05 Sep Dry Ice Safety – Safe Handling and Storage

Dry Ice Safety – Safe Handling and Storage

Dry ice is solid carbon dioxide (CO₂). Unlike ordinary ice, dry ice does not melt into a liquid under normal atmospheric conditions. Instead, it changes directly from a solid into carbon dioxide gas through a process called sublimation. Because dry ice is extremely cold and continuously releases CO₂ gas, improper handling or storage can cause serious cold burns, oxygen-deficient atmospheres, or dangerous pressure buildup.

Handling Dry Ice

Dry ice has a surface temperature of approximately -109.3°F (-78.5°C) and can rapidly freeze skin tissue.

• Never handle dry ice with bare hands.
• Wear insulated, loose-fitting gloves suitable for handling extremely cold materials.
• Use tongs or other appropriate handling tools when practical.
• Avoid prolonged contact with dry ice, even while wearing gloves.
• Do not place dry ice in your mouth or ingest it.
• Keep dry ice away from unauthorized or untrained persons.
• Wear eye protection when breaking, cutting, or otherwise handling dry ice in a manner that could produce flying pieces.
• If skin or eye contact occurs, obtain appropriate first aid or medical attention.

Direct contact can cause frostbite or severe cold burns.

Storage

Dry ice continuously produces carbon dioxide gas as it sublimates. Storage containers and areas must therefore allow the gas to escape safely.

• Store dry ice in an insulated container designed for that purpose.
• Keep the container vented—never airtight.
• Never store dry ice in a sealed glass container or other closed container that could rupture from pressure buildup.
• Do not place dry ice in an ordinary refrigerator or freezer unless specifically permitted by the equipment manufacturer or required by an approved procedure.
• Store dry ice in a well-ventilated location.
• Keep storage containers away from confined or poorly ventilated spaces.
• Protect surfaces that could be damaged by extreme cold.
• Clearly identify containers used to store dry ice.

Never seal dry ice inside a container. Sublimation can create enough pressure to rupture or explosively burst the container.

Carbon Dioxide and Ventilation Hazards

Carbon dioxide is colorless and odorless. As dry ice sublimates, CO₂ can accumulate and displace oxygen, particularly in enclosed or poorly ventilated locations.

Elevated carbon dioxide concentrations can cause:

• Headache.
• Dizziness.
• Shortness of breath.
• Increased breathing or heart rate.
• Confusion.
• Loss of consciousness.
• Asphyxiation and death at sufficiently high concentrations.

Because carbon dioxide can accumulate in low areas, additional precautions may be necessary in basements, pits, walk-in freezers, vehicles, and other enclosed or low-lying spaces.

Never enter an area suspected of having an unsafe atmosphere without following applicable atmospheric testing, ventilation, and confined-space procedures.

Walk-In Freezers and Enclosed Areas

Using dry ice in a walk-in freezer or similar enclosed space can create a significant carbon dioxide exposure hazard.

• Minimize the amount of time spent inside.
• Ensure adequate ventilation.
• Do not enter if a hazardous atmosphere is suspected.
• Follow applicable atmospheric monitoring requirements.
• Never rely on your sense of smell to determine whether the atmosphere is safe.
• Leave immediately if you experience dizziness, headache, difficulty breathing, confusion, or other unusual symptoms.
• Do not attempt to rescue an incapacitated person from a potentially oxygen-deficient or CO₂-enriched area unless properly trained, equipped, and authorized.

Transportation

Dry ice continues releasing CO₂ while being transported, so special precautions are necessary when carrying it in vehicles.

• Pick up dry ice as close as practical to the time it will be used.
• Transport it in a suitable insulated, vented container.
• Never transport dry ice in an airtight container.
• Secure the container against movement during transportation.
• Whenever practical, transport dry ice in a compartment separated from vehicle occupants.
• If it must be carried in the passenger or cargo compartment of an enclosed vehicle, provide adequate fresh-air ventilation.
• Avoid leaving dry ice unattended in a closed vehicle.
• Follow applicable transportation requirements when shipping or transporting larger quantities.

Disposal

Allow unwanted dry ice to sublimate naturally in a secure, well-ventilated location where unauthorized persons cannot contact it.

Never dispose of dry ice:

• In a sink, toilet, or drain.
• In a closed trash container.
• In an airtight container.
• In an enclosed or poorly ventilated room.

Emergency Response

If a worker experiences symptoms consistent with excessive carbon dioxide exposure, move the person to fresh air only when it can be done safely and obtain emergency medical assistance as necessary.

For skin contact, do not rub the affected area. Treat the injury as a cold burn or frostbite and obtain medical attention when appropriate.

Remember

Dry ice presents two primary hazards: extreme cold and carbon dioxide accumulation. Wear appropriate hand protection, keep dry ice in a vented container, provide adequate ventilation, and never enter an area where CO₂ may have accumulated unless the atmosphere has been determined safe.