Shielding gases

SECTION 2: Hazards identification

Main Hazards The above listed Shielding gas mixture does not support life. It can act as simple asphyxiant by diluting the concentration of oxygen in the air to below levels necessary to support life. Adverse Health effects. The carbon dioxide component, of the above mixture could act as a stimulant and a depressant on the central nervous system. Increases in heart rate and blood pressure have been noted at a concentration of 7.6 percent, and dyspnea (laboured breathing), headache, dizziness and sweating occur if exposure at that level is prolonged. Chemical hazards The Argon component of the above gas mixture is extremely inert and forms no known chemical compound. However, Carbon dioxide is relatively non-reactive and non-toxic. It will not burn or support combustion. In the presence of moisture it can aggressively bring about corrosion in a variety of steel materials. Biological Hazards The greatest physiological effect Carbon dioxide is to stimulate the respiratory centre, thereby controlling the volume and rate of respiration. It is able to cause dilation and constriction of blood vessels and is a vital constituent of the acid-base mechanism that controls the pH of the blood. Vapour inhalation At concentrations of approximately 10 percent and above, unconsciousness can result in one minute or less. Impairment of performance has been noted during prolonged exposure to concentrations of 3% carbon dioxide even when the oxygen concentrations were 21%. Eye Contact No known effect. Skin Contact No known effect. Ingestion See “Vapour inhalation” above