Tragically, in June of 2018 a draught installer was found dead inside a walk-in beer cooler at a baseball stadium. The autopsy results indicated that he died of “asphyxia due to carbon dioxide exposure.” Carbon dioxide (CO₂) leaked in the cooler at high concentrations, displacing available oxygen. It was found that the cooler door had a handle that malfunctioned, making it difficult for a person to exit the cooler.

Ensuring a safe workspace for all that work in or around a draught system involves multiple considerations; one of the most life threatening can be exposure to CO₂. When training bar staff about safety precautions, it’s important to discuss how to prevent injuries and fatalities due to carbon dioxide exposure.

The Important Role of CO₂ in a Draught System

In most retail draught systems, delivering beer from a keg to the faucet requires gas. Gas fills up the headspace of a keg and pushes beer up from the bottom through a valve to flow through the draught system all the way to a customer’s glass. The preferred gas to use is CO₂ because it occurs naturally in beer. Not only does it propel the beer through the draught system, it also helps maintain the already present carbonation levels in the beer, keeping it fresh and fizzy.

In the past, bars used an air compressor to push beer from keg to faucet, until it became commonly known to quickly degrade the beer’s quality and cause the beer to go flat and rapidly stale. Thankfully, it’s rare to find a retailer nowadays that would ever consider using air on their beer system. Bars now use CO₂ or a blend of carbon dioxide and nitrogen. Nitrogen makes a great sidekick for long draw draught systems, because while CO₂ is readily absorbed in beer, nitrogen is much less soluble, so it just pushes the beer without increasing the beer’s carbonation. For more information on carbonation management, see Facts About Draught Beer Carbonation.

Considerations for Safe Handling

Carbon dioxide can be delivered in 5, 10, or 20-pound cylinders. Another option is a bulk CO₂ tank where the tank remains at the retail premises and is refilled as needed. This large format option used to be exclusively used at extremely high-volume beverage retailers, such as stadiums and arenas. However, the use of bulk CO₂ tanks has become popular at average sized bars and restaurants for both their soda and beer systems and can be a cost cutting option for many.

It’s important to consider that the volume of CO₂ storage can change the potential for harm. If there’s a CO₂ leak with a small cylinder, once that gas runs out, it’s less common to have a large enough leak to produce harm. Large bulk tanks contain greater amounts of CO₂ which can pose a deadly threat if there’s a leak in the cooler. Carbon dioxide is both colorless and odorless, so it can be very difficult to know if there is a leak until it’s too late.

Below are several strategies and considerations for safely handling carbon dioxide:

• Early Detection with Alarms: A good preventative solution is the use of CO₂ detection monitors with an alarm. Some of these alarms will alert a person by both sounding an audible signal and flashing a strobe light. These devices are relatively inexpensive considering that they can be a life saver. Make sure that all alarms are tested and functioning properly at least once a year.
• Good Ventilation: Walk-in coolers can also be updated or installed with a good ventilation system, mitigating some of the risks of gas accumulating to unsafe levels in an enclosed space.
• Easy Exits: It’s also important to always make sure that the cooler door is working properly from the inside and out, and is easy to exit should there be an emergency.
• Secure and Organized Storage: Keeping a cooler neat and organized is another tactic that can help keep people safe and avoid trip or fall hazards. A CO₂ vessel should always be secured to a wall so it can’t be accidentally knocked over. It should also be kept far from excessive heat.

Tips for Staff Communication and Training

As always, communicating safety hazards to everyone that works in or around a bar space is inexpensive and easy, but also a crucial step in preventing death and injury. Here are some topics to get you started:

• Train staff to never enter a walk-in cooler alone. Enforce a buddy system so one person goes in the cooler and the other stays on the outside of the cooler in case of an emergency.
• Exposure to CO₂ can cause confusion and disorient a person making it difficult to make life-saving decisions in an emergency.
• It doesn’t take long for a person to pass out due to exposure to CO₂. Carbon dioxide will settle low to the ground, engulfing a passed-out person in a blanket of CO₂, leading to asphyxiation.
• Asphyxiation danger is not limited to the cooler environment. Consider areas outside the cooler where CO₂ cylinders and bulk tanks may be stored; these areas may also be at risk for unsafe levels of CO₂ exposure, especially if small and enclosed.
• Train your staff to look out for the physical signs of CO₂ exposure, such as light headedness or drowsiness, increased heart rate, an acidic taste in the mouth, and burning in nostrils (not always experienced). If anyone is experiencing these symptoms, it’s important to immediately get them to a well-ventilated area and loosen any tight clothing. Make sure to maintain an open airway and call for medical help immediately.

Staying on top of the hazards that can affect bar staff as well as vendors and contracted workers is extremely important in preventing accidental injuries adjacent to a draught system. Carbon dioxide is essential to dispensing quality beer but can be deadly if not taking the proper precautions. Investing in the well-being and safety of people is an expense that should never be spared.

Draught Beer Training Resources

• Download a free copy of the Draught Beer Quality Manual for all things draught beer
• Training for Front-of-House: Draught Line Safety for Adjacent Workers
• Training for Professional Line Cleaners: Draught Line Safety for Line Cleaners