Carbon dioxide, dry ice (solid phase) [124-38-9] CO2 (MW 44.01) InChI = 1S/CO2/c2-1-3 InChIKey = CURLTUGMZLYLDI-UHFFFAOYSA-N (supercritical carbon dioxide is used as a solvent, reagent, and reaction medium) Physical Data mp: −56.6 °C; bp: −78.5 °C (sublimes); density: 1.977 kg m−3 (gas at 1 bar and 0 °C); crystal structure: trigonal; molecular shape: linear; critical point: Tc: 31 °C; Pc: 73.825 bar; ρc: 464 kg m−3; triple point: temperature: −56.6 °C, pressure: 5.185 bar; latent heat: 46.84 kcal kg−1 (fusion, 1.013 bar, triple point), 136.40 kcal kg−1 (vaporization, 1.013 bar, boiling point); exposure limits in air: threshold limit value (TLV): 5000 ppm; short-term exposure limit (STEL): 30 000 ppm; immediately dangerous to life or health (IDLH): 40 000 ppm. Solubility soluble in water, ethanol, and acetone. Form Supplied in liquid in equilibrium with gas under pressure; dry ice (solid). Handling, Storage, and Precautions colorless gas/liquid or white solid (dry ice). It is noninflammable, inert in most environments. At concentrations between 2 and 10%, it can cause nausea, dizziness, headache, increased blood pressure, and respiratory rate. Forms carbonic acid with moisture in air and leads to irritation of the eyes. At concentrations above 10%, it is an asphyxiant and cerebral vasodilator. Cylinders must be stored in dry, ventilated areas, away from heat sources and direct sunlight.