Document Jr3Lox9OBgxJRM82gRvkEqQoZ

-f.' V INDUSTRIAL HYGIENE REPORT & Personnel breathing zone samples and area samples were taken during production operations in the High Density Polyethylene Plant, Block 9, for hexane. Seven job classifications and five areas were monitored during the survey. The expo sure levels were acceptable when compared to an eight-hour time-weighted average When performing short-term exposure sampling on specific job procedures, one job classification, SOT - Purification, revealed short-term exposure levels that wen unacceptable. There were three areas monitored that had levels which were unacceptable. While alternate operating procedures were under trial, respiratory protection (3M #8712 Organic Vapor Respirator) was required. Alternate operating procedure: were put into effect and reduced short-term exposure and area levels to an accep' table range for SOT - Purification. Engineer Controls (local ventilation with scrubber) in the two areas reduced una< ceptable area levels to an acceptable range. The Industrial Hygiene Survey for Hexane at the High Density Polyethylene Plant was conducted from September, 1978 to November, 1Q7Q.____________________________________ DISTRIBUTION LOUISIANA C. W. Brannan - 901 *G. W. Daigre - 2501 *C. E. Halphen - 2501 P. L. Harich - 901 A. J. Seidule - 2306 M. F. Currier - 2303 *G. H. Watkins - 2306 MIDLAND L. W. Rampy - 1803 D. J. Roberts - 2020 M. Swank - 1803 *F. D. Axe - Pittsburg *R. L. Daniel - Freeport *S. A. Goode - 0CD *R. J. McCormick - Strongsvill *R. D. Olsen - Sarnia 00 01ig66 CONFTDFNTTAI, -2- INTRODUCTION On September 28, 1978,, an Industrial Hygiene Survey to deter mine employee exposure to hexane was begun at the request of the supervision of the High Density Polyethylene Plant, Block 9. EVALUATION CRITERIA Dow Industrial Hygiene Guides (IHGs) are concentrations of air borne substances to which nearly all employees may be repeatedly exposed throughout a working lifetime without adverse effect. IHGs are established by the health professions of the Dow Industrial Health Board for Chemicals (raw materials, intermediates, byproducts, wastes and products) handled within The Dow Chemical Company. Published exposure criteria are availble for many industrial chemicals. Examples include the Threshold Limit Values (TLVs) of the ACGIH (American Conference of Governmental Industrial Hygienists), the OSHA Standards of the Occupational Safety and Health Administration of the Unisted States Department of Labor, For most of these chemicals, the Industrial Health Board has adopted the published exposure cri teria as the Dow IHGs. In a few instances, the IHG set by the Industrial Health Board differs from the published exposure criteria. In establishing IHGs for chemicals which lack published exposure criteria, the Industrial Health Board con siders toxicological information, occupational exposure data and medical experience. Industrial Hygiene Guides do not represent fine lines between safe and dangerous exposures. As the name indicates, IHGs are properly used as guides for plant design and for evaluating occupational exposures. IHGs for gases and vapors are usually expressed in part per million (ppm, volume/volume); for dusts, fumes, aerosols, and mists, IHGs are usually expressed in milligrams of contaminant per cubic meter of air (mg/m3). Most IHGs are time-weighted average (TWA) concentrations for an 8 - 12-hour work day and a 40-hour work week. Limited excursion exposures to concentrations exceeding the IHG are permitted, provided that the TWA exposure for the entire work day is accep table and the consequences of exposure, within the excursion limit, are minimal and reversible. For most chemicals, no CONFTDFNTTAl -3- excursion limits are calculated from the IHGs and the excursion factors recommended by the ACGIH. Ceiling IHGs are assigned to those materials which cause significant or irreversible effects at concentrations exceeding the IHG. For these chemicals, no excursion exposures are allowed. The following exposure criteria currently apply to the airborne contaminant referred to in this report: Compound *TLV - 8-hr. TWA *STEL - 15-min. Excursion Hexane 100 ppm 125 ppm Published in TLVs of ACGIH EXPERIMENTAL Employees actual breathing zone samples of the hexane vapor were collected using two methods: 1. SKC charcoal tubes containing 600 mg coconut base charcoal using small batery operated DuPont pumps (Model P200) at a flow rate of 100 cc/min. 2. 3M Organic Vapor Monitor #3500. Comparison of the two sampling methods was acceptable. Analysis for hexane was performed by gas chromatography. The instrument and conditions are listed below: Instrument: Hewlett-Packard 5730A/7123A Recorder Column: 6' stainless steel with 15$ TCP on 60/80 mesh Chrom W, acid washed Oven Temp: 60C FID Detector Temp: 200C Inj. Temp: 200C Solvent: CS2 (10 mls-tube) (2 mls-badge) Injection: 2 p, 1. Flow Rates: 20 cc/min-N2; 30 cc/min-H2J 250 cc/rain-Air Min. Det. Limit 1 (j, g/ml CS2 -4- AREA SAMPLING DESCRIPTION Area sampling was performed in areas where possible high levels of airborne hexane would occur leading to a potential overexposure if a job was peformed over an extended period of time in those areas. The areas which were monitored are described below. 1. Area samples were taken at the calcium sterate additive valve which is approximately five (5) feet bove the deck and eight (8) feet southwest of the skimmer tank vent on Train 1. 2. Area samples were taken at the calcium sterate additive valve which is approximately five (5) feet above the deck and eight (8) feet southeast of the skimmer tank vent on Train 2. 3* Area samples were taken at the guard rail approximately four (4) feet above the deck and six (6) feet southwest from the skimmer tank vent on Train 3. 4. Area samples were taken at the guard rail approximately four (4) feet above the deck and six (6) feet southwest from the skimmer tank vent on Train 4. 5. Area samples were taken five (5) feet above the ground at the northwest post approximately six (6) feet from hexane filter 202-D during filter cleaning. 6. Area samples were taken five (5) feet above the ground at the center post between hexane filters 202-C and 202-D during filter cleaning. 7. An area sample was taken five (5) feet above the ground at the southeast post approximately six (6) feet from hexane filter 202-C during filter cleaning. JOB CLASSIFICATION DESCRIPTION The job classifications are described from the viewpoint of personal contact with hexane and only those job classifications are discussed with a possible overexposure to hexane during nor mal operations. DO 011969 CONFIDENTIAL -5- Shift Supervisor Shift Job - Coordinates shift activities. Outside activities dependent upon operational problems. Senior Operating Technician - Purification Shift Job - Performs all phases of operational work that is necessary for smooth operation of the area. Performance inclu des making two rounds per shift, unloading butene, alcohol and hexane rail cars, and cleaning polymer from hexane filters. Senior Operating Technician - Reaction Shift Job (two per shift) - Performs all phases of operational work that is necessary for smooth operation of the area. Makes two rounds per shift and hourly rounds for additives. Lab Personnel Shift Job (two per shift) - Must go outside to catch samples as often as hourly; remainder of time spent in lab running samples. Expanded Day Operations Day Job - Rotates every fifth month, consisting of one month of eight-hour days. Mostly outside work: maintenance, housekeeping, safety observers, etc. Senior Operating Technician - Extrusion Shift Job - Runs and maintains six extruders, checks and moni tors additives. Makes two rounds per shift. Maintenance - Crafts Day Job - Time is spent in warehouse or in block area as required. PRESENTATION OF DATA The floor plan and flow chart of the High Density Polyethylene Plant, Block 9, are located in Figures 1 and 2. (See Attachments.) a 970 -6- The data is separated by job classification and area with the sampling date, duration (minutes) and hexane levels (ppm-v/v) listed for each. The job classifications and areas are listed below with their respective reference tables. (See Attachments.) Job Classification Purification Reaction Lab Personnel EDO Extrusion Supervisor Pipe Fitters Table I II III IV V VI VII Area Classification Above skimmer onTrain 1 Above skimmer onTrain 2 Above skimmer on Train 3 Above skimmer on Train 4 Table VIII VIII VIII VIII DISCUSSION AND CONCLUSIONS The initial sampling of short-term exposures to hexane during normal operating conditions revealed one job classification with unacceptable levels. The job classification was Senior Operating Technician - Purification, while opening and cleaning DO 011971 OONPIDFNTTAl -7- the hexane filters 202-C, 202-D, 201-A and 201-B. In April, 1979, alternate operating procedures were put into effect. The change in procedure consisted of extending the boil out with hot condensate time from four hours to eight hours on 202-C and 202-D and 24 hours to 48 hours on 201-A and 201-B. While this procedure change was being evaluated, respiratory protection (3M #8712 Organic Vapor Respirator) was required. The evaluation of the procedural change in cleaning the hexane filters indicated exposure levels were reduced to an acceptable range. Also, test of engineering controls on Train 4 (a steam-still modification) indicates the frequency of hexane filters cleaning will be reduced due to less powder carry-over, resulting in a decrease in the number of times the personnel are exposed to hexane during filter cleaning. The area sampling indicated unacceptable levels of airborne hexane were present at the calcium sterate additive valves around the skimmer tanks on Trains 1 and 2 and in the immediate area of the hexane filters during the opening and cleaning procedures. Engineering controls (duct work with a water screen) reduced the airborne hexane levels at the calcium sterate additive valves on Trains 1 and 2 to an acceptable range. The procedure change in cleaning the hexane filters reduced area levels to an acceptable range during that operation. Terry Campbell Industrial Hygiene Louisiana Division sb no oi CONFIDENT! At -.as flo r a 00 011973 CONFIDENTIAL POLY-B F IG U R E 10- TABLE I PERSONNEL EXPOSURE TO HEXANE SOT - PURIFICATION Sample Description Date Time Amount (Min.) (ppm-v/v) Short-term exposure opening 10-9-78 and cleaning 201-A filter Short-term exposure opening 11-1-78 and cleaning 201-B filter Changed alcohol filters general rounds 10-13-78 Short-term exposure 9-28-78 checking gauges in catalyst area *(two hexane pumps leaking) Short-term exposure changed 9-28-78 filters in alcohol area General rounds, opened and cleaned 201 filter 10-10-78 General rounds and main tenance, opened and cleaned 201 filter 10-9-78 Short-term exposure opening and cleaning 202 filter 11-6-78 Short-term exposure 11-2-78 unloaded tank car of hexane Short-term exposure opening and cleaning 202 filter 3-7-79 Short-term exposure opening and cleaning 202 filter 3-13-79 90 45 440 45 40 315 360 90 180 20 16 189.0 50.2 20.3 82.4 1.3 60.0 5.9 638.0 4.0 92.0 1104.0 2/23/80 00 OII975 CONFIDENTIAL -11- TABLE I PERSONNEL EXPOSURE TO HEXANE Sample Description SOT - PURIFICATION (continued) Time Date (Min.) Amount (ppm-v/v) Short-term exposure opening and cleaning 202 filter 4-12-79 13 7.5 Short-term exposure opening and cleaning 202 filter 5-16-79 13 127.0 Short-term exposure opening and cleaning 202 filter Short-term exposure opening and cleaning 202 filter 10-23-79 37 11-5-79 28 60.0 61.0 NOTE: Beginning April 2, 1978, the cleaning procedure ' 202 filters was changed from boiling with hot conden sate for four hours prior to opening, to eight hours in an effort to reduce hexane content in the polymer. 2/23/80 DO 011976 CONFTDFNTTAL -12- TABLE II PERSONNEL EXPOSURE TO HEXANE Sample Description SOT - REACTION Date Time (Min. Amount (ppm-v/v) Changed pump at cooling tower, general rounds 10-9-78 315 1.3 Maintenance on compressor deck, general rounds 10-9-78 360 2.6 General rounds 10-13-78 440 12.8 Short-term exposure blew out calcium sterate at additive station 11-6-78 4 19.* Short-term exposure opened 11-3-78 75 23.0 post reactor Short-term exposure opened 11/3/78 75 23.7 post reactor Short-term exposure blew 10-26-78 8 43.4 out calcium sterate at additive station Short-term exposure - spill 11-6-78 interphase pump 38 739.0 General maintenance, general rounds 10-16-78 510 3.1 2/23/80 DO Oil 977 CONFTDFNTTAL. -13- TABLE III PERSONNEL EXPOSURE TO HEXANE LAB PERSONNEL Sample Description Date Time Amount (Min.) (ppm-v/v) General lab duties including catching slurry samples 10-16-78 360 4.0 General lab duties including catching slurry samples 10-18-78 420 10.0 General lab duties including catching slurry samples IO-19-78 615 12.0 General lab duties including catching slurry samples 10-20-78 210 13.0 Short-term exposure collecting slurry samples on Trains 1 and 2, empties samples under hood 10-26-78 12 11.0 Short-term exposure collected slurry sample from Train 3 emptied sample under hood 10-26-78 7 7.0 Short-term exposure collected slurry samples from Trains 1 and 2, emptied samples under hood 10-26-78 9 16.0 Short-term exposure collected slurry sample from Train 1, emptied sample under hood 11-6-78 5 85.0 2/23/80 DO Oil 978 CONFTDEIMTTAl TABLE III PERSONNEL EXPOSURE TO HEXANE Sample Description LAB PERSONNEL (continued) Time Date (Min.) Amount (ppm-v/1 Short-term exposure collected slurry sample, from Train 4, emptied sample unde hood 11-6-78 Short-term exposure collected slurry sample, emptied sample under hood 11-6-78 6 0.5 5 134.0 2/23/80 DO 011979 CONFTDFNTTAl TABLE IV PERSONNEL EXPOSURE TO HEXANE EXPANDED DAY OPERATIONS Sample Description Date Time Amount (Min.) (ppm-v/v) General maintenance by graphic panel room 10-16-78 510 2.7 2/23/80 16- TABLE V PERSONNEL EXPOSURE TO HEXANE Sample Description EXTRUSION OPERATION Date Time (Min.) Amount (ppm-v/v) General maintenance and housekeeping in extrusion area 10-18-78 435 1.0 2/23/80 Oo 01 1 93 -J CONFrDFNTlAl.. -17- TABLE VI PERSONNEL EXPOSURE TO HEXANE SUPERVISOR Sample Description Date Time Amount (Min.) (ppm-v/v) Worked in control room and in Trains 1,2,3, and 4 10-20-78 610 1.1 2/23/80 DO 01198? CONFTDFNTTAl -18- TABLE VII PERSONNEL EXPOSURE TO HEXANE CRAFTS - PIPE FITTERS Sample Description Short-term exposure removing heat exchanger from Train 3 Short-term exposure removing heat exchanger from Train 3 Date 11-6-78 Time (Min.) 45 Amount (ppm-v/v) 17.0 11-6-78 45 7.0 Short-term exposure removing heat exchanger from Train 3 11-6-78 45 9.0 Short-term exposure Removing heat exchanger from Train 3 11-6-78 45 21.0 2/23/80 TM Oil 993 cONFTDFNTTA! -19- TABLE VIII AREA SAMPLING FOR HEXANE Sample Description Sample at calcium sterate valve by skimmer vent on Train 1 Sample at calcium sterate valve by skimmer vent on Train 1 Sample at calcium sterate valve by skimmer vent on Train 1 Sample at calcium sterate valve by skimmer vent on Train 1 Sample at calcium sterate valve by skimmer vent on Train 1 Sample at calcium sterate valve by skimmer vent on Train 1 Sample at calcium sterate valve by skimmer vent on Train 2 Sample at calcium sterate valve by skimmer vent on Train 2 Sample at calcium sterate valve by skimmer vent on Train 2 Date 9-28-78 Time (Min 95 Amount (ppm-y/v) 1067.0 9-28-78 115 2076.0 9-28-78 115 504.0 9-29-78 60 1033.0 9-29-78 80 579.0 9-29-78 60 855.0 9-28-78 95 44.0 9-28-78 115 621.0 9-28-78 115 725.0 2/23/80 DO 011984 CONFTDFNTTAl -20- TABLE VIII AREA SAMPLING FOR HEXANE (continued) Sample Description Date Time (Min.) Sample at calcium sterate valve by skimmer vent on Train 2 9-29-78 60 Sample at calcium sterate valve by skimmer vent on Train 2 Sample at calcium sterate valve by skimmer vent on Train 2 9-29-78 9-29-78 95 80 Sample at calcium sterate valve by skimmer vent on Train 2 9-29-78 * 60 Sample at guardrail by skimmer vent on Train 3 10-2-78 60 Sample at guardrail by skimmer vent on Train 3 Sample at guardrail by skimmer vent on Train 3 Sample at guardrail by skimmer vent on Train 4 10-2-78 10-2-78 120 120 10-2-78 60 Sample at guardrail by skimmer vent on Train 4 Sample at guardrail by skimmer vent on Train 4 10-2-78 10-2-78 120 120 Amount (ppm-v/ 261.0 192.0 87.0 208.0 7.0 4.4 2.5 3.0 4.1 13.5 2/23/80 DO CONFIDENT!Al -21- TABLE VIII AREA SAMPLING FOR HEXANE (continued) Sample Description Date Time (Min.) Sample at calcium sterate valve by skimmer tank on Train 1 10-5-78 60 Sample at calcium sterate valve by skimmer tank on Train 1 10-5-78 90 Sample at calcium sterate valve by skimmer tank on Train 1 10-5-78 60 Sample at calcium sterate valve by skimmer tank on Train 1 10-5-78 120 Sample at calcium sterate valve by skimmer tank on Train 2 10-5-78 60 Sample at calcium sterate valve by skimmer tank on Train 2 10-5-78 90 Sample at calcium sterate valve by skimmer tank on Train 2 10-5-78 60 Sample at calcium sterate valve by skimmer tank on Train 2 10-5-78 120 Amount (ppm-v/ 11.0 3.4 0.2 30.0 63.0 61.0 62.0 0.2 2/23/80 DO 01.1986 CONFTDFNTTAL -22- TABLE VIII AREA SAMPLING FOR HEXANE (continued) Sample Description Date Time (Min.) Purification area, cleaning 202 filter, sample at 5 ft above ground on N.W. post 3-13-79 16 Purification area, cleaning 3-13-79 202 filter, sample at 5 ft above ground on post between 202-C and 202-D 16 Purification area, cleaning 4-12-79 202 filter, sample at 5 ft above ground on N.W. post 13 Purification area, cleaning 4-12-79 202 filter, sample at 5 ft above ground on post between 202-C and 202-D 13 Purification area, cleaning 5-16-79 202 filter, sample at 5 ft above ground on N.W. post 13 Purification area, cleaning 202 filter, sample at 5 ft above ground on post between 202-C and 202-D 10-23-79 37 Purification area, cleaning 202 filter, sample at 5 ft above ground on S.E. post 10-23-79 37 Amount (ppm-v/v) 431.0 513.0 11.0 16.0 52.0 61.0 30.0 2/23/80 DO 011987 OONFXDFNTTAl,, -23- TABLE VIII AREA SAMPLING FOR HEXANE (continued) Sample Description Date Time Amount (Min,) (ppm-v/v) *Purification area, 11-5-79 cleaning 202 filter, sample at 5 ft above ground on post between 202-C and 202-D 28 64,0 Purification area, cleaning 202 filter, sample at 5 ft above ground on post between 202-C and 202-D 11-5-79 28 60.0 In September, 1979, the skimmer vent opening was relocated by duct work with a water screen to reduce hexane emissions, * Beginning April 28, 1979, the cleaning procedure of the 202 filters was changed from boiling out with hot conden sate for four hours prior to opening to eight hours in an effort to reduce hexane content in the polymer. 2/23/80 DO 011980 OONFTDFNTTAl