Skip To Content
logo image

What makes propane gas smell?


The odds are good that you haven’t heard of Ethyl Mercaptan. But it’s just as likely that you’ve smelled its unpleasant presence before. Ethyl Mercaptan is what makes propane gas smell. It’s an additive that is combined with liquified petroleum gas, or LPG, to alert users of a leak.

What does propane gas smell like?

Depending on the makeup of your olfactory senses, Ethyl Mercaptan most often is reported to smell like rotten eggs or sometimes rotten cabbage. Some also say it has a strong garlic, or skunk-like, smell. 

Although the smell of Ethyl Mercaptan might be among the worst in the world, it has proven to be an effective tool in alerting propane users to a problem - and giving them the time they need to ensure their safety.

Why does it smell?

Also sometimes called ethanethiol, this pungent smelling compound is an ideal additive to quickly catch someone’s attention that something is wrong. The chemical is used in both propane and natural gas – both of which are naturally odorless – to help identify a leak. 

If you catch a scent of mercaptan, it’s a sign that you need to take action

There’s at least anecdotal evidence that rotten egg smell can linger and settle into fabrics within a household. But the question of how long propane’s smell lingers depends on several factors, including ventilation in the room, and the types of materials found in the area. Because propane is heavier than air, it and the Ethyl Mercaptan fill the lower spaces of a room first, moving upward as more gas is released.

What to do if you smell propane gas

  1. First, you’ll want to make sure that all potential ignition sources have been neutralized. Immediately put out all smoking materials and other open flames. Do not operate lights, appliances, telephones, or cell phones. Flames or sparks from these sources can trigger an explosion or a fire. Quickly leave the area with anyone else in the building. 
  1. Call your local Ferrellgas office or another qualified expert to come to locate the leak and make the necessary repairs.
  1. Some users report that the smell intensifies as the tank lowers, even if there isn’t a leak. If you notice this happening, and a professional hasn’t found a leak, it might be a good idea to refill your tank and see if that alleviates the scent. This can happen as the propane is burnt off, leaving behind a higher concentration of Ethyl Mercaptan that is released along with the propane. 

Once you’ve taken measures to repair any leaks and ensure the premises are again safe for entry, using an ionizer or ozone device might help rid your home or office of the lingering smell. For materials such as drapes and bedding, a thorough washing should get rid of the scent. 

Safety and health precautions

Since propane is denser than oxygen, it can displace the air you breathe in a room. This can lead to difficulty breathing, headache, elevated heart rate, fatigue, and lack of coordination. 

Overexposure to leaking propane or natural gas can lead to serious and long-lasting issues, including permanent organ damage. Due to the risk of ignition and the risk to your health, it’s important to take action as soon as you detect the smell of Ethyl Mercaptan.

Call your local Ferrellgas if you have a leak

Propane is a safe and reliable fuel source, but like all gases, carry some inherent risks that can be minimized with a few common-sense procedures. If you ever notice the pungent scent of Ethyl Mercaptan, don’t delay in clearing the area, extinguishing all sources of ignitions, and contacting your local Ferrellgas representative to help locate the leak and make any repairs to keep you and your family safe.