Safety in Welding, Cutting, and Allied Processes

ANSI Z49.1:1999
noncombustible sheet material or damp cloth guards where
they could be activated by the heat of the welding process.
6.2.2 Fire Watchers. Fire watchers shall be qualified
individuals, knowledgeable about fire reporting procedures,
and emergency rescue procedures, who are assigned
duties to detect and prevent spread of fires. Fire watchers
shall be posted where welding or cutting is done and where
a large fire might develop, or whenever any of the following
conditions exist:
(1) Proximity of Combustibles. Combustible materials
in building construction or contents are closer than 35 feet
(10.7 meters) to the point of operation.
(2) Openings. There are wall or floor openings within
a radius of 35 feet (10.7 meters) which expose combustible
material in adjacent areas, including concealed spaces
in walls, ceilings or floors.
(3) Metal Walls and Pipes. Combustible materials adjacent
to the opposite side of metal partitions, walls, ceilings,
or roofs, or in contact with pipes, and are likely to be
ignited by conduction or radiation.
(4) Ship Work. Ship work performed on opposite sides
of tank shells, decks, overheads, and bulkheads, where
direct penetration of sparks or heat transfer in welding may
introduce a fire hazard to an adjacent compartment.
6.2.3 Additional Fire Watchers. Where it is necessary
to observe areas that are hidden from the view of a
single fire watcher (other side of partitions, walls, ceilings,
etc.) additional fire watchers shall be posted.
6.2.4 Fire Watch Duties. Fire watchers shall be trained
in the use of fire extinguishing equipment. They shall be
familiar with facilities for sounding an alarm in the event
of a fire, and shall remain outside of any confined space to
be in communication with those working inside.
They shall watch for fires in all exposed areas, try to
extinguish them only when obviously within the capacity
of the equipment available, or otherwise sound the alarm.
A fire watch shall be maintained for at least one-half hour
after completion of welding or cutting operations to detect
and extinguish possible smoldering fires. Fire watchers
shall be permitted to have additional duties, however,
these additional duties shall not distract them from their
fire watcher responsibilities.
6.3 Hot-Work Authorization. Before welding or cutting
is begun in a location not designed for such purposes, inspection
and authorization by a designated management
representative shall be required.
6.4 Welding or Cutting Containers. Welding or cutting
work shall not be started until the container has been prepared
for hot work. Workers shall be fully familiar with
ANSI/AWS F4.1, Recommended Safe Practices for the
Preparation for Welding and Cutting of Containers and
Piping, prior to the commencement of hot work.
E6.2.2 Fire watchers are persons assigned to work with
welders, to watch for fires resulting from welding cutting
and brazing operations. When welding or cutting at elevated
positions, care should be taken to protect against
falling sparks and spatter. Accumulations of dust may be
ignited by sparks or spatter, and carry a fire to other
locations.
Fire watchers normally would watch for fires in areas
not readily observed by the welder, such as on opposite
sides of walls, levels below, or hidden areas, or to observe
in an area after the welder has left.
Processes such as air carbon arc cutting and plasma
arc˚cutting can cause sparks to travel in excess of 35 feet
(10.7 meters).
In Canada, the recommended reference distance has
been increased to 50 feet (15 meters).
E6.2.4 The duration of fire watch should be extended
until the hazard of fire no longer exists.
E6.3 Hot work is any work involving burning, welding,
or similar operations capable of initiating fires or explosions.
Authorization is usually in the form of a written
permit. See NFPA 51B for an example of a hot work permit.
E6.4 All containers should be considered unsafe for welding
or cutting unless they have been rendered safe, or declared
safe by a qualified person. When welding or cutting
containers, there is the possibility of explosions, fires,
and the release of toxic vapors or fumes. Containers include
jacketed vessels, tanks, drums, covered parts or other
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