There are many sources of bad smells in and around the home including spoiled food, mold, volatile organic chemicals, leaky or backed-up pipes and drains, and pet odors. Mixing some household cleaners such as bleach and ammonia or acid can produce toxic fumes. Some toxic fumes such as carbon monoxide are odorless.
Malfunctioning HVAC system: A malfunctioning heating, ventilation, and air conditioning (HVAC) system can sometimes cause the smell of car exhaust to enter your house. This could be due to a problem with the ventilation system or a leak in the ductwork (1).
Phantosmia is a condition that causes you to detect smells that aren't actually in your environment. It can happen in one nostril or both — and the odors may be foul or pleasant. Common causes include colds, allergies, nasal polyps and dental issues. Treatment depends on the underlying cause.
Here's the most obvious reason - you might have leftover fumes from recent home projects. Even if you didn't use paint thinner, lots of products contain things called VOCs (volatile organic compounds) that give off similar smells while they dry.
Air out your house
Open up the windows in your home and bring in some clean, fresh air. This will help dilute the smell. The best thing to do is to start ventilating your home as soon as you notice any smoke smells in the house – to stop it from sticking to any of your furniture or clothes.
If you haven't recently used chemicals or paint, a strong chemical smell could indicate a gas leak, particularly from carbon monoxide. A distinctly chemical odor can result from a crack in the heat exchanger component of your furnace. This component cycles heat out of the combustion chamber.
Unlike particulate matter, gaseous pollutants like VOCs cannot be captured by regular HEPA filter based media. Instead, you need an activated-carbon filter to remove these chemicals.
If your house smells like rotten eggs, gases from your septic tank may be to blame. However, if you find yourself suddenly asking “why does my house smell like rotten eggs?” and the odor is severe, a dangerous gas leak may also be the problem. Check around gas appliances to see if the smell is worse there.
A freon gas leak smells like a combination of sweets, ammonia, paint, or cat urine. It has a very distinguishable smell, and freon is documented as a gas that has contributed directly to the destruction of the ozone layer, so definitely take note if you come across the smell.
Carbon monoxide gas is colourless and does not smell, so you cannot tell if it is around you.
Most people with phantosmia report it as an intermittent smell of something burnt, foul or unpleasant. Cigarette smoke and petrol are common but olfactory experiences can be varied. Sometimes it can be persistent. Smells are typically of something burnt, smoky, or foul but can be pleasant.
So if your new home smells like tobacco, it was likely caused by the previous occupant. If you have ruled out thirdhand smoke as the culprit, electrical faults may be the cause. When insulation on wiring gets too hot, it can emit an acrid smell that some people mistake for cigarette odour.
Smelling smoke, or experiencing phantom smells that are not actually present, can be a symptom associated with certain types of brain tumors. These olfactory hallucinations, known as phantosmia, can occur when a tumor affects the brain regions responsible for processing smell signals.
Phantosmia is a condition that causes you to smell odors that are not there. Phantosmia has several possible causes, including inflamed sinuses, upper respiratory infection, head injury, brain tumor, medication side effects, and Parkinson's disease. Mood disorders and schizophrenia can also involve "phantom smells."
Sometimes, gas is released from your furnace every time you start it. The odor is usually faint and should dissipate within a short time when you open the windows. If the odor seems to be spread across your house and does not go away, it is probably a leak. A leak could pose fire and pollution hazards in your home.
If you smell car exhaust in your home or a strong odor from furnace exhaust, this usually means that there's a problem with how your furnace is vented. Your furnace uses a vent pipe to get rid of gases that are created during the combustion process. If you have a high-efficiency furnace, it'll be vented with PVC pipe.
The smell of rotten eggs.
In its natural state, natural gas is odorless and colorless. To make gas leaks easier to detect, gas companies add chemicals called odorants to create a natural gas smell similar to sulphur or rotting eggs. The stronger this smell, the more likely it is that you have a gas leak.
An olfactory hallucination, known as phantosmia, makes you detect smells that aren't in your environment. The odors you notice in phantosmia are different from person to person and may be foul or pleasant. You may notice the smells in one or both nostrils.
Hydrogen Sulfide
The gas has a strong scent of rotten eggs, which makes it distinct from other, similar gases. If you detect this rotten egg scent and you are using hydrogen sulfide at your facility, this could be evidence of a leak.
The odor comes from volatile organic compounds, or VOCs for short. These are chemicals that easily evaporate at room temperature, releasing gases into the air. In paint, VOCs help keep the mixture liquid and easy to apply, but once the paint is on your wall, they start to evaporate – that's what causes the smell.
Any time there's a high chemical release in your house, such as from painting, construction, or gluing, the first line of attack is to let the space air out. Ventilate the contaminated air out of your house. After a fresh paint, it may take a couple of days for the VOC off-gassing to diminish.
AirDoctor is equipped with an activated carbon filter to remove odors and VOCs (volatile organic compounds).
VOCs can linger long after a fresh coat of paint dries, impacting indoor air quality for days, weeks, or even months.