EH-91-3 Fire Prevention Measures for Cutting-Welding Activities
ENVIRONMENT, SAFETY & HEALTH
BULLETIN
Assistant Secretary for U.S. Department of Energy
Environment, Satety & Health Washington, D.C. 20585
DOE/EH-0196 Issue No. 91-3 June 1991
FIRE PREVENTION MEASURES FOR CUTTING/WELDING ACTIVITIES
In the past year, Department of Energy (DOE) facilities have reported more
than 100 fires, many of which were ignited as a result of cutting or welding
activities. The most recent of these fires, which occurred in mid-March of
this year, was ignited when subcontractor personnel were using an
oxygen-acetylene torch to cut a hole in the decking on the top floor of a
laboratory building. The smoldering fire started when a piece of molten metal
fell into a crack, igniting the polyurethane foam roofing insulation.
Investigations into this fire indicate that the work was being performed in
accordance with the guidelines of the facility's approved work permit and
procedures, but the procedures were interpreted incorrectly.
Order DOE 5480.7, "Fire Protection," establishes requirements for an "improved
risk" level of fire protection. An "improved risk" facility, as defined in
Section 10.a. of the Order, is characterized by "a sufficiently high level of
fire protection to fulfill requirements for insurability by the Factory Mutual
System, Industrial Risk Insurers, or other private industrial fire insurance
companies." Most DOE facilities have fire protection programs based on the
Order's "improved risk" requirements. However, the number of fires that have
occurred over the past 12 months, particularly those related to
cutting/welding activities, indicates that the potential for major fires
continues to persist throughout the DOE complex.
IMPROVED FIRE PREVENTION PRACTICES ARE ESSENTIAL
Data from the Factory Mutual System and other industrial insurers show that
cutting and welding operations account for 10 to 20 percent of industrial fire
losses. Most of these fires result from failure to follow precautionary
practices, such as isolation/protection of combustibles in the work area, use
of a fire watch, and an adequate authorization/supervision process, and from
failure to meet the Occupational Safety and Health Administration (OSHA) fire
protection requirements given in the Code of Federal Regulations (CFR) Title
29, Part 1910. Improvement in these areas of fire prevention and in line
management commitment to the "improved risk" objectives of Order DOE 5480.7
is essential.
Isolation/Protection of Combustibles
During cutting/welding activities, isolation or protection of combustibles in
the surrounding work area is of primary importance. Cutting operations
frequently produce globules of molten metal or hot slag that can ignite
surrounding combustibles. This was the case in the March fire. Although
combustible materials were observed underneath the decking prior to beginning
cutting operations, the material was not removed or protected, as required by
OSHA fire protection requirements, Title 29 1910.252, "General Requirements,"
of the CFR states that "cutting or welding shall be permitted only in areas
that are or have been made fire safe" and that "in most construction areas,
the area shall be made safe by removing combustibles or protecting
combustibles from ignition sources."
The following guidance for the removal and/or protection of combustibles
during welding and cutting operations is taken from the National Fire
Protection Association (NFPA) Industrial Fire Hazards Handbook, Section 9,
Chapter 11, "Welding and Cutting."
o Welding and cutting must not be permitted (1) in flammable (explosive)
atmospheres; (2) near large quantities of exposed, readily ignitable
materials; (3) in areas not authorized by management; or (4) on metal
partitions, walls, or roofs with combustible covering or with combustible
construction.
o Floors should be free of combustibles, such as wood shavings. If the floor
is of combustible material, it should be kept wet or otherwise protected.
o If combustibles are closer than 35 feet to the welding or cutting process,
and the work cannot be moved or the combustibles relocated at least 35 feet
away, they should be protected with flameproofed covers, metal guards, etc.
(Note that only non-asbestos, flame-retardant materials should be used for
protective covers. For information on the use of welding blankets and their
selection, see Environment, Safety and Health Bulletin DOE/EH-0039, Issue 19,
"Welding Blankets: The Unexpected Hazards," dated March 1987.)
o Openings in walls, floors, or ducts within 35 feet of the work should be
covered.
o Cutting or welding on pipes or other metal in contact with combustible
walls, partitions, ceilings, or roofs should not be done when close enough to
cause ignition by heat conduction.
Use of a Fire Watch
A fire watch, comprised of fire watchers trained in the use of fire
extinguishing equipment and the facilities available for sounding an alarm in
the event of a fire, is a necessary element of fire protection and prevention,
particularly during welding and cutting activities. In the March fire, it was
the fire watch that first spotted the smoldering fire. When the fire watch
was unable to extinguish the fire, they called the facility's Emergency
Response Team (ERI), which not only extinguished the fire, but evacuated the
building. The quick response by both the fire watch and the ERT was a major
factor in limiting the damage from the fire and protecting the safety of
workers in the building.
A fire watch is required by 29 CFR 1910 when any of the following conditions
exist:
o Appreciable combustible materials (in the building's construction or
contents) are closer than 35 feet to the point of operation.
o Appreciable combustibles are more than 35 feet away, but are easily ignited
by sparks.
o Wall or floor openings within a 35-foot radius expose combustible material
in adjacent areas, including concealed spaces in walls or floors.
Adequate fire watch procedures should include provisions for maintaining a
fire watch for a minimum of 1/2 hour after completion of welding or cutting
operations, as recommended by the NFPA's standard on fire protection, NFPA
51B, "Standard for Fire Protection In Use of Cutting and Welding Processes."
Authorization/Supervision
The decision of whether or not cutting and welding may be done should not be
left to the judgment of the operator of the equipment. Before beginning any
cutting/welding activities, proposed work must be carefully reviewed by
competent fire protection oversight personnel, such as an on-site fire chief,
a fire protection engineer, or a trained safety engineer, who is independent
of the contractor/subcontractor management chain. In many instances, such a
review may indicate that using a mechanical cutting method rather than an
oxygen-acetylene torch is safer and more appropriate for a particular cutting
operation. A review of proposed soldering work may also show that it is
feasible to replace flame soldering with electric soldering.
Work permits should be clearly written and should specify the precautions to
be taken. Investigators noted several deficiencies in the signed-off work
permit following the March fire.
Prior to signing-off a work permit, fire-protection oversight personnel
should take the following actions.
o Inspect the proposed work area.
o Determine the precautions to be taken.
o Ensure that the work permit is clearly written and specifies precautions to
be taken in such a way that workers understand what is required.
Management Commitment
The most important element of an "improved-risk" facility is management
commitment to loss prevention. One area where this commitment is critical is
in the selection of contractors and subcontractors. Factory Mutual has
determined that approximately one-third of cutting and welding losses are
caused by contractors and/or subcontractors, often during construction.
Although contractors and subcontractors are trained in specialized areas such
as cutting and welding, they may not have adequate training in areas related
to fire protection or in the risks associated with fires at DOE facilities.
When using contractors and/or subcontractors, management should ensure that
they take the following actions.
o Require contractors/subcontractors to attend weekly safety meetings.
o Ensure that subcontractor workers are properly trained in fire protection
and fire watch procedures prior to performing cutting and/or welding
activities.
o Advise contractors of the presence of flammable materials or other hazardous
conditions on the work site.
In addition, management must be responsible for the following:
o Review operations with safety personnel on a daily basis.
o Develop and implement written loss prevention policies.
o Provide adequate training, including fire watch training.
o Promote employee awareness.
RECOMMENDATIONS
The following recommendations provide additional guidance for improving fire
prevention practices.
1. Ensure that all facility and subcontractor cutting and welding fire
protection procedures comply with governing regulations, including NFPA
standards, Order DOE 5480.7, and the OSHA requirements outlined in 29 CFR
1910 and 1926.
2. Provide additional training regarding interpretation and implementation of
procedures and supporting requirements to personnel who issue work permits,
including safety, fire, and health inspectors.
3. Require safety, fire, and health inspectors to verify work permit
conditions before work begins. This process should include verification of
any work control modifications stemming from changes in conditions under
which the permit was originally issued.
4. Provide hazard communication training, as well as training in fire
protection requirements and fire prevention practices, to facility and
subcontractor personnel involved in cutting and welding activities.
5. Ensure that fire watch procedures are adequate and that fire watchers are
properly trained in their duties.
6. Take special precautions for confined space hazards associated with
cutting/welding activities, and ensure that fire watch and emergency
response team entry into confined spaces is in accordance with OSHA
requirements and those of the American National Standards Institute (ANSI).
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This Safety Bulletin is one in a series of publications issued by EH to share
occupational safety and health information throughout the DOE complex. For
more information, contact Eleanor Crampton, Performance Assessment Division,
Office of Environment, Safety and Heath, U.S. Department of Energy,
Washington, DC 20585; Telephone FTS 233-3732, Commercial (301) 353-3732.
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