Document ga5vbxpE6bojERo1DOzKxo6J

151 50983 aatm PLAINTIFF'S EXHIBIT DOW-158 DOW CHEMICAL U.S.A. TEXAS DIVISION FREEPORT, TEXAS 77541 ENVIRONMENTAL HEALTH REPORT ATMOSPHERIC SURVEY FOR HYDROGEN FLUORIDE CHLORINE V, BUILDING A-1324 file mo A13-716 n a T f August 12, 1975 AUTHOR H. N. Edwards if Fn ^P OugtJ'rt ms" Summary When the asbestos containing Kynar is heated on an open hot plate, hydrogen fluoride vapors are given off in high concentrations. It is recommended that this procedure be done in a well vented hood It is also recommended that a respirator be furnished in this area that would be effective against both asbestos dust and acid gases. It is further recommended that the survey be repeated with personnel monitoring after the proper corrections have been made. oo --4 O cr cr o Distribution D. R. Hart A1324 Chuck Hill A1324 S. F. Edquist B-2401 W. H. Fletcher B-101 Pete Schumm B-101 . E. Flake B-101 ile AN OPERATING UNIT OF THE OOW CHEMICAL COMPANY ST06607 I 3 File A13-716 -2- INTRODUCTION At the request of supervision, an analysis was made on impregnated asbestos to determine if vapors being released when heating were harmful. This survey was made in June, 1975. `METHODOLOGY The asbestos in question was impregnated with Kynai which contains vinylidene fluoride. The label states that the temperature should not be raised above 600F when Kynar is used and under ordinary conditions this does not happen, but the samples taken for analyses are often dried on a hot plate. The temperature of the hot plate reaches 1100-1200F. Two grams of the impregnated asbestos was placed in a glass tube and heated while passing nitrogen over it. The effluent was trapped in liquid nitrogen traps. The traps were washed out with 4 mis. of water and made up to 50 mis. Fluoride ion and pH determinations were made by Charley Norman of Central Laboratory, B-2406. RESULTS At 500 F the pH of the solution was 7.3 and the fluoride ion was non detectable. When the temperature was raised to 1100F the pH was 1.8 and the fluoride level was 6500 ppm of hydrogen fluoride. CONCLUSION When asbestos containing Kynar is heated above 600F, fluoride gas is released. The vapor can be harmful and should not be breathed. RECOMMENDATIONS 1. If drying of this material is necessary over a hot plate this should be done within a hood with the hood exhaust vented to the open air. If large quantities are to be heated this way, then the hood vent should be scrubbed to remove the vapors from the atmosphere. -/h. .L2. -c- . File A13-716 -3- RECOMMENDATIONS (continued) 2. Since the breathing of the asbestos dust is harmful and the vapors also, it is recommended that a respirator be provided in the area where this is heated that would be effective against both dust and acid gases. 3. When corrections have been made, it is recommended that workmen be monitored for personal exposure. ST06607 I 4 EHS HNE/bbs 8-12-75