Tig Welding Health and Safetly
Brought a new Tig welder and now wanting to assess the risks and potential health problems.
Also want to access the impact on the environment.
Nz Standards - "work place and exposure standards" - http://www.business.govt.nz/worksafe/information-guidance/all-guidance-items/workplace-exposure-standards-and-biological-exposure-indices/workplace-exposure-standards-and-biological-indices-2013.pdf
this outlines exposure standards.
Note - TIG can also be referred to as GTAW
Also want to access the impact on the environment.
Nz Standards - "work place and exposure standards" - http://www.business.govt.nz/worksafe/information-guidance/all-guidance-items/workplace-exposure-standards-and-biological-exposure-indices/workplace-exposure-standards-and-biological-indices-2013.pdf
this outlines exposure standards.
Note - TIG can also be referred to as GTAW
Eyes
OK So eye protection is vital here. High light levels will damage the eye. The helmet that I have brought has a range from 9 to 13.
Q - how do I know when its not enough.
Q - how do I know its to much
A - ?
Q - how do I know when its not enough.
Q - how do I know its to much
A - ?
Electrical
There are two aspects to this that I can see at the moment
1) exposure to high frequency radiation from cabling, the manual talks about this but I think it might be a bit extreme
Q - is this an issue
2) Electrical shock.
Q - touching the works is not an issue. But I assume that water is not good.
Q - how about touching the tungsten with the filler metal is that really bad or what? looks to be to be but how bad?
1) exposure to high frequency radiation from cabling, the manual talks about this but I think it might be a bit extreme
Q - is this an issue
2) Electrical shock.
Q - touching the works is not an issue. But I assume that water is not good.
Q - how about touching the tungsten with the filler metal is that really bad or what? looks to be to be but how bad?
Tungsten Dust
Looks like the only thing to watch here is that you don't inhale the dust from grinding.
Q - how bad is this, is it OK to leave the dust around, how do you dispose of it?
MSDS for tungsten - http://www.sciencelab.com/msds.php?msdsId=9925358
Q - how bad is this, is it OK to leave the dust around, how do you dispose of it?
MSDS for tungsten - http://www.sciencelab.com/msds.php?msdsId=9925358
Metals I'm working with - mild and 316 Stainless steel- whats in it
Its important to know whats in the metal:
316 316l and 316H - refer http://www.azom.com/article.aspx?ArticleID=863
304 - http://www.azom.com/article.aspx?ArticleID=965
mild steel - ??
316 316l and 316H - refer http://www.azom.com/article.aspx?ArticleID=863
304 - http://www.azom.com/article.aspx?ArticleID=965
mild steel - ??
Gases and Fumes produced from tig welding
Depending on what metal I'm welding will depend on the resulting gases. Lets break it down by the metal we are welding (although we could break it down by the elements within the metal, but I'm wanting to take the more practice orientated approach).
Another factor that you need to consider when tig welding is melt contaminates.
Note - I'm assuming that I'm working with clean metal, having contaminates in the metal results in a lot more gases. You can find more information about this in good reference - http://www.ccohs.ca/oshanswers/safety_haz/welding/fumes.html.
Background Information Fumes
good reference - http://www.ccohs.ca/oshanswers/safety_haz/welding/fumes.html
This reference goes into it quite well, basically we have fumes and gases. Welding fumes are a complex mixture of metallic oxides, silicates and fluorides. Fumes are formed when a metal is heated above its boiling point and its vapours condense into very fine, particles (solid particulates).
Welding Mild Steel Fumes
Fumes from mild steel welding contain mostly iron with small amounts of additive metals (chromium, nickel, manganese, molybdenum, vanadium, titanium, cobalt, copper etc.).
Iron Oxides - The major contaminant in all iron or steel welding processes.
Welding Stainless Steel Fumes
Fumes from Stainless steels have larger amounts of chromium or nickel in the fume and lesser amounts of iron. Also Cadmium if its present. (which it doesn't seem to be in 316. chemical formula Cd)
Iron Oxides - The major contaminant in all iron or steel welding processes.
Gases from TIG Welding
Gases used in welding and cutting processes include:
Other Factors to Consider
Metal that is contaminated - this could be from oil or paint. Gases are not good, how bad, not sure. Effect on environment not sure
Q - how do I quantify this
One solution - work with clean metal
Stainless Steel - Welding stainless gives of hexavalent Chromium and Cadium (check this). Hexavalent Chromium is also call Chromium 6 or Cr VI.
MSDS for 316 - http://www.orthodonsite.com/catalog/manuals/crochets.pdf?osCsid=0686354db547162930bc43ad9d7fc750
MSDS for 316 - http://jr.chemwatch.net/backpack/msdspdf.exe?mode=SAP&passop=checkpass&user=cigwelloutback&pwd=aaaPm3&partno=321406&pdf=y
decay sequence for Cr VI
NZ Safety - P2 with nuisance organic vapour removes chromium gases (Which is the welding filter), Q - I assume that this is chromium VI
Health Effects Cr VI - http://www.cdc.gov/niosh/topics/hexchrom/
Mild Steel -
Another factor that you need to consider when tig welding is melt contaminates.
Note - I'm assuming that I'm working with clean metal, having contaminates in the metal results in a lot more gases. You can find more information about this in good reference - http://www.ccohs.ca/oshanswers/safety_haz/welding/fumes.html.
Background Information Fumes
good reference - http://www.ccohs.ca/oshanswers/safety_haz/welding/fumes.html
This reference goes into it quite well, basically we have fumes and gases. Welding fumes are a complex mixture of metallic oxides, silicates and fluorides. Fumes are formed when a metal is heated above its boiling point and its vapours condense into very fine, particles (solid particulates).
Welding Mild Steel Fumes
Fumes from mild steel welding contain mostly iron with small amounts of additive metals (chromium, nickel, manganese, molybdenum, vanadium, titanium, cobalt, copper etc.).
Iron Oxides - The major contaminant in all iron or steel welding processes.
Welding Stainless Steel Fumes
Fumes from Stainless steels have larger amounts of chromium or nickel in the fume and lesser amounts of iron. Also Cadmium if its present. (which it doesn't seem to be in 316. chemical formula Cd)
Iron Oxides - The major contaminant in all iron or steel welding processes.
Gases from TIG Welding
Gases used in welding and cutting processes include:
- shielding gases - argon
- carbon dioxide from the decomposition of fluxes
- carbon monoxide from the breakdown of carbon dioxide shielding gas in arc welding
- ozone from the interaction of electric arc with atmospheric oxygen
- nitrogen oxides from the heating of atmospheric oxygen and nitrogen
- hydrogen chloride and phosgene produced by the reaction between ultraviolet light and the vapours from chlorinated hydrocarbon degreasing solvents (e.g., trichloroethylene, TCE)
Other Factors to Consider
Metal that is contaminated - this could be from oil or paint. Gases are not good, how bad, not sure. Effect on environment not sure
Q - how do I quantify this
One solution - work with clean metal
Stainless Steel - Welding stainless gives of hexavalent Chromium and Cadium (check this). Hexavalent Chromium is also call Chromium 6 or Cr VI.
MSDS for 316 - http://www.orthodonsite.com/catalog/manuals/crochets.pdf?osCsid=0686354db547162930bc43ad9d7fc750
MSDS for 316 - http://jr.chemwatch.net/backpack/msdspdf.exe?mode=SAP&passop=checkpass&user=cigwelloutback&pwd=aaaPm3&partno=321406&pdf=y
decay sequence for Cr VI
NZ Safety - P2 with nuisance organic vapour removes chromium gases (Which is the welding filter), Q - I assume that this is chromium VI
Health Effects Cr VI - http://www.cdc.gov/niosh/topics/hexchrom/
Mild Steel -
Brazing and soldering
lead fumes and other fumes are important to remember
Health effects from gases and fumes
Fumes
levels and exposure time is important - AP - where do I get these? These levels are also produced from the different setups- current
levels and exposure time is important - AP - where do I get these? These levels are also produced from the different setups- current
Chromium
|
Increased risk of lung cancer. Some individuals may develop skin irritation. Some forms are carcinogens (hexavalent chromium).
|
Source - Most stainless-steel and high-alloy materials, welding rods. Also used as plating material.
|
Iron Oxides
|
Siderosis – a benign form of lung disease caused by particles deposited in the lungs. Acute symptoms include irritation of the nose and lungs. Tends to clear up when exposure stops.
|
source - The major contaminant in all iron or steel welding processes.
|
Lead
|
Chronic effects to nervous system, kidneys, digestive system and mental capacity. Can cause lead poisoning.
|
source - Solder, brass and bronze alloys, primer/coating on steels.
|
Gases
levels and exposure time is important - AP what are the levels
levels and exposure time is important - AP what are the levels
Carbon Monoxide
|
Absorbed readily into the bloodstream, causing headaches, dizziness or muscular weakness. High concentrations may result in unconsciousness and death
|
source - Formed in the arc.
|
Hydrogen Fluoride
|
Irritating to the eyes and respiratory tract. Overexposure can cause lung, kidney, bone and liver damage. Chronic exposure can result in chronic irritation of the nose, throat and bronchi.
|
source - Decomposition of rod coatings.
|
Nitrogen Oxides
|
Eye, nose and throat irritation in low concentrations. Abnormal fluid in the lung and other serious effects at higher concentrations. Chronic effects include lung problems such as emphysema.
|
source - Formed in the arc.
|
Oxygen Deficiency
|
Dizziness, mental confusion, asphyxiation and death.
|
source -Welding in confined spaces, and air displacement by shielding gas.
|
Ozone
|
Acute effects include fluid in the lungs and hemorrhaging. Very low concentrations (e.g., one part per million) cause headaches and dryness of the eyes. Chronic effects include significant changes in lung function.
|
source - Formed in the welding arc, especially during plasma-arc, MIG and TIG processes.
|
Argon
|
source - Shielding Gas
|
Dealing with the tig gases in the workshop
Reducing the Risks
1) Wear and use appropriate safety protection
2) Provide adequate ventilation - Q - what is adequate them?
3) Reduce the use of materials that create an issue
4) Lower current is lower fumes
How to access the risks
1) read other information
2) measure what I'm doing in my environment - This is the gold start. Also measure with and without ventilation, this checks that its actually working or not. Then every so often review this and make sure I'm not overstepping the mark.
Measuring Gas Levels
The ultimate way to know if things are safe or not is to measure the gases involved. This can be a costly exercise. At present this is what I'm thinking
1) One gas may be easy, quick and cheap to measure and could represent if the other gases are present. This would mean that I just measure this one and then from that know that the other ones are at a particular level. For example just by smell the human can detect ozone at 0.1 parts per million, and if this is the main element produced or produced in equal qantities to the other, with similar health effects, then smell could be good enough.
2) Wearing a mask in the workshop that is appropriate to welding will reduce the risks. This is my back up option I would want to have ventilation setup so that levels are fine but there is the risk of being in the welding fume zone. Note - it looks like nz safety have a filter that is used for welding, need to look into the details of what it filters out.
Notes
1) Tig is low fume
2) low current welding on stainless produces less fumes
3)
1) Wear and use appropriate safety protection
2) Provide adequate ventilation - Q - what is adequate them?
3) Reduce the use of materials that create an issue
4) Lower current is lower fumes
How to access the risks
1) read other information
2) measure what I'm doing in my environment - This is the gold start. Also measure with and without ventilation, this checks that its actually working or not. Then every so often review this and make sure I'm not overstepping the mark.
Measuring Gas Levels
The ultimate way to know if things are safe or not is to measure the gases involved. This can be a costly exercise. At present this is what I'm thinking
1) One gas may be easy, quick and cheap to measure and could represent if the other gases are present. This would mean that I just measure this one and then from that know that the other ones are at a particular level. For example just by smell the human can detect ozone at 0.1 parts per million, and if this is the main element produced or produced in equal qantities to the other, with similar health effects, then smell could be good enough.
2) Wearing a mask in the workshop that is appropriate to welding will reduce the risks. This is my back up option I would want to have ventilation setup so that levels are fine but there is the risk of being in the welding fume zone. Note - it looks like nz safety have a filter that is used for welding, need to look into the details of what it filters out.
Notes
1) Tig is low fume
2) low current welding on stainless produces less fumes
3)
Fumes in the environment
So what happens to fumes in the environment? Lets looks at the different fumes and understand what is happening both from a fume point of view and a chemical reaction point of view.
Chromium VI - refer http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Descriptive_Chemistry/Transition_Metals/Group_6%3A_Transition_Metals/Chemistry_of_Chromium
study - http://eagar.mit.edu/EagarPapers/Eagar174.pdf
Chromium VI - refer http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Descriptive_Chemistry/Transition_Metals/Group_6%3A_Transition_Metals/Chemistry_of_Chromium
study - http://eagar.mit.edu/EagarPapers/Eagar174.pdf
gases produced from tig in the environment
The aim of this section is to look at each of the gases produces and understand there impact on the environment and how they breakdown.
Ozone
Ozone is a pale blue-coloured gas with a chemical formula O3. The odor is detectable in air at levels of about 0.1 parts per million, and it is postulated that exposure to ozone becomes fatal to humans at around levels of 100 ppm for 10,000 minutes or 10,000 ppm for 30 seconds.
There are three natural ways that ozone is created:
1.The first is by lighting
2.The second is through waterfalls and crashing surf, which accounts for the energetic feelingand calm experienced near these sites.
3.The third way is by photons from the sun breaking apart nitrous oxide.
Ozone is a gas with half-life of about 5 – 30 minutes depending on the temperature and the pH of the media.
refer - http://www.the-o-zone.cc/HTMLOzoneF/o3liquids/o3lpt03.pdf
Ozone
Ozone is a pale blue-coloured gas with a chemical formula O3. The odor is detectable in air at levels of about 0.1 parts per million, and it is postulated that exposure to ozone becomes fatal to humans at around levels of 100 ppm for 10,000 minutes or 10,000 ppm for 30 seconds.
There are three natural ways that ozone is created:
1.The first is by lighting
2.The second is through waterfalls and crashing surf, which accounts for the energetic feelingand calm experienced near these sites.
3.The third way is by photons from the sun breaking apart nitrous oxide.
Ozone is a gas with half-life of about 5 – 30 minutes depending on the temperature and the pH of the media.
refer - http://www.the-o-zone.cc/HTMLOzoneF/o3liquids/o3lpt03.pdf
Action points
1) 20140327 - John Stock from polytech is going to ring me. He is the pro
2) Ask other people what they know
3) Watch more stuff on the internet.
4) Find some document outlining the risks and issues.
2) Ask other people what they know
3) Watch more stuff on the internet.
4) Find some document outlining the risks and issues.