for the photography and had to be re-constructed. The remaining loose vermiculite material (figure 3), was placed in a large plastic specimen bag for storage. The removed sub-sample of vermiculite was inspected with an Olympus SZ Zoom Stereo Microscope at magnifications from 7X to 40X, as shown in figures 4 and 5. In one of the vermiculite pellets, a fibrous grayish mineral was observed associated with the vermiculite material as shown by the arrows in both figures 4 and 5. Samples of the vermiculite material were then prepared for both SEM and TEM. The SEM preparation was performed by placing one of the vermiculite pellets containing the associated fibrous mineral onto a SEM stub with double-sided carbon tape and carbon paint. The sample was then carbon-coated in a Hitachi Vacuum Evaporator. The SEM analysis was performed using a Hitachi S-800 Field Emission SEM with a Tracor Northern EDXA system. The SEM photomicrographs shown in figures 6 through 11 further show the fibrous mineral intergrowth in between the vermiculite leaves for that particuler sample. The EDXA spectra of the fibrous mineral was consistent with tremolite-actinolite (see figures 12 and 13). Raleigh Office: 2418 Blue Ridge Road Suite 105 Raleigh, North Carolina 27607 (919) 881-7708 FAX (919) 881-8227 Atlanta Office: 3597 Parkway Lane Suite 250 Norcross, Georgia 30092 (404)448-3200 FAX (404)368-8256 J. Conard Metcalf Page 2 ****** a.TM , MATERIALS ANALYTICAL SERVICES m The TEM preparation of the vermiculite sample was performed by suspending between 10 - 30 mg of the fine vermiculite dust fraction in reagent alcohol that was then filtered onto a 0.2 jum polycarbonate (PC) filter. The filter was dried, carbon coated, and a section of the filter was placed on a 200 mesh TEM grid. The PC filter material was dissolved in a chloroform Jaffe washer and the final TEM prep was examined in a JEOL 1200 EX II TEM. The TEM photomicrographs in figures 14 and 16 show that the tremolite-actinolite structures found had an aspect ratio greater than 3:1, and therefore can be classified as an asbestiform structure as specified by current Federal regulations. A Tracor Northern system was used to obtain EDXA spectra, as shown in figure 18, and a selected area electron diffraction (SAED) pattern was recorded as shown in figure 17. The EDXA and SAED information was used to positively identify the fibrous mineral found in the vermiculite samples as asbestiform tremolite-actinolite. DISCUSSION AND CONCLUSION It is well known that in some areas of the country where vermiculite where vermiculite deposits are found, asbestiform tremolite-actinolite can also be found as an associated mineral. However, there has been some suggestion that during the processing of the vermiculite ore at the manufacturing plant, the asbestiform tremolite-actinolite is somehow removed and the final vermiculite product that is then sold to the consumer, is tremolite-actinolite free. This study was designed to test that theory by taking a known sample of a processed vermiculite product (Zonolite Attic Insulation as manufactured by W.R. Grace), and determine if it contained asbestiform tremolite-actinolite. Our analysis showed that there was tremolite-actinolite found in with the vermiculite in the Zonolite Attic Insulation product (figures 5 through 11). The tremolite-actinolite was found both associated with vermiculite and as free respirable fibers in the fine dust as shown in figures 14 through 16. It is therefore our conclusion that the tremolite-actinolite does remain associated with the vermiculite after the ore is fully processed and can be found with the finished product, as demonstrated with the W.R. Grace Zonolite Attic Insulation. FIGURE 1 FIGURE 2 FIGURE 4 FIGURE 16 FIGURE 17 FIGURE 6 FIGURE 7 FIGURE 10 FIGURE 11 FIGURE 1 r* FIGURE 2 ,1. FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 10 FIGURE 11 FIGURE 14 FIGURE 15 FIGURE 16 FIGURE 17