Guidance Document for Fire Prevention During
Cutting and "Hot Works" Operations
Purpose
This procedure has been prepared as a guide for contractors,
building maintenance, and equipment repair personnel (including
persons who perform cutting and welding), fire watchers, their
supervisors (including outside contractors), and building manager
on whose property cutting and welding is to be performed.
Scope
This standard covers provisions to prevent loss of life and
property from fire in the use of oxy-fuel gas and electric
arc cutting and welding equipment.
Procedures
Before any welding or cutting is begun personnel shall
- Establish
approved areas for cutting and welding or establish procedures
for approval of cutting and welding operations;
- Designate
an individual responsible to authorize cutting and welding
operations in areas not specifically designed or approved
for such processes. The individual shall be aware of the
fire hazards involved and shall be familiar with the provisions
of this guide;
- Ensure
that only approved apparatus, such as torches, manifolds,
regulators or pressure reducing valves, and acetylene generators,
be used;
- Ensure
that cutters or welders and their supervisors are suitably
trained in the safe operation of their equipment, and emergency
procedures in the event of a fire;
- Select
contractors to perform cutting or welding who employ suitably
trained personnel and who have an awareness of the magnitude of the
risks involved;
- Advise
all contractors of their duties and responsibilities during "hot
works" operations.
Before cutting and/or welding, a "hot
works" permit must
be obtained from designated* UT Representative. The area shall
be inspected by the supervisor responsible for the work and if
necessary by Physical Safety personnel to ensure that:
- Cutting
and welding equipment is in satisfactory operating condition;
- All combustible materials in the area have been moved to
a safe distance from the work or the combustibles have
been properly shielded from ignition sources;
- The
supervisor shall ensure that appropriate fire protection
and extinguishing equipment are properly located on site;
- The supervisor shall make arrangements for a firewatch
to remain on site at least one-half hour after the completion
of cutting or welding operations to detect and extinguish
possible smoldering fires;
- The
supervisor shall ensure that a copy of the "hot
works" permit
is located on the job site and UT Houston Physical Safety
has been notified and received a copy of the permit.
* Designated UT representatives must
attend annual training provided by the University physical
safety representative. Hot
Works Permit
Prior to
issuing a hot works permit the area will be inspected by
the health science center designated representative.
Before cutting or welding is permitted and
at least once per day while the permit is in effect, the
area shall be inspected by the health scienc center designated
representative to ensure that it is a fire safe area. This
individual shall designate precautions to be followed on
the "hot
works" permit. This individual
shall sign the permit and notify UT Physical Safety that the
work is authorized, and shall verify the following:
- Cutting
and welding equipment to be used shall be in satisfactory
operating condition.
- Where
combustible materials such as paper , wood shavings, or
textile fibers are on the floor, the floor shall be swept
clean for a radius of 35 ft (11 m).
- Combustible
floors (except wood on concrete) shall be kept wet, covered with
damp sand, or protected by fire-resistant shields. Where floors
have been wet down, personnel operating arc welding or
cutting equipment shall be protected from possible electrical
shock.
- All
combustibles shall be relocated at least 35 ft (11 m) horizontally
from the work site. Where relocation is impractical, combustibles
shall be protected with flameproof covers or otherwise shielded
with metal or fire-resistant guards or curtains. Edges of covers
at the floor shall be tight to prevent sparks from going under
them. This precaution is also important at overlaps where several
covers are used to protect a large pile.
- Openings
or cracks in walls, floors, or ducts within 35 ft (11 m)
of the site shall be tightly covered to prevent the passage
of sparks to adjacent areas.
- Conveyor
systems that might carry sparks to distant combustibles
shall be protected.
- Where
cutting or welding is done near walls, partitions, ceilings,
or roofs of combustible construction, fire-resistant shields
or guards shall be provided to prevent ignition. If welding
is to be done on a metal wall, partition, ceiling, or roof,
precautions shall be taken to prevent ignition of combustibles
on the other side, due to conduction or radiation, preferably
by relocating combustibles. Where combustibles are not
relocated, a fire watch on the opposite side from the work
shall be provided. Welding shall not be attempted on a
metal partition, wall, ceiling, or roof having a combustible
covering, nor on walls or partitions of combustible sandwich-type
panel construction.
- Cutting
or welding on pipes or other metal in contact with combustible
walls, partitions, ceilings, or roofs shall not be undertaken
if the work is close enough to cause ignition by conduction.
- Fully charged and operable fire extinguishers, appropriate
for the type of possible fire, shall be available at the
work area. Contractors are responsible to furnish appropriate
fire extinguishers during the project.
- Where
welding or cutting is done in close proximity to a sprinkler
head, a wet rag shall be laid over the head and then
removed at the conclusion of the welding or cutting operation.
Special precautions shall be taken to avoid accidental
operation of automatic fire detection or suppression
systems (e.g., special extinguishing systems).
- Nearby
personnel shall be suitably protected against heat, sparks,
slag, etc.
- The
UTHSC-H
Designated Representative is responsible to isolate fire
detection devices (smoke/heat detectors). Detectors cannot
be covered with gloves, tape, plastic, etc. without prior
approval of UTHSC-H Physical Safety.
- All
personnel involved in the cutting/welding operations
must be familiar with UTHSC-H emergency procedures.
Ventilation
Adequate ventilation (natural, mechanical,
or respirator) must be provided for all welding, cutting,
brazing, and related operations. Adequate ventilation depends
upon the following factors.
- Volume
and configuration of space in which operations occur.
- Number
and type of operations generating contaminants.
- Allowable
levels of specific toxic or flammable contaminants being generated.
- Natural airflow (rate and direction) and general atmospheric
conditions where work is being done.
- Location
of the welder and other person’s breathing zones in
relation to the contaminants or sources.
- Natural
ventilation is acceptable for welding, cutting, and related
processes where the necessary precautions have been taken
to keep the welder’s
breathing zone away from the welding or brazing plume.
Special Ventilation Concerns
Certain
materials, sometimes contained in the consumables, base metals,
coatings, or atmospheres of welding or cutting operations,
have low or very low permissible exposure limits (American
Conference of Governmental Industrial Hygienists, Threshold
Limit Value 1.0 mg/m3 or less). Among these materials are:
- Antimony
- Arsenic
- Barium
- Beryllium
- Cadmium
- Chromium
- Cobalt
- Copper
- Beryllium
- Manganese
- Mercury
- Nickel
- Selenium
- Silver
- Vanadium
The material
safety data sheets must be on site available to identify any of the
materials listed above that may be present.
Whenever these materials are
encountered as designated constituents in welding, brazing, or cutting
operations, special ventilation precautions shall be taken to assure
the level of contaminants in the atmosphere is below permissible
exposure limits or recommendations.
Go to the online
Hot Works Permit.
For further information concerning this guide,
please contact:
Physical Safety Team via Facility Operations "FIXT" 500-3498
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