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NFPA, NBIC, IFC and Stored CO2 Compliance Codes

NFPA, NBIC, and IFC CO2 Compliance Tips

At CO2Meter, we are often asked, "What CO2 level is dangerous?" CO2 levels above 40,000ppm (4%) are life threatening. However, there are many other limits placed on carbon dioxide levels depending on your application.

These limits are defined by agencies such as the Occupational Health and Safety Administration (OSHA) and other regulatory bodies as described in this article.

Even if you don't realize it, inspection codes are always being updated or added to. At CO2Meter, we want to help our partners and customers understand these codes and know what to do to ensure code compliance and protection. The ultimate goal is to keep people safe and that requires a constant cycle of understanding the continual code updates and their additions.

What are the safety guidelines for compressed gas?

The US a workplace safety standard is set by OSHA and it defines gas standards, like CO2. It states that CO2 danger levels begin at 5,000ppm (0.5%) Time Weighted Average (TWA) for an 8-hour period. This means that the average concentration cannot exceed 5,000 ppm over an 8 hour work cycle.

Furthermore, OSHA defines 30,000ppm (3.0%) as it's evacuation threshold.  This means the once the CO2 concentration hits 30,000ppm nobody should be in the space for more than 15 minutes.

Note that carbon dioxide is not generally found at hazardous levels unless there is limited ventilation where gas is being stored or produced, or where the room is considered a confined or enclosed space.

Additional compressed gas guidelines for CO2 include but are not limited to:
  1. Never opening a damaged valve
  2. Avoiding direct skin contact with extremely cold liquids or compressed gases escaping from the cylinder
  3. Never wear watches, rings, or bracelets because they can freeze to exposed skin if splashed by an ultracold gas
  4. Always wear insulated gloves to protect against the cold

Below we highlight the most common compliance codes and standards, as they relate to carbon dioxide gas -  so businesses are aware of and familiar with the requirements, gas sensor installation and testing protocols.

National Board Inspection Codes

High pressure CO2 cylinders and low pressure bulk tanks used by restaurants and breweries for their soft-drink and draft beer systems or by commercial indoor growers are regulated by the National Board Inspection Code (NBIC).

The NBIC was originally called the National Board of Boiler and Pressure Vessel Inspectors. You are probably wondering why a boiler inspector would be interested in a CO2 cylinder or tank. It's because these inspectors also have purview of pressure vessels like cylinders and tanks.

The NBIC codes were first published in 1946 as a guide for chief boiler inspectors. Since that time, it has become the recognized standard for the installation, inspection, and repair and/or alteration of boilers, pressure vessels, and pressure relief devices.

The early codes for carbon dioxide from the NBIC discussed the need for specified alarm set points based on OSHA requirements and that a warning device must be located outside the hazard room to pre-warn occupants of dangerous CO2 levels.

The National Board Inspection Code (NBIC) was one of the first to codify requirements for CO2 monitoring in their 2012 edition.

Even in states that do not officially adopt the NBIC codes, it is often used as the de facto standard for local inspection and code enforcement.

The NBIC and its explanations are revised every 2 years to insure that the regulations meet the changing nature of technology. The most recent change is the 2023 edition with revised carbon dioxide gas detection system requirements for Liquid Carbon Dioxide storage vessels (section S3.4 and S12.5).

NBIC codes are created by a rotating committee of boiler and pressure vessel engineers and experts. These experts update the code and provide guidance and information to those organizations that manufacture, install, repair, and own/use any pressure vessels. It also provides direction to government organizations and inspectors as to how to fairly apply the regulations for the installation and use of the equipment.

The NBIC speaks very directly to the storage of CO2 and monitoring - not just bulk tanks - but cylinders as well. This is explained in an excerpt below from Part 1, Supplement 3 of the 2018 NBIC relating to Installation of Liquid Carbon Dioxide Storage Vessels.

NBIC S3.4 Gas Detection Systems

Rooms or areas where carbon dioxide storage vessel(s) are located indoors or in enclosed or below grade outdoor locations shall be provided with a gas detection and alarm system for general area monitoring that is capable of detecting and notifying building occupants of a CO2 gas release. Alarms will be designed to activate a low level pre-alarm at 1.5% concentration of CO2 and a full high alarm at 3% concentration of CO2 (which is the OSHA & ACGIH 15 minute and NIOSH 10 minute Short Term Exposure Limit for CO2.) These systems are not designed for employee personal exposure monitoring.  Gas detection systems shall be installed and tested in accordance with manufactures installation instructions and the following requirements;

  1. Activation of the gas detection system shall activate an audible alarm within the room or area in which the carbon dioxide storage vessel is located.
  2. Audible alarms shall also be placed at the entrance(s) to the room or area where the carbon dioxide storage vessel and/ or fill box is located to notify anyone who might try to enter the area of a potential problem.

NBIC S3.5 Signage

Warning signs shall be posted at the entrance to the building, room, enclosure, or enclosed area where the container is located. The warning sign shall be at least 8 in (200mm) wide and 6 in (150 mm) high. The wording shall be concise and easy to read and the upper portion of the sign must be orange as shown in figure S3.5. The size of the lettering must be as large as possible for the intended viewing distance and in accordance with jurisdictional requirements. When no jurisdictional requirements exist, the minimum letter height shall be in accordance with NEMA American National Standard for Environmental and Facility Safety Signs (ANSI Z535.2). The warning signs shall state the following:

  • "WARNING – CARBON DIOXIDE GAS. Ventilate the area before entering. A high carbon dioxide (CO2) gas concentration in this area can cause suffocation.”

Additional instruction signage shall be posted outside of the area where the container is located and such signage shall contain at minimum the following information:

  • Carbon Dioxide Monitors for general area monitoring (not employee personal exposure monitoring) are provided in this area. These monitors are set to alarm at 15,000ppm (1.5% concentration) for the low level alarm and at 30,000ppm (3% concentration) for high level alarm.
  • Low Level Alarm (15,000ppm) – Provide appropriate cross ventilation to the area. Personnel may enter area for short periods of time (not to exceed 15 minutes at a time) in order to identify and repair potential leaks.
  • High Level Alarm (30,000ppm) – Personnel should evacuate the area and nobody should enter the affected area without proper self contained breathing apparatus until the area is adequately ventilated and the concentration of CO2 is reduced below the high alarm limit.

FREE - Download the correct CO2 signage to print here

(pdf in English and Spanish).

NBIC Code Updates

The NBIC code was recently updated July 2023, having been accepted by the committee and included the following revisions:

Part 1:

  • Revised carbon dioxide gas detection system requirements for Liquid Carbon Dioxide storage vessels.

Part 2:
  • New requirements for remote visual inspection for confined space entry.

  • Several revisions/updates to the inspection requirements for PVHOs (pressure vessel for human occupancy).

  • Revised carbon dioxide gas detection system requirements for Liquid Carbon Dioxide storage vessels.

    The NBIC also includes Standard Welding Procedure Specifications (SWPS) and requirements for NO2 measurement which have been strengthened in several circumstances.

OSHA & NIOSH Guidelines

Unlike the NBIC, the Occupational Safety and Health Administration - OSHA and the National Institute of Occupational Safety and Health - NIOSH rules cover more than just the CO2 storage vessels. OSHA is uniquely interested in the health and safety of all employees in commercial workspaces.

For CO2, OSHA and NIOSH have created regulations for CO2 exposure for workers that state that no lower than 5,000 ppm TWA (time weighted average) should be utilized for the first alarm, 15,000 ppm as the half STEL (short term exposure limit), 30,000 ppm as the STEL, and 40,000 ppm as IDLH (immediately dangerous to life or health). These standards are fixed by OSHA and do not change.

Read more about OSHA confined space guidelines here.

Read more about compressed gas storage and OSHA guidelines here.

International Fire Code Recommendations

The last organization that has mandated CO2 monitoring is the International Fire Code (IFC). The IFC is part of the International Code Council (ICC) that also creates building, electrical, plumbing and other codes. The IFC has traditionally been the code that is more prescriptive about devices, locations, and alarm setpoints. Some of the common recommendations in the IFC include:

  • 12 inches from the floor-mounted height for sensors
  • First alarm at 5,000 ppm instantaneous
  • A safety monitor or increased ventilation is required whenever 100 lbs. or more of CO2 is stored.

National Fire Protection Association Codes

The next organization to include regulations around stored CO2, CO2 safety, and safety monitoring is the National Fire Protection Association (NFPA). Since the early NFPA regulations did not have a nice, neat place to put CO2 monitoring requirements, they "squeezed" them into NFPA 55 Cryogenic Fluids codes. 

Here is a humorous note - CO2 is NOT a cryogenic fluid!

What is the NFPA 55 Code?

NFPA 55 provides comprehensive coverage of the fundamentals for safer and more effective installation, storage, use, and handling of gases in portable and stationary containers, cylinders, equipment, and tanks. Code content covers: General requirements for emergency readiness and response.

Until the 2023 edition of NFPA 1 the NFPA codes were considered to be the most "vanilla” of all the codes as it relates to CO2 because it mandated almost no specifics about devices, locations, or performance. 

In the 2023 edition, NFPA 1 now includes specifics nearly identical to the IFC. 

Other organizations are preparing requested updates to NFPA 55 to bring the code more into alignment with other codes.

    Compressed Gas Association Standards

    The Compressed Gas Association (CGA) is a trade association that represents the interests of the industrial, medical, and food gases industry. It is based in the United States and was founded in 1913. The CGA develops and publishes standards and guidelines related to the safe manufacture, transportation, storage, and use of compressed gases.

    The CGA also highlights gas safety, best practices, and provides gas safety resources for anyone who is handling or using compressed gas in the workplace.

    What is the CGA Standard for CO2?

    In late 2023, the CGA released a new standard for workplace CO2 safety under the CGA G-6.14 Standard for Carbon Dioxide Monitoring. This standard is designed to assist both national standards and code setting organizations and local code authorities in their creation of code requirements associated with carbon dioxide monitoring systems. This standard is also intended for carbon dioxide gas monitoring system designers and installers and can be of value to system users.

    The primary focus of the standard is associated with assuring life safety. Although the CGA addresses the requirements for an Occupational Safety and Health Administration (OSHA) 8-hour time-weighted average- permissible exposure limit (TWA–PEL) and other regulatory and code requirements, it is the responsibility of the user of the monitoring system to assure compliance with these requirements.

    This publication addresses:

    • Hazards of carbon dioxide in near consumer and industrial applications (the dangerous concentrations, where they can occur and accumulate);
    • Both fixed carbon dioxide monitoring systems and portable monitoring devices;
    • Required components of the system and their intended functionality;
    • Recommendations for installation including locations of the component parts of a carbon dioxide detection monitoring system; and
    • Proper maintenance and periodic system functional verification.

    Compressed Gas Association CO2 Resources

    Below we highlight the CGA recommended resources for best practice and safety guideline in the field:

    CGA Publications

    Free CGA Safety Materials

    The "Authority Having Jurisdiction"

    One of the keys to accurately and effectively monitoring to meet codes is to know specifically what your jurisdiction requires. This isn't always easy. Authorities that have jurisdiction over your business can require more prescriptive codes - but not less.

    CO2Meter recommends you contact your local fire inspector (aka the AHJ) and ask specifically what they require. Inspectors are always open to proactive individuals as it demonstrates your desire to meet their codes and keep your staff and the public safe.

    CO2 Code Inspection Tips

    Here are a few helpful resource notes for you to check if you are required to have a CO2 monitor.

    • Start at the state level. Contact the offices of the State Fire Marshal, Building Inspector, and the Head of the Boiler and Pressure Vessel division. Why the Boiler Inspector? Your state's Boiler Inspector is in charge of enforcing the state and national regulations for boilers, and in most cases, pressure vessels. CO2 storage tanks ARE pressure/storage vessels and can be regulated by these codes. To search for your states Boiler Inspector visit and search by your state.
    • Move to the local level. In some states like Texas the state has abdicated responsibility for the adoption and enforcement of these regulations and codes to local officials. Check with the Fire Marshall and Building Inspector in your town and ask if they have or are considering a code for CO2 monitoring. Know whether your local officials are considering a change.
    • The major issue with leaving code creation to local officials is that it creates a jumbled array of codes across the state. Municipalities next to each other could have completely different codes. For Example: If you are a small business owner you may be required to have a monitor in South Miami but not in North Miami. This “wild west show” leads to ambiguity and confusion for business owners trying to do the right thing for their employees and guests. And know that even though North Miami doesn’t have a code today, they will enact one as soon as they figure out that South Miami has one (and is making money off of it too).
    • Inquire with your CO2 supplier about the codes. They can be helpful and may have a process and devices in place to help you meet the code. They can even support you by offering you device options to help you stay safe and be compliant too.
    • These regulations apply to anyone that is storing or creating CO2. Hospitals and medical facilities, breweries, restaurants and bars, indoor growers, welding shops, and industry should all be mindful that changing CO2 regulations may mean that what was not required yesterday may be required next week. Assign the responsibility of checking regularly to someone on your team.

    CO2 Safety Monitors that Meet All Codes

    Remote CO2 Storage Safety 3 AlarmIn response to CO2 safety monitoring and compliance, the Remote CO2 Storage Safety Alarm (RAD-0102-6) continues to meet the increased requirements for the OSHA STEL (Short Term Exposure Limit) with alarms at 1.5%, and at 3% CO2.

    This device is designed to protect customers and workers near stored carbon dioxide and is also designed to meet NFPA, IFC, and NBIC Requirements.

    In addition, the monitor features both audible and visual alarms and 3 built-in relays that can control an exhaust fan or send an alarm to the fire department or monitoring company. 

    Dependent upon your jurisdiction and application, CO2Meter also provides additional monitoring devices and accessories to meet specific regulations prior to inspection. 

    Below are our devices that meet fire code compliance:

    Where to place a CO2 Safety Monitor?

    Learn more about CO2 safety monitor installation here.

    Deciding if your business or work area is suitable for a CO2 monitor can be concerning. As CO2 safety monitors are critical and must be installed, yet there are areas of limitation.

      If you are nervous about calling an inspector proactively, or do not feel comfortable doing so, contact us about the requirements for your local jurisdiction. We are happy to help.

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