What is Offgassing?

Mary McMahon
Mary McMahon

Offgassing or outgassing refers to the release of chemicals from various substances under normal conditions of temperature and pressure. Offgassing can take a variety of forms, and is an issue of concern for some people, since some of the chemicals released during the offgassing process are potentially harmful. A number of studies have been conducted on offgassing of various chemicals in an assortment of environments with the goal of determining the risk of offgassing to human health.

Offgassing may occur when a room is painted.
Offgassing may occur when a room is painted.

You can probably think of a few examples of outgassing. For example, when an area is painted, varnished, or stained, a strange scent often lingers for a few days. This is offgassing, and the strange scent is caused by volatile organic compounds, some of which are potentially hazardous. Many plastics also offgas. Inhaling these chemicals or absorbing them through the skin and mucus membranes can be very harmful.

Offgassing occurs when stain is applied to an area.
Offgassing occurs when stain is applied to an area.

Offgassing is a special issue of concern when it takes place in an enclosed environment. For example, new cars have a distinctive and famous smell which is actually caused by offgassing. Some people fear that the enclosed environment of the car concentrates the chemical compounds, since they cannot escape, and this could make riding in a car dangerous. The enclosed space concern also explains why people are told to open windows and doors after painting, to help the room dry and to keep the space ventilated.

When smelly chemicals outgas, people are made aware of the issue. Of greater concern is chemicals which do not have odors, as some of these chemicals are very dangerous, and they can cause immediate health effects as well as long term damage. It is possible to use specialized chemical sniffers to search for such chemicals in the air; sniffers can also determine the levels of these chemicals to see how dangerous they are. Offgassing can also be harmful to the environment.

In some cases, dangerous levels of offgassing have been linked to cheap building materials. For example, the inexpensive portable classrooms used by many school districts as a temporary measure to accommodate growing student bodies have been linked with health problems caused by the offgassing of chemicals like formaldehyde. Ironically, levels of offgassing tend to be very high in these structures because of the materials used as fire retardants. These materials are designed to make portable classrooms safer for students and teachers, and sometimes the manufacturer is unaware of the hidden dangers.

New cars have a distinctive smell which is caused by offgassing.
New cars have a distinctive smell which is caused by offgassing.
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

You might also Like

Readers Also Love

Discussion Comments


All these posts bring up many great questions. Each has a great answer and I encourage people to look into getting an air exchanger because it helps to exhaust the offgassing from the house and replace it with fresh air from outdoors.

I encourage you to look or call your local HVAC contractor to ask if he can refer you to someone that deals with these problems.


I am planning to remove the carpet in my bedroom and replace it with wood floors. I am asthmatic and allergic to dust mites. But I am concerned with finding lowest VOC floors and whether to use a laminate or engineered floor or a wood floor to be sanded and stained etc.


Is carpet off gassing bad for your health? I just had a new carpet installed and it stinks to high heaven. I have been getting headaches, and my eyes have been itching since it was installed two days ago. Should I call the company that installed the carpet? Should I leave my house for a few days and let the gas dissipate? How long will it take for my carpet to off gas and is it still off gassing even if I cannot smell it? I am starting to worry that this new carpet was not such a good idea.


@chicada- I have noticed that furniture stores often sell furniture made with formaldehyde free wood. I recently bought a couch from IKEA, and it was certified low VOC. There was no out gassing once I brought the couch home and removed the pieces from their packaging.

Many retailers and manufacturers are realizing that people are becoming much more health conscious, especially concerning indoor air quality. If you look hard enough, you will be able to find reasonably priced goods that will not vent harmful gases into you and your children's home.


@Chicada- Formaldehyde causes cancers in laboratory animals, but because researchers cannot pinpoint the source of cancer in humans, it is labeled as a possible carcinogenic gas. In small concentrations, formaldehyde is mainly a skin, nose, and eye irritant, and can affect respiratory function. Some people also have a much lower tolerance to formaldehyde than others, being affected by the gas at levels below what he or she can even smell.

Formaldehyde is most commonly found in wood products, especially cheaper wood products. The chemical is relatively cheap so it is often used in things like cheap particleboard, cabinet wood, and interior wood on manufactured homes. Formaldehyde is often a concern with manufactured housing, since cheap wood is often used in these structures. If you are concerned with the effects of formaldehyde, you can buy low VOC latex paint to coat the affected surfaces. This will prevent the formaldehyde from off gassing, but it will not get rid of the underlying problem.


What are the effects of formaldehyde off gassing? What types of products contain formaldehyde, and how long will those products continue to off gas once they have been opened/used/installed? What other chemicals are considered VOCs, and how common are they in every day products?

I never used to think of these things, but now I have a young child and I am concerned over her safety. I do not want her t breathe in these harmful chemicals and get cancer or a nervous system disease later in life. The article was great, but I would like more information specifically on formaldehyde. Thanks.

Post your comments
Forgot password?