RISKS AND SAFETY MEASURES IN TIG WELDING PROCESS

Abstract

TIG welding is a method often used for joining of light metals and high-alloy steels and it contains a number of risks as with other arc welding methods. If proper precautions are taken, safe working environment can be provided. Arc welding includes various hazards like dust, gas and smoke, compressed gas cylinders, harmful rays, high temperature and electric shock. These hazards can cause accidents which may occur before, during or after welding. Especially breathing dust, gas and smoke or exposure to the harmful rays may lead to occupational diseases in long term. In this paper, physical and chemical risks that may arise during the TIG welding process are searched and safety measures that set by international and national standards are presented. Storage and use of compressed gas cylinders, safety instructions for TIG welding machine, workplace safety, personal protective equipment specifications and measures must be taken against occupational diseases constitute content of the post.

Full text

2nd International Iron and Steel Symposium (IISS’15), April 1-3, 2015, Karabuk, Turkey
© IISS’15, Karabük University, Karabük, Turkey
RISKS AND SAFETY MEASURES IN TIG WELDING PROCESS
Emre GÜMÜŞa, Bünyamin ÇİÇEKa, Emine GÜNDOĞDU İŞa, Eren YILMAZa and Polat TOPUZa
a Istanbul Gedik University, Istanbul, Turkey, E-mail: emre.gumus@gedik.edu.tr
Abstract
TIG welding is a method often used for joining of light
metals and high-alloy steels and it contains a number of
risks as with other arc welding methods. If proper
precautions are taken, safe working environment can be
provided. Arc welding includes various hazards like dust,
gas and smoke, compressed gas cylinders, harmful rays,
high temperature and electric shock. These hazards can
cause accidents which may occur before, during or after
welding. Especially breathing dust, gas and smoke or
exposure to the harmful rays may lead to occupational
diseases in long term. In this paper, physical and chemical
risks that may arise during the TIG welding process are
searched and safety measures that set by international
and national standards are presented. Storage and use of
compressed gas cylinders, safety instructions for TIG
welding machine, workplace safety, personal protective
equipment specifications and measures must be taken
against occupational diseases constitute content of the
post.
Keywords: TIG welding, safety, occupational diseases
1. Introduction
TIG is an abbreviation of “Tungsten Inert Gas”. The arc is
created between a non-consumable tungsten electrode
and work piece under the shielding atmosphere of argon,
helium or argon helium mixture. For this process also filler
metal is needed. A typical TIG welding set-up consists of
welding power source, welding torch, clamp, shielding gas,
foot control, cooling system with coolant in and out hoses
as shown in Fig. 1.
Figure 1. Typical TIG welding setup [1].
TIG welding is suitable for all positions, almost any type of
metal can be welded. High quality weld and low distortion
next to the welding area is obtained and no flux is needed.
Disadvantage of TIG welding is inert gas can be blown
away by the wind in outdoor applications. Welders also
must be well trained and expensive for thick walled parts,
metal deposition rate is lower compared to other methods
[1].
General instructions for safe use of TIG welding machine:
 Proper installation, grounding, and operating of
the TIG welding machine should be provided
according to local codes.
 Check the welding machine and other equipment.
 Make sure that right gas cylinder mounted to the
system.
 Turn on the main switch.
 Open the gas cylinder valve.
 Set the gas pressure and current according to
welding type.
 Connect work piece to the apparatus.
 Press the start button and start welding process.
2. Welder Safety and Choosing the Right
Equipment
For safe operations, welders must be suitable for the work
and well-trained. Authorization to access welding
equipment should be limited with the welders which are
qualified to operate this unit. An employee checklist below
can be useful for welders [2].
 Do you know how to use the controls properly?
 Use, maintain and store your protective equipment
in accordance with instructions.
 Look for signs of leaks, wear and damage.
 If you find any problems, tell your supervisor.
Don’t just carry on working.
 Co-operate with health monitoring.
 Wash your hands before eating, drinking, or using
the lavatory.
 Never clean your hands with solvents or
concentrated cleaning products.
 Use skin creams provided as instructed.
For manual welding, choosing the right welding set can
avoid the muscle, joint and tendon disorders. It should be
noted that welders usually have to lift, pull or push heavy
equipment and materials. For moving or lifting heavy parts,
cylinders and other equipment sufficient number of people
is needed. Selecting the right welding set size may help to
avoid [3];
 Personal suffering caused by injuries or ill health
from musculoskeletal disorders,
 The financial burden of sickness absence and
increased insurance premiums,
 Reduced productivity,

GÜMÜŞ Emre, ÇİÇEK Bünyamin, GÜNDOĞDU İŞ Emine, YILMAZ Eren and TOPUZ Polat
 Welders being unable to come back to this type of
work, which could affect their future earnings.
Welders should assure that proper personal protective is
used and fire protection fire extinguishing equipment are
properly located at the work site.
3. Risks
Like all of the other welding methods, TIG welding can be
dangerous unless the proper precautions are taken. Using
electric arc is a necessary part of the work. If people who
use, contract or supervise the use of these processes do
not fully appreciate that their improper use can result in
loss of life and property by poisoning, fire, explosion or
electric shock. Here are the main risks below:
 Hot surfaces or parts
 Arc rays
 Fumes and gases
 Electric shock
 Fire and explosion
 Magnetic fields
 Compressed gas cylinders
 Build-up of gas
 Metal vapor and dust
 Noise
3.1. Ventilation
During the welding, metal vapor, dust, fumes and gases
occur. Welding fume includes heavy and light metals like
aluminum, zinc, chromium, cadmium, arsenic, antimony,
manganese, vanadium, titanium, silver, beryllium,
molybdenum, tin, nickel, cobalt, copper and iron. In
addition to shielding gases argon and helium, harmful
gases hydrogen fluoride, carbon dioxide, nitric oxide,
carbon monoxide, phosgene, ozone, nitrogen dioxide are
available too [4]. A good standard of ventilation can avoid
breathing these fume and gases. For general ventilation air
changes 5-10 times per hour is appropriate. If ventilation is
poor, wearing an approved air-supplied respirator can be
life saver. Ventilation criteria according to the welding
process with filler material is shown on Table 1.
OSHA (Occupational Safety and Health Agency) points out
acute exposure to welding fume and gases can result in
eye, nose and throat irritation, dizziness and nausea.
Workers in the area who experience these symptoms
should leave the area immediately, seek fresh air and
obtain medical attention. Prolonged exposure to welding
fume may cause lung damage and various types of
cancer, including lung, larynx and urinary tract. Health
effects from certain fumes may include metal fume fever,
stomach ulcers, kidney damage and nervous system
damage. Prolonged exposure to manganese fume can
cause Parkinson’s like symptoms. Gases such as helium,
argon, and carbon dioxide displace oxygen in the air and
can lead to suffocation, particularly when welding in
confined or enclosed spaces. Carbon monoxide gas can
form posing a serious asphyxiation hazard [5].
Table 1 Ventilation criteria according to welding method
with filler material [6].
Non Alloyed and Low Alloyed Steel,
Aluminum Based Materials
Method
Short Term
Long Term
Local
Natural
Ventilation
Technical
Ventilation
General
Natural
Ventilation
Natural
Ventilation
High Alloyed Steel, Non-Ferrous Metals
(Except Aluminum Based Materials)
Method
Short Term
Long Term
Local
Natural
Ventilation
Technical
Ventilation
General
Natural
Ventilation
Technical
Ventilation
Coated Steel
Method
Short Term
Long Term
Local
Natural
Ventilation
Technical
Ventilation
General
Natural
Ventilation
Technical
Ventilation
3.2. Electric Shock
Arc welding methods includes electric hazards such as
fatal shocks or severe burns. The electrode and work
circuit is electrically live whenever the output is on. The
input power circuit and machine internal circuits are also
live when power is on. In semiautomatic or automatic wire
welding, the wire, wire reel, drive roll housing, and all metal
parts touching the welding wire are electrically live.
Incorrectly installed or improperly grounded equipment
may cause hazards.
Installing, grounding and operating of equipment should
comply with the instructions in owner’s manual. DC output
should be used unless AC is required for the welding
process. If AC output is required, remote output should be
used if present on unit. Additional safety precautions are
required when any of the following electrically hazardous
conditions are present: 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; or when there is a high risk of
unavoidable or accidental contact with the work piece or
ground. For these conditions, use the following equipment
in order presented [7]:
 A semiautomatic DC constant voltage (wire)
welder
 A DC manual (stick) welder
 An AC welder with reduced open-circuit voltage
In most situations, use of a DC constant voltage wire
welder is recommended.
3.2.1. Electric and Magnetic Fields
When a current flows through the electric cables local
electrical and magnetic field occurs. Because of working
with high amount of current values in TIG welding,
electrical and magnetic field may interfere with medical
implants. If the welder has an implant or pacemaker,

GÜMÜŞ Emre, ÇİÇEK Bünyamin, GÜNDOĞDU İŞ Emine, YILMAZ Eren and TOPUZ Polat
protective measures need to be taken. Consulting a doctor
is a necessity to avoid unintended consequences. Welder
should arrange cables to one side or use a cable cover. It
should be noted that coiling or draping cables around the
body multiplies effects of the field.
3.3. Compressed Gas Cylinders
Compressed gas cylinders contain gas under pressure.
Because of being a part of the welding process, cylinders
must be carefully treated. Workers should protect cylinders
from mechanical impact, heat exposure, flames, sparks
and electrical circuit. Welding electrode should be kept
away from cylinders. Gas transferring one cylinder to
another can be really dangerous. Gas transfer activities
require special training and qualifications. Cylinders,
hoses, regulators and fittings must be used for appropriate
applications and gases [8].
Argon and helium gases are used in TIG welding. Two of
them are inert and they are used for shielding. They are
colorless, odorless, non-toxic, inert, non-flammable,
compressed into steel tubes under high pressure. The
cylinders should be used and kept below 45 oC. Although
being a non-toxic gas, argon acts as asphyxiant at high
concentrations [9, 10].
3.4. Fire and Explosion
Welding areas should be designed to reduce fire risk.
Housekeeping should be done well and floor covering
materials should be non-flammable. If the atmosphere is
flammable and combustible presence is known no welding
should be done.
Fire extinguisher equipment should always be ready.
Where sprinkler system protection exists, it shall remain
operable during the welding or cutting. Automatic sprinkler
heads in the immediate vicinity of the welding shall be
permitted to be temporarily shielded with non-combustible
sheet material or damp cloth guards where they could be
activated by the heat of the welding process [11].
Figure 2. 35 feet (11 m.) rule [12].
Especially welding in closed containers like tanks, pipes
can cause blow up. Flying sparks can cause fire or burn
injuries. Cracks and openings in the floor are suitable
areas for flying sparks might drop through. Flammable
materials should be moved outside the welding area.
NFPA (National Fire Protection Association, USA) defines
35 feet (11 m.) rule (Fig. 2). When welding is performed at
an elevated level, it should be noted that sparks or slag
can fall at a trajectory and land farther than 35 feet (11 m)
horizontally from a point directly under welding operator.
Position fire watcher with suitable fire extinguishers to
protect potential hazard area and equip fire watch with for
emergency communications. Fire watcher are qualified
about emergency rescue procedures, they can detect and
prevent spreading of fire. Fire watchers should be posted
where welding is done and where a large fire might
develop [12].
3.5. Personal Protective Equipment
Wearing clothes made from durable, flame-resistant
materials like leather and wool provides protecting from arc
rays and welding sparks. Clothing shall also be selected to
minimize the potential for ignition and burning. Heavier
materials such as woolen clothing or heavy cotton are
preferable to lighter materials because they are more
difficult to ignite. Cotton clothing, if used for protection,
should be chemically treated to reduce its combustibility
[11].
Clothing treated with flame resistant materials can lose
some of its protective characteristics after repeated
washing or cleaning. Materials that can melt and cause
severe burns should not be used as clothing when the
wearer will be welding. Proper foot protection also needed.
Table 2 Protective equipment standards.
Personal Protective
Equipment
Standard
Usage
Goggles
DIN 58211
Not recommended
Fireproof Protective Cloth
-
Usually necessary
Face and Head Mask
DIN 58214
Necessary
Gloves
DIN 4841
Necessary
Eye protection is one of the most important personal
protective equipment. For protecting against slag chips,
grinding fragments, wire wheel bristles and similar hazards
it should be comply with ANSI Z87.1 [13]. For arc rays
especially head welding helmet must be worn. Wearing
goggles alone is not recommended for arc rays as shown
in Table 2. Welding helmets with filter lenses are intended
to protect users from arc rays and from weld sparks and
spatter which impinge directly against the helmet [11].
Table 3 Shade numbers for TIG welding [14].
Arc Current
(Amperes)
Min. Protective
Shade
Suggested Shade
No
<50
8
10
50-150
8
12
150-500
10
14

GÜMÜŞ Emre, ÇİÇEK Bünyamin, GÜNDOĞDU İŞ Emine, YILMAZ Eren and TOPUZ Polat
Table 3 shows which shade number related to arc current
should be chosen according to AWS F2.2 [14]. Welder
should start with a shade that is too dark to see the weld
zone, then he can go to a lighter shade which gives
sufficient view of the weld zone without going below the
minimum. Noise level can be high at the presence of
multiple welding or other processes. Welders should wear
approved ear protection.
7. Conclusion
This paper can be considered as a guidance for TIG
welders and other employees who are working at the same
workplace explaining what they need to do for taking
safety precautions, prevent accidents and ensuring a safe
environment. Arc welding methods include various risks
like hot surfaces or parts, arc rays, fumes and gases,
electric shock, fire and explosion, magnetic fields,
compressed gas cylinders, build-up of gas, metal vapor
dust and noise. These hazards cause accidents which may
occur before, during or after welding. For this reason
certified and well trained welders according to national and
international standards or codes must be employed. Health
monitoring can also prevent work related diseases.
Creating an organized, safe and healthy working
environment, provides productivity and quality.
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