CO2 and nitrogen cylinder safety for restaurants (free checklist)

The soda gun goes flat at lunch, so the dishwasher is sent to the basement to swap the CO2 tank. Nobody has shown them how, the chain that's meant to hold the cylinders is hanging loose, and the new tank's valve won't seat. The room is small, and nobody upstairs knows they're down there.

The gas behind a soda fountain, a draft system or a nitro cold brew tap is easy to forget because it works quietly. This post covers what the gas can do, what OSHA and fire codes say, and gives you a cylinder list, a weekly check, a change procedure, an alarm plan and a training record.

General information, not legal advice. Fire codes are adopted and amended city by city, so your fire marshal decides what applies to your system. Your gas supplier's safety data sheet (SDS) and instructions come first for your equipment.

What the gas can do

OSHA puts it plainly: "Hazards associated with compressed gases include oxygen displacement, fires, explosions, and toxic gas exposures, as well as the physical hazards associated with high pressure systems" (OSHA: Compressed gas and equipment).

Gas	Used for	What the limits say	Source
Carbon dioxide (CO2)	Soda fountains, draft beer, carbonation	OSHA's permissible exposure limit is 5,000 ppm averaged over 8 hours; NIOSH's short-term limit is 30,000 ppm; 40,000 ppm is listed as immediately dangerous to life or health	OSHA: Carbon dioxide
Nitrogen	Nitro cold brew, nitro beer, beer gas blends	A "Simple asphyxiant": "a substance or mixture that displaces oxygen in the ambient atmosphere, and can thus cause oxygen deprivation in those who are exposed, leading to unconsciousness and death."	29 CFR 1910.1200(c)
Low oxygen	What a leak of either gas does to a small room	"Oxygen deficient atmosphere means an atmosphere with an oxygen content below 19.5% by volume."	29 CFR 1910.134(b)

NIOSH lists the symptoms of too much carbon dioxide as "headache, dizziness, restlessness, paresthesia; dyspnea (breathing difficulty); sweating", up to "coma; asphyxia" (NIOSH Pocket Guide: Carbon dioxide). Fire codes put CO2 sensors "within 12 inches of the floor in the area where the gas is expected to accumulate" (see below), so think about the low, closed spaces where cylinders live: a basement, a walk-in, a closet under the stairs.

What OSHA and fire codes ask

OSHA. "Each employer shall determine that compressed gas cylinders under his control are in a safe condition to the extent that this can be determined by visual inspection", and the handling, storage and use of compressed gases in cylinders follows the Compressed Gas Association's pamphlet P-1 (29 CFR 1910.101(a), (b)). Cylinders also come with an SDS, which belongs in your SDS binder with the cleaning chemicals.

Fire codes, for bulk CO2. Many bars and restaurants now have an insulated liquid CO2 tank filled from outside instead of swapping cylinders. Cities that adopt the International Fire Code apply its Section 5307 to these. Thornton, Colorado's fire department, for example, quotes the 2021 code: "Insulated liquid CO2 systems with more than 100 pounds of CO2 used in beverage dispensing applications" need mechanical ventilation, or a gas detection system that sounds a supervisory alarm "at a normally attended location upon detection of a CO2 concentration of 5,000 ppm" and an alarm in the room at 30,000 ppm (Thornton Fire Department: CO2 dispensing systems).

Signs. The Moreno Valley, California fire department (under the 2022 California Fire Code and NFPA 55) asks for an NFPA 704 placard on the outside door and a warning sign at the entrance to the room that reads "CAUTION - Carbon Dioxide Gas. A high carbon dioxide gas concentration in the area can cause suffocation." (Moreno Valley Fire: CO2 detection systems for beverage dispensing).

Your city's edition and amendments may differ, and some need a permit. Ask your fire marshal two questions: does my system need detection or ventilation, and does it need a permit?

The cylinder and tank list

One line for every cylinder or tank on the premises, full or empty.

Gas cylinder and tank list · [location] · updated [date]

Where	Gas	Size	Owned by (us / supplier)	Secured how	In a closed or low space?	Detector?	Supplier and phone
[Basement, by the soda rack]	CO2	[20 lb]	[supplier]	[chain to wall]	[yes]	[yes / no]	[name, phone]
[Behind the bar]	Nitrogen	[cylinder size / generator]
[Spare, storage room]	CO2
[Bulk tank, outside fill]	Liquid CO2	[lb]

SDS for each gas in the binder: [yes] · Fire marshal asked about detection and permits on: [date] · Answer: ……………………

The weekly cylinder check

Weekly gas check · [location] · week of [date] · checked by [name]

Check	OK?	Notes
Every cylinder upright and secured (chain, strap or bracket), full ones and empties
No cylinder near heat: fryers, water heaters, ovens, sun through a window
Valves, regulators and hoses: no damage, no hissing, no frost on fittings
Regulator gauges read normal: CO2 [psi], nitrogen [psi]
Spare cylinders: valve caps on, secured, labeled full or empty
Room ventilated and the door not blocked; nothing stored against the cylinders
Gas detector (if fitted): power light on, no fault; last test or service [date]
Warning sign on the door (where your fire marshal asks for one)

Problems reported to: [manager / supplier] on [date] · Fixed: ……………………

Changing a cylinder

Only people who've been trained do this. Write your supplier's steps in the gaps.

Changing a CO2 or nitrogen cylinder · [location]

Tell someone you're going to change it, and where. Prop the door open if the room is small.
Close the valve on the empty cylinder. Let the line pressure drop as your system's instructions say: [how].
Take the regulator off with the right wrench: [size]. Check the washer or seal; replace it if it's worn: spares are in [place].
Unchain the empty, put its valve cap on, mark it EMPTY and secure it with the other empties.
Bring the full cylinder upright on a cart, never rolled on its side or carried by the valve. Chain it before anything else.
Take off the cap, fit the regulator, tighten it, and open the valve slowly.
Check for leaks at the connection: [soapy water / supplier's leak detector]. A hiss or bubbles means close the valve and refit.
Set the pressure: CO2 [psi], nitrogen [psi]. Pour a test drink.
Log the change: date, gas, cylinder number, your initials.

Never: lay a cylinder down while it's connected, use a cylinder you can't secure, force a valve, or fix a regulator yourself.

When an alarm sounds or someone feels unwell

Gas alarm or leak · [location]

Signs: the CO2 alarm sounds; a hissing you can't stop at the valve; someone in the room has a headache, is dizzy or is short of breath.

Get everyone out of the room and away from stairs leading down to it. Don't stop to find the leak.
Don't go back in for someone who has collapsed. Call 911 and tell them it may be CO2 or nitrogen.
Close the cylinder valve only if you can reach it from outside the room, or on your way out without staying.
Ventilate from outside: open outside doors to the area if you can do it without going in.
Call the gas supplier at [phone] and, if the alarm or leak continues, the fire department.
Keep people out until the fire department or supplier says it's clear.
Write it down: time, what happened, who was exposed, who you called. Anyone who felt unwell is told to get checked by a doctor.

Emergency numbers: 911 · Supplier: [phone] · Manager on call: [phone]

The training record

Gas safety training · [location]

Name	Date	Trained on (cylinder list, weekly check, changing a cylinder, alarm plan)	Can change cylinders?	Trainer	Initials
			[yes / no]

Your gas safety checklist

[ ] Every cylinder and tank on the list, with its supplier's number
[ ] Every cylinder secured upright, full or empty
[ ] SDS for CO2 and nitrogen in the binder
[ ] Fire marshal asked about detection, ventilation, signs and permits
[ ] A weekly check with a name on it
[ ] Only trained people change cylinders
[ ] Everyone knows the alarm plan: get out, don't go back in, call 911

Where Mays fits

The weekly check as a checklist. Add the checks above to a Weekly template on the day you pick, with a Photo answer for the chained cylinders and the gauges, and a Number answer for each pressure. See Creating a checklist template and Scheduling and assigning checklists.
Cylinder changes as a form. Under Tasks → Types, build a Cylinder change form with Single choice (CO2 or nitrogen), Text for the cylinder number, Yes / No for Leak check done and a Photo. Tasks → Data keeps every change in one table, with Export CSV. See Building custom forms and Task Data.
Problems and incidents. A leaking regulator goes in the Logbook under Maintenance; an alarm or someone feeling unwell under Health & Safety, flagged Needs follow-up, so the location's managers see it. See The manager logbook.
The SDS and the training. Upload each SDS (PDF, up to 50 MB) to a Safety folder in the Knowledge Base, and turn your gas safety article into a short quiz with Learning. See Knowledge base basics and Creating learning modules.
The gas supplier. Add it under Inventory → Vendors with the rep's name and phone, so the number is in one place. See Vendors and vendor catalogs.

What Mays doesn't do: it doesn't connect to CO2 or oxygen detectors (its wireless sensors record temperature only), and it doesn't call anyone when a gas alarm sounds. The detector and your alarm plan do that.

Chained, checked, ventilated, and everyone knows to get out first

CO2 and nitrogen are safe in the cylinder and dangerous in a small room. Secure every cylinder, look at them every week, let only trained people change them, ask your fire marshal what your system needs, and make sure everyone on the team knows the one rule that saves lives: get out, and don't go back in.

Start your free trial: 30 days, every module, no card needed. Or book a walkthrough and we'll set up your weekly safety checks with you.