Current through Register Vol. 46, No. 12, March 20, 2024
(a) Where performed. Coating shall be
conducted in a ventilated hood, booth or enclosure complying with this Part
(rule) and section 18.20 of Industrial Code Part (Rule No.) 18.
(b) Vehicles. Vehicles shall not be taken
into or out of spray coating spaces under their own power, unless the exhaust
system is operating.
(c) Use of
different types of coating materials. Where different types of coating
materials are used in the same booth or space, the booth or space shall be
thoroughly cleaned of previous coating deposits before commencing the
application of the new substance.
(d) Sanding. Sanding of surfaces containing
lead or lead pigment shall be done either with sandpaper wetted with water or
in an area provided with an exhaust system providing ventilation at a minimum
rate of 150 f.p.m. in the breathing zone of the worker.
(e) Cleaning of hoods and booths. Exhaust
fans and the interior of hoods, booths and ducts shall be maintained free of
accumulations of coating material.
(f) Lining of spray booths. Material for
lining of spray booths or hoods, if used, shall cover the inner sides of the
booth or hood without overhanging and shall be maintained in contact with the
walls of the booth or hood. Loose sections shall be removed or shall be
reapplied to the wall surface.
(g)
Forced drying and baking.
(1) Construction.
Ovens, cabinets, other enclosures and duct work used for forced drying or
baking systems shall be constructed of incombustible material with expansion
joints provided in the oven framing. Duct work shall be provided with two
inches clearance or three-fourths inch of incombustible rigid insulation where
the duct work passes through combustible walls, floors or roofs. The
temperature of surfaces in contact with walls, floors or roofs shall not exceed
160 degrees Fahrenheit. The floor surface of the oven shall be of incombustible
material and extend at least one foot beyond the oven outline. Interior suraces
shall be smooth.
(2) Ventilation.
(i) Ovens, cabinets and other enclosures used
for such purpose shall be provided with mechanical ventilation to maintain the
concentration of flammable vapors below 25 percent of the lower explosive level
at all times. Ovens shall be exhausted mechanically so that an inward air flow
shall be maintained through all openings to prevent escape of dangerous air
contaminants. The fans of such exhaust ventilating and any recirculating
systems shall be interlocked to the heat supply by means of approved air flow
switches, so that the heat supply shall be cut off unless the fan maintains the
required air flow. Conveyors shall be interlocked with the oven exhaust and any
recirculating fans so that the conveyors cannot operate unless such fans are
operating.
(ii) When persons are
required to enter the drying enclosure, the concentration of air contaminants
shall be maintained below the danger level by mechanical ventilation.
(3) Explosion vents. Ovens located
inside buildings and in which flammable vapors or combustible gases may be
present in amounts exceeding 25 percent of the lower explosive level shall be
equipped with explosion relief panels to relieve internal explosion pressures.
Such vents shall provide an unobstructed aggregate area of one square foot of
panel opening to each 15 cubic feet of oven volume, allowance being made for
access openings and doors arranged to yield easily to internal pressure. Relief
panels shall, if practicable, be located in the top of the enclosure and be
made of material other than glass, which shall yield easily to internal
pressure. On long ovens, relief panels shall be distributed to provide
effective explosion relief. Relief panels shall be located and arranged so as
not to create a hazard to employees or to other work spaces. Panel edges shall
be maintained free of condensate and other solid material to insure proper
operation.
(4) Controls.
(i) Fan switches shall be interlocked with
the fuel valve through a time delay arrangement to assure proper
pre-ventilation before the fuel is ignited. Where necessary, enclosure doors
shall have a limit switch interlock to prevent the time delay relay from
operating unless the enclosure doors are open.
(ii) The fuel supply line shall be provided
with a pressure switch to shut off the fuel supply when the fuel supply
pressure is insufficient. The switch shall not reopen the fuel valve
automatically.
(iii) An excess
temperature limit switch shall be provided to cut off the fuel supply when oven
temperature exceeds the safe limit. The switch shall not reopen the fuel valve
automatically.
(iv) Combustion
safeguards shall be provided to shut off the fuel supply in the event of pilot
light or ignition failure.
(5) Dampers. Air supply or exhaust volume
control dampers shall be adjusted properly and fixed securely. Dampers shall be
designed to prevent full closure.
(6) Combination booths. Where coating and
forced drying are done alternately in the same booth or enclosure, the
following requirements shall be complied with:
(i) During coating operations, the drying
apparatus and electrical connections and wiring thereto shall not be located
within the coating enclosure nor in any location where coating residue may be
deposited thereon.
(ii) Coating
apparatus, drying apparatus and ventilating system of the coating enclosure
shall be equipped with suitable approved interlocks so arranged that coating
apparatus cannot be operated while drying apparatus is inside the coating
enclosure and the coating enclosure shall be purged of coating vapors for a
period of not less than three minutes before drying apparatus can be energized;
the ventilating system shall continue in operation during the drying process
and in the event of failure of the ventilating system, the drying apparatus
shall shut off automatically.
(7) Cleaning. The inside surfaces of the
drying enclosure shall be maintained clean. Cleaning tools shall be of
nonferrous material.
(h)
Lighting. Illumination of hazardous areas through panels of transparent
material is permitted only under the following conditions:
(1) Fixed lighting units shall be used as the
source of illumination.
(2) The
panel shall effectively isolate the hazardous area from the area in which the
lighting unit is located.
(3) The
transparent panel shall conform to subdivision (a) of section 18.20 of
Industrial Code Part (Rule No.) 18.
(4) The installation shall be such that the
normal accumulation of hazardous residue on the exposed surface of the panel
will not be raised to a dangerous temperature by heat radiation or conduction
from the source of illumination.
(i) Electrostatic apparatus.
(1) Installation and use. The installation
and use of electrostatic apparatus shall comply with other applicable
provisions of this Part (rule) and with the following requirements:
(2) Approval required. Only approved
electrostatic apparatus shall be used.
(3) Conductive coatings. This method shall
not be used for spraying conductive coatings.
(4) Hand operations. Manually operated spray
guns or atomizers shall not be used in an electrostatic field unless they are
approved.
(5) Location.
Electrostatic apparatus and devices used in connection with paint spraying,
dipping or other coating operations shall have transformers and power packs
located ouside spray booths or enclosures and areas subject to paint
deposit.
(6) Supports. Electrodes
and electrostatic atomizing heads shall be rigidly supported and permanently
installed and shall be effectively insulated from ground.
(7) Clearance. Space of at least twice the
sparking distance shall be maintained between articles being finished and
electrodes, electrostatic atomizing heads or conductors.
(8) Articles on conveyors. Articles on
conveyors shall be so arranged and supported as to maintain the required
clearances.
(9) Automatic controls.
Electrostatic apparatus shall be equipped with automatic controls arranged to
make the entire equipment dead if the ventilation of the spraying or drying
area falls below a velocity of 100 feet per minute, or if an article on the
conveyor projects into the required clearance, or if the conveyor
stops.
(10) Guarding and isolation
of process. The electrical field and all parts of the equipment carrying high
potential shall be located, guarded and fenced off to provide safe isolation of
the process. Guards and fences shall be of conducting material and shall be
grounded.
(11) Signs. A suitable
sign stating the sparking distance shall be posted conspicuously near the
assembly. Signs designating the process zone as dangerous by reason of fire and
accident hazard shall be posted.
(12) Insulators. Insulators shall be
acceptable to the commissioner for the potential used and shall be maintained
clean and dry.