NFPA, NBIC, CGA, IFC and Stored CO2 Safety Compliance Codes

At CO2Meter, we are often asked, "What CO2 level is dangerous?" and we note that 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 U.S. 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 that once the CO2 concentration hits 30,000ppm nobody should be in the space for more than 15 minutes.

Below we highlight the most common compliance codes and standards, as they relate to carbon dioxide gas so businesses are aware of the requirements and know how to comply.

National Board Inspection Codes (NBIC)

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 CO_2.) 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:

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 (IFC)

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 (NFPA)

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 (CGA)

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.

This publication addresses clear guidelines for CO2 storage, handling and safety:

• Hazards of carbon dioxide in near consumer and industrial applications
• The need for gas detection systems where CO2 is stored or used indoors
• Requires audible and visual alarms on devices to alert occupants if CO2 levels exceed safety thresholds
• System placement recommendations to monitor storage areas, confined spaces, and low-lying areas where CO2 may accumulate.
  

Compressed Gas Association CO2 Resources

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

CGA Publications

• CGA G-6, Carbon Dioxide
• CGA G-6.9, Dry Ice
• CGA G-6.1, Standard for Insulated Liquid Carbon Dioxide Systems at Consumer Sites
• CGA G-6.5, Standard for Small Stationary Insulated Carbon Dioxide Supply Systems
• CGA G-6.7, Safe Handling of Liquid Carbon Dioxide Containers that Have Lost Pressure

Free CGA Safety Materials

• CGA SP-15, Safety Poster (End User), Safe Handling, Transport, and Use of Dry Ice
• CGA SP-16, Safety Poster (End User), Safe Use of Refrigerated & Cryogenic Liquids
• CGA SP-9, Safety Poster (Industrial), Enclosed Spaces Can Be Unsafe

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.

We always recommend that 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.

How to Ensure Your Facility Meets CO2 Code Compliance

Here are a few helpful resources to help you stay compliant with CO2 requirements:

• 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 http://www.nationalboard.org/ViewAllSynopses.aspx and search by your state.
• Understand Applicable Codes: Review NFPA 55, IFC Chapter 53, CGA GC-6.14, NBIC, and OSHA Requirements for your facility and storage quantities.
• Install Certified CO2 Safety Solutions: Use devices like the RAD-0102-6-HS2 and RAD-PMU series that align with code requirements and inspector expectations.
• Maintain and Calibrate: Regular calibration and testing ensure your devices remain accurate and code-compliant.
• Document Your Compliance: Keep records of installation, calibration certificates, and alarm tests for inspections.
• Train Your Team: ensure staff know how alarm actions work and what evacuation protocols would be when CO2 alarms active.
  

CO2 Safety Monitors that Meet All Codes

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 alerts, an included dual horn strobe, and 3 built-in relays that can control an exhaust fan or send an alarm to the fire department or monitoring company. 

RAD-PMU Power Monitor Unit: Meeting IFC 916.5

The RAD-PMU Power Monitor Unit is designed to provide an additional layer of protection by monitoring the power supply to your gas safety devices.

Key requirements from IFC 916.5 include

"Gas detection systems shall be tested in accordance with manufacturer instructions to ensure proper operation" and "the systems shall be monitored to indicate a loss of primary power to the gas detection system, requiring a distinct trouble signal to alert building staff or occupants."

"Standby or emergency power shall be provided, or the gas detection system shall initiate a trouble signal at an approved location if the power supply is interrupted."

The RAD-PMU fulfills these requirements by:

1. Detecting power loss to your gas detection system, triggering audible and visual alarms to notify staff of a system power failure.

2. Provides a relay output to your building management system (BMS) or alarm panel to ensure you meet supervisory requirements under IFC codes.

3. Supports annual testing procedures as part of your facility's inspection and maintenance program to keep your system in 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.