Many air fresheners employ carcinogens, volatile organic compounds and known toxins such as phthalate esters in their formulas. A Natural Resources Defense Council (NRDC) study of 13 common household air fresheners found that most of the surveyed products contain chemicals that can aggravate asthma and affect reproductive development. The NRDC called for more rigorous supervision of the manufacturers and their products, which are widely assumed to be safe:
The study assessed scented sprays, gels, and plug-in air fresheners. Independent lab testing confirmed the presence of phthalates, or hormone-disrupting chemicals that may pose a particular health risk to babies and young children, in 12 of the 14 products—including those marked 'all natural.' None of the products had these chemicals listed on their labels.
On September 19, 2007, along with the Sierra Club, Alliance for Healthy Homes, and the National Center for Healthy Housing, the NRDC filed a petition with the U.S. Environmental Protection Agency and the Consumer Product Safety Commission to report the findings.
The University of Bristol's Avon Longitudinal Study of Parents and Children (ALSPAC) found that exposure to volatile organic compounds through frequent use of air fresheners and other aerosols in the home was found to correlate with increased earaches and diarrhea in infants, and with increased depression and headaches in their mothers.
In 2008, Anne Steinemann of the University of Washington published a study of top-selling air fresheners and laundry products. She found that all products tested gave off chemicals regulated as toxic or hazardous under federal laws, including carcinogens with no safe exposure level, but none of these chemicals were listed on any of the product labels or Material Safety Data Sheets. Chemicals included acetone, the active ingredient in paint thinner and nail-polish remover; chloromethane, a neurotoxicant and respiratory toxicant; and acetaldehyde and 1,4-dioxane, both carcinogens. A plug-in air freshener contained more than 20 different volatile organic compounds, with more than one-third classified as toxic or hazardous under federal laws. Even air fresheners called "organic," "green," or with "essential oils" emitted hazardous chemicals, including carcinogens.
In 2009, Stanley M. Caress of the University of West Georgia and Anne C. Steinemann of the University of Washington published results from two national epidemiological studies of health effects from exposure to air fresheners. They found that nearly 20 percent of the general population and 34 percent of asthmatics report headaches, breathing difficulties, or other health problems when exposed to air fresheners or deodorizers.
Research at the University of Colorado at Boulder revealed a probable mechanism for the carcinogenic effects of mothballs and some types of air fresheners.
I just wanted to say that anyone who has their (home) toothbrush/paste hanging on a holder or sitting on the counter is at risk for fecal contamination!