CO2 in Breweries

Brewers are often confronted with the potential of CO2 poisoning. Yeast releases CO2 as a byproduct in the process of fermenting alcohol (Nelson 2000; Tox. Review 2005), and maturation.

Carbon dioxide is found in most brewing tanks and around filler machines, packaging and closer areas.

Carbon dioxide can be recovered, and carbon dioxide and / or nitrogen are stored and used in many brewery processes where inert atmospheres are required. Uncontrolled release of these gases or inadequate ventilation, particularly in confined or enclosed spaces such as fermentation and maturation rooms can displace oxygen and result in accumulation of sufficient concentration to present asphyxiation risk. Confined spaces are among the most hazardous places in breweries. They include beer storage tanks, brew kettles, vats, sumps, pits and other confined areas where carbon dioxide may be present.

Brewers entering enclosed areas, such as cleaning out tanks subsequent to fermentation, could be overcome by high levels of CO2. A study on brewery workers determined that they are exposed to 1.08% over an 8-hour workday on average (Nelson 2000; NIOSH 1976; Tox. Review 2005).

Appropriate safety measures should be developed based on a risk assessment, and may include guidance on safe working in confined spaces, enhanced ventilation, CO2 detector/s installed and the use of personal gas detectors in high risk areas.

Beer production is a challenge for gas sensing. The brewing process produces many gases, several of which will cause interference problems with any sensor that is not specific to the target gas. Because of this "chemical mix", only a few sensors will operate successfully in breweries where yeast, hops and other ingredients cause most sensors to false trip.

The SHW2000 or SHW5000 IR-CO2 fixed installation infrared sensor, monitors carbon dioxide (CO2) without interference trips.

For oxygen safety levels or confined space entry, the SG-O2 sensor can be installed and can be connected to a remote digital meter which will display local percent level indication at a room entrance or other critical point with programmable alarm functions.

SHCO2P Portable CO2 detectors can identify and pinpoint the source of a gas leak and provide dynamic information for maintenance personnel and emergency responders as well as have the information on record with the logger option.

Temperature and humidity levels should be discussed for any brewery application, as well as any special enclosure modifications to meet sanitary requirements.

The Sigma Gas Safety System (SGSS) is a total, turnkey solution for the detection of toxic gas leaks showing gas safety status of an entire industrial facility at a single glance. It provides a "hardened" gas safety equipment system utilizing dedicated SGSS electrochemical and infrared sensors connected in realtime to dedicated central gas alarm monitors - all protected by a single uninterruptible power system. Multiple relays trigger key emergency safety control of equipment shutdown functions and allow Emergency Responders to easily assess a gas leak situation - even in the event of computer viruses, operating system crashes or human error.

Carbon Dioxide (CO2) Classification: Health: Simple Asphyxiant

AGENCY  Low end CO2 Concentration (ppm)1 High-end CO2 Concentration (ppm)2
OSHA PEL 5,000 TWA 30,000 STEL
ACGIH TLV 5,000 TWA 30,000 STEL
NIOSH REL 5,000 TWA 30,000 STEL

1 Applies to CO2 concentration in the workplace considered safe for a 40-hour week
2 Based on a 10-minute period for NIOSH and a 15-minute period for OSHA and ACGIH

PEL = Permissible Exposure Limit
TLV = Threshold Limit Value
REL = Recommended Exposure Limit
TWA = Time Weighted Average
STEL = Short Term Exposure Limits
OSHA = Occupational Safety and Health Administration
NIOSH = National Institute for Occupational Safety and Health
ACGIH = American Conference of Governmental Industrial Hygienists

Monitoring low pressure CO2 gas off fermentation tanks to CO2 recovery in brewing process

Process parameters
Media: Carbon dioxide
Pipe size: 6 inch
Temperature: 21.1C (70F)
Pressure : 0.69 bar(g) (10 psig

Flow sensor C2060
Measurement of air mass flow Pressure-proofed up to 16 bar
Easy, cost-saving mounting
Analog output
No moving parts