Cooking is bad for indoor air quality.
So, you burnt your morning toast and it’s 2 hours later and you can still smell it. Now you are wondering just what could be lingering around in your air and just how healthy or unhealthy it is for you and your family to be breathing. You are starting to realize that cooking is bad for indoor air quality.
Most folks never think about just how dirty their home’s air really is. Estimates say that the average home indoor air quality is 2 to 5 times worse than what is outside. Worse yet is the fact that we Americans are now spending up to 90% of our lives indoors. You can see why some researchers are calling poor indoor air quality one of the greatest threats to the overall health and well-being of the majority of U.S. residents that exists today.
Cooking, in all its forms, is one of the biggest contributors to poor home air quality. Cooking raises particulate matter levels in our air to potentially dangerous levels. The majority of these particles are very small and most dangerous type to breathe in, usually less than 1 micron. Our home’s air quality is affected by volatile organic compounds (VOCs) that increase to unhealthy levels during cooking. Combustion gases such as carbon monoxide (CO) and nitrogen dioxide (NO2) increase to dangerous levels when using gas powered ovens and cooktops.
Studies suggest that just about any type of cooking spews off large amounts of particles, but stovetop frying seemed to be the worst offender. Baking too, surprisingly, causes large numbers of these tiny particles to enter our air. Even electric ovens emitted particulate albeit less that with gas ovens.
Why do we worry about tiny particles in our air?
When measuring indoor air quality, one of the components that we look for are the very fine particles that are in our air. Scientist use the parameter PM2.5 to refer to refer to these particles. PM2.5 refers to atmospheric particulate matter that is less than 2.5 microns in diameter. To put this number into perspective, the human hair is about 70 microns across.
So what makes these tiny particles so much more of a concern? Well, there are a couple of reasons. First, because they are so small, they tend to linger in the air for long periods of time as compared to their heavier counterparts that tend to fall out of the air rather quickly. This increases the chance of them being inhaled into our bodies.
Secondly, PM2.5 particles are able to penetrate deeper into the lungs and even enter our bloodstream. Studies have shown that these particles can contribute to lung disease as well as heart disease. Because they can get into our lungs, they trigger all types of respiratory problems including allergic reactions and asthma.
PM2.5 particles tend to be combustion products and other organic compounds. Both of which are generated in large amounts when we are cooking.
What VOCs are emitted when cooking?
Volatile organic compounds, or VOCs as they are known, are defined in most scientific literature as organic chemical compounds whose composition makes it possible for them to evaporate under normal indoor atmospheric conditions of temperature and pressure.
Some common VOCs generated from cooking include:
Benzene – A carcinogenic chemical produced by gas appliances. Also found in cooking oil fumes.
Formaldehyde – Generated by gas appliances and is carcinogenic to humans.
Acetaldehyde – Created by heating cooking oils and is considered a probable human carcinogen.
Acrolein – Produced from burning fats such as oils and animal products. Known to cause respiratory irritation.
This is not a complete list by any means. The types of VOCs emitted during cooking can vary greatly depending on what foods are being cooked, how they are being cooked, and what they are being cooked on.
What other dangerous substances are produced from cooking?
Carbon Monoxide – This colorless, odorless, and tasteless chemical is most hazardous because we can’t detect it through our senses, thus we don’t recognize when it is building up in our homes. CO is created from the combustion of fossil fuels like the gases we cook with, primarily natural gas and propane.
Nitrogen Dioxide – NO2 is a highly reactive gas created, mainly, from the burning of fossil fuels. It inflames the lining of the lungs, causing respiratory irritation and reduced immunity to lung infections. It can make asthma symptoms worse and, with chronic exposure, can trigger asthma in those without the disease.
Using a gas oven or stovetop will vent concentrations of these dangerous gases that are above EPA recommended exposure levels into your home’s air. Always make sure you are using ventilation when cooking on a gas appliance. If you take away nothing more from this article than this fact, your health and the health of your family will be better off for it.
What are cooking oil smoke points?
Using the right type of cooking oil can drastically reduce stovetop emissions into your air. When cooking oil burns, it smokes. This smoke is chock full of unhealthy VOCs and other particulates. Oils like corn oil, peanut oil, and canola oil have higher smoke points which means they start to break down and burn at higher temperatures. Be careful using extra virgin olive oil because it is on the lower end of the scale and will smoke at relatively low cooking temperatures.
Frying anything with cooking oil spews tiny oil droplets, PM2.5, into the air along with other hazardous substances like VOCs. Heating the oil past its smoke point just kicks up the emission of these hazardous materials into high gear.
How can I decrease effects of cooking on indoor air quality?
Use ventilation when cooking.
Use a range hood that vents to the outside if possible. If your range hood does not vent out of the building but, instead, vents back into your home’s air after passing through a filter, make sure that filter is maintained properly. If neither of these are an option, use another ventilation type or use a fan and open a window.
Cook on back burners.
Most range hoods that mount to the wall do not extend far out enough to cover all burners on most stovetops. By cooking on the back burners, a large amount of the fumes will be captured and pulled out verses using the front burners.
Avoid self-cleaning ovens.
More precisely, avoid using this feature of your oven. Almost all Modern ovens have a convenience feature known as the self-cleaning feature. This feature does nothing more than heat the oven to a very high temperature, often close to 900°F or more. This high temperature literally bakes the layered-on food and grease build-up until there is nothing left but ashes. Along with the convenience comes a price. This process releases massive amounts of noxious fumes from both electric and gas powered ovens.
Use a high quality air purifier.
Get a HEPA equipped air purifier for your home and make sure it is on all the time. Make sure that the air purifier you select has an activated carbon filter element as well as the HEPA filtration. The HEPA filter will capture the tiny particles but it is not effective at reducing VOCs in the air. That is where the activated carbon filter comes into play. Activated carbon basically acts like a sponge in capturing VOCs and removing them from the air.
What is the range hood?
The range hood is the vent fan and canopy located over the cooking surface of your stove. It usually vents through a pipe to the outside of your home. This is the most desirable type of range hood to have in your kitchen but there are range hoods that do not have a vent pipe and instead will vent back into your home. These usually utilize a charcoal filter to trap contaminates but they are not very effective in trapping those PM2.5 particles that are so hazardous for us.
If you are not sure which type you have, look above the unit, usually inside the cabinet doors, if it is an under-cabinet model. If you see a metal pipe extending up through the ceiling then it is probably vented to the outside.
There are several types of range hoods. The under-cabinet model we just talked about can be just the canopy and vent fan or it can be a microwave oven with the vent fan integrated into it. This is actually a very popular configuration in most homes.
Another type of range hood is the ceiling or island mounted range hood. These units extend down from the ceiling without any attachment to a wall. These are usually designed with wider canopies than are the wall-mount varieties and thus afford more coverage over the cooktop resulting in better collection of particulates.
Range hoods should be used continuously when cooking to vent out the harmful fumes that are created. Underutilization of the valuable appliance is a major cause of poor indoor air quality in most homes today. Until now, most people would only use this device sparingly, when cooking particularly pungent foods or when the occasional kitchen accident occurs and food gets burned.
Chemical contaminates can’t always be detected by smell alone so using the range hood all the time is typically the best idea. Again, if your range hood does not vent to the outside, you need to find another way to ventilate your home. Opening windows and using fans to direct airflow is a good method to do this if you do not alternative mechanical ventilation available.
Cooking puts dangerous particulate matter and chemical compounds into your home’s air. Many of these substances are known carcinogens and respiratory irritants. Ventilation is the most effective method to control these contaminates short of not cooking at all in your home.
Range hoods that vent to the outside should be used continuously when cooking and try to only use the back burners if you use a wall-mounted unit that does not fully cover the stove-top.
Finally, avoid using the self-cleaning feature of your oven. It can emit a great deal of particulates and VOCs into your home’s air, making it dangerous to breathe. If you must use it, make sure the windows are open and go outside for a while. Try using alternative oven cleaning methods that are all natural and won’t contribute to poor indoor air quality.