['Specialized Industries', 'Hazardous Materials Safety - OSHA']
['Flammable Liquids', 'Spraying/Spray Finishing']
08/20/2024
Copyright 2024 J. J. Keller & Associate, Inc. For re-use options please contact copyright@jjkeller.com or call 800-558-5011.
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Most spray finishing materials are flammable so areas where spray finishing is done can present particular safety hazards. OSHA defines a spraying area as any area in which dangerous quantities of flammable vapors or mists, or combustible residues, dusts, or deposits are present due to the operation of spraying processes.
Your company might have a more enclosed structure where your finishing is done. This would be a spray booth, a power-ventilated structure provided to enclose or accommodate a spraying operation to confine and limit the escape of spray, vapor, and residue, and to safely conduct or direct them to an exhaust system.
If your workers perform spray finishing using flammable and combustible liquids, there are several hazards of which to be aware. Due to the flammable and combustible nature of most spray finishing materials, no smoking or sparking tools are allowed. These could cause fire and explosion. Paint fumes, vapors, mists, or powders must be ventilated properly. Respiratory protection must be provided if necessary. If your company has fixed extinguishing systems that use agents such as carbon dioxide in concentrations known to be hazardous to employee safety and health, your company must post warning signs.
Scope
Spray finishing using flammable and combustible liquids, regulated under 29 CFR 1910.107, covers:
- The application of flammable and combustible finishing materials as a spray by compressed air, airless or hydraulic atomization, steam, electrostatic methods, or by any other means in continuous or intermittent processes. This includes all spraying operations involving the use of organic peroxides and other dual component coatings, which must be conducted in approved sprinklered spray booths meeting the requirements of 29 CFR 1910.107.
- The application of combustible powders by powder spray guns, electrostatic powder spray guns, fluidized beds, or electrostatic fluidized beds.
If you have one of these applications at your facility, you must protect your employees who work in or around such spray finishing areas. However, there is an exemption. The regulation does not apply to outdoor spray application of buildings, tanks, or other similar structures, or to small portable spraying apparatus not used repeatedly in the same location. In addition, some automobile undercoating spray operations are exempt from the requirements pertaining to spray finishing operations. The exempt are operations conducted in areas having adequate ventilation, that use undercoating materials not more hazardous than kerosene, or undercoating materials using only solvents listed as having a flash point in excess of 100 degrees Fahrenheit.
Regulatory citations
- 29 CFR 1910.107 — Spray finishing using flammable and combustible materials.
Key definitions
- Aerated solid powders: Any powdered material used as a coating material which must be fluidized within a container by passing air uniformly from below.
- Approved: Approved and listed by a nationally recognized testing laboratory.
- Dry spray booth: A spray booth not equipped with a water washing system. A dry spray booth may be equipped with:
- (i) distribution or baffle plates to promote an even flow of air through the booth or cause the deposit of overspray before it enters the exhaust duct; or
- (ii) overspray dry filters to minimize dusts; or
- (iii) overspray dry filters to minimize dusts or residues entering exhaust ducts; or
- (iv) overspray dry filter rolls designed to minimize dusts or residues entering exhaust ducts; or
- (v) where dry powders are being sprayed, with powder collection systems so arranged in the exhaust to capture oversprayed material.
- Electrostatic fluidized bed: A container holding powder coating material which is aerated from below so as to form an air-supported expanded cloud of such material which is electrically charged with a charge opposite to the charge of the object to be coated; such object is transported, through the container immediately above the charged and aerated materials in order to be coated.
- Fluidized bed: A container holding powder coating material which is aerated from below so as to form an air-supported expanded cloud of such material through which the preheated object to be coated is immersed and transported.
- Spray booth: A power-ventilated structure provided to enclose or accommodate a spraying operation to confine and limit the escape of spray, vapor, and residue, and to safely conduct or direct them to an exhaust system.
- Spraying area: Any area in which dangerous quantities of flammable vapors or mists, or combustible residues, dusts, or deposits are present due to the operation of spraying processes.
- Waterwash spray booth: A spray booth equipped with a water washing system designed to minimize dusts or residues entering exhaust ducts and to permit the recovery of overspray finishing material.
Summary of requirements
- Cleaning. All spraying areas must be kept as free from the accumulation of deposits of combustible residues as practical, with cleaning conducted daily if necessary. Scrapers, spuds, or other such tools used for cleaning purposes must be of nonsparking material. The use of solvents for cleaning operations must be restricted to those having flashpoints not less than 100°F.; however, for cleaning spray nozzles and auxiliary equipment, solvents having flash points not less than those normally used in spray operations may be used. Such cleaning must be conducted inside spray booths and ventilating equipment operated during cleaning.
- Clothing storage. Spray finishing employees’ clothing must not be left on the premises overnight unless kept in metal lockers.
- Drying, curing, or fusion apparatus. Must conform to the Standard for Ovens and Furnaces, NFPA 86A-1969.
- Spray booths, rooms, or other enclosures used for spraying operations must not alternately be used for the purpose of drying by any arrangement which will cause a material increase in the surface temperature of the spray booth, room, or enclosure.
- Drying, curing, or fusion units utilizing a heating system having open flames or which may produce sparks must not be installed in a spraying area, but may be installed adjacent thereto when equipped with an interlocked ventilating system. See 1910.107(j)(3).
- Automobile refinishing spray booths or enclosures, otherwise installed and maintained in full conformity with 1910.107, may alternately be used for drying with portable electrical infrared drying apparatus when conforming with the requirements in 1910.107(j)(4).
- Electrical and other sources of ignition. All electrical equipment, open flames and other sources of ignition must conform to the requirements of 1910.107(c), with some exceptions.
- Electrostatic hand spraying equipment. Must be of approved types.
- Transformers, power-packs, control apparatus, and all other electrical portions of the equipment, with the exception of the handgun itself and its connections to the power supply, must be located outside of the spraying area.
- The handle of the spraying gun must be electrically connected to ground by a metallic connection and to be constructed so the operator in normal operating position is in intimate electrical contact with the grounded handle.
- All electrically conductive objects in the spraying area must be adequately grounded.
- Objects being painted or coated must be maintained in metallic contact with the conveyor or other grounded support.
- The electrical equipment must be interlocked with the ventilation of the spraying area so the equipment cannot be operated unless the ventilation fans are in operation.
- The spraying operation must take place within a spray area which is adequately ventilated to remove solvent vapors released from the operation.
- Fixed electrostatic apparatus. Must be of approved types, and must be equipped with automatic controls which will operate without time delay to disconnect the power supply to the high-voltage transformer and to signal the operator. See 1910.107(h)(9).
- Transformers, power packs, control apparatus, and all other electrical portions of the equipment, with the exception of high-voltage grids, electrodes, and electrostatic atomizing heads and their connections, must be located outside of the spraying area.
- Electrodes and electrostatic atomizing heads must be adequately supported in permanent locations and must be effectively insulated from the ground.
- High-voltage leads to electrodes must be properly insulated and protected from mechanical injury or exposure to destructive chemicals. Electrostatic atomizing heads must be effectively and permanently supported on suitable insulators and must be effectively guarded against accidental contact or grounding. An automatic means must be provided for grounding the electrode system when it is electrically de-energized for any reason. All insulators must be kept clean and dry.
- A safe distance must be maintained between goods being painted and electrodes or electrostatic atomizing heads or conductors of at least twice the sparking distance. A suitable sign indicating this safe distance must be conspicuously posted near the assembly.
- Goods being painted using this process are to be supported on conveyors. The conveyors must be so arranged as to maintain safe distances between the goods and the electrodes for electrostatic atomizing heads at all times.
- Adequate booths, fencing, railings, or guards must be so placed about the equipment that they, either by their location or character or both, assure that a safe isolation of the process is maintained from plant storage or personnel. Such railings, fencing, and guards must be of conducting material, adequately grounded.
- Where electrostatic atomization is used, the spraying area must be so ventilated as to insure safe conditions from a fire and health standpoint.
- All areas used for spraying, including the interior of the booth, must be protected by automatic sprinklers where this protection is available. Where this protection is not available, other approved automatic extinguishing equipment must be provided.
- Flammable liquids and liquids with a flashpoint greater than 199.4°F (93°C). The storage of flammable liquids or liquids with a flashpoint greater than 199.4°F (93°C) in connection with spraying operations must conform to the requirements of 1910.106, where applicable. See also 1910.107(e).
- Hazardous materials combinations. Spray booths must not be alternately used for different types of coating materials, where the combination of the materials may be conducive to spontaneous ignition, unless all deposits of the first used material are removed from the booth and exhaust ducts prior to spraying with the second used material.
- Labeling. The spraying and powder coating equipment must carry a prominent permanently installed warning regarding the necessity for a grounding feature on all electrically conductive objects in the spraying area or within the charging influence of the electrodes. The drying apparatus must contain a prominently located, permanently attached warning sign indicating that ventilation should be maintained during the drying period and that spraying should not be conducted in the vicinity that spray will deposit on apparatus.
- Posting.
- Smoking must be prohibited and No Smoking signs must be prominently displayed and only nonsparking tools may be used in any area where organic peroxides are stored, mixed or applied.
- No smoking signs in large letters on contrasting color background must be conspicuously posted at all spraying areas, paint storage rooms, powder coating areas and powder storage rooms.
- A safe distance must be maintained between goods being painted and electrodes or electrostatic atomizing heads or conductors of at least twice the sparking distance. A suitable sign indicating safe distance must be conspicuously posted near the assembly.
- The spraying and powder coating equipment must carry a prominent permanently installed warning regarding the necessity for a grounding feature on all electrically conductive objects in the spraying area or within the charging influence of the electrodes.
- The drying apparatus must contain a prominently located, permanently attached warning sign indicating that ventilation should be maintained during the drying period and that spraying should not be conducted in the vicinity that spray will deposit on apparatus.
- Powder coating. Electrical equipment and other sources of ignition must conform to the requirements of 1910.107(c)(1)(i)-(iv), (8), and (9)(i), and Subpart S of 1910.
- Exhaust ventilation must be sufficient to maintain the atmosphere below the lowest explosive limits for the materials being applied. All nondeposited air-suspended powders must be safely removed via exhaust ducts to the powder recovery cyclone or receptacle.
- Powders must not be released to the outside atmosphere.
- All areas must be kept free of the accumulation of powder coating dusts, particularly such horizontal surfaces as ledges, beams, pipes, hoods, booths, and floors.
- Transformers, powerpacks, control apparatus, and all other electrical portions of the equipment, with the exception of the charging electrodes and their connections to the power supply must be located outside of the powder coating area.
- All electrically conductive objects within the charging influence of the electrodes must be adequately grounded.
- Objects being coated must be maintained in contact with the conveyor or other support in order to insure proper grounding. Hangers must be regularly cleaned to insure effective contact and areas of contact must be sharp points or knife edges where possible.
- The electrical equipment must be so interlocked with the ventilation system that the equipment cannot be operated unless the ventilation fans are in operation.
- Protection. In sprinklered buildings, the automatic sprinkler system in rooms containing spray finishing operations must conform to the requirements of 1910.159. In unsprinklered buildings where sprinklers are installed only to protect spraying areas, the installation must conform to such standards insofar as they are applicable. Sprinkler heads must be located so as to provide water distribution throughout the entire booth; sprinkler heads must be kept as free from deposits as practical by cleaning daily if necessary. An adequate supply of suitable, portable fire extinguishers must be installed near all spraying areas.
- Residue disposal. Residue scrapings and debris contaminated with residue must be immediately removed from the premises and properly disposed of. Approved metal waste cans must be provided wherever rags or waste are impregnated with finishing material and all such rags or waste deposited therein immediately after use. The contents of waste cans must be properly disposed of at least once daily or at the end of each shift.
- Spray booths. Spray booths must be substantially constructed of steel, securely and rigidly supported, or of concrete or masonry except that aluminum or other substantial noncombustible material may be used for intermittent or low volume spraying. Spray booths must be designed to sweep air currents toward the exhaust outlet. See 1910.107(b).
- Ventilation. Ventilating and exhaust systems must be in accordance with the Standard for Blower and Exhaust Systems for Vapor Removal, NFPA No. 91-1961, which is incorporated by reference as specified in 1910.6, where applicable and must also conform to the provisions of 1910.107(d).
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['Specialized Industries', 'Hazardous Materials Safety - OSHA']
['Flammable Liquids', 'Spraying/Spray Finishing']
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Copyright 2024 J. J. Keller & Associate, Inc. For re-use options please contact copyright@jjkeller.com or call 800-558-5011.