Document G6mzvj89Xd9dYmGodBNoY0q0Y

(conoco) Interoffice Communication To "OSIIA - ENGINEERCNG AND V.'OPK CONEEOLG PLAN" FILE From ' W. F. Revelt Date October, 1975 Subject 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. Several of these sources are expected to be either eliminated or significantly reduced with the advent of steam stripping of reaction slurry. William F. Revelt Process Engineer Conoco Chemicals Oklahoma City Chemical Plant APPROVED: Ralph T. Ferrell Plant Manager Conoco Chemicals Oklahoma' City Chemical Plant CC: (RTF - File) AWS JWW DEM CCS 000ios33 CCR 0 0 0 0 1 0 5 3 9 STATUS REPORT - SEPTEMBER, 1975 UPDATE OF ENGINEERING AND WORK CONTROLS PLAN FOR COMPLIANCE WITH OSHA VCM EXPOSURE STANDARD CONOCO CHEMICALS OKLAHOMA CITY CHEMICAL PLANT EXPOSURE SOURCE 1. Residual Monomer in slurry and resin. 2. Obtaining and handling samples. 3. VCM Railcar Unloading. STATUS 1. Steam stripping equipment has been installed. A few "shakedown" batches have been run. Steam stripping of all batches will be started by Nov ember 1, 1975. 2.a. After careful evaluation of current and future 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 to a lower priority because work practice controls essentially eliminate worker exposure from this source and because the total monomdr release is small. c. With the advent of steam stripping, this exposure source is not expected to continue as a problem, therefore, it is currently a low priority project. After steam stripping is routinely operational, emissions from this source will be monitored and the project's priority re-evaluated. 3. Work practice controls are essentially elimina ting employee exposure to VCM from this source to VCM. Conoco is in the process of installing magnetic level indicators on all VCM cars. Sev eral process designs have been prepared to reduce VCM release to a minimum level. These designs are currently being reviewed relative to the pro- _posed EPA Standards on VCM. The objective is to install a system that will comply with both OSHA and EPA regulations. Keporc - September, 1975 Update of Engineering and Work Controls Plan For Compliance with OSHA VCM Exposure Standard Conoco Chemicals Oklahoma City Chemical Plant Page 2 4. Chemical Wash Screener. 5. Reactor rinse after dump. 6. M-500 dryer exhaust. 7. All Rotary Seals, Flexible Hoses, Pipe Unions, and Flanges, Valve Steins 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.. Steam stripping is expected to significantly reduce exposure at this source. After steam stripping is lined-out, exposure from this source will be monitored. If necessary, revisions to this system will be made when the unit is relocated in 1976 as part of our capacity replacement pro gram. Complied with plan. Installation of the stack is being held pend ing evaluation of the effects of Stripping the reaction slurry. Complied with plan. Work practice controls are being followed. Currently, electropolished internals have been installed in 3 of the 4 polymerization reactors. We are awaiting receipt of the 4th set of in ternals from the contracted electropolishing firm. CCR 0 0 0 0 1 0 5 * EXPOSURE SOURCE 1. Residual monomer in slurry and resin. ENGINEERING AND WORK PRACTICE CONTROLS PLAN FOR COMPLIANCE WITH OSHA VCM EXPOSURE STANDARD CONOCO CHEMICALS OKLAHOMA CITY CHEMICAL PLANT April, L975 W---O--R--K----P---R--A--C--T---IC---E----C--O---N--T--R--O--L--S-- ---E--N---G--I-N---E--E--R--I-N---G-----C--O--N--T--R--O---L-S-- ^ 2 g g oC U 1. Design and install equipment re quired for steam stripping the slurry. Essentially all processing j 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 stjeam 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 problems 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 j leaving the plant will be decreased.) EXPOSURE SOURCE 2B Obtaining and handling samples. 30 VCM rail car unloading WORK PRACTICE CONTROLS ENGINEERING CONTROLS 2o Wear personnel protection equipment wich meets OSHA standards when sampling reactors, slurry, wet cake, or resin. 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 l r\j * the early part of reaction in o contain high concentrations of j O VCM. By enclosing the reactor j o o sampling system, exposure in the ! o reactor area will be decreased eC u because VCM will not be emitted u from the sample in the working area. c) Prepare an engineering design for an improved resin sampling system at the M-500 dryer. 3,, Wear personnel protection equipment which meets OSHA standards while at the un loading rack during car hook up and disconnect. 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. j 1 EXPOSURE SOURCE 4, Chemical wash screener 5c Reactor rinse after dump. 6. M-500 dryer exhaust. 70 All rotary seals, flexible hoses, pipe unions and flanges, valve stems and swivel joints which are in low or high concentration VCM serviceo 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. 0 0 0 0 1 5<f3 5. Transfer the effluent from the initial water rinse after reactor dump to the dump system and eliminate transfer to the sewer. ct o o 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 8. Opening and working on equipment or piping which may contain VCM in low or high concentrations. WORK PRACTICE CONTROLS ENGINEERING CONTROLS 8. a) Before opening, remove 8 VCM from equipment or piping to the lowest practical level by flushing, purging and/or evacuation, where possible,, b) Wear personnel protection equipment which meets OSHA standards when opening equip ment or piping which may contain VCM. c) Before commencing repair work, measure the VCM concentration in or near opened equipment or piping to determine what protective equipment is required and if further VCM removal should be attempted. Install electropolished internals in all reactors. Plant experience has shown that the frequency of reactor entries for cleaning is decreased when electropolished internals are used. This is due to a decrease in polymer build up on electropolished internals as compared to the build-up on other internals. The plant has five sets of internals. Two sets are electropolished and installed. One set is at the shop for electropolishing. The other two sets will be electropolished when they can be switched out. * ur> o o o o o QC o o