Winpower Arc Welder Instruction manual

Arc Welding Safety
Guide for Safe Arc Welding
Safety Practices in Welding
Arc welding is a safe occupation when sufficient measures are
taken to protect the welder from potential hazards. When these
measures are overlooked or ignored, however, welders can
encounter such dangers as electric shock, overexposure to
fumes and gases, arc radiation, and fire and explosion; which
may result in serious, or even fatal injuries.
Important Note:
So that you can protect yourself against these hazards, every
welder should be familiar with American National Standard ANSI
Z49.1, “Safety in Welding and Cutting,” and should follow the
safety practices in that document. Z49.1 is now available for
download at no charge at: or at the
AWS website
This bulletin is written with the arc welding operator in mind,
containing both mandatory safety practices and those based on
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).
Download and read it!
leather high-tops with steel toes (especially when doing heavy
Protective Clothing
Welders, like firemen, must wear clothing to protect them from
being burned. Of all injuries to welders, burns are the most
common due to sparks landing on bare skin. Welding arcs are
very intense and can cause burns to skin and eyes with just a
few minutes of exposure.
Other protective wear for heavy work or especially hazardous
situations includes: flame-resistant suits, aprons, leggings,
leather sleeves/shoulder capes, and caps worn under your
The actual gear varies with the job being performed, but
generally protective clothing must allow freedom of movement
while providing adequate coverage against burns from sparks,
weld spatter, and arc radiation. Many types of clothing will
protect you from ultra-violet radiation exposure, which appears
as a skin burn (much like sunburn). Under the worst conditions,
however, severe burns and skin cancer may result from excessive
Because of its durability and resistance to fire, wool clothing is
suggested over synthetics (which should never be worn because
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.
Heavy, flame-resistant gloves, such as leather, should always be
worn to protect your hands from burns, cuts, and scratches. In
addition, as long as they are dry and in good condition, they will
offer some insulation against electric shock.
As to preventing electric shock, the key word is dry! We’ll have
more on the subject later, but for now keep in mind that moisture
can increase the potential for and severity of electric shock.
When working in wet conditions, or when perspiring heavily, you
must be even more careful to insulate your body from electrically
“live” parts and work on grounded metal.
Avoid rolling up your sleeves and pant-cuffs, because sparks or
hot metal could deposit in the folds; also, wear your trousers
outside your work boots, not tucked in, to keep particles from
falling into your boots. While we’re on the subject, we suggest
ARC RAYS can burn.
• Wear eye, ear and body protection.
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.
Arc Welding Safety
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
recommended lens shade numbers).
Figure A. A helmet (a) required for protecting the
welder’s eyes and face and (b) a hand-held face
shield that is convenient for the use of foremen,
inspectors, and other spectators.
There are two good reasons to wear ear muffs or plugs:
to keep flying sparks or metal out of your ears; and
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.
Arc Welding Safety
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 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
Warning Label.)
Is the work stable and easy to reach from where you’re
For the welder:
Is the Work Lead connected securely?
Are all the connections tight, including the earth ground?
OSHA regulations require output terminals to be insulated.
Rubber boots are available for that purpose.
Is there enough dry insulation between your body and the
work piece?
Is there adequate ventilation in your work area?
Are the electrode holder and welding cable well insulated
and in good condition?
Take some personal responsibility for your own safety. Notify
your supervisor if equipment is in need of repair or not working
properly or any unsafe condition. You have the most to lose if
you get hurt. Don’t allow yourself to work in a hazardous
situation without taking appropriate safety precautions.
Are the settings correct for the job you’re about to begin?
For an engine-driven welder:
Is it running OK?
Are all the hoses on tight?
Is the fuel cap on tight?
Is the engine leaking fuel or oil? Some jobsites look for this
and may refuse entry if your engine is leaking.
Is the original enclosure and fan guarding in place? Check
with your welding equipment distributor if you are unsure.
(See Supplement 6.)
If the hazard is serious and cannot be corrected readily, the
machine should be shut down until the needed repairs are
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
replaced, disconnect power to the welder and correct the
problem per the manufacturers instructions in the
operating/service manual. If the hazard requires repairs to the
inside of the welder or to the electrical input supply lines, call a
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,
protective equipment, safety equipment) or procedures be
Many jobsites require permits for any welding or cutting. Be
sure you have any permits you will need.
If you will be working in a confined space, many special
OSHA regulations and jobsite requirements may apply in
addition to the arc welding precautions in this brochure.
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?
Important Safety Note:
Consider whether the area in which you will be working creates
or increases the level of hazard to you thus requiring special
procedures or equipment. Factors such as electrical safety,
fume ventilation/exhaust and risk of fire or explosion may be
affected. See later sections on those topics and other
documents in “Bibliography and Suggested Reading” for further
Arc Welding Safety
Also, bear in mind that while you’re paying attention to your
work, other welders may be preoccupied with their own tasks
and not watching where they’re going. So be sure that there are
protective screens in place, just in case somebody happens to
be passing into your work area or walks into a shower of sparks
or spatter.
Keeping the area around your work neat is as important as
maintaining your equipment. Perhaps even more-so, as the risk
of injury is amplified by the larger group of people involved. You
may have already inspected your equipment and found it to be
OK, but all your caution won’t matter when, for example, a coworker 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.
the cylinder valve only when standing to one side of the
cylinder, away from welding or other sources of ignition. Return
damaged cylinders to the supplier. Refer to the Compressed
Gas Association pamphlet P-1, “Safe Handling of Gas
Cylinders,” for further information.
Because of the high pressure gas in cylinders, you must pay
particularly close attention to their storage and use. Examine the
cylinders as you did the rest of your equipment; check the
cylinder label to make sure it is the correct shielding gas for the
process, and that the regulators, hoses, and fittings are the right
ones for that gas and pressure, and are in good condition.
Cylinders must be secured in an upright position, with the valve
caps in place, in an area away from combustibles and fuels, and
safeguarded from damage, heat, and flames. When in use, keep
them out of traffic routes and flying sparks, with all hoses run
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
CYLINDER may explode if damaged.
• Keep cylinder upright and chained to support.
• Never allow welding electrode to touch
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.
Arc Welding Safety
welder, check the welder capacity nameplate and connection
instructions to be sure the input is the correct phase (single
phase or three phase) and voltage. Many welders may be set up
for single phase or three phase and for multiple input voltages.
Be certain the welder is set up for the electrical supply to which
it is connected. Only a qualified electrician should connect
input power. The case must be grounded so that if a problem
develops inside the welder a fuse will blow, disconnecting the
power and letting you know that repair is required. Never ignore
a blown fuse because it is a warning that something is wrong.
Possible Shock Hazards
The hazard of electric shock is one of the most serious and
immediate risks facing you as a welder. Contact with metal parts
which are “electrically hot” can cause injury or death because of
the effect of the shock upon your body or a fall which may result
from your reaction to the shock. The electric shock hazard
associated with arc welding may be divided into two categories
which are quite different:
– Primary Voltage Shock (i.e., 230, 460 volts); and
– Secondary Voltage Shock (i.e., 20-100 volts).
• Do not touch electrically live parts or
electrode with skin or wet clothing.
• Insulate yourself from work and ground.
HIGH VOLTAGE can kill.
• Do not operate with covers removed.
• Disconnect input power before servicing.
• Do not touch electrically live parts.
If welding must be performed under electrically hazardous
conditions (in damp locations or while wearing wet clothing;
on metal structures such as floors, gratings or scaffolds;
when in cramped positions such as sitting, kneeling or lying,
if there is a high risk of unavoidable or accidental contact
with the work piece or ground) use the following equipment:
The primary voltage shock is very hazardous because it is
much greater voltage than the welder secondary voltage. You
can receive a shock from the primary (input) voltage if you touch
a lead inside the welder with the power to the welder “on” while
you have your body or hand on the welder case or other
grounded metal. Remember that turning the welder power switch
“off” does not turn the power off inside the welder. To turn the
power inside the welder "off", the input power cord must be
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
properly. Also, your welder should be installed by a qualified
electrician so it will be correctly wired for the primary voltage
which supplies it power and so the case will be connected to an
earth ground. When electrical supply lines are connected to a
Semiautomatic DC Constant Voltage Welder
DC Manual (Stick) Welder
AC Welder with Reduced Voltage Control
A secondary voltage shock occurs when you touch a part of
the electrode circuit — perhaps a bare spot on the electrode
cable — at the same time another part of your body is touching
the metal upon which you’re welding (work). To receive a shock
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.
Arc Welding Safety
These rules are basic to welding and you should already know
them. Check out the warning on your welder or electrode box
next time you weld. You will probably not have a shock while
welding if you follow these rules.
recognize and protect combustible materials from the welding
arc, sparks and spatter. It is also important to be sure the work
is not in contact with any combustible which it may ignite when
heated. These materials fall into three categories: liquid
(gasoline, oil, paints, and thinners); solid (wood, cardboard, and
paper); and gaseous (acetylene and hydrogen).
Though it may be more difficult to follow the rules under some
conditions, the rules still apply. Keep your gloves dry even if you
have to keep an extra pair. Use plywood, rubber mats, or some
other dry insulation to stand or lie upon. Insulate your body from
the metal you are welding. Don’t rest your body, arms, or legs on
the workpiece, especially if your clothing is wet or bare skin is
exposed (and it should not be if you are dressed properly). In
addition to the normal safety precautions, if welding must be
performed under electrically hazardous conditions (in damp
locations or while wearing wet clothing; on metal structures such
as floors, gratings or scaffolds; when in cramped positions such
as sitting, kneeling or lying, if there is a high risk of unavoidable
or accidental contact with the work piece or ground) use the
following equipment:
Semiautomatic DC Constant Voltage Welder
DC Manual (Stick) Welder
AC Welder with Reduced Voltage Control
Watch where the sparks and metals are falling from your work: if
there are flammable materials including fuel or hydraulic lines in
your work area and you can’t move either your work or the
combustible substances, put a fire-resistant shield in place. If
you’re welding above the ground or off a ladder, make sure that
there are no combustibles underneath. Also, don’t forget about
your co-workers, and everybody else who may be in the work
area, as they probably wouldn’t appreciate being hit with slag or
sparks from your work.
Particular care must be taken when welding or cutting in dusty
locations. Fine dust particles may readily oxidize (burn) and
without warning result in a flash fire or even an explosion when
exposed to the welding arc or even sparks.
If you are not sure of the combustible or volatile nature of
residue or dust in the work area, no welding or cutting should
take place until a responsible person has inspected the area and
given approval for the work.
The condition of your electrode holder and electrode cable is
also very important. The plastic or fiber insulation on the
electrode holder protects you from touching the metal
“electrically hot” parts inside. Always inspect your electrode
holder before turning the welder on. Replace the holder if it is
damaged — don’t try to repair it unless you have replacement
Before you start welding, inspect the surface of your work,
looking for flammable coatings or any unknown substances that
would ignite when heated. Because of the extreme fire and
explosion hazards inherent to welding on or around containers
and piping that may have combustible materials, such work
should be handled only by experienced welders who review and
follow the safety practices recommended in the American
Welding Society document F4.1, “Recommended Safe Practices
for the Preparation for Welding and Cutting of Containers and
Piping Which Had Held Hazardous Substances.”
The same is true of the electrode cable except that when not
replaced it may be repaired using good electrical tape. If your
cable has been repaired, be sure to check and see that the tape
is secure before you turn the welder on.
Remember, a stick electrode is always “electrically hot” when the
welder is on — treat it with respect. If you do experience a
shock, think of it as a warning — check your equipment, work
habits and work area to see what is wrong before continuing to
Know where the fire alarms and fire extinguishers are located,
and check the pressure gauges so you don’t rely upon one
that’s empty. If there are none in the area, make sure that you
have access to fire hoses, sand buckets, fire-resistant blankets,
or other fire fighting equipment. If you’re welding within 35 feet
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
smoldering fires that may have resulted from your welding.
WELDING SPARKS can cause fire or explosion.
• 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
Arc Welding Safety
PEL (Permissible Exposure Limit) for chromium (see Supplement
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
zone and general area.
• Keep your head out of the fumes.
• Use enough ventilation or exhaust at the arc, or
both, to keep fumes and gases from your
breathing zone and general area.
Coatings on the metal to be welded, such as paint, may also
contain toxic substances, such as lead, chromium and zinc. In
general, it is always best to remove coatings from the base
metal before welding or cutting.
Cobalt: Exposure to cobalt can cause respiratory disease and
pulmonary sensitization. Cobalt in metallic form has been
reported to cause lung damage.
Fumes and Gases
Because of the variables involved in fume and gas generation
from arc welding, cutting and allied processes (such as the
welding process and electrode, the base metal, coatings on the
base metal, and other possible contaminants in the air), we’ll
have to treat the subject in a rather general way, lumping all but
the more hazardous situations together. The precautions we
describe will hold true for all arc welding processes.
Copper: Prolonged exposure to copper fume may cause skin
irritation or discoloration of the skin and hair.
Manganese: Manganese overexposure may affect the central
nervous system, resulting in poor coordination, difficulty in
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
welding, depending on the amount and length of exposure to
these fumes, most immediate or short term effects are
temporary, and include symptoms of burning eyes and skin,
dizziness, nausea, and fever. For example, zinc fumes can cause
metal fume fever, a temporary illness that is similar to the flu.
Nickel: Nickel and its compounds are on the IARC (International
Agency for Research on Cancer) and NTP (National Toxicology
Program) lists as posing a carcinogenic risk to humans.
Silica: Crystalline silica is present in respirable dust form
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.
Bronchitis and some lung fibrosis have been reported.
Zinc: Overexposure to zinc (from galvanized metals) may cause
metal fume fever with symptoms similar to the common flu.
Some consumables contain certain compounds in amounts
which may require special ventilation and/or exhaust. These
Special Ventilation products can be identified by reading the
labels on the package. If Special Ventilation products are used
indoors, use local exhaust. If Special Ventilation products are
used outdoors, a respirator may be required. Various
compounds, some of which may be in welding fume, and
reported health effects, in summary, are:
The gases that result from an arc welding process also present
potential hazard. Most of the shielding gases (argon, helium, and
carbon dioxide) are non-toxic, but, as they are released, they
displace oxygen in your breathing air, causing dizziness,
unconsciousness, and death, the longer your brain is denied the
oxygen it needs. Carbon monoxide can also be developed and
may pose a hazard if excessive levels are present.
The heat and UV radiation can cause irritation to the eyes and
lungs. Some degreasing compounds such as trichlorethylene
and perchlorethylene can decompose from the heat and
ultraviolet radiation of an arc. Because of the chemical
breakdown of vapor-degreasing materials under ultraviolet
radiation, arc welding should not be done in the vicinity of a
vapor-degreasing operation. Carbon-arc welding, gas tungstenarc welding and gas metal arc welding should be especially
avoided in such areas, because they emit more ultraviolet
radiation than other processes. Also, keep in mind that ozone
and nitrogen oxides are formed when UV radiation passes
through the air. These gases cause headaches, chest pains,
irritation of the eyes, and an itchiness in the nose and throat.
Barium: Soluble barium compounds may cause severe stomach
pain, slow pulse rate, irregular heart beat, ringing of the ears,
convulsions and muscle spasms. In extreme cases can cause
Cadmium also requires extra precautions. This toxic metal can
be found on some steel and steel fasteners as a plating, or in
silver solder. Cadmium fumes can be fatal even under brief
overexposures, with symptoms much like those of metal fume
fever. These two conditions should not be confused.
Overexposure to cadmium can be enough to cause fatalities,
with symptoms appearing quickly, and, in some circumstances,
death a few days later.
There is one easy way to reduce the risk of exposure to
hazardous fumes and gases: keep your head out of the fume
plume! As obvious as this sounds, the failure to follow this
advice is a common cause of fume and gas overexposure
because the concentration of fume and gases is greatest in the
plume. Keep fumes and gases from your breathing zone and
general area using natural ventilation, mechanical ventilation,
fixed or moveable exhaust hoods or local exhaust at the arc.
Finally, it may be necessary to wear an approved respirator if
adequate ventilation cannot be provided (see Ventilation
Chromium: Chromium is on the IARC (International Agency for
Research on Cancer) and NTP (National Toxicology Program) lists
chromium as posing a carcinogenic risk to humans. Fumes from
the use of stainless steel, hardfacing and other types of
consumables contain chromium and/or nickel. Some forms of
these metals are known or suspected to cause lung cancer in
processes other than welding and asthma has been reported.
Therefore, it is recommended that precautions be taken to keep
exposures as low as possible. OSHA recently adopted a lower
Arc Welding Safety
As a rule of thumb, for many mild steel electrode, if the air is
visibly clear and you are comfortable, then the ventilation is
generally adequate for your work.The most accurate way to
determine if the worker exposure does not exceed the applicable
exposure limit for compounds in the fumes and gases is to have
an industrial hygienist take and analyze a sample of the air you
are breathing. This is particularly important if you are welding
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.
Your work area has adequate ventilation when there is enough
ventilation and/or exhaust to control worker exposure to hazardous
materials in the welding fumes and gases so the applicable limits
that there
is enough ventilation
for those materials
is not
See Supplement
2 for the legal
worker Exposure
exposureLimit), and the
limits, the
recommended guideline, the ACGIH TLV (Threshold Limit Value),
for many compounds found in welding fume.
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
hazard. Be sure you are following these safe practices, the
consumable labeling and MSDS and improve the ventilation in
your area. Do not continue welding until the situation has been
There are many methods which can be selected by the user to
provide adequate ventilation for the specific application. The
following section provides general information which may be
helpful in evaluating what type of ventilation equipment may be
suitable for your application. When ventilation equipment is
installed, you should confirm worker exposure is controlled
within applicable OSHA PEL and/or ACGIH TLV. According to
OSHA regulations, when welding and cutting (mild steels),
natural ventilation is usually considered sufficient to meet
requirements, provided that:
NOTE: The MSDS for all Lincoln consumables is available on
Lincoln’s website:
Before we turn to the methods available to control welding fume
exposure, you should understand a few basic terms:
Natural Ventilation is the movement of air through the workplace
caused by natural forces. Outside, this is usually the wind. Inside, this
may be the flow of air through open windows and doors.
Mechanical Ventilation is the movement of air through the
workplace caused by an electrical device such as a portable fan or
permanently mounted fan in the ceiling or wall.
Source Extraction (Local Exhaust) is a mechanical device used
to capture welding fume at or near the arc and filter contaminants
out of the air.
The room or welding area contains at least 10,000 cubic
feet (about 22' x 22' x 22') for each welder.
The ceiling height is not less than 16 feet.
Cross ventilation is not blocked by partitions, equipment, or
other structural barriers.
Welding is not done in a confined space.
Spaces that do not meet these requirements should be
equipped with mechanical ventilating equipment that exhausts
at least 2000 cfm of air for each welder, except where local
exhaust hoods or booths, or air-line respirators are used.
The ventilation or exhaust needed for your application depends
upon many factors such as:
• workspace volume
• workspace configuration
• number of welders
• welding process and current
• consumables used (mild steel, hardfacing, stainless, etc.)
• allowable levels (TLV, PEL, etc.)
• material welded (including paint or plating)
• natural airflow
Important Safety Note:
When welding with electrodes which require special ventilation
such as stainless or hardfacing (see instructions on container or
MSDS) or on lead or cadmium plated steel and other metals or
coatings which produce hazardous fumes, keep exposure as low
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
Source Extraction Equipment
Mechanical ventilation is an effective method of fume control for
many welding processes. Because it captures fume near the arc
or source of the fume, which is more efficient in most cases,
local exhaust, also called "source extraction", is a very effective
means to control welding fume.
Source extraction of welding fumes can be provided by mobile or
stationary, single or multi-station, exhaust and/or filtration
equipment designed with adjustable fume extraction arms
nozzles or guns, by fixed enclosures, booths or tables with
extraction canopies also known as down-draft, or by back-draft
or cross-draft tables/booths. Source extraction of weld fume falls
into two categories: low vacuum/high volume, or high
vacuum/low volume.
Low Vacuum/High Volume
Mobile or stationary, single or multi-station, large centralized
exhaust and/or filtration equipment designed with adjustable
fume extraction arms are usually low vacuum/high volume
systems. When correctly positioned, the capture rate of
adjustable fume extraction arms is suitable for all position
welding and cutting. For more difficult to reach work areas,
flexible hose may be used in place of adjustable fume extraction
These arms generally move between 560 and 860 cubic feet per
minute (CFM) (900 – 1400 m3/hr) of air, but use low vacuum
levels (3 to 5 inches water gauge [750 – 1250 Pa]) to minimize
power requirements. Water gauge (WG) is a measure of negative
pressure: higher numbers mean more negative pressure
(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
and still effectively capture weld fume.
Fume extraction arms generally use a 6 or 8 inch diameter hose,
or hose and tubing combinations. Arm lengths are typically 7,
10, or 13 feet (2, 3, or 4 m), with boom extensions available. The
arms may be wall mounted, attached to mobile units, or
incorporated into a centralized system.
In general, the farther the extraction hose is from the arc, the
more volume of air movement is required to effectively capture
welding fume. Overhead hoods (canopies), for example, capture
most of the fume, but care must be taken to be sure fume is not
pulled through the breathing zone of the operator.
Fixed enclosures, booths or tables with extraction canopies also
known as down-draft, back-draft or cross-draft
booths/tables are a variation of overhead hood technology and
can be used as source extraction equipment. A booth is a fixed
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 backdraft booths/tables can be mobile or stationary, single or multistation, 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.
Source extraction with large volume
of air being extracted from welder
breathing zone.
If not using filtration unit,
exhausting air to outside requires
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
removal of residual fumes.
Welder must stop to reposition arm
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
Low energy consumption
(small fan unit with low rpm).
Adjustable arms suitable for allposition welding.
Mobiflex™ 200-M low vacuum
mobile fume extraction unit.
Arc Welding Safety
High Vacuum/Low Volume
High vacuum/low volume fume extraction systems are designed
for close proximity (2 to 4 inches) positioning. High vacuum/low
volume weld fume extraction is achieved with lower airflow rates
than those encountered when utilizing low vacuum/high volume
systems. There are two methods of high vacuum extraction:
welding guns with built-in extraction (fume extraction guns), or
separate suction nozzles of various designs.
There are advantages and limitations associated with high
vacuum/low volume source extraction systems.
Fume extraction guns use fume capture nozzles built into the
gun tube and handle. The extraction airflow is
approximately 35 to 60 CFM (60 – 100 m3/hr) for integrated fume
extraction guns. Therefore, no repositioning is required, since the
suction automatically follows the arc. The vacuum level is high
(40 to 70 inches WG [9.96 X 103 to 1.74 X 104 Pascal])
permitting the use of hose featuring longer lengths (10 to 25 feet)
and smaller diameters (1.25 to 1.75 inches). Fume extraction gun
designs have been improved to be more ergonomic and user
friendly. Depending upon the type of welding, particularly "in
position" welding, extraction guns may be a good solution.
Suction nozzles are positioned near the weld, and commonly
use capture distances of less than four inches. Depending upon
the design, airflow of suction nozzles is typically between 80 to
100 CFM (135 – 170 m3/hr). Suction nozzles must be kept near
the arc to be used effectively.
The capture rate for fume extraction guns or nozzles is highest
when used in flat and horizontal welding positions. High vacuum
equipment ranges from small, portable, mobile units to
stationary, single or multi-station, large centralized filtration
When using a fume extraction gun,
welder does not need to stop and
reposition extraction device.
Required when using a suction
nozzle. Welder may need to stop to
reposition extraction device.
Low volume of air is displacedresults in energy efficiency and
High noise level due to increased
air velocity and high motor rpm of
the fan unit.
Ductwork smaller in diameter (3 to
10 inches) vs. low vacuum systems.
Possible removal of shielding gases
affecting weld integrity if nozzle or
gun placed too close to source.
Low obstruction of welder vision.
Greater energy consumption
(large fan unit with high rpm).
Suitable for heavier particulate (ie.
grinding dust).
Residual fumes not extracted.
Suitable option for confined,
difficult to reach work spaces.
Less effective in out-of-position
Smaller filter systems due to less
volume of airflow.
Fume extraction is only one component in reducing welding
fume. Users should also consider the selection of the welding
process, welding procedure, or consumable. Many times a
combination of fume extraction, training, process change,
and/or consumable change is needed to reduce the amount of
fume to acceptable levels. Solutions to a particular application
may involve one or all of these factors and the user must
determine which solution best fits their application.
OSHA regulations include specific requirements for exhaust
systems which should be reviewed when selecting fume
extraction systems (see Supplement 2).
Miniflex™ high vacuum portable
fume extraction unit.
Arc Welding Safety
Exhaust vs. Filtration
Source extraction exhaust equipment captures and extracts
weld fumes from the source and exhausts the fumes to the
outside atmosphere. This technique removes welding fume from
the breathing zone of the welder but can also displace large
volumes of conditioned air which may lead to increased utility
and heating costs.
Working in Confined Spaces
When arc welding in a confined area, such as a boiler, tank, or
the hold of a ship, bear in mind that all the hazards associated
with normal arc welding are amplified, so the precautions
mentioned here are even more important. This subject is very
complicated and only these precautions related to arc welding
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
weld fumes from the source and filters the fumes by passing
them through a cellulose and/or polyester filter cartridge or
electrostatic filter. Depending on the weld application,
environment, federal or local regulations, and filtration efficiency
levels, filtered air may be re-circulated back into the facility or
exhausted to the outside atmosphere. By re-circulating filtered
air back into the work environment compared to exhausting to
the outside, source extraction filtration equipment can be more
economical to operate. Particularly in winter months,
substantially lower heating costs may be recognized, as less
replacement air is required with filtration versus exhaust systems.
Using a cellulose or polyester filter cartridge or electrostatic filter
will depend upon the weld application. Electrostatic filters may
also be used however, they lose efficiency if they are not
frequently washed.
Regardless of the type of mechanical ventilation (exhaust or
filtration) source extraction system used, the important factor is
that it is a tool designed to control exposure to welding fume and
its constituents. All forms of mechanical ventilation or source
extraction equipment require routine maintenance. In addition,
when using weld fume source extraction equipment, sparks from
welding, cutting or grinding processes can cause fire within the
equipment. To control this potential fire hazard, operation,
service and maintenance instructions for source extraction
equipment should be followed.
It is the equipment owner and operator’s responsibility to comply
with Occupational Safety, Health Administration (OSHA)
Permissable Exposure Limits (PELs) or American Conference of
Governments Industrial Hygienists (ACGIH) TLVs for welding
fume. It is the responsibility of the equipment owner to research,
test and comply with regulations which may apply to filtered air
recirculated inside the facility or unfiltered air is exhausted
outside of the facility.
1) Is large enough and so configured that an employee can
bodily enter and perform assigned work; and
2) Has limited or restricted means for entry or exit
(for example, tanks, vessels, silos, storage bins,
hoppers, vaults, and pits are spaces that may have
limited means of entry.); and
3) Is not designed for continuous employee occupancy.
There is a greater danger that enough flammable gases may be
present in the confined space to cause an explosion. The metal
of the enclosure can become part of the welding circuit, so any
metal you touch (the walls, floor, ceiling) is electrically "hot".
Welding fumes can accumulate more rapidly, with a higher
concentration; gases can force out the breathable air,
suffocating you in the process.
Per OSHA document 29 CFR 1910.146(d)(5)(iii); after an area has
been deemed a confined space, the existence of the following
atmospheric hazards are to be determined:
1) Test for oxygen
2) Test for combustible gases and vapors
3) Test for toxic gases and vapors
The workplace and OSHA rules regarding confined spaces must
be followed. Make sure that your body is insulated from the
work-piece using dry insulation. Wear dry gloves and only use a
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,
especially when the work area is wet. Make sure that there is
adequate ventilation and exhaust (a respirator or an air-supplied
respirator may be necessary depending on the application), and
that there are no flammable coatings, liquids or gases nearby.
Lastly, you must have someone outside the enclosure trained to
handle emergencies, with rescue procedures and a means to
disconnect power to your equipment and pull you out if danger
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
Arc Welding Safety
1/32 in. (mm)
Shielded metal arc
Less than 3 (2.5)
3-5 (2.5–4)
5-8 (4–6.4)
More than 8 (6.4)
Less than 60
Gas metal arc
welding and flux
cored arc welding
Less than 60
Gas tungsten arc
Less than 50
Less than 500
Less than 20
6 to 8
Less than 300
Torch brazing
3 or 4
Torch soldering
Carbon arc welding
Air carbon
Arc cutting
Plasma arc welding
Plasma arc cutting
Gas welding
Under 1/8
1/8 to 1/2
Over 1/2
Under 3.2
3.2 to 12.7
Over 12.7
4 or 5
5 or 6
6 or 8
Oxygen cutting
Under 1
1 to 6
Over 6
Under 25
25 to 150
Over 150
3 or 4
4 or 5
5 or 6
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
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
Data from ANSI Z49.1-1999
Arc Welding Safety
ANSI Z87.1, Practice for Occupational and Educational Eye and Face
Protection, American National Standards Institute, 11 West 42nd Street, New
York, NY 10036.
AWS F1.1, Method for Sampling Airborne Particulates Generated by Welding
and Allied Processes.
AWS F1.2, Laboratory Method for Measuring Fume Generation Rates and
Total Fume Emission of Welding and Allied Processes.
Arc Welding and Your Health: A Handbook of Health Information for Welding.
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
Safety and Health Administration at or contact your local
OSHA office.
The following publications are published by The American Welding Society,
P.O. Box 351040, Miami, Florida 33135. AWS publications may be purchased
from the American Welding society at or by contacting the
AWS at 800-854-7149.
AWS F3.2, Ventilation Guide for Welding Fume Control
AWS F4.1, Recommended Safe Practices for the Preparation for Welding and
Cutting of Containers and Piping That Have Held Hazardous Substances.
AWS SHF, Safety and Health Facts Sheets. Available free of charge from the
AWS website at
ANSI, Standard Z49.1, Safety in Welding, Cutting and Allied Processes. Z49.1
is now available for download at no charge at or at the AWS website
Arc Welding Safety
Aluminum and/or aluminum alloys (as Al)*****
Aluminum oxide and/or Bauxite*****
Barium compounds (as Ba)*****
Chromium and chromium alloys or compounds (as Cr)*****
Fluorides (as F)
Limestone and/or calcium carbonate
Lithium compounds (as Li)
Magnesium and/or magnesium alloys and compounds (as Mg)
Manganese and/or manganese alloys and compounds (as Mn)*****
Mineral silicates
Molybdenum alloys (as Mo)
Silicates and other binders
Silicon and/or silicon alloys and compounds (as Si)
Strontium compounds (as Sr)
Zirconium alloys and compounds (as Zr)
TLV mg/m3
PEL mg/m3
Supplemental Information:
Not listed. Nuisance value maximum is 10 milligrams per cubic meter. PEL value for
iron oxide is 10 milligrams per cubic meter. TLV value for iron oxide is 5 milligrams
per cubic meter.
As respirable dust.
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.
The PEL for chromium (VI) is .005 milligrams per cubic meter as an 8 hour time weighted
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.
Values are for manganese fume. STEL (Short Term Exposure Limit) is 3.0
milligrams per cubic meter. PEL of 1.0 milligrams per cubic meter proposed
by OSHA in 1989. Present PEL is 5.0 milligrams per cubic meter (ceiling
There is no listed value for insoluble barium compounds. The TLV for soluble
barium compounds is 0.5 mg/m3.
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
Arc Welding Safety
Arc Welding Safety
Arc Welding Safety
Arc Welding Safety
Arc Welding Safety
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 and make the request
Arc Welding Safety
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 – Attatched to Radiator
Typical Fan Gaurd – One Mounted One
Each Side of Radiator
Arc Welding Safety
Welder in or on workpiece
Confined space
Electrode holder and
cable insulation
• Insulate welder from workpiece and ground using dry insulation. Rubber
mat or dry wood.
• Wear dry, hole-free gloves. (Change as necessary to keep dry.)
• Do not touch electrically “hot” parts or electrode with bare skin or wet
• If wet area and welder cannot be insulated from workpiece with dry
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.
Electric shock can
Fumes and gases
can be dangerous
Welding sparks
can cause fire or
• Containers which have held •
• Flammable materials
Arc rays can burn
eyes and skin
• Process: gas-shielded arc
most severe
Confined space
• Carefully evaluate adequacy of ventilation especially where electrode requires
special ventilation or where gas may displace breathing air.
• If basic electric shock precautions cannot be followed to insulate welder from
work and electrode, use semiautomatic, constant-voltage equipment with
cold electrode or stick welder with voltage reducing device.
• Provide welder helper and method of welder retrieval from outside enclosure.
General work area
• Cluttered area
• Keep cables, materials, tools neatly organized.
• Indirect work (welding
ground) connection
• Connect work cable as close as possible to area where welding is being
performed. Do not allow alternate circuits through scaffold cables, hoist
chains, ground leads.
• Electrical equipment
• Use only double insulated or properly grounded equipment.
• Always disconnect power to equipment before servicing.
• Engine-driven equipment
• Gas cylinders
• Never touch cylinder with the electrode.
• Never lift a machine with cylinder attached.
• Keep cylinder upright and chained to support.
Confined area
Positioning of welderʼs head
Lack of general ventilation
Electrode types, i.e.,
manganese, chromium,
etc. See MSDS
• Base metal coatings,
galvanize, paint
Metal enclosure
Restricted entry
Heavier than air gas
Welder inside or on
• Use ventilation or exhaust to keep air breathing zone clear, comfortable.
• Use helmet and positioning of head to minimize fume in breathing zone.
• Read warnings on electrode container and material safety data sheet (MSDS)
for electrode,
• Provide additional ventilation/exhaust where special ventilation
requirements exist.
• Use special care when welding in a confined area.
• Do not weld unless ventilation is adequate.
Do not weld on containers which have held combustible materials (unless
strict AWS F4.1 procedures are followed). Check before welding.
Remove flammable materials from welding area or shield from sparks, heat.
Keep a fire watch in area during and after welding.
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.
Provide non-flammable shielding to protect others.
Wear clothing which protects skin while welding.
Use in only open, well ventilated areas.
Keep enclosure complete and guards in place.
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).
Arc Welding Safety
Arc Welding Safety
Publication E205 | Issue Date 06/14
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