What's That Smell in My House?

You walk in the front door and something smells off. Is it trash? Dirty clothes? Something worse?

A weird smell in your house can be caused by something as benign as old food that needs to be thrown away, but it could reveal a dangerous gas leak, fire or pest problem.

Here’s what you may be smelling in your house, and the potential causes:

Smoke

Where there’s smoke, there’s fire. Cooking over an open flame, burning candles or using your fireplace can increase your chances of starting an accidental fire that can damage your home and spread quickly if not put out. It’s a good idea to have a fire extinguisher on hand in case a fire starts.

However, the electric wiring throughout your home can also become a fire hazard if it’s old, misused or becomes damaged. The U.S. Fire Administration reports there are about 45,000 home electrical fires per year, and half of them involve lighting or electrical wiring. An electrical fire in your home can start in walls, outlets or appliances. If you see smoke coming from an overloaded power strip or appliance and can safely unplug it, do so.

Especially if you’re unaware of the cause, if you smell smoke inside your home, call 911 and leave the building immediately.

Fish

Not all fire hazards smell like smoke. If your nose is catching a fishy smell and you haven’t cooked any fish, it could be a sign of electrical components overheating, which can lead to an electrical fire. Wires, plastic and other parts of a circuit can give off a fishy smell when they’re getting too hot and starting to burn.

If you’re smelling fish and you’re not cooking seafood, contact an electrician for an emergency visit to diagnose the issue. If you start smelling or seeing smoke, call 911 and get out of your home immediately.

Rotten Eggs

Natural gas does not have a smell on its own – utility companies add the smell of rotten eggs to help notify consumers if there’s a gas leak. If you suddenly smell rotten eggs, leave your house immediately and get everyone else out with you. A natural gas leak, if it comes into contact with a flame or spark, can cause an explosion. The American Gas Association advises against turning any lights or appliances on or off or starting your car. You should wait to use a phone to call 911 or your local utility company until you’re safely away from the smell of gas and away from your home. If you can, notify your neighbors to leave the area as well.

Garbage

If you’re smelling rotten garbage, it probably is rotten garbage and you should take it out. If the smell doesn’t appear to be coming from your trash can, go shelf by shelf in your refrigerator and pantry to identify whether food has gone bad. Also check dirty dishes and countertops, and turn on your garbage disposal with the water running and pour some dish soap down the drain.

Aside from the unpleasant smell, rotting food will attract pests of all kinds, from flies to cockroaches to mice and rats, says Chelle Hartzer, an entomologist and technical services manager for national pest control company Orkin. When you discover the source of the smell, “clean it but before (pests) get to it – if they’re not already there,” Hartzer says.

Oily Smell

A dirty, oily smell is often associated with a cockroach infestation. This oily smell may be from the pheromones that cockroaches produce to attract a mate or inform others of a food source.

However, Hartzer notes that the most potent smell to lead you to cockroaches isn’t their pheromones. “Typically, what people are smelling when they have cockroach issues is that food source,” she says.

Getting rid of the food source and adding a couple traps may solve a minor cockroach problem. However, if the infestation appears to be well-established and you’re finding that the insects are getting food in more than one location, contact a pest control company to tackle the problem more aggressively.

Animal Urine

If you’re smelling animal urine or feces in a part of your home and there’s no way a pet had an accident, you may have a wild animal inside your home. Mice and rats aren’t likely to give off a potent odor if they’re just scurrying by, but you’re more likely to smell their urine and feces in places they congregate – either at a food source or nest.

The smell of animal urine could also be from squirrels, raccoons and opossums, which are are known to get into walls and attics and leave behind droppings. Be sure to dispose of any food source to prevent and get rid of any unwanted animals in your house. Close up any holes where the animals may be getting in, and consider setting traps or contacting professionals – especially for an animal nest, which can be difficult to get rid of.

Must

If your house or a specific room has a continuous stuffy, musty scent, you’re likely smelling mold.

Mold can grow just about anywhere in the home where moisture can get in, although attics, basements and crawl spaces are the most common areas to see mold, says Greg Bukowski, founder and CEO of Moldman, a professional mold abatement company in Chicago.

In places where you don’t see mold, it’s possible the growth is occurring behind your walls. In this case, you or a professional will need to cut exploratory holes in the wall to find the source. While you want to remove any and all mold from your home as quickly as possible, you don’t need to evacuate the house – even if the mold is black. A common misconception is that black mold is more toxic to people than other types of mold. While some people may be more sensitive to a certain fungus strain, all types of mold can have negative health effects.

“Really, any type of mold does not belong in a healthy home – treat it all the same. Don’t panic,” Bukowski says.

You may even be able to remove the mold yourself with the right safety equipment, including goggles, gloves and a mask to cover your nose and mouth, as well as over-the-counter cleaning agents designed for mold. Be sure you’re also repairing the source of moisture that’s caused the mold, whether it’s a leaky pipe or high humidity levels in a dark corner.

Sewage

If you suddenly notice the smell of raw sewage somewhere in your home, it’s likely coming from a drain you haven’t used in a while. It could be the result of a dry P-trap, which is a part of your plumbing that stores a small amount of water to prevent sewer gas from coming into your home.

If you’re smelling sewage from the drain, the P-trap has dried up, likely because the water evaporated after not being used for a long time. Simply pour water down the drain to allow the P-trap to fill again, and be sure to periodically run the water in every sink and tub or shower to prevent evaporation in the future. Open some windows to rid of any lingering sewage smell from your home.

If the sewage smell persists, you may have an issue with the wax seal for your toilet or a backup somewhere in your home. A plumber may be able to diagnose the issue quickly.