Document LJ4zxN5q0yZ8bO3pLLnjOrxE3

(conoco) Interoffice Communication To From Date Subject "OSHA - Engineering and Work Controls Plan" File W. F. Revelt April, 1976 UPDATE OF ENGINEERING AND WORK PRACTICE CONTROLS PLAN Attached is an update of this Plant's engineering and work practice controls plan for complying with the OSHA VCM Exposure Standard. This update is in the form of a Status Report keyed to the exposure sources listed in the April, 1975 Plan (copy attached). All work practice controls have been implemented and significant progress has been made on most of the engineering controls. Currently, however, we are having to rely on breathing air to limit the VCM exposure from some exposure sources. WILLIAM F. REVELT Process Engineer CONOCO Chemicals Oklahoma City Chemical Plant APPROVED: RALPH T. FERRELL Plant Manager CONOCO Chemicals Oklahoma City Chemical Plant WFR-st Attachment CC: (RTF-File), AWS, JWW, WVH, DEM CC OOOOIQ531 STATUS REPORT - APRIL, 1976 UPDATE OF ENGINEERING AND WORK CONTROLS PLAN FOR COMPLIANCE WITH OSHA VCM EXPOSURE STANDARD CONOCO CHEMICALS OKLAHOMA CITY CHEMICAL PLANT EXPOSURE SOURCE STATUS 1. Residual monomer in slurry and resin. 1. All batches are routinely being steam stripped. The stripping operation has reduced VCM residual in the slurry and dried resin to such a low level that it has been possitle to deregulate the dryer building. Currently, air purging in the slurry blend tank is being considered to further reduce VCM residual levels. Also, work to optimize steam stripping is continuing. 2. Obtaining and handling samples. 2. a. After evaluation of current sampling programs, our existing lab hood space was found to be adequate. b. Design of a closed sampling system for obtaining reaction slurry samples has been assigned a lower priority because work practice controls have essentially eliminated worker exposure from this source and because the total monomer release is small. A closed sampling system is being designed and will be installed as part of the systems for compliance with the EPA's VCM regulation. c. The advent of steam stripping has virtually eliminated dryer line sampling` exposure problems. If air purging in the blend tank is implemented, exposures from this source will be further reduced. CCR 0 0 0 0 1 0 5 3 2 3. VCM railcar unloading. 3. Work practice controls are essentially eliminating employee exposure to VCM from this source. Also, CONOCO is in the process of installing magnetic level indicators on all VCM railcars. The releases from the railcar unloading operation will be significantly reduced when systems for compliance with the EPA's proposed VCM regulation are installed. EXPOSURE SOURCE 4. Chem wash screener. 5. Reactor rinse after dump. 6. M-500 dryer exhaust. 7. All rotary seals, flexible hoses, pipe unions, and flanges, valve stems and swivel joints which are in low or high concentration VCM service. 8. Opening and working on equipment or piping which may contain VCM in low or high concentration. ro> o hi o UUr 4. Steam stripping has significantly reduced exposure resulting from this source. Work is continuing on developing a "clean wall" formula which will eliminate the need for the chem wash screener. 5. The initial rinse is now going to the sewer. This is done to minimize VCM at the slurry dump screener since the dump screener has a higher potential for VCM exposure. 6. Steam stripping has lowered the total VCM to the dryers by such a great amount that revisions to the exhaust stacks are not necessary. 7. Complied with plan. 8. Specified work practices are being followed. Electropolished internals have been installed in all reactors. Steam stripping also seems to be keeping the reactor cleaner thus further lowering the cleaning frequency. , EXPOSURE SOURCE 1. Residual monomer in slurry and resin. oo 73 OO o ho-* o wUl ENGINEERING AND WORK PRACTICE CONTROLS PLAN FOR COMPLIANCE WITH OSHA VCM EXPOSURE STANDARD CONOCO CHEMICALS OKLAHOMA CITY CHEMICAL PLANT April, 1975 WORK PRACTICE CONTROLS ENGINEERING CONTROLS 1. Design and install equipment re quired for steam stripping the slurry. Essentially all processing equipment downstream of the poly merization reactors is designed for atmospheric pressure and there fore open to the atmosphere. Processing slurry or resin in this equipment causes the emission of unreacted VCM which can lead to exposures above lppm. Plant tests have shown that steam stripping before dumping to the blend tanks substantially reduces the concen tration of VCM in the slurry. Thus, the amount of VCM available for emission from the open proc essing equipment will be greatly reduced by steam stripping and exposure prbblems Will be minimized In particular, exposures at the dump screener, chemical wash screener-, blend tanks, centrifuges, dryers, resin screeners and resin loading areas will be decreased and residual VCM in resin product leaving the plant will be decreased EXPOSURE SOURCE I 2. Obtaining and handling samples. 3. VCM rail car unloading o o70 O o o oM o\J> U! WORK PRACTICE CONTROLS 2. Wear personnel protection equipment wich meets OSHA standards when sampling reactors, slurry, wet cake, or resin. 3. Wear personnel protection equipment which meets OSHA standards while at the un loading rack during car hook up and disconnect. ENGINEERING CONTROLS 2. a) Install a new laboratory hood to provide more work and storage space for slurry and reactor samples. b) Prepare an engineering design for a closed reactor sampling system. Samples obtained during the early part of reaction contain high concentrations of VCM. By enclosing the reactor sampling system, exposure in the reactor area will be decreased because VCM will not be emitted from the sample in the working area. c) Prepare an engineering design for an improved resin sampling system at the M-500 dryer. 3. Prepare an engineering design to install glasses in unloading lines and rearrange valving at the un loading racks. Installation of sight glasses will eliminate venting to the atmosphere when determining liquid to vapor transition at the end of un loading. Rearrangement of valving will minimize the volume vented during disconnect. l ' EX P' OSUR~ E SOU' RCE I 4. Chemical wash screener. 5. Reactor rinse after dump. 6. M-500 dryer exhaust. 7t All rotary seals, flexible hoses, pipe unions and flanges, valve stems and swivel joints which are in low or high concentration VCM service. n TnO hOOOOVOI OJ WORK PRACTICE CONTROLS ENGINEERING CONTROLS 4. Design and install an enclosure and vent system for the chemical wash screener similar to the system on the dump screener. 5. Transfer the effluent from the initial water rinse after reactor dump to the dump system and eliminate transfer to the sewer. 6. Prepare an engineering design to elevate the stack for the M-500 dryer exhaust. Currently, M-500 exhausts at the loading rack level which leads to exposure problems under certain wind conditions. Stack elevation will eliminate this problem. 7. At least once per month, measure VCM concentrations at all hoses, flanges, unions, seals, valve stems and swivel joints in low or high concen tration VCM service. Repair or replace leakers on-the-spot, where necessary. List other leakers for repair or replace ment on the maintenance schedule. The fixed point monitor will detect the occurrence of relatively large leaks which will be attended immediately. EXPOSURE SOURCE I 8. Opening and working on j equipment or piping which j may contain VCM in low or | high concentrations. WORK PRACTICE CONTROLS ENGINEERING CONTROLS 8. a) Before opening, remove 8. Install electropolished internals VCM from equipment or in all reactors. Plant experience piping to the lowest has shown that the frequency of practical level by flushing, reactor entries for cleaning is purging and/or evacuation, decreased when electropolished where possible. internals are used. This is due to a decrease in polymer build b) Wear personnel protection up on electropolished internals equipment which meets OSHA as compared to the build-up on standards when opening equip other internals. The plant has ment or piping which may five sets of internals. Two sets contain VCM. are electropolished and installed. c) Before commencing repair work, One set is at the shop for measure the VCM concentration electropolishing. The other two in or near opened equipment sets will be electropolished or piping to determine what when they can be switched out. protective equipment is required and if further VCM removal should be attempted.