Air Monitoring Applications - Welding

Welding Gases

Air Sampling Media by Regulatory Method Welding Processes main page
Method Contaminants of Interest Sampling Media
OSHA
OSHA ID 172 Carbon Dioxide in Workplace Atmospheres Gas Sampling Bag – Tedlar 5L (24655)
OSHA ID 182 Nitrogen Dioxide in Workplace Atmospheres Sorbent Tube – TEA molesieve (Custom-Inquire)
Passive – Radiello (RAD166 w/ RAD1201)
OSHA ID 190  Nitric Oxide in Workplace Atmospheres Sorbent Tube – TEA molesieve w/oxidizer – ORBO-76 (20826-U)
OSHA ID 209 Carbon Monoxide in Workplace Atmospheres Direct Reading – Detector Tube (28166-U & 28167-U)
OSHA ID 210 Carbon Monoxide in Workplace Atmospheres Aluminized Gas Sampling Bag – 2 to 5 L
OSHA ID 214 Ozone in Workplace Atmospheres Filter – Nitrite Impregnated Glass Fiber Filter (IGFF) in 2-pc cassette (Custom-Inquire)
Passive – Radiello 172 (RAD172 / RAD1201)
NIOSH
NIOSH 6014 Nitrogen Dioxide Sorbent Tube – TEA molesieve (Custom-Inquire)
Passive – Radiello (RAD166 w/ RAD1201)
NIOSH 6603 Carbon Dioxide Aluminized Gas Sampling Bag – 2 to 5 L

Ozone and Nitrogen Oxides
Carbon Monoxide

Ozone and Nitrogen Oxides back to top

The Ultraviolet (UV) light of the welding arc is known to produce ozone (O3) and nitrogen oxides (NO, NO2). Higher concentrations of ozone are produced from gas metal arc welding (GMAW), gas tungsten arc welding (GTAW) and plasma arc cutting methods. Higher nitrogen oxide concentrations are formed if the shielding gas contains nitrogen. Nitrogen dioxide (NO2) has the greatest effect on health.

Exposure to these gases can cause headaches and irritation to mucous membranes; also affects the nose, throat and lungs causing chest pain, shortness of breath and exposure to high concentrations can result in pulmonary edema.


Exposure Limits
Contaminant/
Agency
Exposure Limit
Ozone
OSHA (PEL) for General Industry: 0.1 ppm, 0.2 mg/m³ TWA
for Construction Industry: 0.1 ppm, 0.2 mg/m³ TWA
for Maritime: 0.1 ppm, 0.2 mg/m³ TWA
ACGIH (TLV) Heavy Work - 0.05 ppm TWA; Moderate Work - 0.08 ppm TWA; Light Work - 0.10 ppm TWA; Heavy, Moderate, or light workloads (= 2 hrs) - 0.20 TWA; Appendix A4 - Not Classifiable as a Human Carcinogen
NIOSH (REL) 0.1 ppm, 0.2 mg/m³ Ceiling
NIOSH (IDLH) 5 ppm
Nitrogen Dioxide
OSHA (PEL) for General Industry: 5 ppm, 9 mg/m³ Ceiling
for Construction Industry: 9 mg/m³ Ceiling
for Maritime: 9 mg/m³ Ceiling
ACGIH (TLV) 3 ppm, 5.6 mg/m³ TWA; 5 ppm, 9.4 mg/m³ STEL; Appendix A4 - Not Classifiable as a Human Carcinogen
NIOSH (REL) 1 ppm, 1.8 mg/m³ STEL
NIOSH (IDLH) 20 ppm
(TWA=Time-weighted average; TLV=Threshold Limit Value; PEL=Personal Exposure Limit, REL=Recommended Exposure Limit, STEL=Short Term Exposure Limit; IDLH=Immediately Dangerous to Life and Health concentration)

 


Carbon Monoxide (CO) back to top

This gas is notorious as the “silent killer” in poorly ventilated indoor environments because it cannot be detected by smell, sight or taste. It is formed in welding operations by the incomplete combustion of fuels and/or use of carbon dioxide (CO2) as an inert gas shield which breaks down to form CO. Common symptoms of overexposure include pounding of the heart, a dull headache, flashes before the eyes, dizziness, ringing in the ears, and nausea.

Exposure Limits
Contaminant/
Agency
Exposure Limit
Carbon Monoxide
OSHA (PEL) for General Industry: 50 ppm, 55 mg/m³ TWA
for Construction Industry: 50 ppm, 55 mg/m³ TWA
for Maritime: 50 ppm, 55 mg/m³ TWA
ACGIH (TLV) 25 ppm, 29 mg/m³ TWA
NIOSH (REL) 50 ppm, 40 mg/m³; 200 ppm, 229 mg/m³ Ceiling
NIOSH (IDLH) 20 ppm
Carbon Dioxide
OSHA (PEL) for General Industry: 5000 ppm, 9000 mg/m³ TWA
for Construction Industry: 5000 ppm, 9000 mg/m³ TWA
ACGIH (TLV) 5000 ppm, 9000 mg/m³ TWA; 30,000 ppm, 54,000 mg/m³ STEL
NIOSH (REL) 5000 ppm TWA; 30,000 ppm STEL
(TWA=Time-weighted average; TLV=Threshold Limit Value; PEL=Personal Exposure Limit, REL=Recommended Exposure Limit, STEL=Short Term Exposure Limit; IDLH=Immediately Dangerous to Life and Health concentration)