Why Does My House Smell Like Rotten Eggs? (And Is It Safe?)

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Neutralize nasty house odors with this essential guide

Co-authored by Amy Mikhaiel and Eric McClure

Last Updated: December 9, 2024 Fact Checked

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Causes of the Rotten Egg Smell

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Should I worry if my house smells like rotten eggs?

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Getting Rid of Rotten Egg Smell

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Does a rotten egg smell mean carbon monoxide?

The odds are extremely high that the rotten egg odor you smell in your home is hydrogen sulfide or mercaptan. Hydrogen sulfide is produced by most organic materials as they break down, so if you’ve got sewage, food scraps, or pipe gunk producing a smell, it’s probably hydrogen sulfide. Mercaptan also smells like eggs. This is a chemical added to (otherwise odorless) natural gases so that leaks don’t go undetected. So, if you’re smelling rotten eggs there’s one very serious potential cause and a bunch of other less serious options. We’ll help you figure out what’s causing the gnarly aroma (and how to fix it).

Why Does It Smell Like Rotten Eggs in My House?

The rotten egg aroma is hydrogen sulfide or mercaptan. Mercaptan is found in natural gas, so it’s extremely important to rule out gas leaks first before doing anything else. If there isn’t a gas leak, inspect your drains, walls, and water for hydrogen sulfide—a chemical created by organic materials breaking down.

Section 1 of 4:

Causes of the Rotten Egg Smell

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1
Natural gas leak. Natural gas is colorless and odorless, so most cities and utility companies add a chemical called mercaptan (aka methanethiol) to it so that leaks don’t go completely ignored.^{[1]
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Research source} Mercaptan is designed to be as obnoxious smelling as possible so you can’t ignore it, ergo the rotten egg aroma.
- Diagnosing this source of the odor: Note where you smell the eggs. If you smell rotten eggs in your kitchen, in the heating/AC vents, near an appliance, or in your basement, the odds are very high that you have a natural gas leak. Do not ignore a possible natural gas leak. Grab your family or roommates and evacuate immediately. Do not light your stove or create any sparks in the meantime.
  - If your air vents smell like rotten eggs, your HVAC system is leaking gas.
- How to solve the problem: Contact your utility’s emergency line to tell them you have a natural gas leak. They’ll arrive ASAP and patch the leak or fix the faulty appliance.
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Dried/unused drain pipe. There is a pipe in every sink and drain called a P-trap (or J-pipe/J-bend). It’s shaped like a J so that some water always pools up at the bottom and blocks odors from deeper in the sewage system from traveling up the drain. If you have a drain you haven’t used in a long time though, that water in the P-trap can evaporate and open the door for all those gnarly fumes to get into your home.^{[2]
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- Diagnosing this source of the odor: Do you have a drain, sink, or faucet that doesn’t get a lot of use? Go take a sniff. If the egg odor is especially pungent, this is the problem.
- How to solve the problem: Run the water in all of your sinks/drains for a few minutes. Then, you should be good to go. In the future, aim to run the water every week or two to keep the J-bend full of water.
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Well water. If your home is not hooked up to a municipal water supply and you get your water from a well, the decaying nutrients in the soil and stone of the well can break down into hydrogen sulfide gas. This is a natural process, but it is bad for your health, so don’t ignore this issue if it applies to you.^{[3]
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- Diagnosing this source of the odor: Pour a glass of water and take a deep sniff. If it smells “off” and you have a well, this is likely the source of the odor.
- How to solve the problem: Contact a plumber. You must install a home water treatment system to kill the hydrogen sulfide before the water enters your home.
- Am I okay if I’ve been drinking the water? This is a serious health concern in the long run, but you’d have to drink a lot of very smelly water before anything happens. Unless you’ve ignored this issue for years, you’re probably okay.^{[4]
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Hot water heater failure. If the hot water (and only the hot water) has the rotten egg smell, it’s very likely that your hot water heater is dying or damaged. There are anodes and metal plates inside water heaters that can corrode over time. If that corrosion reaches a high enough level, your hot water will begin to smell.^{[5]
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- Diagnosing this source of the odor: Run the hot water at one sink or shower and the cold water at another sink or shower. After a minute or two, go take a sniff of each. If the cold water seems fine but the hot water stinks, it’s 100% your water heater.
- How to solve the problem: Contact a plumber. They may be able to replace the anodes in your heater. If they can’t, they’ll at least be able to install a new one for you.
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Clogged drain. If you have a partially clogged drain, it could be the source of your woes. The water may drain but there could be a clump of hair, tissue, or food that has degraded far enough to release the rotten egg aroma.^{[6]
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- Diagnosing this source of the odor: If one of your toilets, tubs, or sinks is draining a lot slower than the others, you’ve probably got a clog. In any case, you can sniff the drain in question to see if it smells like eggs and confirm your suspicions.
- How to solve the problem: Try snaking the drain with a drain auger to break up the clog. This will fix your problem.
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Smelly drywall. This seems to be a pretty rare phenomenon at this point, but if you have drywall in your home and the building was constructed between 2001 and 2009, your drywall could be to blame. Drywall that was sourced from China during this period contained an excessive amount of sulfur, which breaks down into hydrogen sulfide over time.^{[7]
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- Diagnosing this source of the odor: Sulfurous drywall will make your whole home smell, so you can’t narrow the source down to the drywall by using your nose alone. Instead, look for any exposed copper (the coils on an AC unit are perfect). If there’s a black ashy substance on the coils, you have sulfurous drywall (the sulfur and copper react to create this ash).^{[8]
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  - This drywall is especially common in the southeastern United States, so take your location into account.
- How to solve the problem: This is not a fun or easy fix, but it does need to be resolved. The drywall must be replaced. Either reach out to a contractor or get started on the project yourself.
- Is this a health concern? Most of the especially egregious examples of this have been remedied by now (this was over a decade ago, after all). Still, extended exposure to this drywall is linked to respiratory issues and headaches, so don’t ignore this problem.
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Actual eggs. You know what really smells like rotten eggs? Actual, factual rotten eggs. Are there expired eggs in your trash? Did someone use the garbage disposal to get rid of omelet scraps? Any of these little cleanliness issues can trigger a rotten egg smell.
- Diagnosing this source of the odor: If you suspect this could be the problem, don’t worry about diagnosing it. Just clean up and see if the problem goes away. At the absolute worst, you just cleaned your home.
- How to solve the problem: Take the trash out, vacuum, clean up, and pour some white vinegar down your sinks and drains to deodorize them.

Section 2 of 4:

Should I worry if my house smells like rotten eggs?

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Yes, you must rule out a gas leak before you can relax. Most of the issues that cause rotten egg odors, like unused drains or smelly drywall, are not the end of the world. They’re not great and you’ll likely want to fix the problem before you try selling your home or getting your security deposit back, but it’s not a health risk. A natural gas leak is a very big deal, and your home could potentially ignite or explode if you continue to ignore the problem. You must rule natural gas out as a cause first.^{[9]
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- If you aren’t entirely sure whether you can rule out natural gas leaks or not, don’t push your luck. Contact your utility company ASAP.

Section 3 of 4:

Getting Rid of Rotten Egg Smell

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1
Open the windows and air your home out. There’s no life hack here that will solve your aroma woes better than good old-fashioned clean air. Crack the windows in your home and turn some fans on. If it’s super cold out, just run the fans and turn your heat on (if you have an HVAC system). Give it a few hours or days depending on how bad the smell was and wait the eggy fumes out.
- If the egg smell reappears, it’s a sign that you didn’t properly deal with the problem the first time. Go back to diagnostics to see if you missed anything.
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Leave baking soda out to soak up any residual odors. Baking soda is a natural deodorizer. Fill a few small containers with a 1–2 in (2.5–5.1 cm) layer of baking soda and leave them wherever the smell is the worst.
- When the odor is finally gone entirely, toss the baking soda out.
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Use candles or incense to make your home smell nice. Once you’ve successfully handled the rotten egg smell, give your living space a little aromatic love. Pick up some scented candles or incense sticks and light them. Let your home be a bastion of heavenly odors once again!
- Don’t leave candles or incense unattended.

Section 4 of 4:

Does a rotten egg smell mean carbon monoxide?

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No, carbon monoxide is odorless and colorless. The only way to detect a carbon monoxide leak is to install carbon monoxide detectors. Carbon monoxide is an extremely dangerous gas that can leak out of faulty gas appliances, so it’s important to keep working carbon monoxide detectors in your home. You will not be able to smell it if there’s a leak.^{[10]
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National Health Service (UK)
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- Symptoms of a carbon monoxide leak include scattered thinking, confusion, headache, dizziness, flu-like symptoms, chest pain, and shortness of breath. If you have any of these symptoms and you do not own a carbon monoxide detector, see a doctor immediately.