Volume I - Section I - Introduction 
Page 1-25 
Other countries’ standards are as follows: 
West Germany (1974), Japan, Yugoslavia, 50 ppm; East Germany (1973) 33 ppm; USSR (1976), 
Sweden (1975), Australia, Belgium, Finland, Hungary, Italy, Netherlands, Poland, Romania, 
Switzerland, all 25 ppm. 
Carbon Dioxide ( CO2): 
Carbon dioxide is a colorless, odorless, noncombustible gas. Chemical and physical properties 
include: 
Molecular weight: 
Density: 
Melting point: 
Vapor pressure: 
Solubility: 
ml/100 ml at 20 °C, 
soluble. 
Carbon dioxide when inhaled in elevated concentrations may act to produce mild narcotic 
effects, stimulation of the respiratory center, and asphyxiation, depending on the concentration 
present and the duration of exposure. The literature contains a variety of reports on human 
response at varying concentrations. Deaths have been reported from asphyxiation in workers 
exposed at high concentrations of carbon dioxide. Winter (1937) found that stimulation of the 
respiratory center is produced at 50,000 ppm (five percent). Schaefer (1951) reported that 
submarine personnel exposed continuously at 30,000 ppm were only slightly affected as long as 
the oxygen content of the air was maintained at normal concentrations (minimal content 18 
percent by volume). When the oxygen content was reduced 15 percent to 17 percent, the crew 
complained of ill effects. The gas is weakly narcotic at 30,000 ppm, giving rise to reduced acuity 
of hearing and increasing blood pressure and pulse. Above this concentration subjective 
symptoms occur. Signs of intoxication are produced by a 30-minute exposure at 50,000 ppm. 
Aero Medical Association: Committee on Aviation Toxicology, Blakiston, New York, (1953) 
concluded that 7 to 10 percent produces unconsciousness within a few minutes. Flury and Zemik 
(1931) quote Lehman-Hess as stating that exposure at 5,500 ppm of carbon dioxide for six hours 
caused no noticeable symptoms. 
Based on the long-term exposure studies, even though the majority of references are concerned 
with studies on physically fit males in confined spaces, the American Conference of 
Governmental Industrial Hygienists (ACGIH) recommended a TLV-TWA of 5,000 ppm (9,000 
mg/m 3 ) for carbon dioxide. In light of the short-term exposure studies of Sinclair and associates 
(1969), ACGIH also recommended a STEL of 30,000 ppm (54,000 mg/m 3 ). 
44.01 
1.527 (air = 1.0) 
sublimes at -78.33 °C at 76 torr 
> 1 atm at 20 °C 
soluble in water to the extent of 171 ml/ 100 ml at 0 °C and 76 torr, 88 
and 36 ml/100 ml at 60 °C. Under higher pressure carbon dioxide is more 
