Working with flammable and hazardous materials and managing the unique hazards of penstocks are among the topics addressed by SSPC: The Society for Protective Coatings in a new “Confined Space Fact Sheet.”
SSPC developed the information at the request of the U.S. Chemical Safety Board, in the wake of its investigation into the catastrophic 2007 fire that claimed the lives of five painters in a penstock at the Xcel Energy Cabin Creek Hydroelectric Plant in Georgetown, CO.
The crew was beginning recoating work on a 1,530-foot steel section of the 4,300-foot penstock tunnel and was using flammable solvent to clean the application equipment when the solvent ignited, probably from a spark, CSB reported later.
“The initial fire quickly grew as it gained additional buckets of solvent and substantial amounts of combustible epoxy material, trapping and preventing five of 11 workers from exiting the single point of egress within the penstock,” the board said.
The Fact Sheet is designed to provide “guidance in addressing the hazards present and controls necessary when working in confined spaces,” according to SSPC.
“It is also meant to reinforce the importance of conducting a job-site safety analysis, developing project-specific safety plans and training field personnel, communicating the key information about [confined space jobs] to local authorities, and having a trained attendant in place and rescue teams nearby.”
The sheet stresses following OSHA’s guidance for fire protection and avoiding confined-space hazards of penstocks and concludes by discussing OSHA’s General Industry Standard for permit-required confined spaces.
The Fact Sheet covers these main topics and identifies these practices and issues.
Working with Flammable Materials
Most solvent-based paints and paint-solvents are flammable. Their vapors can burst into flame when exposed to sparks or flames. They are especially dangerous in confined spaces.
Before beginning work, a job safety analysis (JSA) must be performed, taking into consideration the equipment and materials to be used. Always perform operations and maintenance of equipment in accordance with the equipment manufacturers’ safe operating procedures.
To reduce fire hazards:
· Use paints and solvents with high flash points (above 100F).
· Provide good ventilation that is explosion proof (electrically ground and bond blowers and duct work).
· Avoid flames or sparks in work areas.
· Use explosion-proof lighting that provides adequate illumination.
See SSPC-Guide 12 for further information.
· Use non-sparking tools where feasible in close proximity to the work.
· Electrically ground spray guns and coating containers.
· Ground and bond containers when transferring contents from one container to another.
· Ground hoses, duct work, or piping that carry material such as paints, solvents, and abrasives that can create a static charge while material is moving through them.
· Implement the fire protection plan requirement described in 29 CFR 1926.150.
Avoiding Confined-Space Hazards
Confined spaces are defined as being large enough and so configured that an employee can enter and perform assigned work; having limited or restricted means for entry; and not designed for continuous occupancy. Confined spaces that are large, or part of a continuous system, such as a penstock, should always be managed as permit required as defined in OSHA’s confined space standard.
Such spaces should always be monitored for hazardous atmospheres both prior to entry and continuously in areas where work is being performed.
Whenever a hazard is present in the confined space, it should be considered a permit-required confined space. Examples of hazards include flammable vapors, airborne concentrations of materials above their occupational exposure limits, oxygen concentrations below 19.5% or above 23.5%, or any other atmospheric condition that is immediately dangerous to life or health.
Confined spaces, as may be found in the industrial coatings industry, frequently contain such hazards during surface preparation and coatings application, and therefore should be treated as permit-required confined spaces (PRCS).
Remember that you can create a permit-required confined space by changing the conditions or introducing new hazards such as solvents, combustible dusts (due to blasting or other surface preparation methods), or engulfment hazards.
Some examples of permit-required confined spaces commonly encountered in industrial and marine coating operations include interiors of storage tanks, silos, ship holds, boilers, and penstocks.
To eliminate these hazards:
· Employ the controls described in 29 CFR 1910.146 Permit-Required Confined Spaces.
· Use lockout/tagout controls as described in 29 CFR 1910.147(c)(3)(ii) to secure valves and piping that may otherwise introduce mechanical and/or electrical hazards into the space.
· Always try to substitute with less hazardous materials or methods.
· Perform work outside of the confined space wherever reasonably practicable or substitute a non-flammable for a flammable material whenever possible.
· Try to control the hazards by ventilation alone.
· If it is not possible to control the hazards by ventilation alone, establish a maximum permissible percentage below the <10% acceptable LEL (Lower Explosive Limit) for safe entry and occupancy of permit-required confined spaces.
· Establish and implement a written confined space rescue plan and written permit system that is reviewed annually.
· Ensure all field personnel are trained in every aspect of each project-specific confined space safety plan, including the rescue plan and each person’s role in the event that the plan has to be implemented.
· Visit the closest fire station and provide the chief with a briefing about the job, including all entries. Be sure to give the chief a package including all MSDSs. Make every attempt to have a site visit with the fire chief to review the entry permit and stage a simulated fire drill. This prepares everyone for the worst-case scenario of fire or serious injury.
· Follow the rescue service requirements outlined in 29 CFR 1910.119 (k). When a potential flammable atmosphere exists in a permit-required confined space a properly trained attendant needs to be available to take action immediately when an emergency situation develops inside the space.
· Communicate with the attendant as necessary to enable the attendant to monitor entrant status and to alert entrants of the need to evacuate the space.
· Require that confined space rescue teams be readily available for call out within five minutes at the permit spaces where the hazards pose an immediate threat to life or health, including the hazard of a potential flammable atmosphere.
· Employ appropriate, properly operating, and calibrated (when necessary) safety equipment for air monitoring, ventilation, and emergency retrieval, including special winches for workers entering the confined space through a vertical access more than five feet in depth.
· Continually monitor air quality within the work space.
· Whenever feasible, use safety harnesses with lifelines attached to a fixed point outside the confined space. Examine the workspace for snags and appurtenances that could make retrieval difficult. If obstructions render lifelines unusable, require entrants to wear the harnesses regardless to facilitate rescue.
· Have properly operating fire extinguishers, appropriate for the flammable material, available within the confined space.
Unique Hazards of Penstocks
The tragic accident that was the subject of the CSB investigation took place in a penstock, or enclosed tunnel that delivered water to power turbines in a hydroelectric plant. Confined spaces that are large, or part of a continuous system such as a penstock, pose particularly difficult conditions. They should always be managed as permit-required as defined in 29 CFR 1910.146, OSHA’s Permit-Required Confined Spaces Standard.
Such spaces should always be monitored for hazardous atmospheres both prior to entry and continuously in areas where work is being performed. The evacuation plans for penstocks that have only one egress (exit) point must provide for alternative escape routes or refuge chambers. This is key to avoiding serious injury and death.
OSHA’s Confined Space Standard
SSPC recognizes that the only comprehensive federal regulation currently governing work in confined spaces is outlined in OSHA’s General Industry Standard 29 CFR 1910.146 Permit-Required Confined Spaces.
The agency is working on a proposed rule on confined spaces more specific to construction as part of its upcoming revisions to 29 CFR 1926, Safety and Health Regulations for Construction. OSHA has also issued a Compliance Directive stating that the PRCS rule applies to certain industrial painting performed as maintenance work (see Appendix E, section (a) paragraph 8 of OSHA compliance directive CPL 02-00-100).
In the interim, SSPC continues to believe it is prudent for both facility owners and painting contractors to voluntarily adopt the comprehensive requirements of 29 CFR 1910.146 during industrial painting work in confined spaces.
Accepted industry practices and regulatory requirements should be implemented prior to and during all surface preparation and coating application operations in confined space which may create a hazardous atmosphere, including at a minimum:
· Proper training of workers in the recognition and control of fire and explosion hazards.
· Proper training of workers in every aspect of each project-specific confined space safety plan, including the rescue plan and each person’s role in the event that the plan has to be implemented.
· A job safety analysis (JSA) conducted by the company safety director, site safety officer, and supervisor to determine the hazards of the space, the equipment, and materials to be used. This should be conducted prior to the start of the project and on an ongoing basis when there are changes.
· Proper design and operation of ventilation equipment to reduce concentrations of flammable vapors to less than 10% of the LEL.
· Proper grounding and bonding of paint containers, spray equipment, and blowers.
· Use of explosion-proof lighting and equipment.
· Constant monitoring of the concentration of flammable vapors.
· Implement a project-specific confined space entry permit establishing the specific controls required for the subject project.
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