Document n9Zm61oG9JzzdVGg6BGvd8Zb1

INTERNAL CORRESPONDENCE------ PLAINTIFF'S EXHIBIT CHEMICALS AND PLASTICS ,v;s;on ofdiion Mr. A. A. Sousa Building 741-101 opy ,0 Mr. J. W. Biddle Dr. J. A. Durden P. C BOX 8361, SOUTH CHARLESTON, WEST VIRGINIA 25303 L\,.e November 17, 1977 .Gr.girst'nr, Depr XH/EP f .c-cc: PROJECT Measure dust and asbestos levels during preparation of synthetic soil in Building 741. DATE OF SURVEY September 15, 16, and October 25, 1977. SUMMARY AND CONCLUSIONS The OSHA Threshold Limit Value (TLV) for asbestos exposure is 2.0 fibers per cubic centimeter (f/cc) for an eight-hour time-weighted average (TWA) and five (5) f/cc for a 15-minute Ceiling Limit Value. The OSHA standard for nuisance dust is 15 milligrams per cubic meter for an eight-hour TWA. Both the levels of asbestos (0.004 - 0.007 f/cc) and total dust (0 - 2.4 mg/m3) found during the soil mixing operations were well below these standards. DATA AND RESULTS Asbestos Date Employee Air Cone. 9/15/77 O.N. Payne 0.23 f/cc 9/15/77 Area Sample 0.08 f/cc 9/16/77 Richard Black 0.28 f/cc 9/16/77 Area Sample 3 .19 f/cc TWA 0.004 f/cc -- 0.007 f/cc -- Operation Pouring Vermiculite Pouring Vermiculite Preparing soil Preparing soil UCC 024412 .Mr.--A. A. Sousa 4. 2 11/17/77 Nuisance Dust Date Employee 10/25/77 Area Sample 10/25/77 Area Sample 10/25/77 Area Sample Average AAiirr Cone. 0.8 mg/m^ 0.1 mg/m3 0.5 mg/ra^ TWA Operation Adding components Mixing Dumping DATA BY W. F. Blythe, Jr. Technical Center Industrial Hygiene Group DISCUSSION It was requested by Dr. J. A. Durden of Ag Chemicals that we evaluate employee exposure to asbestos through the handling of TerraLite Vermiculite Soil Conditioner in Building 741. The supplier, W. R. Grace and Company of Cambridge, Massachusettes, has indicated to us that this grade-two vermiculite contains small amounts of tremolite, which is included in the definition of asbestos in the Occupational Safety and Health Standards, Subpart Z - Toxic and Hazardous Substances, Sec. 1910.1001(d)(1)(ii) . In tests conducted by the W. R. Grace and Company, no asbestos was detected after they prepared soil using vermiculite. To determine our employee exposure, personal and area samples were taken in the Greenhouse during soil mixing operations. On September 15, 1977, Mr. 0. N. Payne was sampled while filling small boxes with vermiculite. On September 16, 1977, Mr. Richard Black was sampled for asbestos exposure while preparing soil in Building 741, Room 125. On the days noted above, the eighthour time-weighted averages were 0.004 f/cc and 0.007 f/cc. On October 25, 1977, air samples were taken to determine employee ex posure to the other components of the synthetic soil. Most of these components, tankage, super phosphate, calcium carbonate, gypsum, potassium nitrate, potassium sulfate, are considered nuisance dusts which have an OSHA Threshold Limit Value (TLV) of 15 mg/m3. The others, Tresan 75 and the 5-10-5 fertilizer contain materials which have lower TLV's. However, the concentration of these materials in the overall mixture is very small and the exposure time is less than 30 minutes while the standards are set for an eight-hour TWA. During the handling of these materials, the highest concentration in the air was 2.4 mg/m3, while the average concentration was 0.65 mg/m3. REFERENCES Union Carbide Corporation Asbestos Analytical Method 38C-29X4-R2B UCC 024413 .vMr. -A. A. Sousa 3 INSTRUMENTS USED MSA Model G Portable Pump Mi'llipore Filter Cassettes MAWP 037AO GCA Respirable Dust Monitor Model RDM-101 REPORT PREPARED BY W. F. Blythe, Jr. Technical Center Industrial Hygiene Group 11/17/77 WFBJr/sc UCC 024414