OPERATING ENGINEERS NATIONAL HAZMAT PROGRAM

Transcription

1 OPERATING ENGINEERS NATIONAL HAZMAT PROGRAM INTERNATIONAL ENVIRONMENTAL TECHNOLOGY & TRAINING CENTER LTC AMERICAS, INC. LTC 1072Pn Vacuum Blasting Machine (WALL/CEILING DECONTAMINATION) HUMAN FACTORS ASSESSMENT JANUARY 1999

2 LTC AMERICAS, INC. LTC 1072Pn Vacuum Blasting Machine TABLE OF CONTENTS ACKNOWLEDGMENTS... iii EXECUTIVE SUMMARY... iv SECTION 1 SUMMARY Technology Description...1 Key Results...1 SECTION 2 SYSTEM OPERATION...2 SECTION 3 HEALTH AND SAFETY EVALUATION General Health and Safety Concerns...3 Core Issues...3 Best Management Practices...4 Industrial Hygiene Monitoring...5 Human Factors Interface...9 Technology Applicability...9 SECTION 4 JOB SAFETY ANALYSIS (JSA)...10 SECTION 5 FAILURE MODES AND EFFECTS ANALYSIS (FMEA)...14 SECTION 6 TECHNOLOGY SAFETY DATA SHEET (TSDS)...15 SECTION 7 EMERGENCY RESPONSE/PREPAREDNESS...22 SECTION 8 REGULATORY POLICY ISSUES Core Requirements...22 Technology Specific Requirements...23 Best Management Practices...24 Core Training Requirements...24 Technology Specific Training...24 Special Training...25 Best Management Practice Training...25

3 TABLE OF CONTENTS (continued) SECTION 9 OPERATIONAL CONSIDERATIONS AND RECOMMENDATIONS...25 APPENDIX A - REFERENCES...30 APPENDIX B - INDUSTRIAL HYGIENE DATA...31 APPENDIX C - ACRONYMS...38

4 ACKNOWLEDGMENTS The human factors assessment of LTC Americas, Inc., LTC 1072Pn Vacuum Blasting Machine was conducted under support of the U.S. Department of Energy s Federal Energy Technology Center, under cooperative agreement DE-FC21-95MC32260 with the Operating Engineers National HAZMAT Program. The Operating Engineers National HAZMAT Program would like to thank the following people for their participation on the "research action team" and the professional expertise they provided for this assessment: Barbara McCabe Operating Engineers National Hazmat Program David Curry Operating Engineers Local Union 280 Jim Leslie Operating Engineers Local Union 12

5 EXECUTIVE SUMMARY The LTC 1072Pn Vacuum Blasting technology was tested and is being evaluated by Florida International University (FIU). In conjunction with FIU s evaluation of efficiency and cost, this report covers the hazard analysis and safety evaluation. It is a commercially available technology and has been used for various projects at locations throughout this country. During the testing demonstration of the LTC 1072Pn Vacuum Blasting Machine, two different shot blast heads were utilized. The larger blast head was attached to an articulating arm that supported the blast head and allowed for it's maneuverability. The smaller blast head was hand-held by the operator during blasting operations. The blast heads work on the principle of dry abrasive blasting and a mechanism of simultaneous recovery of the abrasive and the waste that is generated. The LTC 1072Pn Vacuum Blasting Machine is a blasting system with a dual nozzle capability. It uses a compressor linked to a cooler/dryer unit for operation. The air requirement for operation of the vacuum blasting machine is 1300 cfm with a pressure of 150 psi. The 1072Pn itself consists of a dual chamber pressure vessel, two vacuum generators with a built in venturi for each one, two primary filters, a HEPA filter, and a sealed half drum (22 gallon) for waste disposal. The abrasive (shot) from the pressure vessel is carried by a high pressure air stream and blasted out through a nozzle onto the surface to be cleaned. At the point of contact of the blast head with the surface, the blast head functions as a containment structure to allow the waste generated at the surface along with the abrasive to be vacuumed by the blast head and placed back into the dust separator of the machine. This mixture of waste and abrasive passes through a set of screens where the abrasive drops into the dual chambered pressure vessel. This is accomplished by the sieve action of the screens and the effects of gravity. Due to the cyclic motion of the valves in the upper and lower chambers of the pressure vessel, the abrasive passes through the pressure vessel, being recycled and reused. The waste in the dust separator of the machine is vacuumed into a filtering area where it passes through the primary and HEPA filters and collects at the bottom of the filtering area. Periodically, the reverse pulsing and the dust dump button on the vacuum are activated to clean the filters and vibrate the dust dump bellows. The waste is then collected in the drum. This waste collection is done under total vacuum. There is a Concrete Filter Cleaning Valve (CFCV) located on the 1072Pn which increases the continuous blasting time between filter cleanings. The 1072Pn Vacuum Blasting Machine is capable of being fitted with optional electronic controls. These electronic controls enable an automatic shutdown of the blast head if it

6 is moved away from the surface being blasted or if the differential pressure across the filters exceeds the programmed maximum. During the assessment sampling was conducted for dust and noise and general observational techniques were conducted for ergonomics. General observational techniques showed the potential for ergonomic problems during setup, operation, maintenance, and decontamination of the vacuum blasting machine. There is potential for muscle/back stress and/or injuries due to bending, twisting, and lifting. The maneuvering of the large shot blast head attached to the articulating arm onto a scissor lift, and the awkward and static postures the operator has to assume while operating the large shot blast head with the arm and the small hand-held shot blast head were the main ergonomic issues of concern. Personal and area dust sampling was conducted during operation of the vacuum blasting machine. Two samples, one for the operator of the large shot blast head and one for the operator of the small shot blast head, showed results of mg/m 3 and mg/m 3. These results are above the OSHA PEL of 15 mg/m 3 and the ACGIH TLV of 10 mg/m 3 but shot was visible on the filters of the samples. This could account for the results in excess of the PEL and TLV. Area samples and one sample for the operator of the small shot blast head showed negligible results (there was no difference between sample pre-and post- weights). Since the time spent in the work area, the distance from the actual blasting operation, and ventilation in the work area may affect an individual worker s exposure level, a monitoring plan will need to be developed to account for the site specific conditions where the vacuum blasting machine is being used. A complete air sampling plan for a site will need to be developed to include not only dust but other contaminants specific to the coating removal project. Personal and area noise monitoring was also conducted during operation of the vacuum blasting machine. Personal monitoring showed noise doses of % which would give a time-weighted average (TWA), assuming no further noise exposure for the 8-hour shift, of dba and % (TWA dba). Area monitoring showed noise doses of % (TWA dba) and 69.69% (TWA 87.4 dba). These area results show exposures above the OSHA action level of 85 dba and the PEL of 90 dba. A projected 8-hour noise dose and resultant TWA showed noise doses of % (TWA dba) and % (TWA dba) for personal monitoring and % (TWA dba) and % (TWA dba) for area monitoring. These projected 8-hour noise doses also show noise exposures above the OSHA action level and the PEL. The OSHA allowable PEL for noise is a 100% dose or an 8-hour TWA of 90 dba. The above noise levels show noise is a hazard during operation of the vacuum blasting machine. Differences in noise exposure will be affected by the location of the worker in relation to the shot blasting operation and the amount of time the worker spends there.

7 The levels of exposure seen during the assessment will require the operators to be included in a hearing conservation program. In addition, engineering controls, administrative controls, and/or personal protective equipment (PPE - hearing protection devices) may be required. A monitoring plan should also take into consideration the work environment since the noise levels may increase or decrease based on the construction of the enclosure where the shot blasting operation is taking place. Recommendations for improved worker safety and health during use of the LTC 1072Pn Vacuum Blasting Machine include: 1. keeping all hoses and lines as orderly as possible in compliance with good housekeeping requirements; 2. ergonomic training to include techniques in lifting, bending, stooping, twisting, etc.; 3. picking up shot as the work progresses to avoid walking on a slippery surface caused by the shot; 4. assessing an increase in the capture velocity across the collection slot on the vacuum pickup device to determine if this will help with the problem of shot being left on the walking surface; 5. the use of faceshields in addition to goggles or safety glasses with side shields to avoid eye injury from shot that becomes a projectile; 6. an automatic full drum warning system on the vacuum unit; and 7. electronic controls to program the machine to automatically stop if the blast head is displaced from the surface or if the differential pressure across the filters exceeds the programmed maximum become standard on all machines instead of an option.

8 LTC AMERICAS, INC. Human Factors Assessment (WALL/CEILING DECONTAMINATION) TECHNOLOGY DESCRIPTION SECTION 1 - SUMMARY The LTC 1072Pn Vacuum Blasting Machine technology was tested and is being evaluated by Florida International University (FIU). In conjunction with FIU s evaluation of efficiency and cost, this report covers the hazard analysis and safety evaluation. It is a commercially available technology and has been used for various projects at locations throughout this country. The LTC 1072Pn Vacuum Blasting Machine is a shot blasting machine with a dual nozzle capability. The 1072Pn consists of a dual chamber pressure vessel, two vacuum generators with a built in venturi for each one, two primary filters, a high efficiency particulate air (HEPA) filter, and a sealed half drum for waste disposal. The abrasive from the pressure vessel is carried by a high pressure air stream and blasted out through a nozzle onto the surface to be cleaned. At the point of contact of the blast head with the surface, the blast head functions as a containment structure to allow the waste generated at the surface along with the abrasive to be vacuumed by the blast head and placed back into the dust separator of the machine. Due to the cyclic motion of the valves in the upper and lower chambers of the pressure vessel, the abrasive passes through the pressure vessel, being recycled and reused. KEY RESULTS The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Visible dust was seen occasionally during operation of the shot blaster and the air sampling results showed values below and above the Occupational Safety and Health Administration (OSHA) permissible exposure limits (PEL), as well as the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV). This will be discussed in greater detail in the Industrial Hygiene Monitoring section of this report. Noise exposure was above the "action level" and varied from below to above the PEL. This will also be discussed in greater detail in the Industrial Hygiene section of this report. Further testing for each of these exposures is recommended because the environment where the technology is being used, the time the worker spends in the area, and the distance the worker is from the operational area, may cause the results to be higher or lower. In addition, since

9 there is the potential for dust generation and noise during shot blasting operations, dust and noise surveys appear to be required in all operational settings. Other safety and health hazards found were ergonomics, heat stress, tripping hazards, slipping hazards, electrical hazards, lockout/tagout, and hand-arm vibration (with use of the hand-held blasting unit). SECTION 2 - SYSTEM OPERATION During the testing demonstration of the LTC 1072Pn Vacuum Blasting Machine, two different shot blast heads were utilized. The larger blast head was attached to an articulating arm that supported and allowed for maneuverability of the blast head. The smaller blast head was hand-held by the operator during blasting operations. The blast heads work on the principle of dry abrasive blasting and a mechanism of simultaneous recovery of the abrasive and the waste that is generated. The LTC 1072Pn Vacuum Blasting Machine is a shot blasting machine with a dual nozzle capability. It uses a compressor linked to a cooler dryer unit for operation. The air requirement for operation of the vacuuming blast machine is 1300 cfm with a pressure of 150 psi. The 1072Pn consists of a dual chamber pressure vessel, two vacuum generators with a built in venturi for each one, two primary filters, a HEPA filter, and a sealed half drum (22-gallon) for waste disposal. The abrasive (shot) from the pressure vessel is carried by a high pressure air stream and blasted out through a nozzle onto the surface to be cleaned. At the point of contact of the blast head with the surface, the blast head functions as a containment structure to allow the waste generated at the surface, along with the abrasive, to be vacuumed by the blast head and placed back into the dust separator of the machine. This mixture of waste and abrasive passes through a set of screens where the abrasive drops into the dual chambered pressure vessel. This is accomplished by the sieve action of the screens and the effects of gravity. Due to the cyclic motion of the valves in the upper and lower chambers of the pressure vessel, the abrasive passes through the pressure vessel, being recycled and reused. The waste in the dust separator of the machine is vacuumed into a filtering area where it passes through the primary and HEPA filters and collects at the bottom of the filtering area. Periodically, the reverse pulsing and the dust dump button on the vacuum are activated to clean the filters and vibrate the dust dump bellows. The waste is then collected in the drum. This waste collection is done under total vacuum. There is a Concrete Filter Cleaning Valve (CFCV) located on the 1072Pn which increases the continuous blasting time between filter cleanings. The 1072Pn Vacuum Blasting Machine is capable of being fitted with optional electronic controls. These electronic controls enable an automatic shutdown of the blast head if it

10 is moved away from the surface being blasted or if the differential pressure across the filters exceeds the programmed maximum. SECTION 3 - HEALTH AND SAFETY EVALUATION GENERAL SAFETY AND HEALTH CONCERNS Personnel where the vacuum blasting technology is being used need to be concerned with two categories of safety and health issues. Core issues are those that are based on current safety and health regulatory requirements. Best management practices are related to issues that are not based on current safety and health regulations, but are key elements in preventing worker injury and illness on the job. Safety and health issues of concern with the vacuum blasting technology included: Core Issues: Tripping Hazards - The air lines and vacuum hoses, while necessary for the operation of the equipment, can become tripping hazards. Stringent housekeeping must be addressed. Pinch Points - The potential exists for the operator to have his/her fingers/hand injured during operation if the hand is placed in the area of the shot blasting head or near any moving parts of the equipment. The blasting mode should never be activated while maintenance is being conducted on the blast head or before the operator has control of the blast head. This should be considered under a lockout/tagout program. Lockout/Tagout - The user of the technology will need to develop a lockout/tagout program to assure there is not an accidental release of energy during maintenance/repair activities. Noise - The operator and workers in the area were subjected to noise levels above the action level for noise. The action level is 85 dba for an 8-hour work shift. The noise levels varied from below to above the PEL. The PEL is 90 dba for an 8-hour work shift. The level of exposure will be influenced by the amount of time the worker spends in the area where the vacuum operation is taking place and the distance the worker is from the operation. Therefore, noise is a concern and will be discussed in greater detail in the Industrial Hygiene section of this report. Dust - Occasionally the equipment did generate visible dust during operation and larger debris and shot were left on the walking surface below the ceiling/wall being blasted. Air sampling results showed a level of total dust exposure ranging

11 from less than to greater than the OSHA PEL and the ACGIH TLV. The PEL is 15 mg/m 3 and the TLV is 10 mg/m 3. There was, however, visible shot on the filters of the samples that were above the PEL and TLV. This could account for these elevated levels. The amount of dust generated in the breathing zone of the operator may change based on the environment in which the blasting operation is taking place and the location of the operator during the blasting operation. Therefore, the user of the technology will need to develop a sampling plan based on the individual site needs. Shot and larger debris were left on the walking surface and scaffolding during the blasting operation. This has the potential to become an airborne hazard. In addition, the shot left on the surface caused the surface to become very slippery. Figure 1. Operator on scissor lift blasting ceiling using large blast head attached to Best Management Practices: Working at heights Due to the nature of the work, i.e., ceiling and wall decontamination, it may be necessary to work from a scissor lift or scaffolding. Compliance with the OSHA standards for using these devices or for working from heights must be assured. Heat Stress - The operator may be subjected to an increase in heat stress due to the need to utilize personal protective equipment (PPE). The user will need to develop a heat stress program for the environment in which the technology is being used, taking into consideration any necessary PPE, ambient temperatures, etc. Ergonomics - The user was subjected to some ergonomic stressors that need to be taken into consideration, such as stooping, bending, twisting, kneeling, and lifting. The operator was, at times, placed in awkward positions with the potential for a great deal of neck, back, and shoulder stress/strain during operation. Struck by Hazards - The shot was sprayed upward and outward after striking the work surface. This could become a severe eye injury hazard. The operator needs to utilize a face-shield in addition to safety glasses with side shields or goggles. In addition, long sleeves may need to be worn due to the shot being propelled away from the surface and the blast head. Communication - Due to the noise generated by the technology during operation, communication may be difficult. Personnel working in the area should be familiar with and use hand signals when needed.

12 INDUSTRIAL HYGIENE MONITORING During this testing demonstration with the vacuum blasting machine, sampling was conducted for dust and noise. In addition, the wet-bulb globe temperature was monitored to evaluate heat stress. Observational evaluation was conducted for ergonomics and hand-arm vibration. Through general observational techniques the potential for ergonomic problems was evaluated. There is potential for upper and lower back, arm, and leg stress and/or injuries due to bending, twisting, and lifting associated with setup, operation, maintenance, and decontamination. Figure 2. Operator using large blast head attached to articulating arm to blast During setup and tear down activities for ceiling coating removal, the large shot head attached to the articulating arm had to be loaded onto a scissor lift. The scissor lift enabled the shot head to reach the ceiling. The shot head attached to the articulating arm was lifted manually onto the scissor lift. Due to the weight of the shot head/articulating arm and the size which makes handling and balancing while lifting more difficult, there is the potential for back, neck, shoulder, and arm stress and/or injuries. A hand truck, forklift or other materials handling device should be used when ever possible. During operation of the large shot blast head, the articulating arm takes all of the weight of the blast head. This alleviates the ergonomic concerns for stress and/or injury to the back, neck, shoulders, and arms that could be caused if the operator had to manage the weight of the shot blast head. There is, however, concern for the static postures and the overall posturing the operator must take to manipulate the articulating arm to blast the ceiling. This was mostly caused by the fact that the scissor lift was too high, even in its lowest position. The height of the scissor lift and the height of the operator caused the operator to be too high and subsequently he had to be in a hunched and awkward position to operate the blast head. The height of the scissor lift, or any platform that is used, needs to be correct for the operator and therefore, should be adjustable for the shortest to the tallest operator. This needs to be taken into consideration when determining the specifications for the equipment to be used on the job are done. Operation of the large shot blast head attached to the articulating arm to remove coating form the wall presents ergonomic concerns for stress and/or injury to the back, neck, shoulders, arms, and legs from the postures that must be assumed to reach the upper and lower portions of the wall. An articulating arm that could be tele-robotically

13 operated would alleviate many of the ergonomic concerns during both wall and ceiling coating removal. Operation of the small shot blast head for wall coating removal presents ergonomic concerns for stress and/or injury to the back, neck, shoulders, arms, and legs from the postures that must be assumed to hold the blast head against the wall and to reach the upper and lower portions of the wall. There is the potential for stress and/or injury to the back, shoulders, and arms from the static postures that are assumed while pressure must be placed against the blast head to keep it in contact with the wall. In addition, there is concern for arm-hand vibration which has the potential to cause problems such as Raynaud s Syndrome (vibration white finger). One additional ergonomic concern is the potential for back stress/injury when lifting the bags of shot for loading the vacuum blasting machine. The use of mechanical lifting devices or smaller bags of Figure 3. Operator preparing to blast wall using hand-held blast head. shot (and therefore less weight) should be assessed to help alleviate this potential for back injury. Heat stress parameters were monitored using a Quest QuestTemp 15 Heat Stress Monitor. The wet-bulb globe temperature was used to determine the work/rest regimen in accordance with the ACGIH recommendations. The wet-bulb globe temperature was adjusted for the type of clothing, including PPE, that the worker was wearing, in accordance with ACGIH guidelines. While heat stress will be increased when wearing PPE, the overall heat stress response will vary from worker to worker. Each situation in which the vacuum blasting is used will need to be evaluated for the heat stress potential, taking into consideration the wet-bulb globe temperature, PPE in use, physical condition of the worker, worker acclimatization, etc. Dust monitoring was conducted with a sampling train consisting of an SKC IOM Inhalable dust sampler coupled with an MSA Escort Elf air sampling pump. Pre- and post-sampling calibration was accomplished using a BIOS International DryCal DC1 primary calibration system. Sampling filters were desiccated pre- and post-sampling, and weighed on an OHAUS Scout Electronic balance. Sampling was conducted in accordance with National Institute of Occupational Safety and Health (NIOSH) Method 0500.

14 To assess the potential for dust exposure during operation of the LTC 1072Pn Vacuum Blasting Machine, personal and area dust sampling was conducted. Personal samples were taken on the operators and area samples were taken at the scissor lift and at the articulating arm during operation of the large shot blast head. One sample for the operator of the large shot blast head showed a result of mg/m 3 and one sample for the operator of the small shot blast head showed a result of mg/m 3. All of the area samples and one sample for the operator of the large shot blast head showed negligible results (there was no difference between sample preand-post weights). The area results are all below the OSHA PEL of 15 mg/m 3 and the ACGIH TLV of 10 mg/m 3 but the two personal samples for the operators are above these allowable limits. There was, however, visible shot on the filters for the two IOM samplers. This would account for the excessive results. (See Appendix B for sampling data). Since the time spent in the work area, the distance from the actual blasting operation, and ventilation in the work area may affect an individual worker s exposure level, a monitoring plan will need to be developed to account for the site specific conditions where the vacuum blasting machine is being used. A complete air sampling plan for a site will need to be developed to include not only dust but other contaminants specific to the coating removal project. To assess the potential for noise exposure during operation of the LTC 1072Pn Vacuum Blasting Machine, personal and area noise monitoring was conducted. Personal samples for the operator and area samples were taken during the operation of the large shot blast head for ceiling coating removal. The area samples were taken on the scissor lift. During wall coating removal using both the large and the small shot blast head, area samples were taken at the scaffolding. Noise sampling was conducted using Metrosonics db-3100 data logging noise dosimeters. Calibration was conducted pre- and post- monitoring using a Metrosonics CL304 acoustical calibrator. Personal monitoring was conducted for 1.4 hours (85 minutes) on the operator of the large blast head during ceiling coating removal and 1.9 hours (113 minutes) on the operator of the small blast head during wall coating removal. Noise monitoring for the operator of the large shot blast head showed a noise dose of % which would give a time-weighted average (TWA), assuming no further noise exposure for the 8-hour shift, of dba. Noise monitoring for the operator of the small shot blast head showed a noise dose of % (TWA dba). These results show exposures above the OSHA action level of 85 dba and the PEL of 90 dba. A projected 8-hour noise dose and resultant TWA showed the following results for the respective personal samples: % (TWA dba) and % (TWA dba). These projected 8-hour noise dose results show exposures above the OSHA action level and the PEL.

15 Area monitoring was conducted for 3.6 hours (215 minutes) and for 2.7 hours (163 minutes) in the area of the large blast head during ceiling coating removal and 1.3 hours (78 minutes) in the area of the small and large blast head during wall coating removal. Noise monitoring in the area of the large shot blast head during ceiling coating removal showed noise doses of % which would give a time-weighted average (TWA), assuming no further noise exposure for the 8-hour shift, of dba and % (TWA 98.0 dba). Noise monitoring in the area of the small and large shot blast head during wall coating removal showed noise doses of 69.69% (TWA 87.4 dba) and 87.14% (TWA 89.0 dba). These results show exposures above the OSHA action level of 85 dba and above and below the PEL of 90 dba. A projected 8-hour noise dose and resultant TWA showed the following results for the respective area samples: % (TWA dba), % (TWA dba), % (TWA dba), and % (TWA dba). These projected 8-hour noise dose results show exposures above the OSHA action level and the PEL. During the monitoring periods, the noise levels were averaged for each one minute period and then an overall average was calculated. This gave an average exposure level of db and db for the respective personal samples and db, db, db, and db for the respective area samples. The maximum sound levels observed during monitoring were db, and db for the personal samples and db, db, db, and db for the area samples. The OSHA allowable PEL for noise is a 100% dose or an 8-hour TWA of 90 dba. The above sampling results show noise to be a high hazard during shot blasting operations. Differences in noise exposure will be based on the location of the worker in relation to the shot blasting operation and the amount of time the worker spends there. The levels of exposure seen during the testing demonstration will require the operators to be included in a hearing conservation program. In addition, engineering controls, administrative controls, and/or personal protective equipment (PPE - hearing protection devices) will be required, as appropriate. The sampling plan should also take into consideration the work environment since the noise levels may increase or decrease based on the construction of the enclosure where the shot blasting operation is taking place. The percentage of time spent at each loudness level that comprises the exposures can be seen in Appendix B. HUMAN FACTORS INTERFACE Workers using a technology for ceiling or wall decontamination may encounter a variety of contaminants when working in a hazardous waste site environment. This may include contaminants associated with the ceiling or wall coating, the material used to construct the ceiling or wall, or contamination inherent in the environment where the ceiling or wall is located. Therefore, there may be a need to utilize different levels of PPE, such as level A, B, C, or D or different types as PPE such as Anti-C, for radiation

16 contamination. These contaminants should be identified by the site characterization prior to the start of the ceiling or wall decontamination project. The level of protection being utilized has the potential to cause several human factors interface problems. These may include, but not be limited to, visibility, manual dexterity, tactile sensation, an increase in heat stress, and an overall increase in physical stress. TECHNOLOGY APPLICABILITY Occasionally, there was visible dust during the shot blasting operation and the air sampling results showed some sampling values above the OSHA PEL and the ACGIH TLV. This may be accounted for by the visible shot that could be seen on the filter of the IOM samplers used for air sampling. There was a large amount of shot, from the blasting operation left on the walking surface. The system needs to be evaluated to determine if an increase in capture velocity across the collection slot on the vacuum pickup device would help alleviate this problem. The vacuum blasting machine will need to be disassembled to be decontaminated. This will not necessarily guarantee that decontamination will be complete. There is also concern for the amount of contamination that may have been spread to the internal parts of the equipment if shot that has been on the surface is deposited back into the vacuum blaster for use. If total decontamination is not possible, the equipment and/or parts of the equipment may need to be considered a consumable.

17 SECTION 4 - JOB SAFETY ANALYSIS JOB SAFETY ANALYSIS LTC AMERICAS, INC. LTC 1072Pn VACUUM BLAST SYSTEM (WALL/CEILING DECONTAMINATION) HAZARD CORRECTIVE ACTION UNLOADING EQUIPMENT/SETUP AND TEAR DOWN * Pinch Points * Use of hand protection * Use of proper hand tools for the job * Slips/Trips/Falls * Awareness of the specific hazards * Organization of materials (housekeeping) * Walking around areas that are congested/slippery when possible * Walking around tripping hazards when possible * Marking, isolating, and/or bunching together tripping hazards such as vacuum hoses * Fall from above * Prohibit workers from being under or too close to moving objects * Only use equipment appropriate for the load * Inspection program for equipment used to move heavy objects to assure it is in safe operating condition * Struck by/caught Between * Awareness of where equipment is being moved at all times * Prohibit worker from being between moving and stationary objects at all times * Keep personnel clear of moving objects * Use of proper warning devices on equipment (such as backup alarms on forklift)

18 * Muscular/Back Injury * Ergonomic training including safe lifting techniques * Use of equipment such as forklift or crane for unloading BLASTING CEILING/WALL * Slips/Trips/Falls * Awareness of site specific hazards (cords, tether lines, etc.) * Job site organization of materials (housekeeping) * Walk around hazards when possible * Cleaning up shot as it accumulates on surface * Marking, isolating, and/or bunching together tripping hazards such as vacuum hose * Restricted Communication (associated with noise levels) * Hand signals as standard operating procedures (SOPs) * Noise * Use engineering controls * Use administrative controls * Provide proper PPE training * Exposure to Contaminant and Shot * Utilization of proper PPE, including respiratory protection * Always use HEPA filter in vacuum * Better utilization of vacuum system * Assure seal around shot blast head is in good condition * Pinch Points * Use of hand protection * Use of proper hand tools for the job * Muscular/Back Injury * Limit duration of work * Training on proper lifting techniques and positioning for use of hand-held shot blaster * Use of platforms, such as scissor lift, that can be adjusted to the correct height for the operator * Spread of Contamination * Better utilization of vacuum system * Always use HEPA filter in vacuum

19 BLASTING CEILING/WALL (continued) * Struck by coating/substrate/shot * Wear appropriate PPE; safety glasses with side shields or goggles and face - shield, gloves, long sleeves, etc. * Interlock system which shuts shot blast heads off when contact with the surface being blasted is lost; the 1072Pn has an optional electronic controls that can provide automatic shutdown at the blast head if it is displaced away from the surface; the system should always be fitted with this option * Exposure to hand-arm vibration (with hand-held shot blaster) * Use of engineering controls * Use of anti-vibration PPE * Ergonomic training to include hand-arm vibration CHANGING DRUM * Exposure to Contaminants * Use of proper PPE, including respiratory protection * Method other than lid removal to determine drum is full - clear drum, audible alarm, etc. * Muscular/Back Injury * Handles on drum * Ergonomic training to include proper lifting technique * Use of a mechanical lifting device to move drum from vacuum unit pallet to staging area * Slips/Trips/Falls * Awareness of the specific hazards * Organization of materials (housekeeping) * Walking around areas that are congested/slippery when possible * Walking around tripping hazards when possible * Pinch Points * Use hand protection * Use of hand tools appropriate for the job

20 GENERAL MAINTENANCE * Exposure to contaminant * Wear proper PPE, including respiratory protection * Have something to sit or kneel on so do not have additional personnel exposure from sitting or kneeling on contaminated surface * Accidental activation of moving parts * Use proper lockout/tagout techniques * Pinch Points * Use of hand protection * Use of hand tools appropriate for the job * Use of appropriate lockout/tagout procedures * Slips/Trips/Falls * Awareness of the specific hazards * Organization of materials (housekeeping) * Walking around areas that are congested/slippery when possible * Walking around tripping hazards when possible * Ergonomics/Bending/Kneeling/ Lifting * Limit duration of work * Use proper lifting techniques * Ergonomic training to include proper lifting techniques

21 SECTION 5 - FAILURE MODE AND EFFECTS ANALYSIS FAILURE MODE AND EFFECTS ANALYSIS LTC AMERICAS, INC. LTC 1072Pn VACUUM BLAST SYSTEM (WALL/CEILING DECONTAMINATION) FAILURE MODE EFFECT * Lose vacuum pressure *Potential for higher concentration of contaminant to be released into atmosphere *Potential for greater amount of shot to be left on the surface * Reduced capture efficiency * Vacuum line is punctured/ruptured *Potential for higher concentration of contaminant to be released into atmosphere * Potential for greater amount of shot to be left on the surface * Reduced capture efficiency * Improper grounding of electrical components *Potential electrocution hazard for workers * Lose power *Equipment shuts down with potential to momentarily release higher concentration of contaminant into atmosphere * Vacuum hose becomes disconnected * Potential for higher concentration of contaminant to be released into atmosphere * Potential for greater amount of shot to be left on surface * Reduced capture efficiency * Blast seal worn or fails * Shot may be propelled away from work surface and therefore, become a struckby hazard

22 SECTION 6 - TECHNOLOGY SAFETY DATA SHEET TECHNOLOGY SAFETY DATA SHEET LTC AMERICAS, INC. LTC 1072Pn VACUUM BLAST SYSTEM (WALL/CEILING DECONTAMINATION) SECTION 1: TECHNOLOGY IDENTITY Manufacturer s Name and Address: LTC Americas, Inc Davis Drive Suite 142 Sterling, VA Other Names: Shot Blasting Machine 1072Pn Emergency Contact: Bob Miller (800) Information Contact: Bob Miller (800) Date Prepared: Signature of Preparer: Operating Engineers National Hazmat Program 1293 Airport Road, Beaver, WV 25813, phone , fax Under cooperative agreement DE-FC21-95 MC 32260

23 SECTION 2: PROCESS DESCRIPTION This process description and TSDS assume the use of two different shot blast heads with the LTC 1072Pn Vacuum Blasting Machine. The larger blast head was attached to an articulating arm that supported and allowed for maneuverability of the blast head. The smaller blast head was hand-held by the operator during blasting operations. The blast heads work on the principle of dry abrasive blasting and a mechanism of simultaneous recovery of the abrasive and the waste that is generated. The LTC 1072Pn Vacuum Blasting Machine is a shot blasting machine with a dual nozzle capability. It uses a compressor linked to a cooler/dryer unit for operation. The air requirement for operation of the vacuum blasting machine is 1300 cfm with a pressure of 150 psi. The 1072Pn itself consists of a dual chamber pressure vessel, two vacuum generators with a built in venturi for each one, two primary filters, a HEPA filter, and a sealed half drum (22 gallon) for waste disposal. The abrasive (shot) from the pressure vessel is carried by a high pressure air stream and blasted out through a nozzle onto the surface to be cleaned. At the point of contact of the blast head with the surface, the blast head functions as a containment structure to allow the waste generated at the surface along with the abrasive to be vacuumed by the blast head and placed back into the dust separator of the machine. This mixture of waste and abrasive passes through a set of screens where the abrasive drops into the dual chambered pressure vessel. This is accomplished by the sieve action of the screens and the effects of gravity. Due to the cyclic motion of the valves in the upper and lower chambers of the pressure vessel, the abrasive passes through the pressure vessel, being recycled and reused. The waste in the dust separator of the machine is vacuumed into a filtering area where it passes through the primary and HEPA filters and collects at the bottom of the filtering area. Periodically, the reverse pulsing and the dust dump button on the vacuum are activated to clean the filters and vibrate the dust dump bellows. The waste is then collected in the drum. This waste collection is done under total vacuum. There is a Concrete Filter Cleaning Valve (CFCV) located on the 1072Pn which increases the continuous blasting time between filter cleanings. The 1072Pn Vacuum Blasting Machine is capable of being fitted with optional electronic controls. These electronic controls enable an automatic shutdown of the blast head if it is moved away from the surface being blasted or if the differential pressure across the filters exceeds the programmed maximum.

24 SECTION 3: PROCESS DIAGRAMS Process diagram not available SECTION 4: CONTAMINANTS AND MEDIA The technology has the potential to cause paint and primer dust and associated contaminants to become airborne. Specific contaminants need to be evaluated on a site-by-site, job-by-job basis to determine the potential for exposure. SECTION 5: ASSOCIATED SAFETY HAZARDS Probability of Occurrence of Hazard: 1 Hazard may be present but not expected over background level 2 Some level of hazard above background level known to be present 3 High hazard potential 4 Potential for imminent danger to life and health A. ELECTRICAL (LOCKOUT/TAGOUT) RISK RATING: 2 The vacuum blasting machine and blast heads are pneumatically operated. The air compressor used may be electrical or diesel powered. If the air compressor is electrical, appropriate precautions such as ground fault circuit interrupters, proper grounding, etc. will need to be considered. Proper lockout/tagout procedures need to be used when appropriate, i.e. during maintenance activities. B. FIRE AND EXPLOSION RISK RATING: 1 Technology does not pose this hazard in and of itself but could not be used in an explosive environment due to the potential for sparking. Related air compressor may be of concern. C. CONFINED SPACE ENTRY RISK RATING: 1 Not part of this technology unless the specific location where shot blaster is being used is a confined space. In this case, confined space procedures would need to be followed. D. MECHANICAL HAZARDS RISK RATING: 2 Use of large equipment and hand tools may pose the following: pinch points, struck by, and caught between hazards. E. PRESSURE HAZARDS RISK RATING: 3 Airlines may present hazards if rupture occurs.

25 SECTION 5: ASSOCIATED SAFETY HAZARDS F. TRIPPING AND FALLING RISK RATING: 3 Airlines and vacuum hoses present potential hazards. G. LADDERS AND PLATFORM RISK RATING: 4 Due to the nature of the work associated with the technology i.e. ceiling/wall decontamination, it is often necessary to work at a height. This presents the potential for an object falling from above to injure workers at ground level. Proper precautions must be taken. Reaching the ceiling or the top portion of the wall may require the use of a scissor lift or scaffolding. Compliance with the OSHA standards for using these devices or for working from heights must be assured. No one should be permitted to work in the area of the scissor lift or scaffolding without a hard hat. H. MOVING VEHICLE RISK RATING: N/A Not part of this technology. I. BURIED UTILITIES, DRUMS, AND TANKS RISK RATING: N/A Not part of this technology. J. PROTRUDING OBJECTS RISK RATING: N/A Not part of this technology. K. GAS CYLINDERS RISK RATING: N/A Not part of this technology. L. TRENCHING AND EXCAVATIONS RISK RATING: N/A Not part of this technology. M. OVERHEAD LIFTS RISK RATING: 2 Unloading/loading and setup/tear down of technology may require overhead lifts or the use of a forklift. Proper precautions indicated. N. OVERHEAD HAZARDS RISK RATING: 3 Would be present if a crane were required to unload or load equipment. Due to the nature of the work associated with the technology, i.e. ceiling/wall decontamination, it is necessary to work at a height. This presents the potential for objects falling from above to injure workers at ground level. Proper precautions must be taken.

26 SECTION 6: ASSOCIATED HEALTH HAZARDS A. INHALATION HAZARD RISK RATING: 3 Technology may produce dust from the paint, primer, or ceiling/wall and its contaminants. Specific hazards will be identified from the site characterization. At a minimum, evaluation of total dust and/or respirable dust generated should be conducted. The shot may also present an inhalation hazard, especially as it becomes pulverized. B. SKIN ABSORPTION RISK RATING: 1 This would be dependent on the contaminants at the site and would be identified by the site characterization. C. HEAT STRESS RISK RATING: 1-4 Ambient conditions, work rates, and PPE levels must be considered. D. NOISE RISK RATING: 4 The technology presents a noise hazard. E. NON-IONIZING RADIATION RISK RATING: N/A Not part of this technology. F. IONIZING RADIATION RISK RATING: 1-4 Not part of this technology, but may be associated with surface being treated. G. COLD STRESS RISK RATING: 1 Technology does not produce a hazard, but ambient conditions need to be considered. H. ERGONOMIC HAZARDS RISK RATING: 3 Poses ergonomic hazards associated with lifting, bending, twisting, stooping and kneeling. These may cause injury/strain to the back, neck, shoulders, arms, knees, hips and/or legs. There is concern with the lifting of the large shot blast head attached to the articulating arm, the static postures that must be assumed to operate the large shot blast head attached to the articulating arm and to maintain the small hand-held shot blast head against the surface being blasted, and the lifting and dumping of the bags of shot. Mechanical lifting devices should be used when possible. I. OTHER RISK RATING: 3 The small hand-held shot blast head has the potential to cause problems associated with hand-arm vibration. This may lead to associated health problems such as Raynaud s syndrome.

27 SECTION 7: PHASE ANALYSIS A. CONSTRUCTION/START-UP The set-up/start-up phase presents several hazards including pinch points, slips/trips/falls, struck by/caught between, falling from above, electrical hazards, and muscular/back injury. B. OPERATION The operational phase presents several hazards including exposure to contaminant (airborne and from the surface), muscular/back injury, mechanical hazards, electrical hazards, working at heights, exposure to noise and arm-hand vibration. C. MAINTENANCE The maintenance phase presents several hazards including pinch points, slips/trips/falls, struck by/caught between, muscular/back injury, electrical, exposure to contaminants (airborne and from the surface), and accidental activation of moving parts. D. DECOMMISSIONING The decommissioning phase presents several hazards, including exposure to the contaminant, pinch points, slips/trips/falls, and muscular/back injury. SECTION 8: HEALTH AND SAFETY PLAN REQUIRED ELEMENTS A. AIR MONITORING When coatings on concrete or brick are blasted, total dust and respirable dust need to be monitored. Monitoring also needs to be done for specific paint and wall contaminants. In addition, noise monitoring is essential. B. WORKER TRAINING Training that would apply in this case may include but not be limited to: HAZWOPER (Hazardous Waste Operations and Emergency Response), HAZCOM (Hazard Communication), Respiratory Protection, Personal Protective Equipment (PPE), Hearing Conservation, Ergonomics (proper lifting, bending, stooping, kneeling and hand-arm vibration), specific training for equipment operation, CPR/First Aid/Emergency Response/Bloodborne Pathogens, Electrical Safety, Lockout/Tagout, Scaffolding, Working from heights, Materials handling, Hand Signal Communication, Construction Safety (OSHA 500) and/or General Industry Safety (OSHA 501).

28 SECTION 8: HEALTH AND SAFETY PLAN REQUIRED ELEMENTS (continued) C. EMERGENCY RESPONSE Emergency response planning for a site needs to assure adequate coverage for hazards described in the TSDS. Having at least one person per shift trained in CPR and first aid is recommended. D. MEDICAL SURVEILLANCE Evaluation of personnel s general health with emphasis on the cardiovascular and respiratory system, back and peripheral nervous system. In addition, medical surveillance as required by OSHA standards must be conducted. Initial and annual audiograms. E. INFORMATIONAL PROGRAM Workers must be trained in specific operation of equipment before use. SECTION 9: COMMENTS AND SPECIAL CONSIDERATIONS Due to the noise produced, communication may become difficult. Personnel working in the area should be familiar with and use hand signals as necessary. Only personnel who have been adequately trained in the operation of this technology and associated equipment should be permitted to operate and/or work with the equipment.

29 SECTION 7 - EMERGENCY RESPONSE/PREPAREDNESS The LTC 1072Pn Vacuum Blasting Machine would not be applicable to use in an emergency response situation. Emergency response/preparedness must be part of every hazardous waste site safety and health plan. In addition to credible site emergencies, site personnel must plan for credible emergencies in connection with the vacuum blasting machine. All precautions used when responding to an emergency situation at the site will apply. Before entering an area where the vacuum blasting machine is being used, the equipment needs to be completely shut down (de-energized). This technology does not appear to present conditions that could lead to an out-of-theordinary emergency. Consideration does however need to be given to the use of scissor lifts or scaffolding since this may cause additional overhead hazards to be present in an emergency situation. SECTION 8 - REGULATORY/POLICY ISSUES The site safety and health personnel where the LTC 1072Pn Vacuum Blasting Machine is being used need to be concerned with safety and health regulations applicable to the issues discussed above. Regulations that apply may be divided into four categories. Core requirements are those regulations that would apply to any hazardous waste work site, regardless of the type of job. Technology specific requirements are those regulations that apply due to the specific technology being used. Special requirements are standards and policies that are specific to the technology itself and are required by reference in a regulation. Best management practices are not required but are recommended by organizations such as the American National Standards Institute (ANSI), NIOSH, Department of Energy (DOE), National Fire Protection Association (NFPA), etc. These regulations/standards may include but not be limited to the following: Core Requirements: OSHA 29 CFR Housekeeping OSHA 29 CFR Sanitation ( (a)(3) covers housekeeping) OSHA 29 CFR 1926 Subpart Z Toxic and Hazardous Substances OSHA 29 CFR 1910 Subpart Z Toxic and Hazardous Substances

30 OSHA 29 CFR Hazard Communication OSHA 29 CFR Hazard Communication OSHA 29 CFR Hazardous Waste Operations and Emergency Response OSHA 29 CFR Hazardous Waste Operations and Emergency Response Occupational Safety and Health Act 1970(5)(a)(1) General Duty Clause Technology Specific Requirements: OSHA 29 CFR The Control of Hazardous Energy (Lockout/Tagout) OSHA 29 CFR Occupational Noise Exposure OSHA 29 CFR Occupational Noise Exposure OSHA 29 CFR Respiratory Protection OSHA 29 CFR Respiratory Protection OSHA 29 CFR Eye and Face Protection OSHA 29 CFR Eye and Face Protection OSHA 29 CFR Personal Protective Equipment OSHA 29 CFR General Requirements (Personal Protective Equipment) OSHA 29 CFR 1926 Subpart L Scaffolding OSHA Safety Requirements for Scaffolding OSHA 29 CFR Vehicle-Mounted Elevating and Rotating Work Platforms OSHA 1926 Subpart I Tools-Hand and Power OSHA 1910 Subpart P Hand and Portable Powered Tools and Other Hand-Held Equipment OSHA 29 CFR Handling Materials general

31 OSHA 29 CFR Material Handling Equipment OSHA 29 CFR First Aid and Medical Attention OSHA 29 CFR Medical Services and First Aid OSHA 29 CFR Toxic and Hazardous Substances Best Management Practices: ACGIH Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices NIOSH Revised Lifting Equation, 1994 In addition to the above regulations and policies, it is imperative that all workers have appropriate and adequate training for the task and associated safety and health hazards. Training that would be required may be divided into four categories. Core training is that which is required for anyone entering a hazardous waste site to perform work, regardless of the type of job. Technology specific training is that training which is specific to the technology and required by safety and health standards. Special training is that which is specific to the technology to assure the worker is adequately trained for the task, but is not necessarily required by safety and health standards. Best management practices are trainings that while not mandated by health and safety standards, provide information and knowledge to the worker that will allow the worker to perform his/her job safely. Training to be applied for the LTC 1072Pn Vacuum Blasting Machine may include but not be limited to: Core Training Requirements: HAZWOPER HAZCOM Technology Specific Training: Respiratory Protection Hearing Conservation Personal Protective Equipment Lockout/Tagout

32 Scaffolding Special Training: Job specific training for equipment operation Best Management Practice Training: Electrical Safety Ergonomics (proper lifting, bending, stooping, kneeling) Heat stress (learning to recognize signs and symptoms) CPR/First Aid/Emergency Response/Blood-borne Pathogens Hand Signal Communication Construction Safety (OSHA 500) and or General Industry Safety (OSHA 501) SECTION 9 - OPERATIONAL CONSIDERATIONS & RECOMMENDATIONS Recommendations made here for improved worker safety and health take into consideration the operation of the vacuum blasting machine without the optional electronic controls. Specific recommendations include: Workers must be aware of the tripping hazards associated with hoses and cords that are necessary to operate the equipment. Keeping these as orderly as possible in compliance with good housekeeping regulations will help avoid injury due to tripping. The operators need to have training in ergonomics to assure proper techniques in lifting, bending, stooping, twisting, etc. during equipment setup, operation, maintenance and decontamination. During setup and tear down activities for ceiling coating removal, the large shot head attached to the articulating arm had to be loaded onto a scissor lift. The scissor lift enabled the shot blast head to reach the ceiling. The shot blast head attached to the articulating arm was manually lifted onto the scissor lift. Due to the weight of the shot head/articulating arm and the size which makes handling and balancing while lifting more difficult, there is the potential for back, neck, shoulder, and arm stress and/or injuries. It is recommended that a hand truck, forklift or other materials handling device be used whenever possible.

33 During operation of the large shot blast head, the articulating arm takes all of the weight of the blast head. This alleviates the ergonomic concerns for stress and/or injury to the back, neck, shoulders, and arms that could be caused if the operator had to manage the weight of the shot blast head. There is, however, concern for the static postures and the overall posturing the operator must take to manipulate the articulating arm to blast the ceiling. This was mostly caused by the fact that the scissor lift was too high, even in its lowest position. The height of the scissor lift and the height of the operator caused the operator to be too high and subsequently he had to be in a hunched and awkward position to operate the blast head. The height of the scissor lift, or any platform that is used, needs to be of the correct height for the operator and therefore, should be adjustable for the shortest to the tallest operator. This needs to be taken into consideration when determining the specifications for the equipment to be used on the job. Operation of the large shot blast head attached to the articulating arm to remove coating from the wall presents ergonomic concerns for stress and/or injury to the back, neck, shoulders, arms, and legs from the postures that must be assumed to reach the upper and lower portions of the wall. An articulating arm that could reach the ceiling and/or wall area from ground level and be tele-robotically operated would eliminate most of the ergonomic concerns associated with the operation of the vacuum blasting machine with the large shot blast head. Operation of the small shot blast head for wall coating removal presents ergonomic concerns for stress and/or injury to the back, neck, shoulders, arms, and legs from the postures that must be assumed to hold the blast head against the wall and to reach the upper and lower portions of the wall. There is the potential for stress and/or injury to the back, shoulders, and arms from the static postures that are assumed while pressure must be placed against the blast head to keep it in contact with the wall. In addition, there is concern for hand-arm vibration which has the potential to cause problems such as Raynaud s Syndrome (vibration white finger). An articulating arm or telerobotic operation would eliminate most of these ergonomic concerns. One additional ergonomic concern is the potential for back stress/injury when lifting the bags of shot for loading the shot blaster. It is recommended that the use of mechanical lifting devices or smaller bags of shot (and therefore less weight) be assessed to alleviate this potential for back injury. During blasting operations, there was a significant amount of shot left on the walking surface. This shot may be picked up with a magnet and recycled back into the shot blaster. This practice has the potential to spread contamination to the internal parts of the equipment. This practice may need to be eliminated based on the contaminants in the area of operation.

34 The shot left on the walking surface made the surface very slippery. The vacuum system needs to be evaluated to determine if an increase in capture velocity across the collection slot on the vacuum pickup device would help alleviate this problem. Noise monitoring showed the potential for operators to be over the "action level" and the PEL for noise, both during the monitoring period and if this level of exposure had continued for an 8-hour work shift. Noise needs to be considered as a hazard where the shot blasting operation takes place. The operators will need to be included in a hearing conservation program. In addition, engineering controls, administrative controls and/or PPE (hearing protection devices) will be required. Noise exposure will be based on the location of the worker in relation to the shot blasting operation and the amount of time the worker spends there. A sampling plan should also take into consideration the work environment since the noise levels may increase or decrease based on the construction of the enclosure where the shot blasting operation is taking place. During operation of the vacuum blasting machine, shot became a potential projectile. This could lead to a severe eye injury. The operator needs to use a face shield in addition to goggles or safety glasses with side shields. Air samples that showed results in excess of the OSHA PEL and the ACGIH TLV had visible shot on the filter. Therefore, dust does not appear to be a concern during the shot blasting operation but should be considered in the specific environment where the blasting is being conducted. Since the time spent in the work area, the distance from the actual blasting operation, and ventilation in the work area may affect an individual worker s exposure level, a monitoring plan will need to be developed to account for the site specific conditions where the vacuum blasting machine is being used. A complete air sampling plan for a site will need to be developed to include not only dust but other contaminants specific to the coating removal project. The operator must manually check to see if the drum on the vacuum is full. This presents the potential for exposure to the contaminant. An automatic full drum warning system would reduce the potential for exposure to the contaminant. It would also reduce the likelihood of the drum overfilling. If a fitting on an air line were to fail, the flying hose or the high pressure air has the potential to cause a severe injury. A safety line connected to the male and female parts of the fitting would keep the hose from becoming a flying object.

35 Reaching the ceiling and upper portions of the wall requires the use of a scissor lift, scaffolding, or other type of work platform. Proper precautions must be taken including compliance with the OSHA scaffold and vehicle-mounted elevating and, rotating work platforms regulations, falling object protection, and appropriate training. No one should be permitted to work in the area of the scaffolding or elevated platform without a hard hat. If the system is started without the blast head being in contact with the surface to be cleaned, shot will be projected from the blast head. This has the potential to cause a severe injury, especially an eye injury. There is an optional electronic control feature for the LTC 1072Pn Vacuum Blasting Machine that would eliminate this potential. The electronic control enables the operator to program the machine to automatically shutdown if the blast head is displaced away from the surface. It is recommended that this become a standard feature for the machine or the machine is not operated without this feature engaged. Figure 4. Accidental activation has the potential for shot to become projectiles. If the filters become clogged there is the potential for contaminants to be released into the atmosphere and therefore, the potential for worker exposure. There is an optional electronic control feature for the LTC 1072Pn Vacuum Blasting Machine that would eliminate this potential. The electronic control enables the operator to program the machine to automatically shutdown if the differential pressure across the filters exceeds the programmed maximum. It is recommended that this become a standard feature for this machine or the machine is not operated without this feature engaged. In addition, an automatic pre-set blow back filter cleaning feature on the machine would help to eliminate the problem of the filters becoming clogged and the resultant change in the differential pressure across the filters. Therefore, reducing the potential for worker exposure to the contaminants. The environment where the ceiling/wall decontamination is taking place has the potential to affect the dust and noise levels generated. Therefore, the need for an air sampling and noise monitoring program needs to be assessed on a site-by-site job-byjob basis. Additionally, site specific safety and health issues will need to be addressed.