Juan Reynoso, MPH/MUP, Harvard T.H. Chan School of Public Health, Harvard Graduate School of Design
Parichehr Salimifard, PhD, Harvard T.H. Chan School of Public Health
Volatile organic compounds (VOCs) are a diverse set of chemicals, liquids and solids, that can evaporate under ordinary atmospheric conditions.1,2 Some commonly known and used VOCs include acetone3 , benzene4 , and formaldehyde.5 VOCs are highly reactive; therefore, besides themselves being primary pollutants, they can also react with oxidants such as ozone and hydroxyl and nitrate radicals and produce secondary pollutants such as formaldehyde, acetaldehyde, glycol ethers, free radicals, and particles.6
Air fresheners do not clean the air, nor do they reduce air pollutants.
Because of their chemical properties, VOCs are used as essential ingredients in many products and materials. In fact, they are released by numerous commonly used consumer products including air fresheners, cleaning products, cosmetics, pesticides, paints, wax and polish products, and flooring.1,6-9 VOCs are also emitted by various indoor activities, such as smoking tobacco, dry cleaning, office printing, 3D printing, and using wood-fired stoves.1,7,9-11 Additionally, VOCs are also released by motor vehicle exhaust and, when in the presence of sunlight and nitrogen oxides, they are highly reactive and contribute to the formation of ozone and smog.1,2,9 Although VOCs are also present in outdoor environment, concentrations of VOCs in indoor environments are consistently higher than outdoors, and elevated concentrations can persist longer indoors.7 Moreover, since U.S. residents spend on average 90% of their time indoors,12,13 indoor exposure to VOCs are of particular concern. Hence, reducing indoor VOCs is critical for building occupants’ health.
Among indoor consumer products, the product category that releases the highest levels of VOCs is air freshener.14-17 An air freshener is a product that releases a fragrance in order to add a pleasant scent to the space or to mask bad odors. Air fresheners do not clean the air, nor do they reduce air pollutants.14 In 2003, the California Air Resources Board found air fresheners to have some of the highest per capita VOC emissions of any household, followed by cleaning products.18 Like air fresheners, cleaning products are also a major source VOCs emissions indoors. However, while there are objective health benefits in using cleaning products, using air fresheners has only perceived benefits.6 Nonetheless, air fresheners have a growing global market of over US $10 billion.19
VOCs commonly enter the body through two main pathways: 1) inhalation through the lungs and 2) skin contact with products that release VOCs.9 Some immediate symptoms that people may experience after exposure to VOCs include: eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment.1,7,9 Other long-term symptoms associated with exposure to VOCs include: allergic skin reactions, nausea, fatigue, vomiting, nosebleeds, difficulty breathing, and damage to the liver, kidney, and central nervous system.1,7,9 Among the VOCs commonly found to be emitted by air fresheners, benzene and formaldehyde are of particular concern, as they have been linked to cancer among humans.4,5,9,20 Toluene, ethylene, and limonene have also been found in air fresheners and been linked to toxic health effects.14,16,21 Furthermore, exposure to 1,4 dichlorobenzene from air fresheners has led to reductions in lung function8 and has led to decreased function of the liver, kidneys, eyes, and organs of developing embryos and fetuses.22
Among the VOCs commonly found to be emitted by air fresheners, benzene and formaldehyde are of particular concern, as they have been linked to cancer among humans.
Since over 70% of U.S. households use air fresheners at least once a week and their use in the rest of the world is also growing,15,19 millions of people around the world are at risk of the negative health impacts of VOCs. In particular, janitors and other cleaning personnel are exposed to higher levels of VOCs because of their frequent use of air fresheners and other cleaning products.6 It should also be noted that cigarette smokers and vulnerable populations (i.e. young children, older people, pregnant women, and people with asthma) are more susceptible to the effects of VOCs.9 Therefore, it is important to minimize exposure to air fresheners as much as possible.
At the federal level, there are no minimum regulations for air fresheners and there are no laws that require the disclosure of all ingredients in fragranced consumer products.23 However, in 2017, California passed the Cleaning Product Right to Know Act which, starting in 2020, requires manufacturers of air fresheners and other cleaning products to disclose the information related to chemicals contained in the product, on the product label, and on the product’s website, if those chemicals are known to the State of California to cause cancer or reproductive toxicity.24 Given the public reporting requirements of this new state law, all U.S. residents will benefit from learning about the VOCs and other chemicals emitted by air fresheners.
Foremost, the best way to protect yourself from the negative health impacts of air fresheners is to avoid their use altogether in your home and advocate for a fragrance-free policy in your workplace. It should be noted that ALL TYPES of air fresheners, even those referred to as “green”, “organic”, or “natural”, have VOC emission potential.19 However, if you live or work in a building where complete elimination of air fresheners is not an option, consider adopting the following strategies: