The average business owner thinks that the “code” is stagnant and never changes. They wonder why an inspector they haven't seen for 10 years is suddenly asking them for something new. However, even if they don't realize it, inspection codes are always being updated or added to.
One example is food trucks. Twenty years ago inspection codes didn't mention food trucks because the food truck revolution had not started. However, the last few code cycles of code changes have regulations for food trucks appearing as safety requirements for propane, ventilation, and more. The job of these codes is to keep people safe and that requires a constant cycle of updates and additions.
Carbon Dioxide monitoring is similar to food trucks in that the requirements to monitor them have only appeared in the last few code updates. For example, the National Board Inspection Code (NBIC) was the first to codify requirements for CO2 monitoring in their 2012 edition. This was in response to incidents such as the one in Phoenix, AZ.
The Boiler and Pressure Vessel Inspectors started with what was under their purview: cylinders, and bulk storage vessels. The early codes 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 an issue.
What are the NBIC 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). You are probably wondering why a boiler inspector would be interested in a CO2 cylinder or tank. It's because the CO2 tanks are pressure vessels.
The NBIC was 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.
Note that the NBIC code is not a "law" but is a recommended set of guidelines often used to make laws and recommendations. For example the OSHA Occupational Health and Safety Administration rules - which are law - typically follow the NBIC standards.
Even in states that do not officially follow the NBIC, it is often used as the defacto 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 2021 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 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 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;
- 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.
- 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.
Download the correct signage to print here (pdf, English and Spanish).
NBIC Code Updates
The NBIC code was recently updated July 2021, having been accepted by the committee and included the following revisions:
Revised carbon dioxide gas detection system requirements for Liquid Carbon Dioxide storage vessels.
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, OSHA’s expectations 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 (the National Institute of Occupational Safety and Health) have created guidelines for CO2 exposure that clearly state that no lower than 5,000 ppm TWA should be utilized for the first alarm, 15,000 ppm as the Half STEL, 30,000 ppm as the STEL, and 40,000 ppm as it IDLH. These standards are fixed by OSHA and do not change.
The next organization to include regulations around stored CO2, CO2 safety, and safety monitoring was the National Fire Protection Association (NFPA). However, the NFPA did not have a nice, neat place to put CO2 monitoring requirements so they squeezed it into NFPA 55 Cryogenic Fluids codes.
The NFPA 55 is considered to be the most "vanilla” of all the codes as it relates to CO2 because it mandates almost no specifics about devices, locations, or performance. The last update to the NFPA 55 was released in 2020.
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 additional 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 monitors
- First alarm at 5,000 ppm
- A safety monitor or increased ventilation is required whenever 100 lbs. or more of CO2 is stored.
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. CO2Meter recommends you contact your local fire inspector 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 Inspection Code 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 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.
- In most cases the state Fire Code or Building Code will override the NBIC regulations so don’t check just one source. Check at least two.
- Move to the local level. In some states like Michigan the state has abdicated responsibility for 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. 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).
- Do not rely on your gas supplier to know the code. They may be helpful, but keeping track of state local ordinances is not their responsibility.
- These regulations apply to anyone that is storing or creating CO2. Hospitals and medical facilities, breweries, restaurants and bars, indoor growers, 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.
A second resource is your CO2 provider. They may offer an option for you to lease a monitor. However, leasing a safety monitor has two drawbacks First, while your monthly cost seems low, you likely will have paid for that monitor within about 18 months of installation. Second, you can not use the monitor as a capital expense on your taxes.
CO2 Safety Monitors
In 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 (CO2) 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.
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.