Air fresheners emit potentially harmful volatile chemicals, such as pinene and limonene. Don’t assume that “green” ones are any safer.
Researchers from the University of Washington tested eight popular air fresheners, six of which claimed to be “green” or “organic” or to contain “essential oils.” All the products, whether sold as sprays, gels, solids or discs, were found to release at least one chemical classified as toxic or hazardous—and some emitted as many as eight. Moreover, some “green” products emitted chemicals listed as probable carcinogens by the EPA for which there are no safe exposure levels.
Manufacturers are not required to disclose specific fragrance ingredients in air fresheners or other household products (they may simply list “natural fragrance" or “organic perfume” on the label, for instance), so you usually have no way of knowing what’s in your freshener, "green” or otherwise.
The study, in Environmental Assessment Review, did not look at the possible health risks of these products, but some previous studies have found that 20 percent of people report adverse reactions to them, such as headaches and difficulty breathing. And their long-term effects are unknown.
You don’t need air fresheners anyway. They mask odors rather than eliminate them—and if you constantly feel the need to cover up odors, you may have a bigger problem in your home to deal with. For more natural air freshening, open windows and doors when possible, use venting systems in bathrooms and kitchens and turn on fans or air conditioners with the vent open.