CO2 in Fermentation and Brewing

The risk from CO2 isn't direct toxicity but oxygen displacement: as concentration rises, people start feeling fatigued, and at very high concentrations, loss of consciousness or even death can occur. OSHA sets an exposure limit of 5,000 ppm averaged over an eight-hour shift.

During active fermentation, CO2 concentration in a tank's headspace can approach 100% by volume — far above any safe exposure limit. The risk isn't confined to the tank itself: it accumulates around filling machines, in fermentation rooms, barrel cellars, and confined spaces such as sumps, pits, and beer storage tanks.

In breweries, CO2 accumulates naturally in fermentation tanks, around filler machines, and in packaging areas — and particularly in confined spaces (storage tanks, brew kettles, vats, sumps, and pits), where the lack of natural ventilation compounds the risk.

In wineries, the highest-risk areas are fermentation rooms, barrel cellars, and bottling areas. The practical recommendation is to implement continuous measurement in identified risk zones, and to check concentration before entering any enclosed space — because CO2 is odorless and colorless, and levels can become dangerous with no perceptible warning.

For areas where concentration can approach percentage level — near actively fermenting tanks or in confined spaces — the GMP251 probe measures 0 to 20% CO2. For environmental safety monitoring in rooms and work areas, where concentration is measured in parts per million, the GMP252 probe covers the 0 to 10,000 ppm range. Both operate from -40°C to +60°C, with the long-term stability needed for continuous safety monitoring.