Cold rooms are located throughout campus for storage and manipulation of materials at a low and constant temperature. They can function at temperatures less than 35 ºF. Cold rooms do NOT have active ventilation to keep energy costs down. They function similar to a refrigerator. Air inside is chilled and recirculated. No new air is introduced or old air removed except when opening the door. It is important to understand that this limits what can be stored in the cold room and also the amount of time it is safe to be working in the cold room.

Overview of Hazards

Oxygen deficiency: The very low air exchange rate makes work in cold rooms prone to oxygen depletion and asphyxiation. Asphyxiation is the state or process of being deprived of oxygen, which can result in unconsciousness or death.

Mold: Cold rooms often condense moisture and can be good environments for mold to grow. Mold can cause serious health effects. Care must be taken to avoid the conditions that causes mold to grow. High humidity and certain surfaces (e.g., porous) are ideal for mold growth.

Cold work environment: Many cold rooms are used to perform experiments or manipulate materials at a low temperature. The cold temperatures can impact the health of the person in the space.

Slips, trips, and falls: Unleveled surfaces, crowded storage areas, and condensation of water can lead to an elevated risk of slips, trips, and falls. Cold rooms have tightly sealed doors and many doors do not have windows. This creates a scenario where it is difficult to call for help.

Electric shock: Cold rooms do have electrical outlets so lab equipment can be used in controlled temperature conditions. The elevated risk for condensation of moisture can lead to electrical hazards that are not anticipated. 

Proper Use of Cold Rooms

Do Not Store....

Cryogens (liquid nitrogen, liquid argon, dry ice, etc.). The boiling point of these materials are significantly lower than the temperature of the cold room so storing them inside will not reduce the rate of evaporation. Evaporation of cryogens in a cold room can result in asphyxiation by reducing the oxygen level in the room.

Compressed gases. There is no ventilation in cold rooms and introducing these gases via a cylinder leak or use of the gas can lead to asphyxiation. If an inert gas needs to be used inside a cold room, perform a risk assessment based on the flow rate and volume of the room. Flammable, toxic, or corrosive gases must NOT be stored or used in cold rooms.

Food or drinks. These rooms are an extension of the laboratory. They are designed to store research materials and not food or drink meant for human consumption. 

Porous materials. Materials like cardboard, wood, and cloth absorb moisture and are excellent places for mold to grow. Plastic should be used in place of cardboard boxes. If paper materials are needed (e.g., KimWipes) store them in a plastic bag or sealed plastic container. Moisture also compromises the integrity of cardboard boxes. This can lead to collapsed boxes and spills of research materials.

Volatile chemicals. Volatile chemicals especially ones with flammable and toxic properties should not be used or stored inside a cold room. This will help avoid inhalation of harmful vapors and the potential for a fire or explosion. Hazardous vapors can accumulate since there is no ventilation inside the cold room.

Best Practices

Many best practices for working in the laboratory are also applicable in cold rooms. Below highlights some important best practices.

  • Use shelves and racks to avoid accumulation of materials on the floor. This limits a trip hazard and also areas where water can accumulate.
  • Limit the amount of time you spend inside the cold room. Take breaks if you have to perform work inside the cold room for an extended period of time. Dress appropriately for the low temperature.
  • The OSHA Permissible Exposure Limit (PEL) for carbon dioxide is 5000 ppm. This concentration can be reached when 4 individuals occupy an average cold room for a period of 55 minutes. If research requires the cold room to be occupied for periods longer than a few minutes, conduct a risk assessment for how quickly the carbon dioxide PEL will be reached and set a policy for the amount of time allowed in the cold room each day.
  • Use the buddy system or alert others that you are working in the cold room so they can check on you after a period of time.
  • Do not keep the door open for a long period of time. Keeping the door propped open makes it difficult to maintain the temperature and can introduce additional moisture to the room.
  • Check all electrical equipment for integrity of its insulation before bringing it into the cold room. Moisture makes accidental contact with exposed wiring even more dangerous. Be mindful of moisture condensation and place equipment in a dry spot . [MA1] Always plug equipment into GFCI outlets.
  • Remove equipment from the cold room when it is no longer needed. Some equipment will rust after being left in the cold room for an extended period of time.
  • Keep all containers sealed. Containers containing water should be sealed to avoid the introduction of more moisture to the room. Sealing containers will also minimize the risk of a spill.
  • The light switch for a cold room is usually on the outside of the door. Open the door and make sure no one is inside the cold room before you turn off the light or lock the door.

Administrative Procedures

Cold rooms may belong to a single research group or may be a shared space between many research groups. Regardless of ownership, all containers must be labeled with their contents and the owner’s name. For shared cold rooms, it is important that all users agree on the policies for the cold room and follow them. It is encouraged to designate someone in charge of enforcing policies and grant them the ability to dispose of abandoned or prohibited materials. 

All research groups that use the cold room must be assigned to the room in the DRS database.

Emergency Procedures

Oxygen Deficiency

Be aware of the symptoms of oxygen deficiency. If you are experiencing lightheadedness, confusion, or lethargy, leave the room immediately and get to fresh air.

Mold Exposure

Exposure to mold may affect people differently. Exposure may cause an allergic reaction or cause respiratory conditions to worsen. Symptoms include coughing, wheezing, breathing difficulties, nasal or sinus congestion, sore throat, skin and eye irritation, etc. If you suspect mold growth or an exposure contact Safety and Compliance to investigate.


Since cold rooms have no ventilation it is important to take extra care and limit the risk of spills. Use secondary containment (e.g., bottle carriers) when transporting materials to, from, and inside the cold room. Limit the size of containers. Avoid storage of materials on the floor. Use threaded bottle caps and plastic bottles when able to do so. 

Be prepared for a spill of the materials you are working with. Know where the spill clean-up materials are located. It is best to have these materials in the immediate area. It is best to keep the materials in a sealed plastic container until they are needed. 

All spills must be cleaned immediately. Keep in mind there is no ventilation in a cold room. If a spill is left to evaporate, it can create a more hazardous scenario. Follow established procedures for simple and complicated spills

Last Updated: 11/2/2022