Document wqREdBQv8QQ3RGrZkGeyaQL03

-1 ^ TEXAS CITY SUSPENSION/'NON-SOLVENT. -UNI_T CALCULATION OF 8-HR TWA VINYL CHLORIDE EXPOSURE FROM VFA DATA Operating Position 1. Non-Solvent autoclaves Bldg. 174 control room (6 hrs.) Outs ide (2 hrs . ) 2. Off-Gas Recovery Bldg. 174 Control Room (6 hrs.) Outside (2 hrs. ) 3. Suspension Utility- Bldg. 174 Control Room (2 hrs. ) Outside (6 hrs. ) 4. Suspension, North line autoclaves Bldg. 174 Control Room (6 hrs. ) Outside (2 hrs , ) 5. Suspension, South line Autoclaves Bldg. 174 Control Room (6 hrs. ) Outside (2 hrs. ) 6. Suspension, East line Autoclaves Bldg. 174, Control Room (5. 6 hrs. ) Outside (2. 4 hrs. ) 7. Dryer, Inside Bldg. 120, Control Room (6.4 hrs.) Outside (1.6 hrs. ) 8. Dryer, Outside Bldg. 120, Control Room (2. 4 hrs. ) Outside (5, 6 hrs. ) 9- Refrigeration & VC1 Unloading Bldg. 113 Control Room (6.5 hrs. ) Outside (1.5 hrs. ) 10. Chief Operator Control Room - 174 & 120 (4. 8 hrs. ) Outside `(3. 2 hrs. ) Area (ppm) 8-Hour TWA (ppm) RECEIVED 1 5 JA N 1 7 1375 1 A. B3 STEELE 10 1 8 1 6 1 6 1 7 0. 5 6 0. 5 6 0. 5 7 1 5 6 2 2 3 2 4 *2 `3 To prevent operator exposure to over 50 ppm VCM currently requires two operators to wear respiratory equipment 5% of the time. This is equivalent to one percent of the total operator time. itVw'V' January 10, 1975 '' ucc 042446 _.... ACTION TAKEN IN 1Q74 TO REDUCE VINYL CHLORIDE EXPOSURES IN THE SU5PENS ICN/NQN-SO LVENT/ VINYL REFRIGERATION UNIT 1. Discontinued standard operating procedure of water rinsing D-autoclaves to pad between batches. Z. Installed ZO point VFA/VCl analyzer ($Z0M) in Bldg. 174 control room to analyze and record VCl concentrations at sample heads Located throughout the unit. 3. Issued instructions to operating personnel to log, locate, and stop sources of vinyl chloride emission whenever the VFA/VCl high exposure alarm sounds. 4. Relocated dumping of Nos. 3 and 4 stripping tanks from highly traveled area to remote location. J 5. Purchased portable vinyl chloride analyzer (MSA) for testing vessels (which previously contained vinyl chloride) for vinyl chloride content to minimize personnel exposure upon vessel entry. 6. Conducted in-depth stripping study to determine relative importance of operating parameters in reducing residual monomer content. 7. Replaced styrene with more efficient sodium nitrite terminator for "killing" runaway reactions. * 8. Revised procedure to use resin analysis as a guide instead of "boil-off" sampling of recovered monomer. 9. Developed method for heating suspension autoclaves to reaction temperature using direct steam injection. 10. Replace PVP suspending agent with HEMC to provide more stable VAc/VCl copolymer reactions. 11. Installed Off-Gas Recovery system to recover vinyl chloride flashed from resin in vacuum strippers. r--TVV ^i-iV SJ'Wv. '. ' 'u4r1 i .- .r uec 042447 Action Taken in 174 To Reduce Vinyl Chloride Ksposures in (he Suspension 'Non-Solvent Vinvl Refrigeration Unit 2, 1Z. Issued SOP to vent autoclaves with high reaction pressure to Off-Gas Recoverysystem vacuum header instead of the atmosphere. 13. Used 50 M gallon suspension surge tank in Non-Solvent service to provide additional surge capacity between Non-Solvent autoclaves and dryers to prevent overflow of resin slurry. 14. Reduced premature D-autoclaves rupture disc failures by changing from type PLDV to type RB-90 for more accurate bursting pressures. 15. Modified No. 1 VC1 recovery system to allow recovery of contained vinyl chloride in the high pressure vent by scrubbing insolvent Vinyls acetone stripping system. 16. Modified No. 2 VC1 recovery system to send high pressure vent stream to the No. 1 Powerhouse for burning in boilers as fuel. 17. Revised Off-Gas Recovery System to send high pressure vent to the No. 1 Powerhouse for incineration as boiler fuel. 18. Enclosed the atmospheric packing areas of Nos. 1 and 2 compressors for venting outside the compressor room. 19. Designed and installed exposure-proof slurry samplers for D-autoclaves. 20. Added an additional operating position to allow closer monitoring of vinyl chloride recovery facilities. 21. 22. Barricaded compressor room doors with chains and hun^ signs on each doorway which read, "Entry Without Fresh Air Protection Requires Chief Operator Approval". m Changed packing on Nash compressor to improve reliability and lessen vinyl chloride emissions to the atmosphere. 23. Revised procedurs for flushing skin-pots to minimize operator exposures to vinyl chloride. . 24. Relocated maintenance eating facilities outside the manufacturing area to reduce potential exposures. ucc 0*42448 Action Taken in 174 To Reduce YiruT Chloride Exposure.- in the Suspension X on-S ol ven t ' Y i n\T R e fr igo ra I ion Unit 3. 25. Revised piping to allow decanting of recovered monomer tanks to a closed vessel instead of the sewer. 26. Removed walls from Bldg. 127 (upstairs) to improve ventilation and lessen operator exposure. 27. Increased technical staff (67%) to devote more time to minimize vinyl chloride monomer losses. 2 8. Installed DMV in No. 1 Blowdown tank feed header to avoid autoclave blowdowns during vacuum stripping which result in blown rupture discs. 29. Revised piping to vent VC1 filters to an enclosed vessel rather than the atmosphere prior to opening for maintenance. 30. Install piping on all VCl pumps to allow priming to an enclosed vessel instead of the atmosphere. 31. Purchased portable Century OVA/VC1 analyzer for use as a tool for locating emission sources of vinyl chloride. 32. Revised piping to recover vinyl chloride and vinyl acetate in seal water in the No. 3 vacuum stripper. 33. Modified pilot plant operating procedures to recover most vinyl chloride emissions in the No. 2 VCl recovery system. Otis A. Shelton January 13, 1975 i, * ' l.TkTU.'k" ` . S- i'- UCC 042449 ' - " - ' ^'' "V -r- TO (NAM tO COMPANY LOCATION Mr. R. L. Frantz * COPY TO * Mr. M. E. Eisenhour Mr. R. W. Sesler * # ate January 9, 1975 .. subject VFA Analysis for VCl*at the Suspension/Non-Solvent Unit The VFA instrument was installed at the Suspension/Non-Solvent Unit in June to monitor for VC1. The instrument is., primarily, being used as a tool to locate VC1 release problem areas. ; ` .! i Table I shows a summary of the number of high readings for the JuneDecember period. The sensitivity of the instrument was changed from 100 ppm to 25 ppm full scale on November 4. Basically, the data shows that the number of high readings has been decreasing as steps have been taken to reduce leaks and releases. Based on observations and data taken from the monitoring of the VFA charts for December, the following statements can be made: 1. The VC1 level in the control rooms (Bldgs. 174 and 120) is normally less than 1 ppm. 2. The readings in Bldg. 174 - Bldg. 119 work area indicate that the average VCM concentration is normally slightly below 5 ppm. 3. Data given in Table II show the current problem areas (based on the critical few - 40 readings exceeding 2 5 ppm) are: a) The Off-Gas Recovery Systern. The system (seal water and knock-out pot) had to be released to the sewer several times during the month to overcome resin contamination problems. Steps are being taken to eliminate the need for these releases. b) The Cofnpressor Room in Bldg. 119- Although several steps have been taken to eliminate leakage, the compressors still constitute a problem. However, personnel entry into the com pressor room is seldom required. ucc 042450 I : t f.'f . v yf I* r il Y S- 1 -I1/ , c) Vinyl Chloride Unloading Facilities. Because of the colder weather, nitrogen was used to unload the VC1 monomer tankcars. Subsequent venting to remove the N2 was responsible for the number of high points. Revised procedures are planned. d) Downstairs, North and South Lines. These points were high, primarily, because of the releases from the Off-Gas Recovery System and wind blowing the gas across these areas. * e) Second Level, East Line. This may have also been due to the Off-Gas Recovery System. A printer-log has been requested from SID at the Tech Center that will give 8 and 24-hour averages of each point and other pertinentfMata. This addition will allow accumulation of more complete data which currently is done visually and tabulated by hand. FLJ/sld Attachments Frank Johnson I k I F 'f .ft * fi HI ` " i. H1 - * p 4 *T- *4 ;k ucc 042451 3; fl nfc TABLE I VFA ANALYSIS FOR VC1 AVER AGE /DAY (1' m June 22 - July 21 % Aug. 19 - Sept. 5 September October November ^ December Number of Points Exceeding 50 Exceeding 2 5 Exceeding 10 19 11 8 5 12 18 74 18 64 ' ' Out of 720/day, until Oct. 5 when it changed to 684/day. ^ Changed sensitivity of VFA on Nov. 4 from 100 to 25 ppm, full scale. ucc 042452 TABLE II DATA FROM VFA ANALYZER FOR DECEMBER Point Location l Control Room, B. 174 2 Downstairs* East Line 3 Downstairs * North Line 4 Downstairs, South Line 5 Second Level, East Line w 6 Second Level, North Line 7 Second Level, South Line 8 North Line, B.119, first level, West end 9 B. 127, Second Level 10 B. 119, North Side, Second level, center 11 B.119, North Side, third level, center 12 Off-Gas Rec. Facilities 13 B.119, Compressor Room 14 B.119, Maint. Room 15 B.119, South Side, NW of Strip Tank 16 VC1 Unloading Facilities 17 Tank Area A, Gnd. Level 18 Pilot Plant Grating 19 Control Room, B. 120 No. of Readings Exceeding 25 ppm 0* 15 47 * 46 42 * 23 23 % of Readings (Time) less than 25 ppm 100 99 96 96 96 98 98 25 98 19 98 7 99 17 112 52 23 98 90 95 98 16 98 48 96 33 97 2 99+ 0 100 TOTAL Average/day 550, or 2.6% 18 UCC 042453