Air fresheners make the indoor atmosphere aromatic by spreading fragrances into the air through different methods. They contain a variety of ingredients and chemicals including aerosol propellants, formaldehyde, petroleum distillates and p-dichlorobenzenes.
Air fresheners are available in various types including candles, sprays, plug-ins, beads, gels and oils. Some non-commercial air fresheners use organic household items.
Some air fresheners use adsorbents, such as zeolite or activated charcoal, to get rid of unpleasant odors. Oxidizing agents are used to oxidize and eliminate the odor’s organic sources. Air sanitizer works by inactivating airborne bacteria that produce odors. Other air fresheners use masking, in which a fragrant scent is released into the air to mask the odor. Some air fresheners also contain surfactants and soaps.
Instant-action air fresheners, such as aerosol sprays, are composed of a propellant and fragrance that are put under pressure in a secure metal or glass container. They have a button containing a spray nozzle, called the "actuator," which opens the valve when pushed. Fragrance is released in the form of a mist of droplets when the valve is opened.
Continuous-action air fresheners include scented candles; incense burners; devices that use a heat source, such as a candle flame, to turn fragrance into vapor; and wall plug-ins that use heat to vaporize a scent or piezoelectric technology to aerosolize the fragrance formulation.