Respirator Protection Devices and Methods to Detect and Remove Toxic Gases from the Air - Cobinamide Encapsulated Silica-based Materials for Respirator Canisters

A respirator protects the wearer from inhaling dangerous substances, such as chemicals and infectious particles. CDC developed devices and methods to detect and remove chemicals such as hydrogen cyanide, cyanogen, hydrogen sulfide, nitrite, and nitric oxide from the air for those wearing respirators. Cobinamide (a Vitamin B12 analog with a high affinity to cyanide) molecules are immobilized within a silica matrix that allows for the infiltration and containment of gaseous chemicals. Since the chemical(s) bind to the cobinamide, such material is embedded into respirator canisters to help facilitate the removal of toxic molecules from the air.

The chemical(s) binding to the cobinamide also result in a color change that can be analyzed qualitatively or quantitatively. The cobinamide-loaded silica matrix can be incorporated into a respirator canister (such as a canister designed to protect workers against chemical, biological, radiological and nuclear weapons (CBRN)) to act as an end-of-service-life indicator (ESLI) alerting when to change equipment. Different absorbance of the cobinamide/silica composite within the respirator canister can be monitored, and the device can be configured to trigger a visual and/or audible alarm once a particular concentration of the chemical(s) meets a certain threshold, indicating that the canister needs to be replaced. Current ESLI technology only depends on the user to monitor a color change via a colorimetric indicator, viewed through a clear box on the outside of the gas mask canister. This is an issue for color-blind persons, those in low-light settings, and users if they are preoccupied and unable to continuously monitor the indicator. The CDC/NIOSH technology can be configured for both a visual and/or audible alarm.

Potential Commercial Applications: Competitive Advantages:
  • Detection and removal of chemical, biological, radiological, and nuclear (CBRN) agents for military and emergency response workers such as police, EMTs and fire fighters
  • Detection of nitric oxide for miners exposed from the use of explosives for blasting and diesel engine emissions
  • Occupational safety for manufacturing, agriculture, chemicals/pesticides, construction, roofing, painting, etc.
  • Technology senses and removes particles
  • Ability to monitor several ligands (molecules that bind with others) at once
  • An "active" vs. "passive" ESLI that will alert user to thresholds of CBRN agents important for replacing respirator canisters
  • To the inventor’s knowledge, there is no known commercially-available ESLI for hydrogen cyanide gas, a significant risk with fires and chemical explosions
  • Not based on electrochemical technology
  • Apparatus is added to gas canisters
  • Light weight and inexpensive
  • Uses a light source and mini spectrometer
  • Uses color and/or audible detection


Lee Greenawald (CDC)  ➽ more inventions...

Gerry Boss

Nicole Fry

Michael Sailor

Intellectual Property:
US Pat: - issued -
US Application No. 14/748,163 filed on 2015-06-23

Greenawald LA, et al. PMID 26213448.

Collaboration Opportunity:

The CDC Technology Transfer Office (TTO) is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize: Respirator Protection Devices and Methods to Detect and Remove Toxic Gases from the Air - Cobinamide Encapsulated Silica- based Materials for Respirator Canisters. For collaboration opportunities, please contact CDC TTO at tto@cdc.govor 1-404-639-1330.

Licensing Contact:
Karen Surabian, J.D., M.B.A.
Phone: 301-594-9719

OTT Reference No: E-144-2015-0
Updated: Jun 7, 2018