Safety Practices in Welding
INTRODUCTION
Arc welding is a safe occupation when sufficient measures are Important Note:
taken to protect the welder from potential hazards. When these So that you can protect yourself against these hazards, every
measures are overlooked or ignored, however, welders can welder should be familiar with American National Standard ANSI
encounter such dangers as electric shock, overexposure to Z49.1, “Safety in Welding and Cutting,� and should follow the
fumes and gases, arc radiation, and fire and explosion; which safety practices in that document. Z49.1 is now available for
may result in serious, or even fatal injuries. download at no charge at:
http://www.lincolnelectric.com/community/safety/ or at the
This bulletin is written with the arc welding operator in mind, AWS website http://www.aws.org.
containing both mandatory safety practices and those based on
Download and read it!
shop experience. Be sure to read ANSI Z49.1, and refer to the
other publications listed at the end of the bulletin for more
detailed information on specific topics of arc welding safety, as
well as the manufacturers� instructions and material safety data
sheets (MSDS’s).
PERSONAL PROTECTIVE EQUIPMENT
leather high-tops with steel toes (especially when doing heavy
Protective Clothing
work).
Welders, like firemen, must wear clothing to protect them from
being burned. Of all injuries to welders, burns are the most
Other protective wear for heavy work or especially hazardous
common due to sparks landing on bare skin. Welding arcs are
situations includes: flame-resistant suits, aprons, leggings,
very intense and can cause burns to skin and eyes with just a
leather sleeves/shoulder capes, and caps worn under your
few minutes of exposure.
helmet.
The actual gear varies with the job being performed, but
Heavy, flame-resistant gloves, such as leather, should always be
generally protective clothing must allow freedom of movement
worn to protect your hands from burns, cuts, and scratches. In
while providing adequate coverage against burns from sparks,
addition, as long as they are dry and in good condition, they will
weld spatter, and arc radiation. Many types of clothing will
offer some insulation against electric shock.
protect you from ultra-violet radiation exposure, which appears
as a skin burn (much like sunburn). Under the worst conditions,
As to preventing electric shock, the key word is dry! We’ll have
however, severe burns and skin cancer may result from excessive
more on the subject later, but for now keep in mind that moisture
radiation.
can increase the potential for and severity of electric shock.
When working in wet conditions, or when perspiring heavily, you
Because of its durability and resistance to fire, wool clothing is
must be even more careful to insulate your body from electrically
suggested over synthetics (which should never be worn because
“live� parts and work on grounded metal.
it melts when exposed to extreme heat) or cotton, unless it is
specially treated for fire protection. If possible, keep your clothes
clean of grease and oil, as these substances may ignite and burn
uncontrollably in the presence of oxygen.
WARNING
Avoid rolling up your sleeves and pant-cuffs, because sparks or
ARC RAYS can burn.
hot metal could deposit in the folds; also, wear your trousers
� Wear eye, ear and body protection.
outside your work boots, not tucked in, to keep particles from
falling into your boots. While we’re on the subject, we suggest
Note To Arc Welding Educators and Trainers:
This Arc Welding Safety brochure may be freely copied for educational purposes if
distributed to welders and welding students at no additional charge.
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SAFETY PRACTICES IN WELDING
ARC RAYS
It is essential that your eyes are protected from radiation
exposure. Infrared radiation has been known to cause retinal
burning and cataracts. And even a brief exposure to ultraviolet
(UV) radiation can cause an eye burn known as “welder’s
flash.� While this condition is not always apparent until several
hours after exposure, it causes extreme discomfort, and can
result in swelling, fluid excretion, and temporary blindness.
Normally, welder’s flash is temporary, but repeated or
prolonged exposure can lead to permanent injury of the eyes.
Other than simply not looking at an arc, the primary preventive
measure you can take is to use the proper shade lens in your
helmet. Refer to the lens shade selector chart in Supplement 1
for the recommended shade numbers for various arc welding
processes. The general rule is to choose a filter too dark to
see the arc, then move to lighter shades without dropping
below the minimum rating. The filters are marked as to the
manufacturer and shade number, the impact-resistant variety
are marked with an “H.�
Helmets and hand-held face shields (see Figure A) offer the most
complete shading against arc radiation. The shade slips into a window
at the front of the shield so that it can be removed and replaced easily.
The shields are made from a hard plastic or fiberglass to protect your
head, face, ears, and neck from electric shock, heat, sparks, and
flames. You should also use safety glasses with side shields or goggles
to protect your eyes from flying particles.
Visible light can also be harmful, but it is easy to tell if the light is
dangerous: if it hurts to look at, then it’s too bright. The same is true for
infrared radiation: it can usually be felt as heat. However, there’s no real
way for you to tell if you’re being over exposed to UV radiation, so just
don’t take chances: always wear eye protection (see Supplement 1 for Figure A. A helmet (a) required for protecting the
recommended lens shade numbers). welder’s eyes and face and (b) a hand-held face
shield that is convenient for the use of foremen,
inspectors, and other spectators.
NOISE
There are two good reasons to wear ear muffs or plugs:
a) to keep flying sparks or metal out of your ears; and
b) to prevent hearing loss as a result of working around noisy arc welding equipment, power sources, and
processes (like air carbon arc cutting or plasma arc cutting).
As with radiation exposure to the eyes, the length and number of times that you are exposed to high levels of
noise determine the extent of the damage to your hearing, so be sure to avoid repeated exposure to noise. If it
is not possible to reduce the level of noise at the source (by moving either yourself or the equipment, utilizing
sound shields, etc.), then you should wear adequate ear protection.
If the noise in your work area becomes uncomfortable, causing a headache or discomfort of the ears, you
could be damaging your hearing and should immediately put on ear muffs or plugs.
In fact, the use of ear protection at all times is a good idea, as hearing loss is both gradual and adds up over
time. Damage to your hearing may not be noticed until you have a complete hearing test, and then it could be
too late.
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SAFETY PRACTICES IN WELDING
INSPECTION AND MAINTENANCE OF EQUIPMENT
AND WORK
Before starting any arc welding operation, you should make a
complete inspection of your equipment. All it takes on your part
is 5-10 minutes before you turn on your welder; is that too much
to spend in preventing injury to yourself or your co-workers?
To begin with:
� Have you read the instruction manual and do you
understand the instructions? The instruction manual for your
welder is available upon request to your welding distributor
or the manufacturer. Manuals for Lincoln Electric welders
may be downloaded from lincolnelectric.com at no charge.
� Have you read the warnings and instructions on the
equipment nameplates and decals as well as the
consumables labels and material safety data sheets? (For
older equipment see Supplement 5 to request a FREE
� Is the work stable and easy to reach from where you’re
Warning Label.)
standing?
For the welder: � Is the Work Lead connected securely?
� Are all the connections tight, including the earth ground? � Is there enough dry insulation between your body and the
work piece?
� OSHA regulations require output terminals to be insulated.
Rubber boots are available for that purpose. � Is there adequate ventilation in your work area?
� Are the electrode holder and welding cable well insulated
Take some personal responsibility for your own safety. Notify
and in good condition?
your supervisor if equipment is in need of repair or not working
� Are the settings correct for the job you’re about to begin?
properly or any unsafe condition. You have the most to lose if
you get hurt. Don’t allow yourself to work in a hazardous
For an engine-driven welder: situation without taking appropriate safety precautions.
� Is it running OK?
If the hazard is serious and cannot be corrected readily, the
� Are all the hoses on tight?
machine should be shut down until the needed repairs are
� Is the fuel cap on tight? made. If the problem is limited to the outside of the welder, such
as a loose connection or a damaged cable that needs to be
� Is the engine leaking fuel or oil? Some jobsites look for this
replaced, disconnect power to the welder and correct the
and may refuse entry if your engine is leaking.
problem per the manufacturers instructions in the
� Is the original enclosure and fan guarding in place? Check
operating/service manual. If the hazard requires repairs to the
with your welding equipment distributor if you are unsure.
inside of the welder or to the electrical input supply lines, call a
(See Supplement 6.)
service technician or an electrician. Never attempt to make
these repairs if you are untrained.
For the work in general: (See also Supplements 4 and 7)
� Are the work area conditions such that normal safety
precautions can be observed or must special equipment
(i.e., ventilation, exhaust, or respirator, welding equipment,
Important Safety Note:
protective equipment, safety equipment) or procedures be
Consider whether the area in which you will be working creates
used?
or increases the level of hazard to you thus requiring special
� Many jobsites require permits for any welding or cutting. Be
procedures or equipment. Factors such as electrical safety,
sure you have any permits you will need.
fume ventilation/exhaust and risk of fire or explosion may be
� If you will be working in a confined space, many special affected. See later sections on those topics and other
OSHA regulations and jobsite requirements may apply in documents in “Bibliography and Suggested Reading� for further
addition to the arc welding precautions in this brochure. information.
Understand which of these apply to your jobsite and comply
with them.
� Are the cables the right size for your job? Be sure any
damaged cable insulation is repaired.
� Are they spread out and run neatly to prevent overheating?
� Is the gas cylinder connected properly?
� Is the cylinder secure?
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SAFETY PRACTICES IN WELDING
CARE AND CLEANING OF THE WORK AREA Also, bear in mind that while you’re paying attention to your
Keeping the area around your work neat is as important as work, other welders may be preoccupied with their own tasks
maintaining your equipment. Perhaps even more-so, as the risk and not watching where they’re going. So be sure that there are
of injury is amplified by the larger group of people involved. You protective screens in place, just in case somebody happens to
may have already inspected your equipment and found it to be be passing into your work area or walks into a shower of sparks
OK, but all your caution won’t matter when, for example, a co- or spatter.
worker trips over your cable, causing you, and/or the people
around you, to be injured by shock, hot metal, or from falling.
Keep all your equipment, cables, hoses, cylinders, etc. out of any
traffic routes such as doors, hallways, and ladders. A good
practice is to avoid clutter � and clean up your work area
when you’re done! Not only will it help to protect yourself and
others, you'll find it much easier for you to work efficiently.
GAS CYLINDERS
the cylinder valve only when standing to one side of the
Because of the high pressure gas in cylinders, you must pay
cylinder, away from welding or other sources of ignition. Return
particularly close attention to their storage and use. Examine the
damaged cylinders to the supplier. Refer to the Compressed
cylinders as you did the rest of your equipment; check the
Gas Association pamphlet P-1, “Safe Handling of Gas
cylinder label to make sure it is the correct shielding gas for the
Cylinders,� for further information.
process, and that the regulators, hoses, and fittings are the right
ones for that gas and pressure, and are in good condition.
WARNING
Cylinders must be secured in an upright position, with the valve
CYLINDER may explode if damaged.
caps in place, in an area away from combustibles and fuels, and
� Keep cylinder upright and chained to support.
safeguarded from damage, heat, and flames. When in use, keep
� Never allow welding electrode to touch
them out of traffic routes and flying sparks, with all hoses run
cylinder.
neatly to the welding area. Never allow the electrode or other
“electrically hot� parts of your welder to touch a cylinder. “Crack�
the valve open to prevent dirt from entering the regulator; open
Electric and Magnetic Fields
Electric current flowing through any conductor causes localized
Electric and Magnetic Fields (EMF). Welding current creates
EMF fields around welding cables and welding machines. EMF
fields may interfere with some pacemakers, and welders having
a pacemaker should consult their physician before welding.
Exposure to EMF fields in welding may have other health effects
which are now not known. All welders should use the following
procedures in order to minimize exposure to EMF fields from the
welding circuit:
� Route the electrode and work cables together � Secure
them with tape when possible.
� Never coil the electrode lead around your body.
� Do not place your body between the electrode and work
cables. If the electrode cable is on your right side, the work
cable should also be on your right side.
� Connect the work cable to the workpiece as close as
possible to the area being welded.
� Do not work next to welding power source.
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SAFETY PRACTICES IN WELDING
SPECIFIC CONCERNS
welder, check the welder capacity nameplate and connection
Possible Shock Hazards
instructions to be sure the input is the correct phase (single
The hazard of electric shock is one of the most serious and
phase or three phase) and voltage. Many welders may be set up
immediate risks facing you as a welder. Contact with metal parts
for single phase or three phase and for multiple input voltages.
which are “electrically hot� can cause injury or death because of
Be certain the welder is set up for the electrical supply to which
the effect of the shock upon your body or a fall which may result
it is connected. Only a qualified electrician should connect
from your reaction to the shock. The electric shock hazard
input power. The case must be grounded so that if a problem
associated with arc welding may be divided into two categories
develops inside the welder a fuse will blow, disconnecting the
which are quite different:
power and letting you know that repair is required. Never ignore
� Primary Voltage Shock (i.e., 230, 460 volts); and
a blown fuse because it is a warning that something is wrong.
� Secondary Voltage Shock (i.e., 20-100 volts).
WARNING
WARNING
ELECTRIC SHOCK can kill.
HIGH VOLTAGE can kill. � Do not touch electrically live parts or
� Do not operate with covers removed. electrode with skin or wet clothing.
� Disconnect input power before servicing. � Insulate yourself from work and ground.
� Do not touch electrically live parts.
If welding must be performed under electrically hazardous
conditions (in damp locations or while wearing wet clothing;
The primary voltage shock is very hazardous because it is on metal structures such as floors, gratings or scaffolds;
much greater voltage than the welder secondary voltage. You when in cramped positions such as sitting, kneeling or lying,
can receive a shock from the primary (input) voltage if you touch if there is a high risk of unavoidable or accidental contact
a lead inside the welder with the power to the welder “on� while with the work piece or ground) use the following equipment:
you have your body or hand on the welder case or other
� Semiautomatic DC Constant Voltage Welder
grounded metal. Remember that turning the welder power switch
� DC Manual (Stick) Welder
“off� does not turn the power off inside the welder. To turn the
power inside the welder "off", the input power cord must be � AC Welder with Reduced Voltage Control
unplugged or the power disconnect switch turned off. You should
never remove fixed panels from your welder; in fact, always have
a qualified technician repair your welder if it isn’t working
A secondary voltage shock occurs when you touch a part of
properly. Also, your welder should be installed by a qualified
the electrode circuit � perhaps a bare spot on the electrode
electrician so it will be correctly wired for the primary voltage
cable � at the same time another part of your body is touching
which supplies it power and so the case will be connected to an
the metal upon which you’re welding (work). To receive a shock
earth ground. When electrical supply lines are connected to a
your body must touch both sides of the welding circuit �
electrode and work (or welding ground) � at the same time. To
prevent secondary voltage shock, you must develop and use
safe work habits. Remember the voltage at the electrode is
highest when you are not welding (open circuit voltage).
� Wear dry gloves in good condition when welding.
� Do not touch the electrode or metal parts of the electrode
holder with skin or wet clothing.
� Keep dry insulation between your body (including arms and
legs) and the metal being welded or ground (i.e., metal floor,
wet ground).
� Keep your welding cable and electrode holder in good
condition. Repair or replace any damaged insulation.
Figure B. Always inspect your electrode holder before turning the welder on.
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[6]
SAFETY PRACTICES IN WELDING
These rules are basic to welding and you should already know recognize and protect combustible materials from the welding
them. Check out the warning on your welder or electrode box arc, sparks and spatter. It is also important to be sure the work
next time you weld. You will probably not have a shock while is not in contact with any combustible which it may ignite when
welding if you follow these rules. heated. These materials fall into three categories: liquid
(gasoline, oil, paints, and thinners); solid (wood, cardboard, and
Though it may be more difficult to follow the rules under some paper); and gaseous (acetylene and hydrogen).
conditions, the rules still apply. Keep your gloves dry even if you
have to keep an extra pair. Use plywood, rubber mats, or some Watch where the sparks and metals are falling from your work: if
other dry insulation to stand or lie upon. Insulate your body from there are flammable materials including fuel or hydraulic lines in
the metal you are welding. Don’t rest your body, arms, or legs on your work area and you can’t move either your work or the
the workpiece, especially if your clothing is wet or bare skin is combustible substances, put a fire-resistant shield in place. If
exposed (and it should not be if you are dressed properly). In you’re welding above the ground or off a ladder, make sure that
addition to the normal safety precautions, if welding must be there are no combustibles underneath. Also, don’t forget about
performed under electrically hazardous conditions (in damp your co-workers, and everybody else who may be in the work
locations or while wearing wet clothing; on metal structures such area, as they probably wouldn’t appreciate being hit with slag or
as floors, gratings or scaffolds; when in cramped positions such sparks from your work.
as sitting, kneeling or lying, if there is a high risk of unavoidable
or accidental contact with the work piece or ground) use the Particular care must be taken when welding or cutting in dusty
following equipment: locations. Fine dust particles may readily oxidize (burn) and
without warning result in a flash fire or even an explosion when
� Semiautomatic DC Constant Voltage Welder
exposed to the welding arc or even sparks.
� DC Manual (Stick) Welder
If you are not sure of the combustible or volatile nature of
� AC Welder with Reduced Voltage Control
residue or dust in the work area, no welding or cutting should
take place until a responsible person has inspected the area and
The condition of your electrode holder and electrode cable is
given approval for the work.
also very important. The plastic or fiber insulation on the
electrode holder protects you from touching the metal
Before you start welding, inspect the surface of your work,
“electrically hot� parts inside. Always inspect your electrode
looking for flammable coatings or any unknown substances that
holder before turning the welder on. Replace the holder if it is
would ignite when heated. Because of the extreme fire and
damaged � don’t try to repair it unless you have replacement
explosion hazards inherent to welding on or around containers
parts.
and piping that may have combustible materials, such work
should be handled only by experienced welders who review and
The same is true of the electrode cable except that when not
follow the safety practices recommended in the American
replaced it may be repaired using good electrical tape. If your
Welding Society document F4.1, “Recommended Safe Practices
cable has been repaired, be sure to check and see that the tape
for the Preparation for Welding and Cutting of Containers and
is secure before you turn the welder on.
Piping Which Had Held Hazardous Substances.�
Remember, a stick electrode is always “electrically hot� when the
Know where the fire alarms and fire extinguishers are located,
welder is on � treat it with respect. If you do experience a
and check the pressure gauges so you don’t rely upon one
shock, think of it as a warning � check your equipment, work
that’s empty. If there are none in the area, make sure that you
habits and work area to see what is wrong before continuing to
have access to fire hoses, sand buckets, fire-resistant blankets,
weld.
or other fire fighting equipment. If you’re welding within 35 feet
WARNING or so of flammable materials, you should have a fire watcher to
see where your sparks are flying, and to grab an extinguisher or
alarm if needed. Both you and the fire watcher should wait for a
half hour after all welding is finished to find and put out any
WELDING SPARKS can cause fire or explosion.
smoldering fires that may have resulted from your welding.
� Keep flammable material away.
As with other emergencies that may result from welding
accidents, the first rule is: don’t panic. Depending on the size of
the fire, sound the fire alarm to warn others and call the fire
department; shut off your welder; and get to the fire exits as
quickly as possible.
Fire Hazards
Because of the extreme temperatures associated with any arc
welding process, you should always be aware of fire hazards.
The heat of the welding arc can reach temperatures of 10,000°F,
but this heat in itself is not generally a fire hazard. The danger of
fire actually results from the effects of this intense heat upon
your work and in the form of sparks and molten metals.
Because these can spray up to 35 feet from your work, you must
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SAFETY PRACTICES IN WELDING
PEL (Permissible Exposure Limit) for chromium (see Supplement
WARNING 3). The use of local exhaust and/or an approved respirator may
be required to avoid overexposure.
FUMES & GASES can be dangerous to your health
� Keep fumes and gases from your breathing
Coatings on the metal to be welded, such as paint, may also
zone and general area.
contain toxic substances, such as lead, chromium and zinc. In
� Keep your head out of the fumes.
general, it is always best to remove coatings from the base
� Use enough ventilation or exhaust at the arc, or
metal before welding or cutting.
both, to keep fumes and gases from your
breathing zone and general area.
Cobalt: Exposure to cobalt can cause respiratory disease and
pulmonary sensitization. Cobalt in metallic form has been
Fumes and Gases reported to cause lung damage.
Because of the variables involved in fume and gas generation
from arc welding, cutting and allied processes (such as the Copper: Prolonged exposure to copper fume may cause skin
welding process and electrode, the base metal, coatings on the irritation or discoloration of the skin and hair.
base metal, and other possible contaminants in the air), we’ll
have to treat the subject in a rather general way, lumping all but Manganese: Manganese overexposure may affect the central
the more hazardous situations together. The precautions we nervous system, resulting in poor coordination, difficulty in
describe will hold true for all arc welding processes. speaking, and tremor of arms or legs. This condition is
considered irreversible.
The fume plume contains solid particles from the consumables,
base metal, and base metal coating. For common mild steel arc Nickel: Nickel and its compounds are on the IARC (International
welding, depending on the amount and length of exposure to Agency for Research on Cancer) and NTP (National Toxicology
these fumes, most immediate or short term effects are Program) lists as posing a carcinogenic risk to humans.
temporary, and include symptoms of burning eyes and skin,
dizziness, nausea, and fever. For example, zinc fumes can cause Silica: Crystalline silica is present in respirable dust form
metal fume fever, a temporary illness that is similar to the flu. submerged arc flux. Overexposure can cause severe lung
damage (silicosis).
Long-term exposure to welding fumes can lead to siderosis
(iron deposits in the lungs) and may affect pulmonary function. Zinc: Overexposure to zinc (from galvanized metals) may cause
Bronchitis and some lung fibrosis have been reported. metal fume fever with symptoms similar to the common flu.
Some consumables contain certain compounds in amounts The gases that result from an arc welding process also present
which may require special ventilation and/or exhaust. These potential hazard. Most of the shielding gases (argon, helium, and
Special Ventilation products can be identified by reading the carbon dioxide) are non-toxic, but, as they are released, they
labels on the package. If Special Ventilation products are used displace oxygen in your breathing air, causing dizziness,
indoors, use local exhaust. If Special Ventilation products are unconsciousness, and death, the longer your brain is denied the
used outdoors, a respirator may be required. Various oxygen it needs. Carbon monoxide can also be developed and
compounds, some of which may be in welding fume, and may pose a hazard if excessive levels are present.
reported health effects, in summary, are:
The heat and UV radiation can cause irritation to the eyes and
Barium: Soluble barium compounds may cause severe stomach lungs. Some degreasing compounds such as trichlorethylene
pain, slow pulse rate, irregular heart beat, ringing of the ears, and perchlorethylene can decompose from the heat and
convulsions and muscle spasms. In extreme cases can cause ultraviolet radiation of an arc. Because of the chemical
death. breakdown of vapor-degreasing materials under ultraviolet
radiation, arc welding should not be done in the vicinity of a
Cadmium also requires extra precautions. This toxic metal can vapor-degreasing operation. Carbon-arc welding, gas tungsten-
be found on some steel and steel fasteners as a plating, or in arc welding and gas metal arc welding should be especially
silver solder. Cadmium fumes can be fatal even under brief avoided in such areas, because they emit more ultraviolet
overexposures, with symptoms much like those of metal fume radiation than other processes. Also, keep in mind that ozone
fever. These two conditions should not be confused. and nitrogen oxides are formed when UV radiation passes
Overexposure to cadmium can be enough to cause fatalities, through the air. These gases cause headaches, chest pains,
with symptoms appearing quickly, and, in some circumstances, irritation of the eyes, and an itchiness in the nose and throat.
death a few days later.
There is one easy way to reduce the risk of exposure to
Chromium: Chromium is on the IARC (International Agency for hazardous fumes and gases: keep your head out of the fume
Research on Cancer) and NTP (National Toxicology Program) lists plume! As obvious as this sounds, the failure to follow this
chromium as posing a carcinogenic risk to humans. Fumes from advice is a common cause of fume and gas overexposure
the use of stainless steel, hardfacing and other types of because the concentration of fume and gases is greatest in the
consumables contain chromium and/or nickel. Some forms of plume. Keep fumes and gases from your breathing zone and
these metals are known or suspected to cause lung cancer in general area using natural ventilation, mechanical ventilation,
processes other than welding and asthma has been reported. fixed or moveable exhaust hoods or local exhaust at the arc.
Therefore, it is recommended that precautions be taken to keep Finally, it may be necessary to wear an approved respirator if
exposures as low as possible. OSHA recently adopted a lower adequate ventilation cannot be provided (see Ventilation
section).
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SAFETY PRACTICES IN WELDING
As a rule of thumb, for many mild steel electrode, if the air is Your work area has adequate ventilation when there is enough
visibly clear and you are comfortable, then the ventilation is ventilation and/or exhaust to control worker exposure to hazardous
generally adequate for your work.The most accurate way to materials in the welding fumes and gases so the applicable limits
determine if the worker exposure does not exceed the applicable Adequate Ventilation means that thereSupplement ventilation
for those materials is not exceeded. See is enough 2 for the legal
exposure limit for compounds in the fumes and gases is to have and/orthe OSHAto control worker Exposure Limit), and the
limits, exhaust PEL (Permissible exposure
an industrial hygienist take and analyze a sample of the air you recommended guideline, the ACGIH TLV (Threshold Limit Value),
are breathing. This is particularly important if you are welding for many compounds found in welding fume.
with stainless, hardfacing or Special Ventilation products. All
Lincoln MSDS have a maximum fume guideline number. If
exposure to total fume is kept below that number, exposure to all
fume from the electrode (not coatings or plating on the work) will
be below the TLV.
There are also steps that you can take to identify hazardous
substances in your welding environment. First, read the product
label and material safety data sheet for the electrode posted in
the work place or in the electrode or flux container to see what
fumes can be reasonably expected from use of the product and
to determine if special ventilation is needed. Secondly, know
what the base metal is, and determine if there is any paint,
plating, or coating that could expose you to toxic fumes and/or
gases. Remove it from the metal being welded, if possible. If you
start to feel uncomfortable, dizzy or nauseous, there is a
possibility that you are being overexposed to fumes and gases,
or suffering from oxygen deficiency. Stop welding and get some
fresh air immediately. Notify your supervisor and co-workers so
the situation can be corrected and other workers can avoid the
Ventilation
hazard. Be sure you are following these safe practices, the
consumable labeling and MSDS and improve the ventilation in There are many methods which can be selected by the user to
your area. Do not continue welding until the situation has been provide adequate ventilation for the specific application. The
corrected. following section provides general information which may be
helpful in evaluating what type of ventilation equipment may be
NOTE: The MSDS for all Lincoln consumables is available on
suitable for your application. When ventilation equipment is
Lincoln’s website: www.lincolnelectric.com
installed, you should confirm worker exposure is controlled
within applicable OSHA PEL and/or ACGIH TLV. According to
Before we turn to the methods available to control welding fume
OSHA regulations, when welding and cutting (mild steels),
exposure, you should understand a few basic terms:
natural ventilation is usually considered sufficient to meet
requirements, provided that:
Natural Ventilation is the movement of air through the workplace
caused by natural forces. Outside, this is usually the wind. Inside, this
1. The room or welding area contains at least 10,000 cubic
may be the flow of air through open windows and doors.
feet (about 22' x 22' x 22') for each welder.
Mechanical Ventilation is the movement of air through the
2. The ceiling height is not less than 16 feet.
workplace caused by an electrical device such as a portable fan or
permanently mounted fan in the ceiling or wall. 3. Cross ventilation is not blocked by partitions, equipment, or
other structural barriers.
Source Extraction (Local Exhaust) is a mechanical device used
to capture welding fume at or near the arc and filter contaminants 4. Welding is not done in a confined space.
out of the air.
Spaces that do not meet these requirements should be
The ventilation or exhaust needed for your application depends equipped with mechanical ventilating equipment that exhausts
upon many factors such as: at least 2000 cfm of air for each welder, except where local
� workspace volume exhaust hoods or booths, or air-line respirators are used.
� workspace configuration
� number of welders Important Safety Note:
� welding process and current When welding with electrodes which require special ventilation
� consumables used (mild steel, hardfacing, stainless, etc.) such as stainless or hardfacing (see instructions on container or
� allowable levels (TLV, PEL, etc.) MSDS) or on lead or cadmium plated steel and other metals or
� material welded (including paint or plating) coatings which produce hazardous fumes, keep exposure as low
� natural airflow as possible and below exposure limit values (PEL and TLV) for
materials in the fume using local exhaust or mechanical
ventilation. In confined spaces or in some circumstances, for
example outdoors, a respirator may be required if exposure
cannot be controlled to the PEL or TLV. (See MSDS and
Supplement 3 of this brochure.) Additional precautions are also
required when welding on galvanized steel.
Arc Welding Safety
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[9]
SAFETY PRACTICES IN WELDING
Source Extraction Equipment These arms generally move between 560 and 860 cubic feet per
minute (CFM) (900 � 1400 m3/hr) of air, but use low vacuum
Mechanical ventilation is an effective method of fume control for
many welding processes. Because it captures fume near the arc levels (3 to 5 inches water gauge [750 � 1250 Pa]) to minimize
or source of the fume, which is more efficient in most cases, power requirements. Water gauge (WG) is a measure of negative
local exhaust, also called "source extraction", is a very effective pressure: higher numbers mean more negative pressure
means to control welding fume. (more "suction"). With this volume of airflow, the end of the arm
can be placed 6 to 15 inches (160 � 375 mm) away from the arc
Source extraction of welding fumes can be provided by mobile or and still effectively capture weld fume.
stationary, single or multi-station, exhaust and/or filtration
equipment designed with adjustable fume extraction arms Fume extraction arms generally use a 6 or 8 inch diameter hose,
nozzles or guns, by fixed enclosures, booths or tables with or hose and tubing combinations. Arm lengths are typically 7,
extraction canopies also known as down-draft, or by back-draft 10, or 13 feet (2, 3, or 4 m), with boom extensions available. The
or cross-draft tables/booths. Source extraction of weld fume falls arms may be wall mounted, attached to mobile units, or
into two categories: low vacuum/high volume, or high incorporated into a centralized system.
vacuum/low volume.
In general, the farther the extraction hose is from the arc, the
more volume of air movement is required to effectively capture
Low Vacuum/High Volume
welding fume. Overhead hoods (canopies), for example, capture
Mobile or stationary, single or multi-station, large centralized
most of the fume, but care must be taken to be sure fume is not
exhaust and/or filtration equipment designed with adjustable
pulled through the breathing zone of the operator.
fume extraction arms are usually low vacuum/high volume
systems. When correctly positioned, the capture rate of
Fixed enclosures, booths or tables with extraction canopies also
adjustable fume extraction arms is suitable for all position
known as down-draft, back-draft or cross-draft
welding and cutting. For more difficult to reach work areas,
booths/tables are a variation of overhead hood technology and
flexible hose may be used in place of adjustable fume extraction
can be used as source extraction equipment. A booth is a fixed
arms.
enclosure that consists of a top and at least two sides that
surround the welding operation. These systems use a plenum
with openings to the side, back or bottom of the work space
rather than above it to capture the weld fume. The weld fume is
extracted through the plenum and away from the breathing zone
of the operator that is welding or cutting. Down-draft or back-
draft booths/tables can be mobile or stationary, single or multi-
station, exhaust and/or filtration systems. They are particularly
suitable for in-position bench welding or cutting jobs and can be
effective when small parts are being welded. The airflow
required for effectiveness varies depending upon the installation
design, but may be 1,000 CFM or higher.
There are advantages and limitations associated with low
vacuum/high volume source extraction systems.
Advantages Limitations
Source extraction with large volume If not using filtration unit,
of air being extracted from welder exhausting air to outside requires
breathing zone. make-up air systems and make-up
heaters (ie. large volumes of
displaced air need to be replaced,
resulting in increased utility costs).
Auto-stop delay assists with Welder must stop to reposition arm
removal of residual fumes. over weld area(s).
Low noise level. Filtration systems larger due to
volume of air flow.
Flexible arm for repositioning. Depending on design, ductwork
can be large.
Low installation costs
(ductwork).
Low energy consumption
(small fan unit with low rpm).
Adjustable arms suitable for all-
position welding.
Mobiflexâ„? 200-M low vacuum
mobile fume extraction unit.
Arc Welding Safety
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[10]
SAFETY PRACTICES IN WELDING
High Vacuum/Low Volume There are advantages and limitations associated with high
High vacuum/low volume fume extraction systems are designed vacuum/low volume source extraction systems.
for close proximity (2 to 4 inches) positioning. High vacuum/low
Advantages Limitations
volume weld fume extraction is achieved with lower airflow rates
When using a fume extraction gun, Required when using a suction
than those encountered when utilizing low vacuum/high volume
welder does not need to stop and nozzle. Welder may need to stop to
systems. There are two methods of high vacuum extraction: reposition extraction device. reposition extraction device.
welding guns with built-in extraction (fume extraction guns), or Low volume of air is displaced- High noise level due to increased
separate suction nozzles of various designs. results in energy efficiency and air velocity and high motor rpm of
conservation. the fan unit.
Ductwork smaller in diameter (3 to Possible removal of shielding gases
Fume extraction guns use fume capture nozzles built into the
10 inches) vs. low vacuum systems. affecting weld integrity if nozzle or
gun tube and handle. The extraction airflow is gun placed too close to source.
approximately 35 to 60 CFM (60 � 100 m3/hr) for integrated fume Low obstruction of welder vision. Greater energy consumption
(large fan unit with high rpm).
extraction guns. Therefore, no repositioning is required, since the
suction automatically follows the arc. The vacuum level is high Suitable for heavier particulate (ie. Residual fumes not extracted.
grinding dust).
(40 to 70 inches WG [9.96 X 103 to 1.74 X 104 Pascal])
Suitable option for confined, Less effective in out-of-position
permitting the use of hose featuring longer lengths (10 to 25 feet)
difficult to reach work spaces. welding.
and smaller diameters (1.25 to 1.75 inches). Fume extraction gun
Smaller filter systems due to less
designs have been improved to be more ergonomic and user volume of airflow.
friendly. Depending upon the type of welding, particularly "in
position" welding, extraction guns may be a good solution.
Fume extraction is only one component in reducing welding
Suction nozzles are positioned near the weld, and commonly fume. Users should also consider the selection of the welding
use capture distances of less than four inches. Depending upon process, welding procedure, or consumable. Many times a
the design, airflow of suction nozzles is typically between 80 to combination of fume extraction, training, process change,
100 CFM (135 � 170 m3/hr). Suction nozzles must be kept near and/or consumable change is needed to reduce the amount of
the arc to be used effectively. fume to acceptable levels. Solutions to a particular application
may involve one or all of these factors and the user must
The capture rate for fume extraction guns or nozzles is highest determine which solution best fits their application.
when used in flat and horizontal welding positions. High vacuum
equipment ranges from small, portable, mobile units to OSHA regulations include specific requirements for exhaust
stationary, single or multi-station, large centralized filtration systems which should be reviewed when selecting fume
systems. extraction systems (see Supplement 2).
Miniflexâ„? high vacuum portable
fume extraction unit.
Arc Welding Safety
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[11]
SAFETY PRACTICES IN WELDING
Exhaust vs. Filtration Working in Confined Spaces
Source extraction exhaust equipment captures and extracts When arc welding in a confined area, such as a boiler, tank, or
weld fumes from the source and exhausts the fumes to the the hold of a ship, bear in mind that all the hazards associated
outside atmosphere. This technique removes welding fume from with normal arc welding are amplified, so the precautions
the breathing zone of the welder but can also displace large mentioned here are even more important. This subject is very
volumes of conditioned air which may lead to increased utility complicated and only basic precautions related to arc welding
and heating costs. will be discussed in this brochure. Per OSHA document 29 CFR
1910.146, a particular area is considered a confined space if it:
Source extraction filtration equipment captures and extracts 1) Is large enough and so configured that an employee can
weld fumes from the source and filters the fumes by passing bodily enter and perform assigned work; and
them through a cellulose and/or polyester filter cartridge or
2) Has limited or restricted means for entry or exit
electrostatic filter. Depending on the weld application,
(for example, tanks, vessels, silos, storage bins,
environment, federal or local regulations, and filtration efficiency
hoppers, vaults, and pits are spaces that may have
levels, filtered air may be re-circulated back into the facility or
limited means of entry.); and
exhausted to the outside atmosphere. By re-circulating filtered
3) Is not designed for continuous employee occupancy.
air back into the work environment compared to exhausting to
the outside, source extraction filtration equipment can be more
There is a greater danger that enough flammable gases may be
economical to operate. Particularly in winter months,
present in the confined space to cause an explosion. The metal
substantially lower heating costs may be recognized, as less
of the enclosure can become part of the welding circuit, so any
replacement air is required with filtration versus exhaust systems.
metal you touch (the walls, floor, ceiling) is electrically "hot".
Welding fumes can accumulate more rapidly, with a higher
Using a cellulose or polyester filter cartridge or electrostatic filter
concentration; gases can force out the breathable air,
will depend upon the weld application. Electrostatic filters may
suffocating you in the process.
also be used however, they lose efficiency if they are not
frequently washed.
Per OSHA document 29 CFR 1910.146(d)(5)(iii); after an area has
been deemed a confined space, the existence of the following
Regardless of the type of mechanical ventilation (exhaust or
atmospheric hazards are to be determined:
filtration) source extraction system used, the important factor is
that it is a tool designed to control exposure to welding fume and 1) Test for oxygen
its constituents. All forms of mechanical ventilation or source 2) Test for combustible gases and vapors
extraction equipment require routine maintenance. In addition,
3) Test for toxic gases and vapors
when using weld fume source extraction equipment, sparks from
welding, cutting or grinding processes can cause fire within the
The workplace and OSHA rules regarding confined spaces must
equipment. To control this potential fire hazard, operation,
be followed. Make sure that your body is insulated from the
service and maintenance instructions for source extraction
work-piece using dry insulation. Wear dry gloves and only use a
equipment should be followed.
well-insulated electrode holder. Semiautomatic constant voltage
welders with cold electrode or stick welders equipped with a
device to lower the no-load voltage are recommended,
Note:
especially when the work area is wet. Make sure that there is
It is the equipment owner and operator’s responsibility to comply
adequate ventilation and exhaust (a respirator or an air-supplied
with Occupational Safety, Health Administration (OSHA)
respirator may be necessary depending on the application), and
Permissible Exposure Limits (PELs) or American Conference of
that there are no flammable coatings, liquids or gases nearby.
Governments Industrial Hygienists (ACGIH) TLVs for welding
fume. It is the responsibility of the equipment owner to research,
Lastly, you must have someone outside the enclosure trained to
test and comply with regulations which may apply to filtered air
handle emergencies, with rescue procedures and a means to
recirculated inside the facility or unfiltered air is exhausted
disconnect power to your equipment and pull you out if danger
outside of the facility.
arises. We cannot stress this strongly enough: however
experienced you are, do not attempt work of this nature without
constant communication with the person outside the confined
area. When welding within a confined area, problems which
arise can immediately become very serious and, in some cases,
life-threatening. It is for that reason that OSHA regulations and
workplace procedures for confined space work must be
followed.
Arc Welding Safety
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[12]
SUPPLEMENT 1
GUIDE FOR SHADE NUMBERS
OPERATION ELECTRODE SIZE ARC MINIMUM SUGGESTED(1)
1/32 in. (mm) CURRENT (A) PROTECTIVE SHADE NO.
SHADE (COMFORT)
Shielded metal arc Less than 3 (2.5) Less than 60 7 �
welding 3-5 (2.5�4) 60-160 8 10
5-8 (4�6.4) 160-250 10 12
More than 8 (6.4) 250-550 11 14
Gas metal arc Less than 60 7 �
welding and flux 60-160 10 11
cored arc welding 160-250 10 12
250-500 10 14
Gas tungsten arc Less than 50 8 10
welding 50-150 8 12
150-500 10 14
Air carbon (Light) Less than 500 10 12
Arc cutting (Heavy) 500-1000 11 14
Plasma arc welding Less than 20 6 6 to 8
20-100 8 10
100-400 10 12
400-800 11 14
Plasma arc cutting (Light)(2) Less than 300 8 9
(Medium)(2) 300-400 9 12
(Heavy)(2) 400-800 10 14
Torch brazing � � 3 or 4
Torch soldering � � 2
Carbon arc welding � � 14
PLATE THICKNESS
Gas welding
in. mm
Light Under 1/8 Under 3.2 4 or 5
Medium 1/8 to 1/2 3.2 to 12.7 5 or 6
Heavy Over 1/2 Over 12.7 6 or 8
Oxygen cutting
Light Under 1 Under 25 3 or 4
Medium 1 to 6 25 to 150 4 or 5
Heavy Over 6 Over 150 5 or 6
(1)
As a rule of thumb, start with a shade that is too dark, then go to a lighter shade which gives sufficient view of the weld zone without going below the
minimum. In oxyfuel gas welding or cutting where the torch produces a high yellow light, it is desirable to use a filter lens that absorbs the yellow or
sodium line the visible light of the (spectrum) operation
(2)
These values apply where the actual arc is clearly seen. Experience has shown that lighter filters may be used when the arc is hidden by the
workpiece.
Data from ANSI Z49.1-2005
Arc Welding Safety
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[13]
SUPPLEMENT 2
BIBLIOGRAPHY AND SUGGESTED READING
ANSI Z87.1, Practice for Occupational and Educational Eye and Face AWS F1.1, Method for Sampling Airborne Particulates Generated by Welding
Protection, American National Standards Institute, 11 West 42nd Street, New and Allied Processes.
York, NY 10036.
AWS F1.2, Laboratory Method for Measuring Fume Generation Rates and
Arc Welding and Your Health: A Handbook of Health Information for Welding. Total Fume Emission of Welding and Allied Processes.
Published by The American Industrial Hygiene Association, 2700 Prosperity
Avenue, Suite 250, Fairfax, VA 22031-4319. AWS F1.3, Evaluating Contaminants in the Welding Environment: A Strategic
Sampling Guide.
NFPA Standard 51B, Cutting and Welding Processes, National Fire Protection
Association, 1 Batterymarch Park, P.O. Box 9146, Quincy, MA 02269-9959. AWS F1.5, Methods for Sampling and Analyzing Gases from Welding and
Allied Processes.
OSHA General Industry Standard 29 CFR 1910 Subpart Q. OSHA Hazard
Communication Standard 29 CFR 1910.1200. Available from the Occupational AWS F3.2, Ventilation Guide for Welding Fume Control
Safety and Health Administration at http://www.osha.org or contact your local
OSHA office. AWS F4.1, Recommended Safe Practices for the Preparation for Welding and
Cutting of Containers and Piping That Have Held Hazardous Substances.
The following publications are published by The American Welding Society,
P.O. Box 351040, Miami, Florida 33135. AWS publications may be purchased AWS SHF, Safety and Health Facts Sheets. Available free of charge from the
from the American Welding society at http://www.aws.org or by contacting the AWS website at http://www.aws.org.
AWS at 800-443-9353.
ANSI, Standard Z49.1, Safety in Welding, Cutting and Allied Processes. Z49.1
is now available for download at no charge at
http://www.lincolnelectric.com/community/safety/ or at the AWS website
http://www.aws.org.
Arc Welding Safety
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[14]
SUPPLEMENT 3
LISTED BELOW ARE SOME TYPICAL INGREDIENTS IN WELDING ELECTRODES AND
THEIR TLV (ACGIH) GUIDELINES AND PEL (OSHA) EXPOSURE LIMITS
INGREDIENTS CAS No. TLV mg/m3 PEL mg/m3
Aluminum and/or aluminum alloys (as Al)***** 7429-90-5 10 15
Aluminum oxide and/or Bauxite***** 1344-28-1 10 5**
Barium compounds (as Ba)***** 513-77-9 **** ****
Chromium and chromium alloys or compounds (as Cr)***** 7440-47-3 0.5(b) .005(b)
Fluorides (as F) 7789-75-5 2.5 2.5
Iron 7439-89-6 10* 10*
Limestone and/or calcium carbonate 1317-65-3 10 15
Lithium compounds (as Li) 554-13-2 10* 10*
Magnesite 1309-48-4 10 15
Magnesium and/or magnesium alloys and compounds (as Mg) 7439-95-4 10* 10*
Manganese and/or manganese alloys and compounds (as Mn)***** 7439-96-5 0.2 5.0(c)
Mineral silicates 1332-58-7 5** 5**
Molybdenum alloys (as Mo) 7439-98-7 10 10
Nickel***** 7440-02-0 1.5 1
Silicates and other binders 1344-09-8 10* 10*
Silicon and/or silicon alloys and compounds (as Si) 7440-21-3 10* 10*
Strontium compounds (as Sr) 1633-05-2 10* 10*
Zirconium alloys and compounds (as Zr) 12004-83-0 5 5
Supplemental Information:
(*) Not listed. Nuisance value maximum is 10 milligrams per cubic meter. PEL value for (c) Values are for manganese fume. STEL (Short Term Exposure Limit) is 3.0
iron oxide is 10 milligrams per cubic meter. TLV value for iron oxide is 5 milligrams milligrams per cubic meter. OSHA PEL is a ceiling value.
per cubic meter.
(****) There is no listed value for insoluble barium compounds. The TLV for soluble
(**) As respirable dust. barium compounds is 0.5 mg/m3.
(*****) Subject to the reporting requirements of Sections 311, 312, and 313 of the
Emergency Planning and Community Right-to-Know Act of 1986 and of 40CFR 370
and 372. TLV and PEL values are as of April 2006. Always check Material Safety
Data Sheet (MSDS) with product or on the Lincoln Electric website at
(b) The PEL for chromium (VI) is .005 milligrams per cubic meter as an 8 hour time weighted
http://www.lincolnelectric.com
average. The TLV for water-soluble chromium (VI) is 0.05 milligrams per cubic meter. The
TLV for insoluble chromium (VI) is 0.01 milligrams per cubic meter.
Arc Welding Safety
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[15]
WARNING
SUPPLEMENT 4
CALIFORNIA PROPOSITION 65 WARNINGS
The engine exhaust from this product contains
Diesel engine exhaust and some of its constituents
chemicals known to the State of California to cause
are known to the State of California to cause can-
cancer, birth defects, or other reproductive harm.
cer, birth defects, and other reproductive harm.
The Above For Gasoline Engines
The Above For Diesel Engines
ARC WELDING CAN BE HAZARDOUS. PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH.
KEEP CHILDREN AWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING.
Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you
purchase a copy of “Safety in Welding & Cutting - ANSI Standard Z49.1� from the American Welding Society, P.O. Box
351040, Miami, Florida 33135 or CSA Standard W117.2-1974. A Free copy of “Arc Welding Safety� booklet E205 is available
from the Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.
BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE
PERFORMED ONLY BY QUALIFIED INDIVIDUALS.
FOR ENGINE 1.h. To avoid scalding, do not remove the
powered equipment. radiator pressure cap when the engine is
hot.
1.a. Turn the engine off before troubleshooting and maintenance
work unless the maintenance work requires it to be running.
____________________________________________________
1.b. Operate engines in open, well-ventilated
areas or vent the engine exhaust fumes
outdoors.
ELECTRIC AND
MAGNETIC FIELDS
may be dangerous
____________________________________________________
1.c. Do not add the fuel near an open flame
welding arc or when the engine is running.
Stop the engine and allow it to cool before 2.a. Electric current flowing through any conductor causes
refueling to prevent spilled fuel from vaporiz- localized Electric and Magnetic Fields (EMF). Welding
ing on contact with hot engine parts and current creates EMF fields around welding cables and
igniting. Do not spill fuel when filling tank. If welding machines
fuel is spilled, wipe it up and do not start
engine until fumes have been eliminated. 2.b. EMF fields may interfere with some pacemakers, and
____________________________________________________ welders having a pacemaker should consult their physician
1.d. Keep all equipment safety guards, covers and devices in before welding.
position and in good repair.Keep hands, hair, clothing and
tools away from V-belts, gears, fans and all other moving 2.c. Exposure to EMF fields in welding may have other health
parts when starting, operating or repairing equipment. effects which are now not known.
____________________________________________________
2.d. All welders should use the following procedures in order to
1.e. In some cases it may be necessary to remove safety
minimize exposure to EMF fields from the welding circuit:
guards to perform required maintenance. Remove
guards only when necessary and replace them when the
2.d.1. Route the electrode and work cables together - Secure
maintenance requiring their removal is complete.
them with tape when possible.
Always use the greatest care when working near moving
parts.
2.d.2. Never coil the electrode lead around your body.
___________________________________________________
1.f. Do not put your hands near the engine fan.
Do not attempt to override the governor or 2.d.3. Do not place your body between the electrode and
idler by pushing on the throttle control rods work cables. If the electrode cable is on your right
while the engine is running. side, the work cable should also be on your right side.
2.d.4. Connect the work cable to the workpiece as close as
possible to the area being welded.
___________________________________________________
1.g. To prevent accidentally starting gasoline engines while 2.d.5. Do not work next to welding power source.
turning the engine or welding generator during maintenance
work, disconnect the spark plug wires, distributor cap or
Mar �95
magneto wire as appropriate.
Arc Welding Safety
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[16]
ARC RAYS can burn.
ELECTRIC SHOCK can
kill. 4.a. Use a shield with the proper filter and cover
plates to protect your eyes from sparks and
3.a. The electrode and work (or ground) circuits
the rays of the arc when welding or observing
are electrically “hot� when the welder is on. open arc welding. Headshield and filter lens
Do not touch these “hot� parts with your bare should conform to ANSI Z87. I standards.
skin or wet clothing. Wear dry, hole-free
gloves to insulate hands. 4.b. Use suitable clothing made from durable flame-resistant
material to protect your skin and that of your helpers from
3.b. Insulate yourself from work and ground using dry insulation. the arc rays.
Make certain the insulation is large enough to cover your full
area of physical contact with work and ground. 4.c. Protect other nearby personnel with suitable, non-flammable
screening and/or warn them not to watch the arc nor expose
In addition to the normal safety precautions, if welding themselves to the arc rays or to hot spatter or metal.
must be performed under electrically hazardous
FUMES AND GASES
conditions (in damp locations or while wearing wet
clothing; on metal structures such as floors, gratings or
can be dangerous.
scaffolds; when in cramped positions such as sitting,
kneeling or lying, if there is a high risk of unavoidable or
accidental contact with the workpiece or ground) use 5.a. Welding may produce fumes and gases
the following equipment: hazardous to health. Avoid breathing these
� Semiautomatic DC Constant Voltage (Wire) Welder. fumes and gases. When welding, keep
� DC Manual (Stick) Welder. your head out of the fume. Use enough
� AC Welder with Reduced Voltage Control. ventilation and/or exhaust at the arc to keep
fumes and gases away from the breathing zone. When
welding with electrodes which require special
3.c. In semiautomatic or automatic wire welding, the electrode,
ventilation such as stainless or hard facing (see
electrode reel, welding head, nozzle or semiautomatic
instructions on container or MSDS) or on lead or
welding gun are also electrically “hot�.
cadmium plated steel and other metals or coatings
which produce highly toxic fumes, keep exposure as
3.d. Always be sure the work cable makes a good electrical
low as possible and below Threshold Limit Values (TLV)
connection with the metal being welded. The connection
using local exhaust or mechanical ventilation. In
should be as close as possible to the area being welded.
confined spaces or in some circumstances, outdoors, a
respirator may be required. Additional precautions are
3.e. Ground the work or metal to be welded to a good electrical
also required when welding on galvanized steel.
(earth) ground.
5. b. The operation of welding fume control equipment is affected
3.f. Maintain the electrode holder, work clamp, welding cable and
by various factors including proper use and positioning of
welding machine in good, safe operating condition. Replace
the equipment, maintenance of the equipment and the spe-
damaged insulation.
cific welding procedure and application involved. Worker
exposure level should be checked upon installation and
3.g. Never dip the electrode in water for cooling.
periodically thereafter to be certain it is within applicable
OSHA PEL and ACGIH TLV limits.
3.h. Never simultaneously touch electrically “hot� parts of
electrode holders connected to two welders because voltage
5.c. Do not weld in locations near chlorinated hydrocarbon vapors
between the two can be the total of the open circuit voltage
coming from degreasing, cleaning or spraying operations.
of both welders.
The heat and rays of the arc can react with solvent vapors to
form phosgene, a highly toxic gas, and other irritating prod-
3.i. When working above floor level, use a safety belt to protect
ucts.
yourself from a fall should you get a shock.
5.d. Shielding gases used for arc welding can displace air and
3.j. Also see Items 6.c. and 8.
cause injury or death. Always use enough ventilation,
especially in confined areas, to insure breathing air is safe.
5.e. Read and understand the manufacturer’s instructions for this
equipment and the consumables to be used, including the
material safety data sheet (MSDS) and follow your
employer’s safety practices. MSDS forms are available from
your welding distributor or from the manufacturer.
5.f. Also see item 1.b.
Arc Welding Safety
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[17]
WELDING and CUTTING CYLINDER may explode
SPARKS can if damaged.
cause fire or explosion. 7.a. Use only compressed gas cylinders
6.a. Remove fire hazards from the welding area. containing the correct shielding gas for the
If this is not possible, cover them to prevent process used and properly operating
the welding sparks from starting a fire. regulators designed for the gas and
Remember that welding sparks and hot pressure used. All hoses, fittings, etc. should be suitable for
materials from welding can easily go through small cracks the application and maintained in good condition.
and openings to adjacent areas. Avoid welding near
hydraulic lines. Have a fire extinguisher readily available. 7.b. Always keep cylinders in an upright position securely
chained to an undercarriage or fixed support.
6.b. Where compressed gases are to be used at the job site,
special precautions should be used to prevent hazardous 7.c. Cylinders should be located:
situations. Refer to “Safety in Welding and Cutting� (ANSI � Away from areas where they may be struck or subjected to
Standard Z49.1) and the operating information for the physical damage.
equipment being used.
� A safe distance from arc welding or cutting operations and
6.c. When not welding, make certain no part of the electrode any other source of heat, sparks, or flame.
circuit is touching the work or ground. Accidental contact
can cause overheating and create a fire hazard. 7.d. Never allow the electrode, electrode holder or any other
electrically “hot� parts to touch a cylinder.
6.d. Do not heat, cut or weld tanks, drums or containers until the
proper steps have been taken to insure that such procedures 7.e. Keep your head and face away from the cylinder valve outlet
will not cause flammable or toxic vapors from substances when opening the cylinder valve.
inside. They can cause an explosion even though they have
been “cleaned�. For information, purchase “Recommended 7.f. Valve protection caps should always be in place and hand
Safe Practices for the Preparation for Welding and Cutting of tight except when the cylinder is in use or connected for
Containers and Piping That Have Held Hazardous use.
Substances�, AWS F4.1 from the American Welding Society
(see address above). 7.g. Read and follow the instructions on compressed gas
cylinders, associated equipment, and CGA publication P-l,
6.e. Vent hollow castings or containers before heating, cutting or “Precautions for Safe Handling of Compressed Gases in
welding. They may explode. Cylinders,� available from the Compressed Gas Association
1235 Jefferson Davis Highway, Arlington, VA 22202.
6.f. Sparks and spatter are thrown from the welding arc. Wear oil
FOR ELECTRICALLY
free protective garments such as leather gloves, heavy shirt,
cuffless trousers, high shoes and a cap over your hair. Wear
powered equipment.
ear plugs when welding out of position or in confined places.
Always wear safety glasses with side shields when in a
welding area.
8.a. Turn off input power using the disconnect
6.g. Connect the work cable to the work as close to the welding switch at the fuse box before working on
area as practical. Work cables connected to the building the equipment.
framework or other locations away from the welding area
8.b. Install equipment in accordance with the U.S. National
increase the possibility of the welding current passing
Electrical Code, all local codes and the manufacturer’s
through lifting chains, crane cables or other alternate cir-
recommendations.
cuits. This can create fire hazards or overheat lifting chains
or cables until they fail.
8.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturer’s recommendations.
6.h. Also see item 1.c.
Jan, 07
6.I. Read and folllow NFPA 51B � Standard for Fire Prevention
During Welding, Cutting and Other Hot Work�, available
from NFPA, 1 Batterymarch Park,PO box 9101, Quincy, Ma
022690-9101.
6.j. Do not use a welding power source for pipe thawing.
Arc Welding Safety
www.lincolnelectric.com
[18]
PRÉCAUTIONS DE SÛRETÉ 5. Toujours porter des lunettes de sécurité dans la zone de
soudage. Utiliser des lunettes avec écrans lateraux dans les
zones où l’on pique le laitier.
Pour votre propre protection lire et observer toutes les instructions
et les précautions de sûreté specifiques qui parraissent dans ce
6. Eloigner les matériaux inflammables ou les recouvrir afin de
manuel aussi bien que les précautions de sûreté générales suiv-
prévenir tout risque d’incendie dû aux étincelles.
antes:
7. Quand on ne soude pas, poser la pince à une endroit isolé de
Sûreté Pour Soudage A L’Arc
la masse. Un court-circuit accidental peut provoquer un
1. Protegez-vous contre la secousse électrique:
échauffement et un risque d’incendie.
a. Les circuits à l’électrode et à la piéce sont sous tension
8. S’assurer que la masse est connectée le plus prés possible
quand la machine à souder est en marche. Eviter toujours
de la zone de travail qu’il est pratique de le faire. Si on place
tout contact entre les parties sous tension et la peau nue
la masse sur la charpente de la construction ou d’autres
ou les vétements mouillés. Porter des gants secs et sans
endroits éloignés de la zone de travail, on augmente le risque
trous pour isoler les mains.
de voir passer le courant de soudage par les chaines de lev-
b. Faire trés attention de bien s’isoler de la masse quand on
age, câbles de grue, ou autres circuits. Cela peut provoquer
soude dans des endroits humides, ou sur un plancher
des risques d’incendie ou d’echauffement des chaines et des
metallique ou des grilles metalliques, principalement dans
câbles jusqu’� ce qu’ils se rompent.
les positions assis ou couché pour lesquelles une grande
partie du corps peut être en contact avec la masse.
9. Assurer une ventilation suffisante dans la zone de soudage.
c. Maintenir le porte-électrode, la pince de masse, le câble
Ceci est particuliérement important pour le soudage de tôles
de soudage et la machine à souder en bon et sûr état
galvanisées plombées, ou cadmiées ou tout autre métal qui
defonctionnement.
produit des fumeés toxiques.
d.Ne jamais plonger le porte-électrode dans l’eau pour le
refroidir.
10. Ne pas souder en présence de vapeurs de chlore provenant
e. Ne jamais toucher simultanément les parties sous tension
d’opérations de dégraissage, nettoyage ou pistolage. La
des porte-électrodes connectés à deux machines à souder
chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs
parce que la tension entre les deux pinces peut être le
du solvant pour produire du phosgéne (gas fortement toxique)
total de la tension à vide des deux machines.
ou autres produits irritants.
f. Si on utilise la machine à souder comme une source de
courant pour soudage semi-automatique, ces precautions
11. Pour obtenir de plus amples renseignements sur la sûreté,
pour le porte-électrode s’applicuent aussi au pistolet de
voir le code “Code for safety in welding and cutting� CSA
soudage.
Standard W 117.2-1974.
2. Dans le cas de travail au dessus du niveau du sol, se protéger
contre les chutes dans le cas ou on recoit un choc. Ne jamais
enrouler le câble-électrode autour de n’importe quelle partie
PRÉCAUTIONS DE SÛRETÉ POUR
du corps.
LES MACHINES À SOUDER À
3. Un coup d’arc peut être plus sévère qu’un coup de soliel,
TRANSFORMATEUR ET À
donc:
REDRESSEUR
a. Utiliser un bon masque avec un verre filtrant approprié
ainsi qu’un verre blanc afin de se protéger les yeux du ray-
onnement de l’arc et des projections quand on soude ou
quand on regarde l’arc. 1. Relier à la terre le chassis du poste conformement au code de
b. Porter des vêtements convenables afin de protéger la l’électricité et aux recommendations du fabricant. Le dispositif
peau de soudeur et des aides contre le rayonnement de de montage ou la piece à souder doit être branché à une
l‘arc. bonne mise à la terre.
c. Protéger l’autre personnel travaillant à proximité au
soudage à l’aide d’écrans appropriés et non-inflammables. 2. Autant que possible, I’installation et l’entretien du poste seront
effectués par un électricien qualifié.
4. Des gouttes de laitier en fusion sont émises de l’arc de
soudage. Se protéger avec des vêtements de protection libres 3. Avant de faires des travaux à l’interieur de poste, la debranch-
de l’huile, tels que les gants en cuir, chemise épaisse, pan- er à l’interrupteur à la boite de fusibles.
talons sans revers, et chaussures montantes.
4. Garder tous les couvercles et dispositifs de sûreté à leur
place.
Arc Welding Safety
www.lincolnelectric.com
[19]
SUPPLEMENT 5
WARNING LABEL/OPERATING MANUAL REQUEST FORM
NOTE: S18494 WARNING LABELS, SUCH AS THE ONE BELOW FOR LINCOLN ELECTRIC
WELDERS, ARE AVAILABLE FREE OF CHARGE to update your welding equipment. Operating
manuals are also available upon request. PLEASE write to The Lincoln Electric Company, 22801 St.
Clair Ave., Cleveland, Ohio 44117-1199 or visit www.lincolnelectric.com and make the request
online.
Arc Welding Safety
www.lincolnelectric.com
[20]
SUPPLEMENT 6
ENGINE WELDER FAN GUARDS
In order to determine whether your engine welder has the proper fan guards, compare your welder with the
photo below. If your welder lacks the guards shown, contact your nearest Lincoln Field Service Shop or
Distributor for assistance.
NOTE: On some engine welders, including the SA-200, the original fan guard design shown below has been
modified to provide added protection and/or to make it more likely to be replaced after maintenance. Check
with a Lincoln Field Service Shop or Distributor to determine if updated guarding is available for your welder.
Doors � One Each Side
Fan Shroud � Attached to Radiator
Typical Fan Guard � One Mounted On
Each Side of Radiator
Arc Welding Safety
www.lincolnelectric.com
[21]
SUPPLEMENT 7
WHAT IS NEXTWELD®? WELDING SAFETY CHECKLIST
HAZARD FACTORS TO CONSIDER PRECAUTION SUMMARY
� Insulate welder from workpiece and ground using dry insulation. Rubber
mat or dry wood.
Electric shock can � Wetness
� Wear dry, hole-free gloves. (Change as necessary to keep dry.)
kill � Welder in or on workpiece
� Do not touch electrically “hot� parts or electrode with bare skin or wet
� Confined space
clothing.
� Electrode holder and
� If wet area and welder cannot be insulated from workpiece with dry
cable insulation
insulation, use a semiautomatic, constant-voltage welder or stick welder
with voltage reducing device.
� Keep electrode holder and cable insulation in good condition. Do not
use if insulation damaged or missing.
� Use ventilation or exhaust to keep air breathing zone clear, comfortable.
� Use helmet and positioning of head to minimize fume in breathing zone.
Fumes and gases � Confined area
� Read warnings on electrode container and material safety data sheet (MSDS)
can be dangerous � Positioning of welder’s head
for electrode,
� Lack of general ventilation
� Provide additional ventilation/exhaust where special ventilation
� Electrode types, i.e.,
requirements exist.
manganese, chromium,
� Use special care when welding in a confined area.
etc. See MSDS
� Do not weld unless ventilation is adequate.
� Base metal coatings,
galvanize, paint
� Do not weld on containers which have held combustible materials (unless
strict AWS F4.1 procedures are followed). Check before welding.
Welding sparks � Containers which have held
� Remove flammable materials from welding area or shield from sparks, heat.
can cause fire or combustibles
� Keep a fire watch in area during and after welding.
explosion � Flammable materials
� Keep a fire extinguisher in the welding area.
� Wear fire retardant clothing and hat. Use earplugs when welding overhead.
� Select a filter lens which is comfortable for you while welding.
� Always use helmet when welding.
Arc rays can burn � Process: gas-shielded arc
� Provide non-flammable shielding to protect others.
eyes and skin most severe
� Wear clothing which protects skin while welding.
� Carefully evaluate adequacy of ventilation especially where electrode requires
special ventilation or where gas may displace breathing air.
Confined space � Metal enclosure
� If basic electric shock precautions cannot be followed to insulate welder from
� Wetness
work and electrode, use semiautomatic, constant-voltage equipment with
� Restricted entry
cold electrode or stick welder with voltage reducing device.
� Heavier than air gas
� Provide welder helper and method of welder retrieval from outside enclosure.
� Welder inside or on
workpiece
� Keep cables, materials, tools neatly organized.
General work area � Cluttered area
� Connect work cable as close as possible to area where welding is being
hazards
performed. Do not allow alternate circuits through scaffold cables, hoist
� Indirect work (welding
chains, ground leads.
ground) connection
� Use only double insulated or properly grounded equipment.
� Always disconnect power to equipment before servicing.
� Electrical equipment
� Use in only open, well ventilated areas.
� Keep enclosure complete and guards in place.
� Engine-driven equipment
� See Lincoln service shop if guards are missing.
� Refuel with engine off.
� If using auxiliary power, OSHA may require GFI protection or assured
grounding program (or isolated windings if less than 5KW).
� Never touch cylinder with the electrode.
� Never lift a machine with cylinder attached.
� Gas cylinders
� Keep cylinder upright and chained to support.
Arc Welding Safety
www.lincolnelectric.com
[22]
NOTES
Arc Welding Safety
www.lincolnelectric.com
[23]
LINCOLN NORTH AMERICA
DISTRICT SALES OFFICES
U.S.A. IDAHO MINNESOTA OKLAHOMA WASHINGTON
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BIRMINGHAM 35124-1156 TULSA 74146-1622 SPOKANE 99005-9637
ILLINOIS MISSISSIPPI
(205) 988-8232 (918) 622-9353 (509) 468-2770
CHICAGO 60440-3538 JACKSON 39212-9635
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(630) 783-3600 (601) 372-7679 PENNSYLVANIA WASHINGTON DC
(251) 443-6524
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Contact VANCOUVER, WA PITTSBURGH 15001-4800
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(919) 303-1972
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(813) 477-5817 LEESBURG, VA 20176-4113
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AKRON 44236-4680
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(703) 904-7735
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Phone: 61 2 9772 7222
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Consumables: ph: 1-800-733-8912, fax: (513) 754-8778 � Equipment: ph: 1-800-241-0804, fax: (770) 535-0544
Arc Welding Safety
E205 1/07
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