(1) You must make sure hot work is not
performed in confined space until all requirements of chapter
296-809 WAC, are
met.
(2) You must provide fire
protection for employees performing hot work as follows:
(a) To the extent possible, hot work must be
performed in designated locations that are free of fire hazards.
(b) When hot work must be performed in a
location that is not free of fire hazards, all necessary precautions must be
taken to confine heat, sparks, and slag so that they cannot contact flammable
or combustible material.
(c) Fire
extinguishing equipment suitable for the location must be immediately available
and must be maintained in readiness for use at all times.
(d) When the hot work operation is such that
normal fire prevention precautions are not sufficient, additional personnel
must be assigned to guard against fire during hot work and for a sufficient
time after completion of the work to ensure that no fire hazard remains. The
employer must instruct all employees involved in hot work operations as to
potential fire hazards and the use of firefighting equipment.
(e) Drums and containers which contain or
have contained flammable liquids must be kept closed. Empty containers must be
removed from the hot work area.
(f)
When openings or cracks in flooring cannot be closed, precautions must be taken
to ensure that no employees or flammable or combustible materials are exposed
to sparks dropping through the floor. Similar precautions must be taken
regarding cracks or holes in walls, open doorways and open or broken
windows.
(g) Hot work shall not be
performed:
(i) In flammable or potentially
flammable atmospheres;
(ii) On or
in equipment or tanks that have contained flammable gas or liquid or
combustible liquid or dust-producing material, until a designated person has
tested the atmosphere inside the equipment or tanks and determined that it is
not hazardous; or
(iii) Near any
area in which exposed readily ignitable materials such as bulk sulphur, baled
paper or cotton are stored. Bulk sulphur is excluded from this prohibition if
suitable precautions are followed, the person in charge is knowledgeable and
the person performing the work has been instructed in preventing and
extinguishing sulphur fires.
(h) Drums, containers or hollow structures
that have contained flammable or combustible substances must either be filled
with water or cleaned, and must then be ventilated.
(i) A designated person must test the
atmosphere and determine that it is not hazardous before hot work is performed
on or in such structures.
(ii)
Before heat is applied to a drum, container or hollow structure, an opening to
release built-up pressure during heat application must be provided.
(3) You must follow
these requirements for gas welding and cutting:
(a) Compressed gas cylinders must be used
only as follows:
(i) Must have valve
protection caps in place except when in use, hooked up or secured for movement.
Oil must not be used to lubricate caps;
(ii) Must be hoisted only while secured, as
on a cradle or pallet, and must not be hoisted by magnet, choker sling or
cylinder caps;
(iii) Must be moved
only by tilting or rolling on their bottom edges;
(iv) Must be secured when moved by
vehicle;
(v) Must be secured while
in use;
(vi) Must have valves
closed when cylinders are empty, being moved or stored;
(vii) Must be secured upright except when
hoisted or carried;
(viii) Must not
be freed when frozen by prying the valves or caps with bars or by hitting the
valve with a tool;
(ix) Must not be
thawed by boiling water;
(x) Must
not be exposed to sparks, hot slag, or flame;
(xi) Must not be permitted to become part of
electrical circuits or have electrodes struck against them to strike
arcs;
(xii) Must not be used as
rollers or supports;
(xiii) Must
not have contents used for purposes not authorized by the supplier;
(xiv) Must not be used if damaged or
defective;
(xv) Must not have gases
mixed within, except by gas suppliers;
(xvi) Must be stored so that oxygen cylinders
are separated from fuel gas cylinders and combustible materials by either a
minimum distance of twenty feet (6.1 m) or a barrier having a fire-resistance
rating of thirty minutes; and
(xvii) Must not have objects that might
either damage the safety device or obstruct the valve placed on top of the
cylinder when in use.
(b) Fuel gas must be used only as follows:
(i) Before regulators are connected to
cylinder valves, the valves must be opened slightly (cracked) and closed
immediately to clear away dust or dirt. Valves must not be cracked if gas could
reach possible sources of ignition;
(ii) Cylinder valves must be opened slowly to
prevent regulator damage and must not be opened more than one and one-half
turns. Any special wrench required for emergency closing must be positioned on
the valve stem during cylinder use. For manifolded or coupled cylinders, at
least one wrench must be immediately available. Nothing must be placed on top
of a cylinder or associated parts when the cylinder is in use;
(iii) Pressure-reducing regulators must be
attached to cylinder valves when cylinders are supplying torches or devices
equipped with shut-off valves;
(iv)
Cylinder valves must be closed and gas released from the regulator or manifold
before regulators are removed;
(v)
Leaking fuel gas cylinder valves must be closed and the gland nut tightened. If
the leak continues, the cylinder must be tagged, removed from service, and
moved to a location where the leak will not be hazardous. If a regulator
attached to a valve stops a leak, the cylinder need not be removed from the
workplace but must be tagged and may not be used again before it is repaired;
and
(vi) If a plug or safety device
leaks, the cylinder must be tagged, removed from service, and moved to a
location where the leak will not be hazardous.
(c) Hose must be used only as follows:
(i) Fuel gas and oxygen hoses must be easily
distinguishable from each other by color or sense of touch. Oxygen and fuel
hoses must not be interchangeable. Hoses having more than one gas passage must
not be used.
(ii) When oxygen and
fuel gas hoses are taped together, not more than four of each twelve inches
(10.16 cm of each 30.48 cm) must be taped.
(iii) Hose must be inspected before use. Hose
subjected to flashback or showing evidence of severe wear or damage must be
tested to twice the normal working pressure but not less than two hundred
p.s.i. (1378.96 kPa) before reuse. Defective hose must not be used.
(iv) Hose couplings must not unlock or
disconnect without rotary motion.
(v) Hose connections must be clamped or
securely fastened to withstand twice the normal working pressure but not less
than three hundred p.s.i. (2068.44 kPa) without leaking.
(vi) Gas hose storage boxes must be
ventilated.
(d) Torches
must be used only as follows:
(i) Torch tip
openings must only be cleaned with devices designed for that purpose.
(ii) Torches must be inspected before each
use for leaking shut-off valves, hose couplings and tip connections. Torches
must be inspected before each use for leaking shut-off valves, hose couplings
and tip connections. Torches with such defects must not be used.
(iii) Torches must not be lighted from
matches, cigarette lighters, other flames or hot work.
(e) Pressure regulators, including associated
gauges, must be maintained in safe working order.
(f) Gas welding equipment must be maintained
free of oil and grease.
(4) You must meet these requirements for arc
welding and cutting:
(a) Manual electrode
holders must be used as follows:
(i) You must
ensure that only manual electrode holders intended for arc welding and cutting
and capable of handling the maximum current required for such welding or
cutting must be used.
(ii)
Current-carrying parts passing through those portions of the holder gripped by
the user and through the outer surfaces of the jaws of the holder must be
insulated against the maximum voltage to ground.
(b) Welding cables and connectors must be
used as follows:
(i) Arc welding and cutting
cables must be insulated, flexible and capable of handling the maximum current
required by the operation, taking into account the duty cycles.
(ii) Only cable free from repair or splice
for ten feet (3 m) from the electrode holder must be used unless insulated
connectors or splices with insulating quality equal to that of the cable are
provided.
(iii) When a cable other
than the lead mentioned in (b)(ii) of this subsection wears and exposes bare
conductors, the portion exposed must not be used until it is protected by
insulation equivalent in performance capacity to the original.
(iv) Insulated connectors of equivalent
capacity must be used for connecting or splicing cable. Cable lugs, where used
as connectors, must provide electrical contact. Exposed metal parts must be
insulated.
(c) Ground
returns and machine grounding must be used as follows:
(i) Ground return cables must have
current-carrying capacity equal to or exceeding the total maximum output
capacities of the welding or cutting units served.
(ii) Structures or pipelines, other than
those containing gases or flammable liquids or conduits containing electrical
circuits, may be used in the ground return circuit if their current-carrying
capacity equals or exceeds the total maximum output capacities of the welding
or cutting units served.
(iii)
Structures or pipelines forming a temporary ground return circuit must have
electrical contact at all joints. Arcs, sparks or heat at any point in the
circuit must cause rejection as a ground circuit.
(iv) Structures or pipelines acting
continuously as ground return circuits must have joints bonded and maintained
to ensure that no electrolysis or fire hazard exists.
(v) Arc welding and cutting machine frames
must be grounded, either through a third wire in the cable containing the
circuit conductor or through a separate wire at the source of the current.
Grounding circuits must have resistance low enough to permit sufficient current
to flow to cause the fuse or circuit breaker to interrupt the
current.
(vi) Ground connections
must be mechanically and electrically adequate to carry the current.
(d) When electrode holders are
left unattended, electrodes must be removed and holders placed to prevent
employee injury.
(e) Hot electrode
holders must not be dipped in water.
(f) You must ensure that when arc welders or
cutters leave or stop work or when machines are moved, the power supply switch
is kept in the off position.
(g)
Arc welding or cutting equipment having a functional defect must not be
used.
(h) Arc welding and cutting
operations must be separated from other operations by shields, screens, or
curtains to protect employees in the vicinity from the direct rays and sparks
of the arc.
(i) Employees in areas not
protected from the arc by screening must be protected by appropriate filter
lenses in accordance with subsection (8) of this section.
(ii) When welders are exposed to their own
arc or to each other's arc, they must wear filter lenses complying with the
requirements of subsection (8) of this section.
(i) The control apparatus of arc welding
machines must be enclosed, except for operating wheels, levers, and
handles.
(j) Input power terminals,
top change devices and live metal parts connected to input circuits must be
enclosed and accessible only by means of insulated tools.
(k) When arc welding is performed in wet or
high-humidity conditions, employees must use additional protection, such as
rubber pads or boots, against electric shock.
(5) You must meet the following requirements
in ventilation and employee protection in welding, cutting and heating:
(a) You must ensure that general mechanical
ventilation or local exhaust systems must meet the following requirements:
(i) General mechanical ventilation must
maintain vapors, fumes and smoke below a hazardous level;
(ii) Local exhaust ventilation must consist
of movable hoods positioned close to the work and must be of such capacity and
arrangement as to keep breathing zone concentrations below hazardous
levels;
(iii) Exhausts from working
spaces must be discharged into the open air, clear of intake air
sources;
(iv) Replacement air must
be clean and respirable; and
(v)
Oxygen must not be used for ventilation, cooling or cleaning clothing or work
areas.
(b) You must
ensure that when hot work is performed in a confined space, in addition to the
requirements of chapter
296-809 WAC and except as specified in (c)(ii) and
(iii) of this subsection, the following requirements for ventilation are met:
(i) General mechanical or local exhaust
ventilations must be provided; or
(ii) Employees in the space must wear
respirators in accordance with chapter
296-842 WAC.
(c)Requirements for welding, cutting or
heating of toxic metals are as follows:
(i)
In confined or enclosed spaces, hot work involving the following metals must
only be performed with general mechanical or local exhaust ventilation that
ensures that employees are not exposed to hazardous levels of fumes:
(A) Lead base metals;
(B) Cadmium-bearing filler materials;
and
(C) Chromium-bearing metals or
metals coated with chromium-bearing materials.
(ii) In confined or enclosed spaces, hot work
involving the following metals must only be performed with local exhaust
ventilation meeting the requirements of this subsection or by employees wearing
supplied air respirators in accordance with chapter
296-842 WAC;
(A) Zinc-bearing base or filler metals or
metals coated with zinc-bearing materials;
(B) Metals containing lead other than as an
impurity, or coated with lead-bearing materials;
(C) Cadmium-bearing or cadmium-coated base
metals; and
(D) Metals coated with
mercury-bearing materials.
(iii) Employees performing hot work in
confined or enclosed spaces involving beryllium-containing base or filler
metals must be protected by local exhaust ventilation and wear supplied air
respirators or self-contained breathing apparatus, in accordance with the
requirements of chapter
296-842 WAC.
(iv) You must ensure that employees
performing hot work in the open air that involves any of the metals listed in
(c)(i) and (ii) of this subsection must be protected by respirators in
accordance with the requirements of chapter
296-842 WAC and those working on
beryllium-containing base or filler metals must be protected by supplied air
respirators, in accordance with the requirements of chapter
296-842
WAC.
(v) Any employee exposed to
the same atmosphere as the welder or burner must be protected by the same type
of respiratory and other protective equipment as that worn by the welder or
burner.
(d) You must
make sure employees will not engage in and not be exposed to the inert-gas
metal-arc welding process unless the following precautions are taken:
(i) Chlorinated solvents must not be used
within two hundred feet (61 m) of the exposed arc. Surfaces prepared with
chlorinated solvents must be thoroughly dry before welding is performed on
them.
(ii) Employees in areas not
protected from the arc by screening must be protected by appropriate filter
lenses in accordance with the requirements of subsection (7) of this section.
When welders are exposed to their own arc or to each other's arc, filter lenses
complying with the requirements of subsection (7) of this section must be worn
to protect against flashes and radiant energy.
(iii) Employees exposed to radiation must
have their skin covered completely to prevent ultraviolet burns and damage.
Helmets and hand shields must not have leaks, openings or highly reflective
surfaces.
(iv) Inert-gas metal-arc
welding on stainless steel must not be performed unless exposed employees are
protected either by local exhaust ventilation or by wearing supplied air
respirators in accordance with the requirements of chapter
296-842
WAC.
(6) You
must meet these requirements for welding, cutting and heating on preservative
coatings:
(a) Before hot work is commenced on
surfaces covered by a preservative coating of unknown flammability, a test must
be made by a designated person to determine the coating's flammability.
Preservative coatings must be considered highly flammable when scrapings burn
with extreme rapidity.
(b)
Appropriate precaution must be taken to prevent ignition of highly flammable
hardened preservative coatings. Highly flammable coatings must be stripped from
the area to be heated. An uncoiled fire hose with fog nozzle, under pressure,
must be immediately available in the hot work area.
(c) Surfaces covered with preservative
coatings must be stripped for at least four inches (10.16 cm) from the area of
heat application or employees must be protected by supplied air respirators in
accordance with the requirements of chapter
296-842 WAC.
(7) You must protect employees against
radiant energy as follows:
(a) Employees must
be protected from radiant energy eye hazards by spectacles, cup goggles,
helmets, hand shields or face shields with filter lenses complying with the
requirements of this subsection.
(b) Filter lenses must have an appropriate
shade number, as indicated in Table G-1, for the work performed. Variations of
one or two shade numbers are permissible to suit individual
preferences.
(c) If filter lenses
are used in goggles worn under the helmet, the shade numbers of both lenses
equals the value shown in Table G-1 for the operation.
Table G-1
Filter Lenses for Protection Against Radiant
Energy
|
Operation
|
Shade No.
|
| Soldering |
2 |
| Torch Brazing |
3 or 4 |
| Light Cutting, up to 1 inch |
3 or 4 |
| Medium Cutting, 1-6 inches |
4 or 5 |
| Heavy Cutting, over 6 inches |
5 or 6 |
| Light Gas Welding, up to 1/8 inch |
4 or 5 |
| Medium Gas Welding, 1/8-1/2 inch |
5 or 6 |
| Heavy Gas Welding, over 1/2 inch |
6 or 8 |
| Shielded Metal-Arc Welding 1/16 to 5/32-inch electrodes
|
10 |
| Inert Gas Metal-Arc Welding (nonferrous) 1/16 to |
| 5/32-inch electrodes |
11 |
| Shielded Metal-Arc Welding: |
| 3/16 to 1/4-inch electrodes |
12 |
| 5/16 and 3/8-inch electrodes |
14 |