There have been various concerns about air fresheners having adverse health effects, due to factors including harmful ingredients, secondary substances formed by the chemical interactions of ingredients with other substances, allergy-provoking ingredients, misuse, and accidental injury.
Harmful ingredients and secondary substances 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. Research at the
University of Colorado at Boulder revealed the carcinogenic nature of
paradichlorobenzene (PCDB) and
naphthalene, present in some types of air fresheners. The pesticide substances were mainly used in mothballs but also in room sprays and toilet rim blocks. 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 C. 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. A report issued in 2005 by the Bureau Européen des Unions de Consommateurs (
BEUC) found that many air freshener products emit
allergens and toxic
air pollutants including
benzene,
formaldehyde,
terpenes,
styrene,
phthalate esters, and
toluene. In the United States, since 2020 air fresheners (as well as cleaning solutions and products used to clean cars) have been required to list any of their ingredients which are on California's list of 2,300 harmful chemicals, based on a California law passed in 2017. A California study in 2006 found that the prominent products of the reaction of terpenes found in air fresheners with ozone included formaldehyde,
hydroxyl radical, and secondary
ultrafine particles. It is not clear if manufacturers will need to list such chemicals which are not ingredients, but form during deployment and are thus able to affect human health.
Allergens and irritants 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.
Misuse and accidental injury Air freshener aerosols with certain propellants are susceptible to misuse as an
inhalant. Air fresheners have also been used to cause
aerosol burn. In rare cases aerosol burns are reported to have been caused by air freshener canisters exploding. ==Alternatives to fragranced air fresheners==