As a recognized leader in O₂ safety monitoring, PureAire recently explored the need for an O₂ monitor where carbon dioxide is used. There are four key cryogenic gases; nitrogen, helium, argon, and carbon dioxide (CO₂), which can create an oxygen deficient atmosphere.   Material Safety Data Sheets (MSDS) covering cryogenic gases cite that a cryogenic leak can create an unsafe environment by lowering the breathable oxygen levels.  If an oxygen monitor is required for N₂, He, and argon, then why not for CO₂?  Carbon dioxide is a cryogen that is often overlooked because it’s considered a harmless gas that provides the fizz in soda. The reality is that during a leak, it rapidly depletes the oxygen in the room.

“In June 2011, a McDonald’s restaurant in Phoenix, Arizona, was evacuated because of a leaking CO₂ cylinder in the basement.  A pregnant employee reportedly collapsed while exiting the basement and two firefighters were injured during the incident”^1.  This is only one of many similar incidents of asphyxiation due to a CO₂ release where people felt symptoms from lack of oxygen before the toxic effects occurred.  With the current use of larger 100 + gallon liquid CO₂ tanks, any leak can cause severe asphyxiation hazards.  Although a CO₂ monitor is recommended, we believe that an oxygen deficiency monitor should also be employed because the asphyxiation risk is due to the depletion of breathable oxygen.

PureAire believes that an O₂ deficiency sensor should be used where carbon dioxide is stored because, “asphyxiation is likely to occur before the effects of carbon dioxide overexposure.”²   As a result, PureAire is introducing a new Dual gas monitor for detecting Oxygen and Carbon dioxide.  The unit’s digital display shows O2 in percent and CO₂ in ppm.  It has dedicated individual visual alarms and relays for each gas, a built-in audible horn, and gas selected analog 4-20mA output.  It’s designed for early warning when either gas exceeds their safety limits.  It can also be used to control carbon dioxide dispensing systems used in grow rooms by shutting off the flow of CO2 when levels get too high.

The risks associated with carbon dioxide are; “It’s a colorless, odorless non-flammable gas with a vapor density 1.5 times that of room air.  It is non-toxic, but by displacing oxygen in confined spaces, the gas can cause asphyxiation”³.  Recently, new fire department laws are being discussed to provide proper safety regulations in environments where carbon dioxide is stored and used  in establishments dispensing beverages and in indoor grow rooms.  The Denver fire department recognized that carbon dioxide causes asphyxiation and is considering the use of an O₂ monitor as well as in grow rooms where low concentrations of carbon dioxide are present.

Additionally, with the increasing sales of kraft beers that require nitrogen dispensing, a CO₂ monitor can never be used for protection because it will not detect oxygen deficiency in the event of a leak.  PureAire’s new dual gas monitor can provide early warning alarms for a leak of CO₂ and N2.  Al Carrino, president of PureAire wanted to add one more line of defense for safety by detecting oxygen deficiency while also monitoring for CO₂. With our new dual monitor we feel that we can now cover all the risks when using cryogenic gases.

For more information please visit PureAire Monitoring Systems web sites; pureairemonitoring.com or monitoroxygen.com or call to speak with a representative at 888-788-8050.

¹ March 2013. Fire Engineering. Carbon Dioxide: A Hidden Danger for Firefighters. Retrieved April 8, 2013, from http://www.fireengineering.com/articles/2013/03/carbon-dioxide–a-hidden-danger-for-firefighters.html

² BOC Gases, Material Safety Data Sheet, MSDS: G-8 Revised: 6/7/96

3. July 2007. Praxair Material Safety Data Sheet. Retrieved March 2, 2013, from

http://www.praxair.com/praxair.nsf/AllContent/D3CBF4EF4186073485256A860080D221/$File/p4574j.pdf