November 1, 2021 

After reviewing recent updates to regulatory authorities' recommendations on low alarm activation for CO2 %vol sensors, we have adjusted our suggested (and factory default) alarm setpoints as follows: 



LOW ALARM = 0.5% vol (5,000 ppm)

MID ALARM = 1.5% vol (15,000 ppm)

HIGH ALARM = 3.0% vol (30,000 ppm)

1.0% vol

1.5% vol

3.0% vol


Exposure Limits:

NIOSH REL: TWA 5,000 ppm / STEL 30,000 ppm

OSHA PEL: TWA 5,000 ppm

IDLH = 40,000 ppm

Regulatory Authorities 

National Board Inspection Code (NBIC) Part 1 Supplement 3

National Fire Protection Association (NFPA) 55

International Fire Code (IFC) Sections 5307.5,1 and 5307.5,2

Compressed Gas Association (CGA) (Note: the CGA is not a regulatory body)


If your application requires specific alarm relay setpoints, values are easily changed in the field or can be specified at time of order. 

NOTE: These alarm setpoints are for applications where CO2 is used or produced by means other than breathing, such as wineries/breweries, greenhouses, CO2 storage rooms, chiller/mechanical rooms for CO2 refrigerant leak detection. Indoor air quality applications commonly use CO2 ppm sensors and specify different guidelines.