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Research Summary: Volatile Organic Compounds and Air Fresheners

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Contributors:

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

What are volatile organic compounds?

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

How do VOCs in air fresheners impact health?

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.

What regulations exist?

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.

What can I do?

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:

  • Address the root of the problem: When odor becomes an issue in indoor spaces, consider addressing the source of the unpleasant odor instead of using air fresheners to mask it. Such an approach may even help address other indoor air quality issues.
  • Before installing products with high VOCs, such as new carpet, in buildings, let them stay outside to release their VOCs.1
  • In spaces where occupants have higher breathing rates, such as gyms and sports facilities, using air fresheners can lead to elevated exposure risks. Therefore, it is recommended to avoid air fresheners particularly in those spaces; e.g. burning candles and incense in yoga studios.
  • Natural ventilation: A simple mitigation measure is to open the windows and increase the air change rate with natural ventilation.25
  • Mechanical ventilation: If you live in an area with poor outdoor air quality or with extreme outdoor air temperatures where natural ventilation is not feasible, consider increasing the air change rate by increasing the fresh air intake of the building’s heating, ventilation, and air conditioning (HVAC) system.

References

  1. American Lung Association. Volatile Organic Compounds. (2018). Available at: https://www.lung.org/our-initiatives/ healthy-air/indoor/indoor-air-pollutants/volatile-organic-compounds.html. (Accessed: 16th May 2019)
  2. U.S. Environmental Protection Agency. Technical Overview of Volatile Organic Compounds. (2017). Available at: https:// www.epa.gov/indoor-air-quality-iaq/technical-overview-volatile-organic-compounds#main-content. (Accessed: 16th May 2019)
  3. Agency for Toxic Substances and Disease Registry. Toxic Substances Portal: Acetone. (2011). Available at: https://www. atsdr.cdc.gov/substances/toxsubstance.asp?toxid=1. (Accessed: 16th May 2019)
  4. Agency for Toxic Substances and Disease Registry. Toxic Substances Portal: Benzene. (2011). Available at: https://www. atsdr.cdc.gov/substances/toxsubstance.asp?toxid=14. (Accessed: 16th May 2019)
  5. Agency for Toxic Substances and Disease Registry. Toxic Substances Portal: Formaldehyde. (2011). Available at: https:// www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=39. (Accessed: 16th May 2019)
  6. Nazaroff, W. W. & Weschler, C. J. Cleaning products and air fresheners: exposure to primary and secondary air pollutants. Atmos. Environ. 38, 2841–2865 (2004).
  7. U.S. Environmental Protection Agency. Volatile Organic Compounds’ Impact on Indoor Air Quality. (2017). Available at: https://www.epa.gov/indoor-air-quality-iaq/volatile-organic-compounds-impact-indoor-air-quality#main-content. (Accessed: 16th May 2019)
  8. National Institute of Environmental Health Sciences. Chemical in Many Air Fresheners May Reduce Lung Function. (2006). Available at: https://www.niehs.nih.gov/news/newsroom/releases/2006/july27/index.cfm. (Accessed: 16th May 2019)
  9. National Library of Medicine. Volatile Organic Compuounds (VOCs): Your Environment, Your Health. (2017). Available at: https://toxtown.nlm.nih.gov/chemicals-and-contaminants/volatile-organic-compounds-vocs. (Accessed: 16th May 2019)
  10. Azimi, P., Zhao, D., Pouzet, C., Crain, N. E. & Stephens, B. Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments. Environ. Sci. Technol. 50, 1260–1268 (2016).
  11. Miller, S. L., Branoff, S. & Nazaroff, W. W. Exposure to toxic air contaminants in environmental tobacco smoke: an assessment for California based on personal monitoring data. J. Expo. Anal. Environ. Epidemiol. 8, 287–311 (1998).
  12. Klepeis, N. E. et al. The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. J. Expo. Anal. Environ. Epidemiol. 11, 231–52 (2001).
  13. U.S. Environmental Protection. Report to Congress on indoor air quality: Vol II: Assessment and control of indoor air pollution. EPA/400/1-89/001C. (1989).
  14. Kim, S., Hong, S.-H., Bong, C.-K. & Cho, M.-H. Characterization of air freshener emission: the potential health effects. J. Toxicol. Sci. 40, 535–550 (2015).
  15. National Resources Defense Fund. New Study: Common Air Fresheners Contain Chemicals That May Affect Human Reproductive Development. (2007). Available at: https://www.nrdc.org/media/2007/070919. (Accessed: 16th May 2019
  16. Singer, B. C. et al. Indoor secondary pollutants from cleaning product and air freshener use in the presence of ozone. Atmos. Environ. 40, 6696–6710 (2006).
  17. Wallace, L. A., Pellizzari, E., Leaderer, B., Zelon, H. & Sheldon, L. Emissions of volatile organic compounds from building materials and consumer products. Atmos. Environ. 21, 385–393 (1987).
  18. California Air Resources Board (CARB). 1997 Consumer and Commercial Products Survey – Summary of Sales and Emissions (as of 3/21/00). (2003).
  19. Steinemann, A. Ten questions concerning air fresheners and indoor built environments. Build. Environ. 111, 279–284 (2017).
  20. California Office of Environmental Health Hazard Assessment (OEHHA). The Proposition 65 List. (2018). Available at: https://oehha.ca.gov/proposition-65/proposition-65-list. (Accessed: 16th May 2019)
  21. Liu, X., Mason, M., Krebs, K. & Sparks, L. Full-Scale Chamber Investigation and Simulation of Air Freshener Emissions in the Presence of Ozone. Environ. Sci. Technol. 38, 2802–2812 (2004).
  22. Agency for Toxic Substances and Disease Registry. Toxic Substances Portal: Dichlorobenzenes. (2011). Available at: https://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=126. (Accessed: 16th May 2019)
  23. Steinemann, A. Fragranced consumer products: exposures and effects from emissions. Air Qual. Atmos. Heal. 9, 861–866 (2016).
  24. California Legislature. Senate Bill No. 258 Cleaning Product Right to Know Act of 2017. (2017). Available at: https:// leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201720180SB258. (Accessed: 16th May 2019)
  25. Howard-Reed, C., Wallace, L. A. & Ott, W. R. The Effect of Opening Windows on Air Change Rates in Two Homes. J. Air Waste Manage. Assoc. 52, 147–159 (2002).