Document DKrjYRpmJyQ4dbB93BO6vOvO

;w-32 'REV 5 78) 123 ENVIWflEKM/1,1. HYGIENE Shell Oil Company Interoffice Memorandum MARCH 17, 1987 Return Document to Fils ---- Record Coov in File Information Coov Hecora uopy m xsjQ, Cop> <34uj .a vs Circulate: k~ FROM: SR. INDUSTRIAL HYGIENIST, HEALTH & SAFETY, MFG. & TECH. TO: SEE ATTACHED DISTRIBUTION LIST SUBJECT: SANDBLASTING GUIDELINE PLAINTIFF'S EXHIBIT SH-891 Recently several questions were raised concerning the requirements for sandblasting when grit containing 1-5% silica is used. These questions were addressed in light of the planned inspection of equipment in wet hydrogen sulfide services in Shell refineries. The attached guideline identifies several industrial hygiene considerations, many of which will not be new to location programs. Please feel free to utilize the attached as a check against established procedures or procedures planned to be used. If you have any questions or comments, please give me a call. P. J. Snyder PJS:bjd Attachment cc: J. H. Blunt A. D. Ditmar H. C. Grant P. J. Johnson L. L. LaRose J. D. Ransdell BT8707603 LAM 016392 DPMC-13137 DISTRIBUTION LIST ANACORTES REFINERY MANAGER, HEALTH, SAFETY AMD ENVIRONMENT DEER PARK MANUFACTURING COMPLEX SUPERINTENDENT, HEALTH, SAFETY AND ENVIRONMENTAL MANAGER, HEALTH AND SAFETY GEISMAR PLANT MANAGER, HEALTH, SAFETY AND ENVIRONMENT MARIETTA PLANT MANAGER, HEALTH, SAFETY AND ENVIRONMENT MARTINEZ MANUFACTURING COMPLEX MANAGER, HEALTH AND SAFETY NORCO MANUFACTURING COMPLEX MANAGER, HEALTH, SAFETY AND MEDICAL ODESSA REFINERY MANAGER, HEALTH, SAFETY AND ENVIRONMENTAL TAFT PLANT SAFETY AND TRAINING REPRESENTATIVE WILMINGTON MANUFACTURING COMPLEX MANAGER, HEALTH, SAFETY AND ENVIRONMENTAL WOODBURY PLANT MANAGER, HEALTH, SAFETY AND ENVIRONMENT WOOD RIVER MANUFACTURING COMPLEX MANAGER, SAFETY AND INDUSTRIAL HYGIENE 2 BT8707603 LAM 016393 DPMC-13138 HEALTH AND SAFETY WORKPRACTICE GUIDELINE FOR ABRASIVE BLASTING INSIDE VESSELS AND TANKS WITH SILICA I GENERAL 1. Each location conducting dry abrasive blasting with grit containing silica should establish local health and safety procedures for it's use. This is particularly important where the abrasive blasting is to be conducted inside confined spaces such as vessels, or tanks. The following outline illustrates some of the factors to be consi dered in establishing a local program. 2. While abrasive blasting in itself involves potential exposure to a variety of health and safety hazards, additional precautionary measure should be considered where silica containing grits are used. Abrasive grits containing more than 1% free silica are considered relevant to this discussion e.g. "Starblast". 3. The permissible exposure limit (PEL) associated with the use of silica containing grits is a primarily a function of the % silica present. For example, the Federal OSHA PEL for a grit containing 5% free silica would be: For "respirable" dust exposure 10 mg/m3 ------------- =1.4 mg/m3 XSio2 +2 This can be compared to a 5 mg/m3 limit associated with respirable "nuisance dust". Consideration should also be given to any state OSHA regulations that may apply. 4. Due to the lower permissible exposure limits associated with silica, assuring compliance with the PEL during abrasive blasting activities requires additional considerations for the integrity of the blasting hood, filtration systems on compressors used for breathing air and exposure to downwind personnel. 5. Where blasting is conducted inside vessels high dust levels should be assumed. With regard to downwind exposure potential, studies have shown that exposure during (pure) silica sandblasting can occur for significant distances, e.g. 150+ feet. 6. While skin contact and ingestion of silica are not relevant routes of entry, appropriate hygienic procedures should be adopted to minimize gross contamination of skin and street clothing. This is particularly important if toxic metals are known to be present (e.g. nickel, chromium, lead, etc.). LAM 016394 BT8707601 DPMC-13139 2 II TRAINING REQUIREMENTS 1. Employees who engage in silica blasting operations should be trained in the specific health hazards associated with silica and the required procedures for safe blasting. Where contractor employees are used, training is the responsibility of the contractor employer. Whether or not this training has been accomplished should be ascer tained by Shell. Ill PROCEDURES FOR ABRASIVE BLASTING INSIDE VESSELS 1. A pre-job orientation should be conducted with any contractor to be employed. 2. Warning signs and isolation of the work area: As a minimum, the blasting area is to be roped off or otherwise bar ricaded so as to isolate the immediate work area. Signs containing the following warning or its equivalent should be posted: Caution - Silica Sandblasting INHALATION HAZARD Respiratory Protection Required Note: Where the silica content is less than \% , the sign in use should refer to abrasive blasting rather than silica sandblasting. The purpose of isolating the work area is to preclude pedestrian traffic from entering the restricted area without using respiratory .protection. 3. Air compressors used to supply breathing air are to be located and maintained upwind of any dust emission sources. Requirements for air compressors include: a. An exhaust stack to be separated from the intake (8 ft minimum). b. A particulate filter maintained in-line between the compressor and respirator c. Carbon monoxide measurements to be performed at least monthly on each compressor used for breathing air or at least once during each different sandblasting job. d. Grade D quality breathing air is required regardless of the air source used. lam 016395 4. Hearing protection should be worn at all times during sandblasting and as may be required where noise levels exceed 90 dbA. Hearing protection requirements may be more restrictive if the work shift is longer than 8 hours. BT8707601 DPMC-13140 3 5. Where necessary to protect adjacent work areas, vessel blower exhaust should be deflected or otherwise filtered to minimize airborne dust levels outside the vessel. 6. Where applicable, the safety permit issued should state the required procedures. A copy of the required procedures should be provided to the contractor. IV RESPIRATORY PROTECTIVE EQUIPMENT 1. A program meeting the minimum requirements of the OSHA respiratory standard should be followed. This program should include: a. Adequate cleaning of respiratory equipment. Generally blasting hoods used by a single employee should be cleaned at least weekly. Prior to each use the inside of each sandblasting hood is to be free of visible dust, and accumulation of dirt. b. Fit testing of tight fitting (air purifying) respirators. Fit testing should not be conducted where facial hair exists between the sealing surface of the respirator and the face. c. Blasters are to wear NIOSH approved airline hoods. Typically such hoods, require a minimum airflow of 4 cfm. Air supplied equipment is also required of other personnel who enter vessels or tanks when blasting is underway. An air purifying dust mask may have to be worn under the airline hood of the blaster as supplemental protection when blasting is conducted inside vessels with poor ventilation. d. Potmen, other ancillary personnel, and inspectors are to wear at least NIOSH approved air purifying respirators inside the restricted area. Air purifying respiratory protection is to be worn by employees removing spent grit from vessels. e. For hot work environments, use of in-line air conditioning should be considered. V EXPOSURE MONITORING REQUIREMENTS 1. Personnel and area monitoring should be conducted where necessary to verify the acceptability of the procedures put in place with regard to downwind personnel, placement of the barricade, exposure to the potman, etc. LAM 016396 BT8707601 DPMC-13141 4 VI BULK SILICA ANALYSIS 1. As a minimum the material safety data sheet for the abrasive grit in use should be obtained prior to commencing work. Where necessary information on the estimated level of silica and toxic metals should be obtained from the supplier. This should be supplemented by an analysis by Shell or an outside laboratory periodically for verifica tion purposes. a. As an example, Duponts' Starblast is primarily composed of naturally occuring mineral staurolite. It is mined and shipped from a mineral deposit in Florida. The free silica content of their 1986 production averaged 2.5%. VII MEDICAL SURVEILLANCE 1. Shell employees should be included in the Shell Special Medical Surveillance program for Silica where exposures exceed 1/2 the permissible exposure limit for at least 30 days per year. This includes pulmonary function exams, chest xrays, and appropriate other medical tests to detect any early signs of pulmonary effects. The facility Industrial Hygienist should be consulted with regard to the minimum entrance criteria and exposure potential. 2. Contractor management should be advised of the silica medical surveillance program that Shell has in place for it's employees. Note: no specific OSHA standards presently require medical exams for silica exposure although they have been recommended by NIOSH. VIII ADDITIONAL INFORMATION 1. Health and Safety Procedure Guidelines, No.508A on Sandblasting (is sued July 1982) may be consulted for general safety considerations. 2. Abrasive Blasting Safety and Equipment Protection, a Dupont publica tion dated 5/2/85. BT8707601 LAM 016397 DPMC-13142