DRY ICE
SAFETY RESOURCE CENTER
Understanding Dry Ice Hazards
Dry ice is the solid form of carbon dioxide (CO2). Dry ice is extremely cold (−109.3 °F / −78.5 °C) and rapidly sublimates, or converts, into carbon dioxide gas at room temperature. It is used extensively as a cooling agent in a variety of applications such as food chilling and freezing, vaccine cooling, expendable refrigeration, blood and tissue sample preservation, heat treating of metals, and many more.Anyone who handles dry ice should be aware of its unique properties and potential hazards. These include the extremely cold temperature, potential to create an oxygen-deficient atmosphere, and rapid conversion from a solid to gas. It is critical that users read and follow the instructions and safety precautions provided by their dry ice supplier.This safety poster, provided by the Compressed Gas Association, provides basic safety information for the handling, transport, and use of dry ice. To learn more, see the section, “Product Information: Carbon Dioxide” at the bottom of this page.
Dry Ice Safety Reminders
Handling Dry Ice
Use protective gloves or tongs
NEVER handle with bare hands or place in mouth
Storing Dry Ice
Store in cool, well ventilated areas
Ventilation systems should exhaust from lowest level and make up from higher point
Install carbon dioxide monitors
Check carbon dioxide concentration before entering storage area
NEVER store in airtight containers
Transporting Dry Ice
NEVER transport in airtight containers
Open windows or ensure constant supply of fresh air in vehicles
Poster Downloads
Solvent Direct offers safety posters as educational resources to support the safe use of our industry’s products and equipment. It is important to note that these posters are not a substitute for reading and following codes and regulations, industry standards, and supplier instructions. Purchase your dry ice safety poster today or the full set.
Product Information:
DRY ICE
GENERAL INFORMATION
Carbon dioxide gas/vapor is colorless, odorless, and about 1.5 times as heavy as air, while dry ice is white/opaque. Carbon dioxide can exist simultaneously at its triple point as a solid, liquid, and gas at a temperature of –69.9 °F (–56.6 °C) and a pressure of 60.4 psig (416 kPa). At temperatures and pressures below the triple point, carbon dioxide can be either a solid (dry ice) or a gas, depending upon temperature conditions. At temperatures and pressures above the triple point and below 87.9 °F (31.1 °C), carbon dioxide liquid and gas can exist in equilibrium in a closed container.
SAFETY CONSIDERATIONS
Precautions for handling dry ice are found in CGA G-6.9, Dry Ice. General precautions for the safe handling of gaseous carbon dioxide are contained in CGA G-6, Carbon Dioxide.
Dry ice has a temperature of –109.3 °F (–78.5 °C) at 1 atmosphere and must be protected during storage with thermal insulation in order to minimize loss through sublimation. When entering low or confined areas where a high concentration of carbon dioxide gas may be present, use a self-contained breathing apparatus (SCBA) or supplied-air respirator. Do not use a cartridge-type respirator.
Dry ice should be stored in a cool, well-ventilated area in well-insulated storage containers designed to prevent pressure buildup. If transporting in the passenger compartment or trunk of a vehicle, limit dry ice to small quantities and open all windows or ensure constant supply of fresh air for the duration of the trip.
Care should be taken when handling dry ice. Use protective gloves such as work gloves or ice tongs; do not handle dry ice with bare hands. Blocks of dry ice can weigh in excess of 50 lb (22.7 kg) and can cause injury if dropped.
Dry ice is extremely cold and can freeze human tissue on contact. Never place dry ice in your mouth. If swallowed, the dry ice will rapidly expand and can cause serious injury or death.
The best method for disposal is to allow the dry ice to sublime or evaporate to the atmosphere in a well-ventilated area where no buildup of carbon dioxide vapor can occur. Such areas should be secured to ensure controlled access to authorized personnel only. Unused dry ice may be returned to the supplier for proper disposal.
Do not dispose of dry ice:
in sewers, sinks or toilets;
in bodies of water;
in garbage receptacles;
on the ground when located over underground utilities;
in unprotected boxes; or
in areas accessible to the general public.
LEAKS AND SPILLS
Because dry ice rapidly sublimates, or converts, into carbon dioxide gas ventilate adjacent enclosed areas to prevent the formation of dangerous concentrations of carbon dioxide. A concentration of 3% of carbon dioxide can be dangerous while higher concentrations can be lethal. Persons including rescue workers should not enter areas in which the carbon dioxide content exceeds 3% unless wearing an SCBA or supplied-air respirators (see the Physiological Effects tab).
RELATED EQUIPMENT
FIRST AID / EMERGENCY RESPONSE
Inhalation. Persons who have inhaled large amounts of carbon dioxide and are exhibiting adverse effects such as rapid respiration and headaches should be removed to fresh air immediately, if safe to do so. Perform artificial respiration if breathing has stopped. Keep the victim warm and at rest and obtain medical attention at once. Fresh air and assisted breathing (if required) is appropriate for all cases of overexposure. Recovery is usually complete with no residual effects.
Skin contact. In case of frostbite from contact with dry ice or cold gases, place the frostbitten part in warm water, 100 °F to 105 °F (37.8 °C to 40.6 °C). If warm water is not available or is impractical to use, wrap the affected part gently in blankets. Do not rub. Consult a physician.
Eye contact. If the eyes are involved, obtain prompt medical attention. The only appropriate first aid measure is a soft sterile pad held in place over both eyes.
PHYSIOLOGICAL EFFECTS
Carbon dioxide is normally present in the atmosphere at about 0.035% by volume. It is also a normal end-product of human and animal metabolism. The greatest physiological effect of carbon dioxide is to stimulate the respiratory center, 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.
Carbon dioxide acts 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% in air, and dyspnea (labored breathing), headache, dizziness, and sweating occur if exposure at that level is prolonged. At concentrations of 10% and above, unconsciousness can result in 1 minute or less. Impairment in performance has been noted during prolonged exposure to concentrations of 3% carbon dioxide even when the oxygen concentration was 21%.
Gaseous carbon dioxide is an asphyxiant. Concentrations of 10% or more can produce unconsciousness or death. Lower concentrations can cause headache, sweating, rapid breathing, increased heartbeat, shortness of breath, dizziness, mental depression, visual disturbances, and shaking. The seriousness of the latter manifestations are dependent upon the concentration of carbon dioxide and the length of time the individual is exposed.
OSHA provides a list of occupational exposure limits (OELs) for carbon dioxide. Please refer to OSHA’s website https://www.osha.gov/annotated-pels/table-z-1 for more information.
PHYSICAL CONSTANTS
Chemical formula = CO2
Molecular weight = 44.01
Vapor pressure
U.S. Units
at 70 °F = 838 psig
at 32 °F = 491 psig
at 2 °F = 302 psig
at –20 °F = 200 psig
at –69.9 °F = 60.4 psig
at –109 3 °F = 0 psig
SI Units
at 21.1 °C = 5778 kPa
at 0 °C = 3385 kPa
at –16.7 °C = 2082 kPa
at –28.9 °C = 1379 kPa
at –56.6 °C = 416 kPa
at –78.5 °C = 0 kPa
Density of the gas
U.S. Units
at 70 °F and 1 atm = 0.1144 lb/ft
at 32 °F and 1 atm = 0.1234 lb/ft
SI Units
at 21.1 °C and 1 atm = 31.833 kg/m3
at 0 °C and 1 atm = 31.977 kg/m3
Specific gravity of the gas
U.S. Units
at 70 °F and 1 atm = 1.522
at 32 °F and 1 atm = 1.524
SI Units
at 21.1 °C and 1 atm = 1.522
at 0 °C and 1 atm = 1.524
Specific volume of the gas
U.S. Units
at 70 °F and 1 atm = 8.741 ft3/lb
at 32 °F and 1 atm = 8.104 ft3/lb
SI Units
at 21.1 °C and 1 atm = 0.5457 m3/kg
at 0 °C and 1 atm = 0.5059 m3/kg
Density of the liquid, saturated
U.S. Units
at 70 °F = 47.6 lb/ft
at 32 °F = 58.0 lb/ft
at 2 °F = 63.3 lb/ft
at –20 °F = 66.8 lb/ft
at –69.9 °F = 73.5 lb/ft
SI Units
at 21.1 °C = 3762 kg/m3
at 0 °C = 3929 kg/m3
at –16.7 °C = 31014 kg/m3
at –28.9 °C = 31070 kg/m3
at –56.6 °C = 31177 kg/m3
Latent heat of vaporization
U.S. Units
at 32 °F = 100.8 Btu/lb
at 2 °F = 119.0 Btu/lb
at –20 °F = 129.7 Btu/lb
SI Units
at 0 °C = 234.5 kJ/kg
at–16.7 °C = 276.8 kJ/kg
at –28.9 °C = 301.7 kJ/kg
Cylinder pressure at 68% filling density = 42.5 lb/ft3
U.S. Units
at 70 °F = 838 psig
at 100 °F = 1450 psig
at 130 °F = 2250 psig
Cylinder pressure at 68% filling density = 681 kg/m3
SI Units
at 21.1 °C = 5778 kPa
at 37.8 °C = 9998 kPa
at 54.4 °C = 15 514 kPa
Specific heat of the gas at 77 °F (25.0 °C) and 1 atm
U.S. Units
Cp = 0.203 Btu/(lb)(°F)
Cv = 0.157 Btu/(lb)(°F)
Ratio of specific heats (Cp/Cv) at 59 °F = 1.304
SI Units
Cp = 0.850 kJ/(kg)(°C)
Cv = 0.657 kJ/(kg)(°C)
Ratio of specific heats (Cp/Cv) at 15.0 °C = 1.304
Other
U.S. Units
Sublimation temperature at 1 atm = –109.3 °F
Critical temperature = 87.9 °F
Critical pressure = 1070.6 psia
Critical density = 29.2 lb/ft
Triple point = –69.9 °F at 60.4 psig
Latent heat of fusion at –69.9 °F = 85.6 Btu/lb
Solubility in water, vol/vol at 68 °F = 0.90
Weight of the liquid at 2 °F = 8.46 lb/gal
Latent heat of sublimation at –109.3 °F = 245.5 Btu/lb
Viscosity of saturated liquid at 2 °F = 0.287 lb/(ft)(hr)
SI Units
Sublimation temperature at 1 atm = –78.5 °C
Critical temperature = 31.1 °C
Critical pressure = 7381.8 kPa
Critical density = 3468 kg/m3
Triple point = –56.6 °C at 416 kPa
Latent heat of fusion at –56.6 °C = 199 kJ/kg
Solubility in water, vol/vol at 20.0 °C = 0.90
Weight of the liquid at –16.7 °C = 1014 kg/m3
Latent heat of sublimation at –78.5 °C = 571.3 kJ/kg
Viscosity of saturated liquid at –16.7 °C = 0.000119 Pa•s