GENERAL SAFETY PRECAUTIONS
a. To prevent injury to personnel, extreme
caution should be exercised when using any types of welding equipment.
Injury can result from fire, explosions, electric shock, or harmful
agents. Both the general and specific safety precautions listed below
must be strictly observed by workers who weld or cut metals.
b. Do not permit unauthorized
persons to use welding or cutting equipment.
c. Do not weld in a building with wooden
floors, unless the floors are protected from hot metal by means of fire
resistant fabric, sand, or other fireproof material. Be sure that hot
sparks or hot metal will not fall on the operator or on any welding
d. Remove all flammable material, such
as cotton, oil, gasoline, etc., from the vicinity of welding.
e. Before welding or cutting, warm those
in close proximity who are not protected to wear proper clothing or
f. Remove any assembled parts from the
component being welded that may become warped or otherwise damaged by
the welding process.
g. Do not leave hot rejected electrode
stubs, steel scrap, or tools on the floor or around the welding equipment.
Accidents and/or fires may occur.
h. Keep a suitable fire extinguisher
nearby at all times. Ensure the fire extinguisher is in operable condition.
i. Mark all hot metal after welding operations
are completed. Soapstone is commonly used for this purpose.
2-2. PERSONAL PROTECTIVE EQUIPMENT
a. General. The electric arc is
a very powerful source of light, including visible, ultraviolet, and
infrared. Protective clothing and equipment must be worn during all
welding operations. During all oxyacetylene welding and cutting proccesses,
operators must use safety goggles to protect the eyes from heat, glare,
and flying fragments of hot metals. During all electric welding processes,
operators must use safety goggles and a hand shield or helmet equipped
with a suitable filter glass to protect against the intense ultraviolet
and infrared rays. When others are in the vicinity of the electric welding
processes, the area must be screened so the arc cannot be seen either
directly or by reflection from glass or metal.
b. Helmets and Shields.
(1) Welding arcs are intensely brilliant
lights. They contain a proportion of ultraviolet light which may cause
eye damage. For this reason, the arc should never be viewed with the
naked eye within a distance of 50.0 ft (15.2 m). The brilliance and
exact spectrum, and therefore the danger of the light, depends on
the welding process, the metals in the arc, the arc atmosphere, the
length of the arc, and the welding current. Operators, fitters, and
those working nearby need protection against arc radiation. The intensity
of the light from the arc increases with increasing current and arc
voltage. Arc radiation, like all light radiation, decreases with the
square of the distance. Those processes that produce smoke surrounding
the arc have a less bright arc since the smoke acts as a filter. The
spectrum of the welding arc is similar to that of the sun. Exposure
of the skin and eyes to the arc is the same as exposure to the sun.
(2) Being closest, the welder needs
a helmet to protect his eyes and face from harmful light and particles
of hot metal. The welding helmet (fig. 2-1) is generally constructed
of a pressed fiber insulating material. It has an adjustable headband
that makes it usable by persons with different head sizes. To minimize
reflection and glare produced by the intense light, the helmet is
dull black in color. It fits over the head and can be swung upward
when not welding. The chief advantage of the helmet is that it leaves
both hands free, making it possible to hold the work and weld at the
(3) The hand-held shield (fig. 2-1)
provides the same protection as the helmet, but is held in position
by the handle. This type of shield is frequently used by an observer
or a person who welds for a short period of time.
(4) The protective welding helmet has
lens holders used to insert the cover glass and the filter glass or
plate. Standard size for the filter plate is 2 x 4-1/4 in. (50 x 108
mm). In some helmets lens holders open or flip upwards. Lenses are
designed to prevent flash burns and eye damage by absorption of the
infrared and ultraviolet rays produced by the arc. The filter glasses
or plates come in various optical densities to filter out various
light intensities, depending on the welding process, type of base
metal, and the welding current. The color of the lens, usually green,
blue, or brown, is an added protection against the intensity of white
light or glare. Colored lenses make it possible to clearly see the
metal and weld. Table 2-1 lists the proper filter shades to be used.
A magnifier lens placed behind the filter glass is sometimes used
to provide clear vision.
A cover plate should be placed outside
the filter glass to protect it from weld spatter. The filter glass
must be tempered so that is will not break if hit by flying weld spatter.
Filter glasses must be marked showing the manufacturer, the shade
number, and the letter "H" indicating it has been treated for impact
Colored glass must be manufactured
in accordance with specifications detailed in the "National Safety
Code for the Protection of Hands and Eyes of Industrial Workers",
issued by the National Bureau of Standards, Washington DC, and OSHA
Standards, Subpart Q, "Welding, Cutting, and Brazing", paragraph 1910.252,
and American National Standards Institute Standard (ANSI) Z87.1-1968,
"American National Standard Practice for Occupational and Educational
Eye and Face Protection".
(5) Gas metal-arc (MIG) welding requires
darker filter lenses than shielded metal-arc (stick) welding. The
intensity of the ultraviolet radiation emitted during gas metal-arc
welding ranges from 5 to 30 times brighter than welding with covered
(6) Do not weld with cracked or defective
shields because penetrating rays from the arc may cause serious burns.
Be sure that the colored glass plates are the proper shade for arc
welding. Protect the colored glass plate from molten metal spatter
by using a cover glass. Replace the cover glass when damaged or spotted
by molten metal spatter.
(7) Face shields (fig. 2-2) must also
be worn where required to protect eyes. Welders must wear safety glasses
and chippers and grinders often use face shields in addition to safety
(8) In some welding operations, the
use of mask-type respirators is required. Helmets with the "bubble"
front design can be adapted for use with respirators.
c. Safety Goggles. During all
electric welding processes, operators must wear safety goggles (fig.
2-3) to protect their eyes from weld spatter which occasionally gets
inside the helmet. These clear goggles also protect the eyes from slag
particles when chipping and hot sparks when grinding. Contact lenses
should not be worn when welding or working around welders. Tinted safety
glasses with side shields are recommended, especially when welders are
chipping or grinding. Those working around welders should also wear
tinted safety glasses with side shields.
d. Protective Clothing.
(1) Personnel exposed to the hazards
created by welding, cutting, or brazing operations shall be protected
by personal protective equipment in accordance with OSHA standards,
Subpart I, Personal Protective Equipment, paragraph 1910.132. The
appropriate protective clothing (fig. 2-4) required for any welding
operation will vary with the size, nature, and location of the work
to be performed. Welders should wear work or shop clothes without
openings or gaps to prevent arc rays from contacting the skin. Those
working close to arc welding should also wear protective clothing.
Clothing should always be kept dry, including gloves.
(2) Woolen clothing should be worn
instead of cotton since wool is not easily burned or damaged by weld
spatter and helps to protect the welder from changes in temperature.
Cotton clothing, if used, should be chemically treated to reduce its
combustibility. All other clothing, such as jumpers or overalls, should
be reasonably free from oil or grease.
(3) Flameproof aprons or jackets made
of leather, fire resistant material, or other suitable material should
be worn for protection against spatter of molten metal, radiated heat,
and sparks. Capes or shoulder covers made of leather or other suitable
materials should be worn during overhead welding or cutting operations.
Leather skull caps may be worn under helmets to prevent head burns.
(4) Sparks may lodge in rolled-up sleeves,
pockets of clothing, or cuffs of overalls and trousers. Therefore,
sleeves and collars should be kept buttoned and pockets should be
eliminated from the front of overalls and aprons. Trousers and overalls
should not be turned up on the outside. For heavy work, fire-resisant
leggings, high boots, or other equivalent means should be used. In
production work, a sheet metal screen in front of the worker's legs
can provide further protection against sparks and molten metal in
(5) Flameproof gauntlet gloves, preferably
of leather, should be worn to protect the hands and arms from rays
of the arc, molten metal spatter, sparks, and hot metal. Leather gloves
should be of sufficient thickness so that they will not shrivel from
the heat, burn through, or wear out quickly. Leather gloves should
not be used to pick up hot items, since this causes the leather to
become stiff and crack. Do not allow oil or grease to cane in contact
with the gloves as this will reduce their flame resistance and cause
them to be readily ignited or charred.
e. Protective Equipment.
(1) Where there is exposure to sharp
or heavy falling objects or a hazard of bumping in confined spaces,
hard hats or head protectors must be used.
(2) For welding and cutting overhead
or in confined spaces, steel-toed boots and ear protection must also
(3) When welding
in any area, the operation should be adequately screened to protect
nearby workers or passers-by froman the glare of welding. The screens
should be arranged so that no serious restriction of ventilation exists.
The screens should be mounted so that they are about 2.0 ft above
the floor unless the work is performed at such a low level that the
screen must be extended closer to the floor to protect adjacent workers.
The height of the screen is normally 6.0 ft (1.8 m) but may be higher
depending upon the situation. Screen and surrounding areas must be
painted with special paints which absorb ultraviolet radiation yet
do not create high contrast between the bright and dark areas. Light
pastel colors of a zinc or titanium dioxide base paint are recommended.
Black paint should not be used.
2-3. FIRE HAZARDS
a. Fire prevention and protection is
the responsibility of welders, cutters, and supervisors. Approximately
six percent of the fires in industrial plants are caused by cutting
and welding which has been done primarily with portable equipment or
in areas not specifically designated for such work. The elaboration
of basic precautions to be taken for fire prevention during welding
or cutting is found in the Standard for Fire Prevention in Use of Cutting
and Welding Processes, National Fire Protection Association Standard
51B, 1962. Some of the basic precautions for fire prevention in welding
or cutting work are given below.
b. During the welding
and cutting operations, sparks and molten spatter are formal which sometimes
fly considerable distances. Sparks have also fallen through cracks,
pipe holes, or other small openings in floors and partitions, starting
fires in other areas which temporarily may go unnoticed. For these reasons,
welding or cutting should not be done near flammable materials unless
every precaution is taken to prevent ignition.
c. Hot pieces of base metal may come
in contact with combustible materials and start fires. Fires and explosions
have also been caused when heat is transmitted through walls of containers
to flammable atmospheres or to combustibles within containers. Anything
that is combustible or flammable is susceptible to ignition by cutting
d. When welding or cutting parts of vehicles,
the oil pan, gasoline tank, and other parts of the vehicle are considered
fire hazards and must be removed or effectively shielded from sparks,
slag, and molten metal.
e. Whenever possible, flammable materials
attached to or near equipment requiring welding, brazing, or cutting
will be removed. If removal is not practical, a suitable shield of heat
resistant material should be used to protect the flammable material.
Fire extinguishing equipment, for any type of fire that may be encountered,
must be present.
(1) All welding and thermal cutting
operations carried on in confined spaces must be adequately ventilated
to prevent the accumulation of toxic materials, combustible gases,
or possible oxygen deficiency. Monitoring instruments should be used
to detect harmful atmospheres. Where it is impossible to provide adequate
ventilation, air-supplied respirators or hose masks approved for this
purpose must be used. In these situations, lookouts must be used on
the outside of the confined space to ensure the safety of those working
within. Requirements in this section have been established for arc
and gas welding and cutting. These requirements will govern the amount
of contamination to which welders may be exposed:
(a) Dimensions of the area in which
the welding process takes place (with special regard to height of
(b) Number of welders in the room.
(c) Possible development of hazardous
fumes, gases, or dust according to the metals involved.
(d) Location of welder's breathing
zone with respect to rising plume of fumes.
(2) In specific cases, there are other
factors involved in which respirator protective devices (ventilation)
should be provided to meet the equivalent requirements of this section.
(a) Atomspheric conditions.
(b) Generated heat.
(c) Presence of volatile solvents.
(3) In all cases, the required health
protection, ventilation standards, and standard operating procedures
for new as well as old welding operations should be coordinated and
cleaned through the safety inspector and the industrial hygienist
having responsibility for the safety and health aspects of the work
b. Screened Areas. When welding
must be performed in a space entirely screened on all sides, the screens
shall be arranged so that no serious restriction of ventilation exists.
It is desirable to have the screens mounted so that they are about 2.0
ft (0.6 m) above the floor, unless the work is performed at such a low
level that the screen must be extended closer to the floor to protect
workers from the glare of welding. See paragraph 2-2 e (3).
c. Concentration of Toxic Substances.
Local exhaust or general ventilating systems shall be provided and arranged
to keep the amount of toxic frees, gas, or dusts below the acceptable
concentrations as set by the American National Standard Institute Standard
7.37; the latest Threshold Limit Values (TLV) of the American Conference
of Governmental Industrial Hygienists; or the exposure limits as established
by Public Law 91-596, Occupational Safety and Health Act of 1970. Compliance
shall be determined by sampling of the atmsphere. Samples collected
shall reflect the exposure of the persons involved. When a helmet is
worn, the samples shall be collected under the helmet.
Where welding operations are incidental
to general operations, it is considered good practice to apply local
exhaust ventilation to prevent contamination of the general work area.
d. Respiratory Protective Equipment.
Individual respiratory protective equipment will be well retained. Only
respiratory protective equipment approved by the US Bureau of Mines,
National Institute of Occupational Safety and Health, or other government-approved
testing agency shall be utilized. Guidance for selection, care, and
maintenance of respiratory protective equipment is given in Practices
for Respiratory Protection, American National Standard Institute Standard
788.2 and TB MED 223. Respiratory protective equipment will not be transferred
from one individual to another without being disinfected.
e. Precautionary Labels. A number
of potentially hazardous materials are used in flux coatings, coverings,
and filler metals. These materials, when used in welding and cutting
operations, will become hazardous to the welder as they are released
into the atmosphere. These include, but are not limited to, the following
materials: fluorine compounds, zinc, lead, beryllium, cadmium, and mercury.
See paragraph 2-4 i through 2-4 n. The suppliers of welding materials
shall determine the hazard, if any, associated with the use of their
materials in welding, cutting, etc.
(1) All filler metals and fusible granular
materials shall carry the following notice, as a minimum, on tags,
boxes, or other containers:
Welding may produce fumes and gases
hazardous to health. Avoid breathing these fumes and gases. Use adequate
ventilation. See American National Standards Institute Standard Z49.1-1973,
Safety in Welding and Cutting published by the American Welding Society.
(2) Brazing (welding) filler metals
containing cadmium in significant amounts shall carry the following
notice on tags, boxes, or other containers:
CONTAINS CADMIUM - POISONOUS FUMES MAY BE FORMED ON HEATING
Do not breathe fumes. Use only with
adequate ventilation, such as fume collectors, exhaust ventilators,
or air-supplied respirators. See American National Standards Institute
Standard Z49.1-1973. If chest pain, cough, or fever develops after
use, call physician immediately.
(3) Brazing and gas welding fluxes
containing fluorine compounds shall have a cautionary wording. One
such wording recommended by the American Welding Society for brazing
and gas welding fluxes reads as follows:
This flux, when heated, gives off fumes
that may irritate eyes, nose, and throat.
Avoid fumes--use only in well-ventilated spaces.
Avoid contact of flux with eyes or skin.
Do not take internally.
f. Ventilation for General Welding
(1) General. Mechanical ventilation
shall be provided when welding or cutting is done on metals not covered
in subparagraphs i through p of this section, and under the following
(a) In a space of less than 10,000
cu ft (284 cu m) per welder.
(b) In a roan having a ceiling height
of less than 16 ft (5 m).
(c) In confined spaces or where the
welding space contains partitions, balconies, or other structural
barriers to the extent that they significantly obstruct cross ventilation.
(2) Minimum rate. Ventilation
shall be at the minimum rate of 200 cu ft per minute (57 cu m) per
welder, except where local exhaust heeds, as in paragraph 2-4 g below,
or airline respirators approved by the US Bureau of Mines, National
Institute of Occupational Safety and Health, or other government-approved
testing agency, are used. When welding with rods larger than 3/16
in. (0.48 cm) in diameter, the ventilation shall be higher as shown
in the following:
1/4 (0.64 cm)
Natural ventilation is considered sufficient
for welding or cutting operations where the conditions listed above
are not present. Figure 2-5 is an illustration of a welding booth
equipped with mechanical ventilation sufficient for one welder.
g. Local Exhaust
Ventilation. Mechanical local exhaust ventilation may be obtained
by either of the following means:
(1) Hoods. Freely movable hoods
or ducts are intended to be placed by the welder as near as practicable
to the work being welded. These will provide a rate of airflow sufficient
to maintain a velocity the direction of the hood of 100 in linear
feet per minute in the zone of welding. The ventilation rates required
to accomplish this control velocity using a 3-in. wide flanged suction
opening are listed in table 2-2.
(2) Fixed enclosure. A fixed
enclosure with a top and two or more sides which surrounds the welding
or cutting operations will have a rate of airflow sufficient to maintain
a velocity away from the welder of not less than 100 linear ft per
minute. Downdraft ventilation tables require 150 cu ft per minute
per square foot of surface area. This rate of exhausted air shall
be uniform across the face of the grille. A low volume, high-density
fume exhaust device attached to the welding gun collects the fumes
as close as possible to the point of origin or at the arc. This method
of fume exhaust has become quite popular for the semiautomatic processes,
particularly the flux-cored arc welding process. Smoke exhaust systems
incorporated in semiautomatic guns provide the most economical exhaust
system since they exhaust much less air they eliminate the need for
massive air makeup units to provide heated or cooled air to replace
the air exhausted. Local ventilation should have a rate of air flow
sufficient to maintain a velocity away from the welder of not less
than 100 ft (30 m) per minute. Air velocity is measurable using a
velometer or air flow inter. These two systems can be extremely difficult
to use when welding other than small weldments. The down draft welding
work tables are popular in Europe but are used to a limited degree
North America. In all cases when local ventilation is used, the exhaust
air should be filtered.
h. Ventilation in Confined
(1) Air replacement. Ventilation
is a perquisite to work in confined spaces. All welding and cutting
operations in confined spaces shall be adequately ventilated to prevent
the accumulation of toxic materials -or possible oxygen deficiency.
This applies not only to the welder but also to helpers and other
personnel in the immediate vicinity.
(2) Airline respirators. In
circumstances where it is impossible to provide adequate ventilation
in a confined area, airline respirators or hose masks, approved by
the US Bureau of Mines, National Institute of Occupational Safety
and Health, or other government-approved testing agency, will be used
for this purpose. The air should meet the standards established by
Public Law 91-596, Occupational Safety and Health Act of 1970.
(3) Self-contained units. In
areas immediately hazardous to life, hose masks with blowers or self-contained
breathing equipment shall be used. The breathing equipment shall be
approved by the US Bureau of Mines or National Institute of Occupational
Safety and Health, or other government-approved testing agency.
(4) Outside helper. Where welding
operations are carried on in confined spaces and where welders and
helpers are provided with hose masks, hose masks with blowers, or
self-contained breathing equipment, a worker shall be stationed on
the outside of such confined spaces to ensure the safety of those
(5) Oxygen for ventilation.
Oxygen must never be used for ventilation.
i. Fluorine Compounds.
(1) General. In confined spaces,
welding or cutting involving fluxes, coverings, or other materials
which fluorine compounds shall be done in accordance with paragraph
2-4 h, ventilation in confined spaces. A fluorine compound is one
that contains fluorine as an element in chemical combination, not
as a free gas.
(2) Maximum allowable concentration.
The need for local exhaust ventilation or airline respirators for
welding or cutting in other than confined spaces will depend upon
the individual circumstances. However, experience has shown that such
protection is desirable for fixed-location production welding and
for all production welding on stainless steels. When air samples taken
at the welding location indicate that the fluorides liberated are
below the maximum allowable concentration, such protection is not
(1) Confined spaces. In confined
spaces, welding or cutting involving zinc-bearing filler metals or
metals coated with zinc-bearing materials shall be done in accordance
with paragraph 2-4 h, ventilation in confined spaces.
(2) Indoors. Indoors, welding
or cutting involving zinc-bearing metals or filler metals coated with
zinc-bearing materials shall be done in accordance with paragraph
(1) Confined spaces. In confined
spaces, welding involving lead-base metals (erroneously called lead-burning)
shall be done in accordance with paragraph 2-4 h.
(2) Indoors. Indoors, welding
involving lead-base metals shall be done in accordance with paragraph
2-4 g, local exhaust ventilation.
(3) Local ventilation. In confined
spaces or indoors, welding or cutting involving metals containing
lead or metals coated with lead-bearing materials, including paint,
shall be done using local exhaust ventilation or airline respirators.
Outdoors, such operations shall be done using respirator protective
equipment approved by the US Bureau of Mines, National Institute of
Occupational Safety and Health, or other government-approved testing
agency. In all cases, workers in the immediate vicinity of the cutting
or welding operation shall be protected as necessary by local exhaust
ventilation or airline respirators.
l. Beryllium. Welding or cutting
indoors, outdoors, or in confined spaces involving beryllium-bearing
material or filler metals will be done using local exhaust ventilation
and airline respirators. This must be performed without excep-tion unless
atmospheric tests under the most adverse conditions have established
that the workers' exposure is within the acceptable concentrations of
the latest Threshold Limit Values (TLV) of the American Conference of
Governmental Industrial Hygienists, or the exposure limits established
by Public Law 91-596, Occupational Safety and Health Act of 1970. In
all cases, workers in the immediate vicinity of the welding or cutting
operations shall be protected as necessary by local exhaust ventilation
or airline respirators.
(1) General. Welding or cutting
indoors or in confined spaces involving cadmium-bearing or cadmium-coated
base metals will be done using local exhaust ventilation or airline
respirators. Outdoors, such operations shall be done using respiratory
protective equipment such as fume respirators, approved by the US
Bureau of Mines, National Institute of Occupational Safety and Health,
or other government-approved testing agency, for such purposes.
(2) Confined space. Welding
(brazing) involving cadmium-bearing filler metals shall be done using
ventilation as prescribed in paragraphs 2-4 g, local exhaust ventilation,
and 2-4 h, ventilation in confined spaces, if the work is to be done
in a confined space.
Cadmium-free rods are available and
can be used in most instances with satisfactory results.
n. Mercury. Welding or cutting
indoors or in a confined space involving metals coated with mercury-bearing
materials, including paint, shall be done using local exhaust ventilation
or airline respirators. Outdoors, such operations will be done using
respiratory protective equipment approved by the National Institute
of Occupational Safety and Health, US Bureau of Mines, or other government-approved
o. Cleaning Compounds.
(1) Manufacturer's instructions.
In the use of cleaning materials, because of their toxicity of flammability,
appropriate precautions listed in the manufacturer's instructions
will be followed.
(2) Degreasing. Degreasing or
other cleaning operations involving chlorinated hydrocarbons will
be located so that no vapors from these operations will reach or be
drawn into the area surrounding any welding operation. In addition,
trichloroethylene and perchloroethylene should be kept out of atmospheres
penetrated by the ultraviolet radiation of gas-shielded welding operations.
p. Cutting of Stainless Steels.
Oxygen cutting, using either a chemical flux or iron powder, or gas-shielded
arc cutting of stainless steel will be done using mechanical ventilation
adequate to remove the fumes generated.
q. First-Aid Equipment. First-aid
equipment will be available at all times. On every shift of welding
operations, there will be personnel present who are trained to render
first-aid. All injuries will be reported as soon as possible for medical
attention. First-aid will be rendered until medical attention can be
2-5. WELDING IN CONFINED SPACES
a. A confined space is intended to mean
a relatively small or restricted space such as a tank, boiler, pressure
vessel, or small compartment of a ship or tank.
b. When welding or cutting is being performed
in any confined space, the gas cylinders and welding machines shall
be left on the outside. Before operations are started, heavy portable
equipment mounted on wheels shall be securely blocked to prevent accidental
c. Where a welder must enter a confined
space through a manhole or other all opening, means will be provided
for quickly removing him in case of emergency. When safety belts and
life lines are used for this purpose, they will be attached to the welder's
body so that he cannot be jammed in a small exit opening. An attendant
with a preplanned rescue procedure will be stationed outside to observe
the welder at all times and be capable of putting rescue operations
d. When arc welding is suspended for
any substantial period of time, such as during lunch or overnight, all
electrodes will be removed from the holders with the holders carefully
located so that accidental contact cannot occur. The welding machines
will be disconnected from the power source.
e. In order to eliminate the possibility
of gas escaping through leaks or improperly closed valves when gas welding
or cutting, the gas and oxygen supply valves will be closed, the regulators
released, the gas and oxygen lines bled, and the valves on the torch
shut off when the equipment will not be used for a substantial period
of time. Where practical, the torch and hose will also be removed from
the confined space.
f. After welding operations
are completed, the welder will mark the hot metal or provide some other
means of warning other workers.