Air fresheners are consumer products used in homes, or commercial products used in restrooms, that typically emit fragrance. There are many different methods and brands of air freshener. Some of the different types of air fresheners include sprays, candles, oils, gels, beads, and plug-ins. There are also solid and passive versions, which use ceramic material and water based ingredients - these combine and create a 'multi-phasing' effect which provides a constantly evolving fragrance. Some air fresheners have been known to have chemicals that provoke allergy and asthma symptoms raising argument about how safe it is to use.
However, some air fresheners are VOC exempt, such as a passive, multi-phasing air freshener, that reduces the effects. Air freshening is not only limited to modern day sprays, air freshening also can involve the use of organic and everyday house hold items. Although air freshener is primarily used for odor elimination some people simply use air freshener for the pleasant odors they emit.
Air fresheners introduce fragrance into the air of interior spaces either as droplets which transition to vapor, or as the molecules of fragrance ingredients directly evaporating from a source. Fragrance diffuses into the air to mask other odors or to introduce a specific odor.
Removing the source of an unpleasant odor will decrease the chance that people will smell it. Ventilation is also important to maintaining indoor air quality and can aid in eliminating unpleasant odors. Simple cleaners such as white vinegar and baking soda, as well as absorbents like zeolite, are effective at removing odors. Other solutions are bad smells removers that are adapted to different types of odor. The result is odor-free air that is also pollution-free and safer to breathe. Some house plants may also aid in the removal of toxic substances from the air in building interiors.
Fragrances have been used to mask odors since antiquity. A variety of compounds have been used over the past two millennia for their abilities to create pleasant aromas or eliminate unpleasant odors.