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The Potential Causes of Bad Odors in a House

Smells in the home can be annoying.

Stenches from bathrooms, trash cans, and the pets can make your home nearly unbearable. Some are even dangerous. Sewer smells, for example, often contain harmful chemicals that can cause people to get sick. The odor from natural gas can signal a safety hazard, and the lingering smell of smoke can indicate the potential for long-term health issues.

Fortunately, you don’t have to live with these annoying and occasionally dangerous smells. There are steps that you can take to make your home more enjoyable for everyone. By removing smells, you’ll have a safer, more pleasant home.

Smell: The Unsung Hero of Our Senses

Before we take a look at the bad smells that linger in our homes, it helps to start with a basic understanding of a sense that often gets taken for granted: our sense of smell.

Among all the senses, smell might just get the least attention. After all, we don’t have inventions that enhance our sense of smell; the nose doesn’t get the equivalent of prescription glasses or hearing aids, yet our nose can be important for protecting our health.

Using olfactory neurons, we are able to decipher molecules that travel into our nose. Odor molecules come into contact with olfactory receptors that lock onto these molecules and generate an electrical signal that is eventually relayed to the brain. All of this, of course, happens virtually at the speed of light.

While human smell is not considered particularly keen, at least not compared to dogs and most wild animals, humans are actually able to detect millions of airborne odors, and we can sense them in concentrations that are surprisingly small.

One of the most important functions for the sense of smell is allowing us to decipher foods and contaminants that are bad for our health. There’s a reason, for example, that rotten meat smells bad to a human; we have evolved to associate the smell with something unhealthy. The ones that found the smell disgusting lived and passed on their aversion; in this way, we steadily gained an aversion for rotten, repulsive things.

And this sense of smell continues to serve us today in ways that may not seem obvious. By helping us sense foul odors in the home, the nose is actually protecting our health. It’s detecting molecules in the air and sending a warning to the brain. How we respond to that warning, however, is entirely up to us…


The Potential Causes of Bad Odors in the House

Sewer Odors

From unused bathrooms to kitchen sinks, the smell of sewage can often permeate from our drains. This is especially common in unused bathrooms, which can give off a sulfuric, rotten-egg stench.

What’s causing this issue?
Drains have a U-shaped pipe near the bottom that holds water, which acts as a barrier between the sewer pipes and the sink. If left unused, the water can eventually evaporate, allowing the stench to move into your bathroom. If you don’t run water into the drain regularly, you’ll eventually have a sewer gas smell in your home, similar to a rotten egg odor.

Even if you don’t use a bathroom regularly, it’s best to run water down the drain at least weekly, which will help remove some of the gasses and effectively recharge the water seal that protects your home. This will help the smell go away and the bathroom will be far more pleasant if someone has to use it.

Lingering Smoke

From the moment you walk in a house, you can tell if someone has smoked inside. Cigarette smoke is a pervasive odor that embeds itself in fabrics, carpets, walls, and flooring, leaving a lingering odor that is difficult to remove.

The harms of cigarettes are well documented, so we won’t go over them here, but you should understand that the chemicals that make cigarettes so dangerous don’t disappear when the cigarette is extinguished.

The chemicals and carcinogens actually stay in the area and settle on surfaces or fabrics, waiting to be released at a later time. Called thirdhand smoke, this puts people at risk from the common harms of cigarette-smoke, long after smoke has disappeared from the air.

Removing cigarette smoke is a difficult task, but it’s far from impossible. You need to take an approach that encompasses the entire home from top to bottom. Cleaning the walls and ceiling may help, and you could use a treatment that will neutralize the chemical odors that are left from smoke.

You could also repaint the interior, which will cover the unsightly smoke stains and seal in harmful contaminants. If you decide to paint, use a sealer and primer, which will effectively trap the contaminants.

If the home has been smoked in for years, it’s probably best to have the carpets steam cleaned, which will help remove microscopic particles. If the carpet is seriously damaged, you may need to have it replaced.


If you have ever noticed a musty smell in your home, there’s a good chance that you have mildew or mold growing somewhere inside. Mold is one of the most common sources of smells in the house, and it can grow in many places but is most common in damp areas, especially the basement but also bathrooms and kitchens.

Mold is not just smelly, it can actually be toxic. Mold also releases microscopic spores that are used for reproduction, and these spores, which float on the air like pollen, can be inhaled, causing respiratory and allergy issues.

Getting rid of mold should be considered a two-phase process:Phase 1 is eliminating the source of moisture, which will reduce the musty smell. Mold feeds off moisture in the home, and even dampness in the air is a possible source of water for mold.

Make sure your pipes are sealed, your basement is dry, and your windows, doors, and other areas are not leaking water. You may also want to run a dehumidifier to reduce the amount of moisture in the air. By reducing moisture sources, you reduce the chances of future mold growth.

Phase 2 will be to clean the mold that has already grown. Using cleaning solutions and a little effort, you can remove mold from the home and keep it from coming back. Using a cleaning solution of bleach and water, you can kill the mold where it lives.

There are also chemicals made specifically for mold, but if the problem is significant, you may want to use a professional mold-removal service, which will virtually guarantee the mold is removed completely from your home. 


Natural gas, which is used for cooking and heating all over the country, is an odorless, colorless gas. In its natural state, it is completely undetectable, making it an extremely dangerous hazard when it leaks into the home. For this reason, natural gas is given an additive that makes it smell like rotten eggs. This additive helps you detect a gas leak and allows you to take the appropriate steps before a fire or explosion.

If you smell a light odor of gas in the home, check your burner valves and pilot lights to make sure no sources of gas have been left on. If you can’t find the source, open your windows and call a professional immediately.

If the smell is particularly strong, don’t stay in the house; instead, treat the situation like an emergency (which it is) and leave the home. Call 911 from a safe distance for emergency services, then let trained professionals handle the issue. Don’t take chances trying to solve the issue, as a spark could trigger a fire or explosion.

Trash Smells

After just a week, your household trash can become extremely disgusting, radiating smells that linger throughout the kitchen and into the entire home. From old leftovers to thrown out vegetables, your trash can become a central source for odors, but you don’t have to ignore it.

There are many different strategies that you can use to reduce the smells coming from a trash can. One tried-and-true strategy is to simply sprinkle baking soda in the bottom of the trash can, where is will absorb odors.

When it comes time to scrub out the bottom of the can, you simply rinse away the baking soda and away goes the odor. If you need to get tough with the smell, you can use a bleach solution to attack the odors while killing germs. Regular rinsing and cleaning of the trash can is usually enough to keep smells down, but you have to do it often. 

Pet Odors

While the smell of your pets may not be a significant health issue, dirty or wet pets can certainly be unpleasant. In some cases, dogs and cats may have “accidents” on the carpet, and animals that go in and out of the home can pick up odors and drag them into the house.

Getting rid of pet smells will require you to first pinpoint the issue. The smell may be coming directly from the pet, but they could also be coming from the carpet, furniture, or bedding where the pet sleeps.

If your pet stinks, the obvious solution is a bath. Washing their fur is important, but you may want to wash their paws as well to remove dirt and anything else the animal has picked up during their little outdoor adventures. Steam cleaning the carpet may also be useful, and you’ll want to consider spot cleaning with a stain remover to eliminate the issue.

Decaying Animals

Of all the issues with household odors, this is arguably the most repulsive. But it’s one that certainly needs to be addressed. Decaying animals, ones as small as a mouse, can create a strong, pungent odor in the home, and if they aren’t removed, they will become a significant problem.

If you smell a dying animal, start by checking behind appliances and various corners of the home. Obviously, you’ll want to start in the area where the smell is worst. If you can’t find the source, you may need to call professional help to remove the issue from your home.

Tips for a Fresh Home with Clean Air

Regardless of the source, there are many things you can do to improve the overall quality of the air in your home. These tips will help you maintain fresh, clean, pleasant air, all without filling your home with harmful artificial chemicals.

First, we need to discuss whether or not you should use artificial air fresheners and scented candles. Aerosol sprays, for example, are listed by the EPA as a source of volatile organic chemicals, or VOCs.

VOCs are chemicals that have short and long-term health implications, and can cause issues ranging from throat irritation to cancer. Scented candles can also be an issue, as they also release VOCs and other chemicals. For these reasons, it’s often best to scent the air with natural options.

You should also avoid using ozone generators to remove strong foul odors. These machines can remove smells, but they also create ozone, which is a harmful contaminant linked to numerous health issues.

If you want to scent the air in your home, it’s best to use natural fragrances. Essential oils, for example, can be placed in a diffuser or in a bowl to give a natural aroma all through the home.

You can also simmer spices, including cinnamon or cloves to create a healthy scent all through the house. You can also create your own potpourri from flowers, fruit rinds, berries, and other items to improve the smells radiating through your house.

Possibly the most important step you can take, however, is to simply open the windows and let fresh air permeate your home. Assuming the weather is nice and the outdoor air is not contaminated by pollen, smoke, car exhaust, or industrial pollution, opening your windows is one of the best ways to make your home clean and fresh.

Letting outdoor air into the home will dilute many of the harmful chemicals that are often found in the home, and it will clear away many of the foul odors that you’re working so hard to remove!

Using an Air Purifier to Reduce Odors

If you want to take a proactive approach to reducing smells in your home, an air purifier from Oransi is a great choice. With advanced technology, including activated carbon, our air cleaners can remove the molecules that create the smell in your home.

Contact us today to learn more about advanced air purifiers from Oransi.