[Code of Federal Regulations]
[Title 29, Volume 5]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 29CFR1910.107]
[Page 270-279]
TITLE 29--LABOR
CHAPTER XVII--OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT
OF LABOR
PART 1910_OCCUPATIONAL SAFETY AND HEALTH STANDARDS--Table of Contents
Subpart H_Hazardous Materials
Sec. 1910.107 Spray finishing using flammable and combustible materials.
(a) Definitions applicable to this section--(1) Aerated solid
powders. Aerated powders shall mean any powdered material used as a
coating material which shall be fluidized within a container by passing
air uniformly from below. It is common practice to fluidize such
materials to form a fluidized powder bed and then dip the part to be
coated into the bed in a manner similar to that used in liquid dipping.
Such beds are also used as sources for powder spray operations.
(2) 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.
(3) 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.
(4) 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.
(5) Dry spray booth. A spray booth not equipped with a water washing
system as described in subparagraph (4) of this paragraph. 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.
(6) 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.
(7) 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.
(8) Approved. Shall mean approved and listed by a nationally
recognized testing laboratory. Refer to Sec. 1910.7 for definition of
nationally recognized testing laboratory.
(9) Listed. See ``approved'' in Sec. 1910.107(a)(8).
(b) Spray booths--(1) Construction. Spray booths shall 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 shall be designed to sweep air currents toward
the exhaust outlet.
(2) Interiors. The interior surfaces of spray booths shall be smooth
and continuous without edges and otherwise designed to prevent pocketing
of residues and facilitate cleaning and washing without injury.
(3) Floors. The floor surface of a spray booth and operator's
working area, if
[[Page 271]]
combustible, shall be covered with noncombustible material of such
character as to facilitate the safe cleaning and removal of residues.
(4) Distribution or baffle plates. Distribution or baffle plates, if
installed to promote an even flow of air through the booth or cause the
deposit of overspray before it enters the exhaust duct, shall be of
noncombustible material and readily removable or accessible on both
sides for cleaning. Such plates shall not be located in exhaust ducts.
(5) Dry type overspray collectors--(exhaust air filters). In
conventional dry type spray booths, overspray dry filters or filter
rolls, if installed, shall conform to the following:
(i) The spraying operations except electrostatic spraying operations
shall be so designed, installed and maintained that the average air
velocity over the open face of the booth (or booth cross section during
spraying operations) shall be not less than 100 linear feet per minute.
Electrostatic spraying operations may be conducted with an air velocity
over the open face of the booth of not less than 60 linear feet per
minute, or more, depending on the volume of the finishing material being
applied and its flammability and explosion characteristics. Visible
gauges or audible alarm or pressure activated devices shall be installed
to indicate or insure that the required air velocity is maintained.
Filter rolls shall be inspected to insure proper replacement of filter
media.
(ii) All discarded filter pads and filter rolls shall be immediately
removed to a safe, well-detached location or placed in a water-filled
metal container and disposed of at the close of the day's operation
unless maintained completely in water.
(iii) The location of filters in a spray booth shall be so as to not
reduce the effective booth enclosure of the articles being sprayed.
(iv) Space within the spray booth on the downstream and upstream
sides of filters shall be protected with approved automatic sprinklers.
(v) Filters or filter rolls shall not be used when applying a spray
material known to be highly susceptible to spontaneous heating and
ignition.
(vi) Clean filters or filter rolls shall be noncombustible or of a
type having a combustibility not in excess of class 2 filters as listed
by Underwriters' Laboratories, Inc. Filters and filter rolls shall not
be alternately used for different types of coating materials, where the
combination of materials may be conducive to spontaneous ignition. See
also paragraph (g)(6) of this section.
(6) Frontal area. Each spray booth having a frontal area larger than
9 square feet shall have a metal deflector or curtain not less than 2\1/
2\ inches deep installed at the upper outer edge of the booth over the
opening.
(7) Conveyors. Where conveyors are arranged to carry work into or
out of spray booths, the openings therefor shall be as small as
practical.
(8) Separation of operations. Each spray booth shall be separated
from other operations by not less than 3 feet, or by a greater distance,
or by such partition or wall as to reduce the danger from juxtaposition
of hazardous operations. See also paragraph (c)(1) of this section.
(9) Cleaning. Spray booths shall be so installed that all portions
are readily accessible for cleaning. A clear space of not less than 3
feet on all sides shall be kept free from storage or combustible
construction.
(10) Illumination. When spraying areas are illuminated through glass
panels or other transparent materials, only fixed lighting units shall
be used as a source of illumination. Panels shall effectively isolate
the spraying area from the area in which the lighting unit is located,
and shall be of a noncombustible material of such a nature or so
protected that breakage will be unlikely. Panels shall be so arranged
that normal accumulations of residue on the exposed surface of the panel
will not be raised to a dangerous temperature by radiation or conduction
from the source of illumination.
(c) Electrical and other sources of ignition--(1) Conformance. All
electrical equipment, open flames and other sources of ignition shall
conform to the requirements of this paragraph, except as follows:
[[Page 272]]
(i) Electrostatic apparatus shall conform to the requirements of
paragraphs (h) and (i) of this section;
(ii) Drying, curing, and fusion apparatus shall conform to the
requirements of paragraph (j) of this section;
(iii) Automobile undercoating spray operations in garages shall
conform to the requirements of paragraph (k) of this section;
(iv) Powder coating equipment shall conform to the requirements of
paragraph (c)(1) of this section.
(2) Minimum separation. There shall be no open flame or spark
producing equipment in any spraying area nor within 20 feet thereof,
unless separated by a partition.
(3) Hot surfaces. Space-heating appliances, steampipes, or hot
surfaces shall not be located in a spraying area where deposits of
combustible residues may readily accumulate.
(4) Wiring conformance. Electrical wiring and equipment shall
conform to the provisions of this paragraph and shall otherwise be in
accordance with subpart S of this part.
(5) Combustible residues, areas. Unless specifically approved for
locations containing both deposits of readily ignitable residue and
explosive vapors, there shall be no electrical equipment in any spraying
area, whereon deposits of combustible residues may readily accumulate,
except wiring in rigid conduit or in boxes or fittings containing no
taps, splices, or terminal connections.
(6) Wiring type approved. Electrical wiring and equipment not
subject to deposits of combustible residues but located in a spraying
area as herein defined shall be of explosion-proof type approved for
Class I, group D locations and shall otherwise conform to the provisions
of subpart S of this part, for Class I, Division 1, Hazardous Locations.
Electrical wiring, motors, and other equipment outside of but within
twenty (20) feet of any spraying area, and not separated therefrom by
partitions, shall not produce sparks under normal operating conditions
and shall otherwise conform to the provisions of subpart S of this part
for Class I, Division 2 Hazardous Locations.
(7) Lamps. Electric lamps outside of, but within twenty (20) feet of
any spraying area, and not separated therefrom by a partition, shall be
totally enclosed to prevent the falling of hot particles and shall be
protected from mechanical injury by suitable guards or by location.
(8) Portable lamps. Portable electric lamps shall not be used in any
spraying area during spraying operations. Portable electric lamps, if
used during cleaning or repairing operations, shall be of the type
approved for hazardous Class I locations.
(9) Grounding. (i) All metal parts of spray booths, exhaust ducts,
and piping systems conveying flammable or combustible liquids or aerated
solids shall be properly electrically grounded in an effective and
permanent manner.
(ii) [Reserved]
(d) Ventilation--(1) Conformance. Ventilating and exhaust systems
shall 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 Sec. 1910.6, where applicable and shall also conform to
the provisions of this section.
(2) General. All spraying areas shall be provided with mechanical
ventilation adequate to remove flammable vapors, mists, or powders to a
safe location and to confine and control combustible residues so that
life is not endangered. Mechanical ventilation shall be kept in
operation at all times while spraying operations are being conducted and
for a sufficient time thereafter to allow vapors from drying coated
articles and drying finishing material residue to be exhausted.
(3) Independent exhaust. Each spray booth shall have an independent
exhaust duct system discharging to the exterior of the building, except
that multiple cabinet spray booths in which identical spray finishing
material is used with a combined frontal area of not more than 18 square
feet may have a common exhaust. If more than one fan serves one booth,
all fans shall be so interconnected that one fan cannot operate without
all fans being operated.
(4) Fan-rotating element. The fan-rotating element shall be
nonferrous or nonsparking or the casing shall consist of or be lined
with such material.
[[Page 273]]
There shall be ample clearance between the fan-rotating element and the
fan casing to avoid a fire by friction, necessary allowance being made
for ordinary expansion and loading to prevent contact between moving
parts and the duct or fan housing. Fan blades shall be mounted on a
shaft sufficiently heavy to maintain perfect alignment even when the
blades of the fan are heavily loaded, the shaft preferably to have
bearings outside the duct and booth. All bearings shall be of the self-
lubricating type, or lubricated from the outside duct.
(5) Electric motors. Electric motors driving exhaust fans shall not
be placed inside booths or ducts. See also paragraph (c) of this
section.
(6) Belts. Belts shall not enter the duct or booth unless the belt
and pulley within the duct or booth are thoroughly enclosed.
(7) Exhaust ducts. Exhaust ducts shall be constructed of steel and
shall be substantially supported. Exhaust ducts without dampers are
preferred; however, if dampers are installed, they shall be maintained
so that they will be in a full open position at all times the
ventilating system is in operation.
(i) Exhaust ducts shall be protected against mechanical damage and
have a clearance from unprotected combustible construction or other
combustible material of not less than 18 inches.
(ii) If combustible construction is provided with the following
protection applied to all surfaces within 18 inches, clearances may be
reduced to the distances indicated:
(a) 28-gage sheet metal on \1/4\-inch 12 inches.
asbestos mill board.
(b) 28-gage sheet metal on \1/8\-inch 9 inches.
asbestos mill board spaced out 1 inch on
noncombustible spacers.
(c) 22-gage sheet metal on 1-inch rockwool 3 inches.
batts reinforced with wire mesh or the
equivalent.
(d) Where ducts are protected with an
approved automatic sprinkler system,
properly maintained, the clearance
required in subdivision (i) of this
subparagraph may be reduced to 6 inches.
(8) Discharge clearance. Unless the spray booth exhaust duct
terminal is from a water-wash spray booth, the terminal discharge point
shall be not less than 6 feet from any combustible exterior wall or roof
nor discharge in the direction of any combustible construction or
unprotected opening in any noncombustible exterior wall within 25 feet.
(9) Air exhaust. Air exhaust from spray operations shall not be
directed so that it will contaminate makeup air being introduced into
the spraying area or other ventilating intakes, nor directed so as to
create a nuisance. Air exhausted from spray operations shall not be
recirculated.
(10) Access doors. When necessary to facilitate cleaning, exhaust
ducts shall be provided with an ample number of access doors.
(11) Room intakes. Air intake openings to rooms containing spray
finishing operations shall be adequate for the efficient operation of
exhaust fans and shall be so located as to minimize the creation of dead
air pockets.
(12) Drying spaces. Freshly sprayed articles shall be dried only in
spaces provided with adequate ventilation to prevent the formation of
explosive vapors. In the event adequate and reliable ventilation is not
provided such drying spaces shall be considered a spraying area. See
also paragraph (j) of this section.
(e) Flammable and combustible liquids--storage and handling--(1)
Conformance. The storage of flammable or combustible liquids in
connection with spraying operations shall conform to the requirements of
Sec. 1910.106, where applicable.
(2) Quantity. The quantity of flammable or combustible liquids kept
in the vicinity of spraying operations shall be the minimum required for
operations and should ordinarily not exceed a supply for 1 day or one
shift. Bulk storage of portable containers of flammable or combustible
liquids shall be in a separate, constructed building detached from other
important buildings or cut off in a standard manner.
(3) Containers. Original closed containers, approved portable tanks,
approved safety cans or a properly arranged system of piping shall be
used for bringing flammable or combustible liquids into spray finishing
room. Open or glass containers shall not be used.
(4) Transferring liquids. Except as provided in paragraph (e)(5) of
this section the withdrawal of flammable and combustible liquids from
containers having
[[Page 274]]
a capacity of greater than 60 gallons shall be by approved pumps. The
withdrawal of flammable or combustible liquids from containers and the
filling of containers, including portable mixing tanks, shall be done
only in a suitable mixing room or in a spraying area when the
ventilating system is in operation. Adequate precautions shall be taken
to protect against liquid spillage and sources of ignition.
(5) Spraying containers. Containers supplying spray nozzles shall be
of closed type or provided with metal covers kept closed. Containers not
resting on floors shall be on metal supports or suspended by wire
cables. Containers supplying spray nozzles by gravity flow shall not
exceed 10 gallons capacity. Original shipping containers shall not be
subject to air pressure for supplying spray nozzles. Containers under
air pressure supplying spray nozzles shall be of limited capacity, not
exceeding that necessary for 1 day's operation; shall be designed and
approved for such use; shall be provided with a visible pressure gage;
and shall be provided with a relief valve set to operate in conformance
with the requirements of the Code for Unfired Pressure Vessels, Section
VIII of the ASME Boiler and Pressure Vessel Code--1968, which is
incorporated by reference as specified in Sec. 1910.6. Containers under
air pressure supplying spray nozzles, air-storage tanks and coolers
shall conform to the standards of the Code for Unfired Pressure Vessels,
Section VIII of the ASME Boiler and Pressure Vessel Code--1968 for
construction, tests, and maintenance.
(6) Pipes and hoses. (i) All containers or piping to which is
attached a hose or flexible connection shall be provided with a shutoff
valve at the connection. Such valves shall be kept shut when spraying
operations are not being conducted.
(ii) When a pump is used to deliver products, automatic means shall
be provided to prevent pressure in excess of the design working pressure
of accessories, piping, and hose.
(iii) All pressure hose and couplings shall be inspected at regular
intervals appropriate to this service. The hose and couplings shall be
tested with the hose extended, and using the ``inservice maximum
operating pressures.'' Any hose showing material deteriorations, signs
of leakage, or weakness in its carcass or at the couplings, shall be
withdrawn from service and repaired or discarded.
(iv) Piping systems conveying flammable or combustible liquids shall
be of steel or other material having comparable properties of resistance
to heat and physical damage. Piping systems shall be properly bonded and
grounded.
(7) Spray liquid heaters. Electrically powered spray liquid heaters
shall be approved and listed for the specific location in which used
(see paragraph (c) of this section). Heaters shall not be located in
spray booths nor other locations subject to the accumulation of deposits
or combustible residue. If an electric motor is used, see paragraph (c)
of this section.
(8) Pump relief. If flammable or combustible liquids are supplied to
spray nozzles by positive displacement pumps, the pump discharge line
shall be provided with an approved relief valve discharging to a pump
suction or a safe detached location, or a device provided to stop the
prime mover if the discharge pressure exceeds the safe operating
pressure of the system.
(9) Grounding. Whenever flammable or combustible liquids are
transferred from one container to another, both containers shall be
effectively bonded and grounded to prevent discharge sparks of static
electricity.
(f) Protection--(1) Conformance. In sprinklered buildings, the
automatic sprinkler system in rooms containing spray finishing
operations shall conform to the requirements of Sec. 1910.159. In
unsprinklered buildings where sprinklers are installed only to protect
spraying areas, the installation shall conform to such standards insofar
as they are applicable. Sprinkler heads shall be located so as to
provide water distribution throughout the entire booth.
(2) Valve access. Automatic sprinklers protecting each spray booth
(together with its connecting exhaust) shall be under an accessibly
located separate outside stem and yoke (OS&Y) subcontrol valve.
(3) Cleaning of heads. Sprinklers protecting spraying areas shall be
kept as
[[Page 275]]
free from deposits as practical by cleaning daily if necessary. (See
also paragraph (g) of this section.)
(4) Portable extinguishers. An adequate supply of suitable portable
fire extinguishers shall be installed near all spraying areas.
(g) Operations and maintenance--(1) Spraying. Spraying shall not be
conducted outside of predetermined spraying areas.
(2) Cleaning. All spraying areas shall 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 shall be of nonsparking material.
(3) Residue disposal. Residue scrapings and debris contaminated with
residue shall be immediately removed from the premises and properly
disposed of. Approved metal waste cans shall 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 shall be properly disposed of at least once daily or at the end of
each shift.
(4) Clothing storage. Spray finishing employees' clothing shall not
be left on the premises overnight unless kept in metal lockers.
(5) Cleaning solvents. The use of solvents for cleaning operations
shall be restricted to those having flashpoints not less than 100
[deg]F.; however, for cleaning spray nozzles and auxiliary equipment,
solvents having flashpoints not less than those normally used in spray
operations may be used. Such cleaning shall be conducted inside spray
booths and ventilating equipment operated during cleaning.
(6) Hazardous materials combinations. Spray booths shall 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.
(7) ``No Smoking'' signs. ``No smoking'' signs in large letters on
contrasting color background shall be conspicuously posted at all
spraying areas and paint storage rooms.
(h) Fixed electrostatic apparatus--(1) Conformance. Where
installation and use of electrostatic spraying equipment is used, such
installation and use shall conform to all other paragraphs of this
section, and shall also conform to the requirements of this paragraph.
(2) Type approval. Electrostatic apparatus and devices used in
connection with coating operations shall be of approved types.
(3) Location. 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, shall be located outside of the spraying area, or shall
otherwise conform to the requirements of paragraph (c) of this section.
(4) Support. Electrodes and electrostatic atomizing heads shall be
adequately supported in permanent locations and shall be effectively
insulated from the ground. Electrodes and electrostatic atomizing heads
which are permanently attached to their bases, supports, or
reciprocators, shall be deemed to comply with this section. Insulators
shall be nonporous and noncombustible.
(5) Insulators, grounding. High-voltage leads to electrodes shall be
properly insulated and protected from mechanical injury or exposure to
destructive chemicals. Electrostatic atomizing heads shall be
effectively and permanently supported on suitable insulators and shall
be effectively guarded against accidental contact or grounding. An
automatic means shall be provided for grounding the electrode system
when it is electrically deenergized for any reason. All insulators shall
be kept clean and dry.
(6) Safe distance. A safe distance shall 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 shall be conspicuously posted near the
assembly.
(7) Conveyors required. Goods being painted using this process are
to be supported on conveyors. The conveyors
[[Page 276]]
shall be so arranged as to maintain safe distances between the goods and
the electrodes or electrostatic atomizing heads at all times. Any
irregularly shaped or other goods subject to possible swinging or
movement shall be rigidly supported to prevent such swinging or movement
which would reduce the clearance to less than that specified in
paragraph (h)(6) of this section.
(8) Prohibition. This process is not acceptable where goods being
coated are manipulated by hand. When finishing materials are applied by
electrostatic equipment which is manipulated by hand, see paragraph (i)
of this section for applicable requirements.
(9) Fail-safe controls. Electrostatic apparatus shall 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 under any of the following conditions:
(i) Stoppage of ventilating fans or failure of ventilating equipment
from any cause.
(ii) Stoppage of the conveyor carrying goods through the high
voltage field.
(iii) Occurrence of a ground or of an imminent ground at any point
on the high voltage system.
(iv) Reduction of clearance below that specified in paragraph (h)(6)
of this section.
(10) Guarding. Adequate booths, fencing, railings, or guards shall
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 shall be of conducting material, adequately grounded.
(11) Ventilation. Where electrostatic atomization is used the
spraying area shall be so ventilated as to insure safe conditions from a
fire and health standpoint.
(12) Fire protection. All areas used for spraying, including the
interior of the booth, shall be protected by automatic sprinklers where
this protection is available. Where this protection is not available,
other approved automatic extinguishing equipment shall be provided.
(i) Electrostatic hand spraying equipment--(1) Application. This
paragraph shall apply to any equipment using electrostatically charged
elements for the atomization and/or, precipitation of materials for
coatings on articles, or for other similar purposes in which the
atomizing device is hand held and manipulated during the spraying
operation.
(2) Conformance. Electrostatic hand spraying equipment shall conform
with the other provisions of this section.
(3) Equipment approval and specifications. Electrostatic hand spray
apparatus and devices used in connection with coating operations shall
be of approved types. The high voltage circuits shall be designed so as
to not produce a spark of sufficient intensity to ignite any vapor-air
mixtures nor result in appreciable shock hazard upon coming in contact
with a grounded object under all normal operating conditions. The
electrostatically charged exposed elements of the handgun shall be
capable of being energized only by a switch which also controls the
coating material supply.
(4) Electrical support equipment. Transformers, powerpacks, control
apparatus, and all other electrical portions of the equipment, with the
exception of the handgun itself and its connections to the power supply
shall be located outside of the spraying area or shall otherwise conform
to the requirements of paragraph (c) of this section.
(5) Spray gun ground. The handle of the spraying gun shall be
electrically connected to ground by a metallic connection and to be so
constructed that the operator in normal operating position is in
intimate electrical contact with the grounded handle.
(6) Grounding--general. All electrically conductive objects in the
spraying area shall be adequately grounded. This requirement shall apply
to paint containers, wash cans, and any other objects or devices in the
area. The equipment shall carry a prominent permanently installed
warning regarding the necessity for this grounding feature.
(7) Maintenance of grounds. Objects being painted or coated shall be
maintained in metallic contact with the conveyor or other grounded
support.
[[Page 277]]
Hooks shall be regularly cleaned to insure this contact and areas of
contact shall be sharp points or knife edges where possible. Points of
support of the object shall be concealed from random spray where
feasible and where the objects being sprayed are supported from a
conveyor, the point of attachment to the conveyor shall be so located as
to not collect spray material during normal operation.
(8) Interlocks. The electrical equipment shall be so interlocked
with the ventilation of the spraying area that the equipment cannot be
operated unless the ventilation fans are in operation.
(9) Ventilation. The spraying operation shall take place within a
spray area which is adequately ventilated to remove solvent vapors
released from the operation.
(j) Drying, curing, or fusion apparatus--(1) Conformance. Drying,
curing, or fusion apparatus in connection with spray application of
flammable and combustible finishes shall conform to the Standard for
Ovens and Furnaces, NFPA 86A-1969, which is incorporated by reference as
specified in Sec. 1910.6, where applicable and shall also conform with
the following requirements of this paragraph.
(2) Alternate use prohibited. Spray booths, rooms, or other
enclosures used for spraying operations shall 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.
(3) Adjacent system interlocked. Except as specifically provided in
paragraph (j)(4) of this section, drying, curing, or fusion units
utilizing a heating system having open flames or which may produce
sparks shall not be installed in a spraying area, but may be installed
adjacent thereto when equipped with an interlocked ventilating system
arranged to:
(i) Thoroughly ventilate the drying space before the heating system
can be started;
(ii) Maintain a safe atmosphere at any source of ignition;
(iii) Automatically shut down the heating system in the event of
failure of the ventilating system.
(4) Alternate use permitted. Automobile refinishing spray booths or
enclosures, otherwise installed and maintained in full conformity with
this section, may alternately be used for drying with portable
electrical infrared drying apparatus when conforming with the following:
(i) Interior (especially floors) of spray enclosures shall be kept
free of overspray deposits.
(ii) During spray operations, the drying apparatus and electrical
connections and wiring thereto shall not be located within spray
enclosure nor in any other location where spray residues may be
deposited thereon.
(iii) The spraying apparatus, the drying apparatus, and the
ventilating system of the spray enclosure shall be equipped with
suitable interlocks so arranged that:
(a) The spraying apparatus cannot be operated while the drying
apparatus is inside the spray enclosure.
(b) The spray enclosure will be purged of spray vapors for a period
of not less than 3 minutes before the drying apparatus can be energized.
(c) The ventilating system will maintain a safe atmosphere within
the enclosure during the drying process and the drying apparatus will
automatically shut off in the event of failure of the ventilating
system.
(iv) All electrical wiring and equipment of the drying apparatus
shall conform with the applicable sections of subpart S of this part.
Only equipment of a type approved for Class I, Division 2 hazardous
locations shall be located within 18 inches of floor level. All metallic
parts of the drying apparatus shall be properly electrically bonded and
grounded.
(v) The drying apparatus shall 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.
(k) Automobile undercoating in garages. Automobile undercoating
spray operations in garages, conducted in areas having adequate natural
or mechanical
[[Page 278]]
ventilation, are exempt from the requirements pertaining to spray
finishing operations, when using undercoating materials not more
hazardous than kerosene (as listed by Underwriters' Laboratories in
respect to fire hazard rating 30-40) or undercoating materials using
only solvents listed as having a flash point in excess of 100 [deg]F.
Undercoating spray operations not conforming to these provisions are
subject to all requirements of this section pertaining to spray
finishing operations.
(l) Powder coating--(1) Electrical and other sources of ignition.
Electrical equipment and other sources of ignition shall conform to the
requirements of paragraphs (c)(1) (i)-(iv), (8) and (9)(i) of this
section and subpart S of this part.
(2) Ventilation. (i) In addition to the provisions of paragraph (d)
of this section, where applicable, exhaust ventilation shall be
sufficient to maintain the atmosphere below the lowest explosive limits
for the materials being applied. All nondeposited air-suspended powders
shall be safely removed via exhaust ducts to the powder recovery cyclone
or receptacle. Each installation shall be designed and operated to meet
the foregoing performance specification.
(ii) Powders shall not be released to the outside atmosphere.
(3) Drying, curing, or fusion equipment. The provisions of the
Standard for ovens and furnaces, NFPA No. 86A-1969 shall apply where
applicable.
(4) Operation and maintenance. (i) All areas shall be kept free of
the accumulation of powder coating dusts, particularly such horizontal
surfaces as ledges, beams, pipes, hoods, booths, and floors.
(ii) Surfaces shall be cleaned in such manner as to avoid scattering
dust to other places or creating dust clouds.
(iii) ``No Smoking'' signs in large letters on contrasting color
background shall be conspicuously posted at all powder coating areas and
powder storage rooms.
(5) Fixed electrostatic spraying equipment. The provisions of
paragraph (h) of this section and other subparagraphs of this paragraph
shall apply to fixed electrostatic equipment, except that electrical
equipment not covered therein shall conform to paragraph (l)(1) of this
section.
(6) Electrostatic hand spraying equipment. The provisions of
paragraph (i) of this section and other subparagraphs of this paragraph,
shall apply to electrostatic handguns when used in powder coating,
except that electrical equipment not covered therein shall conform to
paragraph (l)(1) of this section.
(7) Electrostatic fluidized beds. (i) Electrostatic fluidized beds
and associated equipment shall be of approved types. The maximum surface
temperature of this equipment in the coating area shall not exceed 150
[deg]F. The high voltage circuits shall be so designed as to not produce
a spark of sufficient intensity to ignite any powder-air mixtures nor
result in appreciable shock hazard upon coming in contact with a
grounded object under normal operating conditions.
(ii) 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 shall be located
outside of the powder coating area or shall otherwise conform to the
requirements of paragraph (l)(1) of this section.
(iii) All electrically conductive objects within the charging
influence of the electrodes shall be adequately grounded. The powder
coating equipment shall carry a prominent, permanently installed warning
regarding the necessity for grounding these objects.
(iv) Objects being coated shall be maintained in contact with the
conveyor or other support in order to insure proper grounding. Hangers
shall be regularly cleaned to insure effective contact and areas of
contact shall be sharp points or knife edges where possible.
(v) The electrical equipment shall be so interlocked with the
ventilation system that the equipment cannot be operated unless the
ventilation fans are in operation.
(m) Organic peroxides and dual component coatings--(1) Conformance.
All spraying operations involving the use of organic peroxides and other
dual component coatings shall be conducted in approved sprinklered spray
booths
[[Page 279]]
meeting the requirements of this section.
(2) Smoking. Smoking shall be prohibited and ``No Smoking'' signs
shall be prominently displayed and only nonsparking tools shall be used
in any area where organic peroxides are stored, mixed or applied.
(n) Scope. This section applies to flammable and combustible
finishing materials when applied as a spray by compressed air,
``airless'' or ``hydraulic atomization,'' steam, electrostatic methods,
or by any other means in continuous or intermittent processes. The
section also covers the application of combustible powders by powder
spray guns, electrostatic powder spray guns, fluidized beds, or
electrostatic fluidized beds. The section does not apply to outdoor
spray application of buildings, tanks, or other similar structures, nor
to small portable spraying apparatus not used repeatedly in the same
location.
[39 FR 23502, June 27, 1974, as amended at 45 FR 60704, Sept. 12, 1980;
49 FR 5322, Feb. 10, 1984; 53 FR 12121, Apr. 12, 1988; 61 FR 9237, Mar.
7, 1996]
