In late winter, the cellar team at Ridgeway Brewing were finishing a routine transfer from a fermentation vessel to a bright beer tank. The brewer on duty, Alex, noticed the beer pushing slower than usual. Assuming there was a pressure issue, he opened the manway of the bright tank to “check the headspace.”
Within seconds he felt dizzy.
Unbeknownst to him, the tank had just been purged with CO₂ to remove oxygen before filling. Carbon dioxide is colourless, odourless, and heavier than air. As Alex leaned into the opening, the CO₂-rich atmosphere displaced the oxygen he needed to breathe. Fortunately, another brewer nearby saw him slump against the tank and quickly pulled him away. Alex recovered after a few minutes of fresh air, but it could easily have been fatal.
The incident investigation revealed several gaps:
- The CO₂ monitor in the cellar had not been calibrated in over a year.
- There was no confined space permit system for tanks.
- Staff had not received recent training on CO₂ hazards.
- The brewery relied on natural ventilation rather than mechanical extraction.
The brewery implemented several risk management changes immediately:
1. Continuous gas monitoring
Fixed CO₂ detectors were installed near tanks, fermentation areas, and low points in the cellar, with audible alarms at 0.5% and 1.5% CO₂ concentrations.
2. Confined space procedures
Any tank entry now requires a confined space permit, gas testing, lock-out of CO₂ supply lines, and a standby observer.
3. Ventilation upgrades
Mechanical extraction fans were added because CO₂ pools at floor level and in vessels.
4. Training and signage
Staff were trained that CO₂ is one of the leading causes of fatalities in beverage production, particularly in breweries and wineries during fermentation and tank cleaning.
5. Portable monitors
Anyone working alone in the cellar carries a personal CO₂ detector.
Six months later, during peak fermentation, the new alarm sounded when CO₂ levels briefly spiked in the cellar after multiple tanks vented simultaneously. Staff evacuated automatically. What might once have been another near-miss became proof that the new controls worked.
Lesson: In breweries, wineries, and distilleries, CO₂ is a normal part of production, but without monitoring, ventilation, and confined-space controls, it can quietly turn a routine task into a life-threatening hazard.