Tell customers to leave the area at once if they smell gas or suspect a propane leak. Once safely away, call 911, then your propane supplier. Explain carbon monoxide on its own: it has no smell. A CO alarm calls for fresh air and help, not a search for the source inside the home.
Reviewed Oct 2026
Make the first action clear
NFPA tells people with a suspected fuel-gas leak to leave right away. Once safely away, call 911, then the gas supplier. Avoid switches, appliances and phones in the area of the leak. Put that action in the first line customers see. Do not turn the warning into instructions for finding or fixing a leak.
Give carbon monoxide its own heading
NFPA describes CO as an odorless gas that can form when fuel burns incompletely. The smell of gas is not a way to judge whether CO is present.
For a CO alarm, move to fresh air and call for help. Stay out until emergency personnel say it is safe to return. Follow the alarm maker's placement instructions.
Review the whole brochure before it goes out
As an office check, read the leak message and the CO message side by side. Keep both short. Have the safety reviewer approve the full piece before you send it.
Questions and answers
Can a customer smell carbon monoxide?
No. CO is odorless. Keep the CO warning separate from the gas-smell warning.
Should someone stay inside to call about a gas leak?
Get safely away from the leak first. NFPA says to call 911, then the gas supplier.
Should the notice teach customers to repair a leak?
Keep this warning focused on leaving and calling for help. Do not add repair steps to the consumer notice.
Where should the CO alarm instructions come from?
Use the alarm maker’s instructions along with the safety guidance that applies to the home. NFPA advises following those placement instructions.
About Bill Stomp
Bill Stomp built Propane Safety Pro. He is a war veteran who ran over 87 propane branch offices across 12 states, and he has helped more than 200 propane companies improve their profits, sales, safety and operations.
Next step
See the propane Duty to Warn mailing service. Tell us how many customers need your reviewed leak and CO brochure; we'll plan the mailing.
General information, not legal advice.