Cold storage and freezer facilities are inherently dangerous; low temperatures can seriously injure or kill someone, ice can create slip hazards, and many facilities store products on tall shelves, creating the potential for falling objects. However, many cold storage facilities contain a less obvious hazard: confined spaces.

In OSHA terms, a confined space is defined as a space:

• Large enough for a worker to enter and perform activities in
• Featuring limited means of entry and exit, and
• Not designed for continuous occupancy.

Confined Space Hazards

The reason confined spaces are so hazardous to workers is that their very design makes them prone to two invisible, deadly threats: oxygen content issues and toxic levels of harmful gasses.

Oxygen content is a factor in cold storage units for obvious reasons: doors are meant to seal in product and protect it from the elements. Oxygen may even be purposefully pumped out of the room to preserve the items inside. If a worker is inside a freezer unit, they may have no idea oxygen levels have dipped to dangerous levels until it’s too late and they pass out (or worse).

Beyond oxygen or lack thereof, cold storage facilities by their very nature carry the risk of toxic levels of other chemicals, in particular, ammonia. Ammonia has been a common refrigerant for decades; it’s cost-effective and easy to get. However, like any system, refrigeration equipment can malfunction or leak ammonia, which is extremely dangerous when it escapes into a facility.

Ammonia is no joke:

• Ammonia is corrosive. Even moderate amounts can burn the eyes, nose, mouth, and throat.
• Swallowing ammonia can burn the stomach
• Prolonged exposure can cause the destruction of a person’s airway
• Contact with ammonia can cause permanent eye damage and blindness
• High levels of ammonia can result in death from a swollen throat or burnt lungs

(NYSDOH, 2004)

Ammonia exposure is no joke to OSHA either: just a few years ago OSHA fined a Texas frozen food storage facility over $76,000 for several serious violations that exposed its workers to nonlethal levels of ammonia. (OSHA, n.d.)

While many of the hazards associated with oxygen levels and toxic gasses can be addressed with equipment maintenance and regular inspection, it’s important that workers are outfitted with personal gas detection equipment to alert them as early as possible to potentially deadly problems. While gas monitors are designed for a variety of workplaces, the extreme temperatures present in a cold storage facility create some additional considerations. According to Industrial Scientific,

• If you plan to use a gas detector for 20 minutes or less, there’s no need to let the device stabilize and acclimate to the cold
• For usage 20 minutes or longer, it’s best to let the device adjust to the ambient temperature about 15 or 20 minutes prior to use and then turning it on to let it zero
• Extreme cold often creates dry air conditions that can affect the performance of gas monitors. It’s important to store gas monitors in a humidified area – about 40% to 50% is best for helping maintain equipment sensitivity.
• Temperatures of -20 degrees Celsius and below can cause the monitor to respond sluggishly or even lose display capabilities. Industrial Scientific says the device will probably still detect gasses and alert the worker, but it’s important to bump test before every use and to get it warmed up as soon as possible.
• Temperatures of -20 degrees Celsius and below may also freeze the aqueous electrolytes in the chemical sensors with oxygen being the first to lose effectiveness. Frozen sensors do not provide reliable readings but generally return to normal once warmed up.
• Subzero temperatures can reduce the battery life of gas detection equipment, sometimes by up to 50%.
• The closer the monitor is to your body, the longer it will take to succumb to colder temperatures.
• Lastly, a good rule of thumb is that gas detectors and the workers that use them are equally tolerant to cold weather. When it’s time for a worker to warm up, it’s time for the equipment to do so as well.

(Wagner, 2017)

Inherent to any effective gas detection program is regular testing, calibration, and maintenance. This can be conducted on-site by specially-trained staff or it can be outsourced as part of an equipment rental program. If you need to purchase gas monitors, rent them, or simply service monitors you bought somewhere else, ORR Safety can help craft a solution that makes the most sense for your company (and your budget).

Want to learn more about proper Confined Space Entry? CLICK HERE to download a poster for your worksite.