Uschi Mannl, a manager at Austria-based V&F Analyse- und Messtechnik GmbH, says transport and time in storage could impact the actual gas composition of beverages and no true CO2 assessment can be done. This is why V&F created the CO2Sense mass spectrometer, which can offer continuous real-time monitoring and detects inorganic and organic impurities.
“The rising demand for pure carbon dioxide and the shortage experienced during the summer months of 2018 has opened the door for new feed gas sources for carbon dioxide,” she says. “Depending on the gas source, the degree of contamination may vary, rendering the CO2 non-viable for its use in food and beverage if contamination levels are exceeding industry prescribed limits.”
The Regulatory Landscape
Many international societies of gas quality governance groups—for example, ISBT, CGA, and EIGA—have responded to the changes in CO2 source-based manufacturing and new applications that occurred the last two decades and continue to evolve.
“Associated upgrades of CO2 quality standards were primarily spearheaded and driven by several major beverage manufacturers in the late 1990s who themselves were most severely impacted by major, expensive recalls and brand name damage caused by the unrecognized use of poor quality CO2,” Dr. Pachuta says. “To date, however, food-grade purity regulating bodies have not in our opinion significantly upgraded their traditional purity specifications in response to the many new types and levels of impurities that can come from non-traditional commercial CO2 sources.”
Richard Craig, technical director at CGA, says since FSMA came into play, the facilities that manufacture CO2 for beverage or food need to do so in accordance to the Code of Federal Regulations Title 21, Part 117, which is the Good Manufacturing Practices for foods, including ingredients.
“We are a regulated industry and we take compliance with regulation very seriously,” he says.
Airborne Labs International recommends taking a second look at these medical and food-grade CO2 specification issues. For instance, liquid CO2 is a strong solvent and can leach various plasticizers from transfer hoses that feed storage tanks at restaurants and bars. The hose materials used for liquid CO2 transfers has to be carefully selected and tested for plasticizer leaching, which sometimes is not done.
“Even though filters are many times used, the quality of CO2 stored in special tanks used in most fast food restaurants and bars are not regularly checked for the slow buildup of many, potentially harmful, non-volatile impurities that can accumulate with time,” Dr. Pachuta says. “New, non-traditional, home-based personal ‘carbonated beverage’ manufacturing applications do not require the use of beverage quality-tested CO2 cartridges. This can pose a potential risk that has not been adequately studied or monitored to date.”
Retaining Quality Control
Industry insiders agree that all carbonated beverage manufacturers, including fountain operators, should become familiar with the educational guidelines available from various organizations such as the ISBT.
“We recommend that, when possible, ISBT Purity Grade CO2 be used for their carbonated beverage products. ISBT CO2 purity is higher than food-grade purity levels, but both are acceptable,” Dr. Pachuta comments. “Users of mini-bulk tanks or large storage tanks with only gas phase CO2 removal should periodically test their liquid CO2 for any slow buildup of non-volatile residues.”
Additionally, all CO2 manufacturers should routinely monitor and test their CO2 feed gas sources for any changes in composition as well as routinely monitor the quality of their CO2 throughout the in-process, cleanup, bulk storage, and truck or rail car-filling steps.
Regional CO2 storage and trans-fill depots also need to have some basic and low-cost CO2 purity monitoring systems available that can quickly catch any incoming off-quality CO2 “bad apple” loads in order to prevent any major CO2 quality upsets.