Document DvQJZ6R7pgrOrGBVZNngVBxxQ

t u n 't w's-50 \ t -Yp.57.0S PLAINTIFF'S EXHIBIT ( \ l fei-aoa^a'.atrais^-nyx^isnosi DE 004942. t I ! INTERNAL CORRESPONDS "JCE uc t CHEM1CAL5 AND PLASTICS TO (NAME) C O MPANV UOCATlON COPY* ro See list. OATE " O BOX *> TEXAS C* TV TEXAS ' IW December 18, 1967 Subject Sandblasting Gentlemen J Recent industrial hygiene studies of sandblasting operations at two of our Gulf Coast plants caused great concern for the health of the operators. Dust counts were determined within the breathing zone inside the abrasiveblasting hoods. Further study of the respirator equipment was conducted to explain the high dust counts found. Silicosis is a disease characterized by nodular fibrosis of the tissue of the lungs. It is caused by breathing free-crystalline silica dust (SiO;>)--of which sand is almost 100%. The duration of exposure, size, composition and concentration of particles are factors related to the development of the disease. A properly installed, properly worn and properly maintained air-supplied abrasive-blasting hood will offer complete protection from silicosis for the operator. The following recommendations are designed to provide clean, respirable and comfortable air with no more than one million particles of silica dust per cubic foot of air m the 0 3 to 5 micron size. This matter should be given prompt consideration. If I can be of further help, please do not hesitate to contact me. Very truly yours, DED:bb Attachments D. E- Deese Industrial Hygienist Gulf Coast Area DE 004943 I o 1 I I I rI t I I I i DISTRIBUTION I 1 I 515 Mr. R P. Barry Mr. W C. Hill Mr. J W. Hunter Dr. R. E Joyner Mr. H Ritchie Mr. B. C. Wright 526 Mr. H. B. Coons Mr. R. E CoIrkrean Mr. E. G. Diets Mr. J. A Gannon . Dr. C. A. Roth I 519 Mr. H. E. Allspach Dr. T. S. Dunn. Jr. Mr. D. W. McClung Mr. A. M. Robinson Mr. R. E. Williams Mr. M. G. Collins (8). 510 Mr. R E. Peele, 512 Mr. N. H. Ketcham, 511 Mr. B. L. Murray, 514 Mr. Fred Williams, 511 i i l t i l I l I I \ [ I i i i I t i I i i DE 004944 I RECOMMENDATIONS FOR SANDBLASTING OPERATIONS l Respirators a. A supplied-air abrasjve-Dlastmg hood (Type CE) is essential respiratory protection for sandblast operators. Each operator should be assigned his own hood. b.' Only a U. S. Bureau of Mines approved hood should be used for sandblasting work. Any unit not marked "B. M. ", followed by the approval number, should not be accepted. (See the attached . list of hoods that are approved.) c. The neck drawstrings should be kept snug. If the operator becomes aware of sand penetration inside the hood, a Dustfoe respirator should be used additionally for the remainder of the 10b. Corrective measures should be taken immediately. d. A rack or other device from which to suspend hoods should be provided at the sandblasting shed. The purpose is to prevent contamination of hoods with sand from the ground or shelving. e. At the end of each day. hoods should be cleaned with a vacuum device so that all accumulated sand may be removed. Defective parts should be replaced then. At least once a week hoods should be cleaned with soap ar.d water. f. This type respirator is not to be used in atmospheres that are immediately dangerous to life or from which the wearer cannot escape without the aid of the' respirator. Air Hose ~ ~ a. Each hood requires a minimum air supply of 6 cu. ft, per minute to prevent dust from entering. b. It is a serious mistake to provide valves by which the wearer can adjust his air supply to less|than this minimum safe amount. The air supply should be engineered to deliver into the hood the correct amount of air as measured by a suitable air-flow metering device. The flow should then be checked periodically to see that the flow does not fall below this minimum. i i t i i i 1 DE 004945 i I i i l I 1 I ) I I t II l Recommendations for Saidblastmg Operations - continued d. The compressor air intake should be located in an area of clean air. This means upwind from the sandblasting area. High dust concentrations have been shown to exist many feet downwind. Compressor air-intake filters are designed to protect only the compressor and have very low efficiency in the microscopic range of respirable dust. Where portable compressors are used, the location of the compressor upwind in clean air should be the responsibility of one individual. 4. Air Conditioning j a. Heat stress is a very real problem on the Gulf Coast because of * high temperature and humidity. A sandblasting hood adds to the problem by further limiting the rate of skin evaporation. Two methods are available to cool air for sandblast hoods: (1) the Vortex tube for high pressure systems (60 to 100 psi) and (2) the compressed refrigerant cycle unit such as has been devised for the Texas City plant. (See attached diagrams.) i 5. Sandblast Shed Location Discretion should be exercised m permanently locating sandblasting sheds. Since dust may be airborne some distance downwind, workmen and machinery in nearby areas may be exposed to adverse concentrations. l > t i -3- I i l i i i t i i I I t i DE 004947 t I t TYPE CE I ABRASIVE-BLASTING IHELMETS, HOODS. OR MASKS The type CE supplied-air respirator {abrasive-blasting helmet, hood, or mask} is approved for respiratory protection during abrasive blasting in atmospheres that are not immediatel> harmful or from which the wearer can escape without the aid of the respirator. I 1. Pangborn type DD-4 blast helmet. | Approval BM-1908, issued to Pangborn Corporation, Hagerstown, Maryland 21740, July 15, 1938, under schedule 19A j Z. Sly'"Purair" helmet. Approval BM-1911, issued to W. W. Sly Manufacturing Company, 47 35 Tram Avenue, Cleveland, Ohio 44102, July 16, 1938, under schedule I9A; and July 11, 1957, under schedule 19B. 3. Willson Nos. 31 and 33 abrasive-blasting helmets. Approval BM-1914, issued to Willson Products, Inc., Willson Products Division. P. O- Box 622, Reading, Pennsylvania 19603, March 10, 1939. under schedule 19A. 4. Pangborn type DF-2 blast helmet. ! Approval BM-1915, issued to Pangborn Corporation, March 23, .1939, under schedule 19A. 5. METCO air-line respirator. Extension of approval BM-1920, issued to Metallizing Engineering Company. Inc., 1101 Prospect Avenue, Westbury, New York 11590, December 8, 1948. under schedule I9A. I 6. Willson No. 52 lightweight abrasive-blasting helmet. Approval BM-1923, issued to Willson Products, Inc., July 19. 1949, under schedule I9A. 7. M-S-A "Blastfoe" abrasive helmets. Approval BM-1926, issued to Mine Safety Appliances Company. 201 North Braddock Avenue, Pittsburgh, Pennsylvania 15208, May 9, 1951,' under schedule 19A. 8. Cesco Nos. 603-RH, 603-RS, and 603-RG abrasive blasting hood3. Approval BM- 19B-35, issued to Chicago Eye Shield Company, (Cesco Safety Products, Inc.,)2727 West Roscoe Street, Chicago, Illinois 66018, January 9, 1962, under schedule ipB. 9\. M-S-A "Flexi-Flo" abrasive masks with lightweight or heavyweight hoods. Approval BM-19B-38, issued to Mine Safety Appliances Company, May 7, 1962, under schedule I9B.(> I I i t \ i \ \ | DE 004948 i i i t \ i i t i i Type CE Abrasive-Blasting Helmets, Hoods, or Masks - continued t i 10. M-S-A() "Hyperflo" abrasive masks with lightweight or heavyweight hoods Approval BM-19B-38A, issued to Mine Safety Appliances Company, June 14. 1962, under schedule 19B, I 11. Bullard No. 37-V abrasive blasting helmet. Approval BM-I9B-39, issued to E D. Bullard Company, 26 80 Bridgeway, Sausalito, California 94965, April 24, 1962, under schedule 19B. 12. Bullard No. 37-LD lightweight abrasive blasting helmet. Approval BM-19B-40, issued to E. D Bullard Company, April 30, 1962, under schedule I9B. i I 13. M-S-A "Flexi-Flo" abrasive mask. Approval BM- 19B-41, issued to Mine Safety Appliances Company, March 5, 1964, under schedule 19B. 14. M-S-A "Hyperflo" abrasive mask. Approval BM-19B-41 A, issued to Mine Safety Appliances Company, March 5, 1964, under schedule 19B. i 15. Pulmosan HA-99 hood. Approval BM-19B-44, issued to Pulmosan Safety Equipment Corporation. 644*( Pacific Street, Brooklyn, New York 22217, January 20, 1965, under schedule 3 9B. 2- - i DE 004949 I I I I V  1 I t I \ \ I t t ( I