Is Synthetic Fragrance the New Secondhand Smoke? The Studies

I get migraines and feel sick after smelling many common scented products, so I come to this topic with a bias. My opinion is that synthetic fragrance will one day be regulated in shared indoor spaces the way secondhand smoke is now. This article covers what researchers have measured coming off scented products, what the health studies report, where that evidence is thinner than the evidence on secondhand smoke, and how I keep a house with four pets smelling clean without fragrance.

Key takeaways

• The word "fragrance" or "parfum" on a US label can stand for a blend drawn from the 3,619 ingredients the fragrance industry reports using, and US law does not yet require the individual ingredients to be named.
• In a 2016 survey of 1,136 US adults, 34.7% reported health problems such as migraine headaches or breathing difficulty around fragranced products. The answers were self-reported, so the survey shows how common the complaint is and cannot show cause.
• Terpenes from scented products react with ozone in indoor air and form formaldehyde and nanoparticles. A 2025 Purdue University study measured nanoparticle levels from scented wax melts that were comparable to gas stoves and diesel engines.
• Secondhand smoke has decades of long-term studies behind it, but the fragrance research cited here is made up of surveys, air measurements, biomonitoring and cell tests. The comparison in the title is my opinion.
• Essential oils release many of the same terpenes as synthetic fragrance.
• At home I use fragrance-free products and a homemade cleaning spray made from isopropyl alcohol and castile soap.

Disclaimer: This article is for education only and does not diagnose, treat or prevent any condition. I am a clinical herbalist, not a physician. Do not start, stop or change a medication or a fertility protocol because of anything written here, and take questions about asthma, migraines, pregnancy or fertility treatment to a qualified clinician who knows your history. People react differently to the same exposure. If you have trouble breathing, call your local emergency number.

What is synthetic fragrance made of?

Evidence: strong. The ingredient count comes from the fragrance industry's own list, the labeling rules come from statute text, and the emission numbers come from lab tests of store-bought products.

The International Fragrance Association (IFRA), the industry's trade group, publishes a Transparency List of the ingredients its member companies report using. The 2022 edition lists 3,619 ingredients: 3,224 used for scent and 395 functional ingredients.^[1]

A finished fragrance is a blend of some of those ingredients, and on a US cosmetic label the whole blend can appear as the single word "fragrance." The Modernization of Cosmetics Regulation Act of 2022 directed the FDA to write a rule naming the fragrance allergens that must be listed individually, with a proposed rule due 18 months after December 29, 2022. That deadline passed in June 2024, and no proposed rule had been published when this article was updated in October 2026.^[2] Cleaning products fall outside that law, and the University of Washington researchers cited below noted that manufacturers are not required to disclose any ingredients in cleaning supplies.^[3]

California and the European Union require more disclosure:

• California cleaning products: the Cleaning Product Right to Know Act requires a label to list fragrance allergens present at or above 0.01% (100 ppm), or to carry the statement "Contains fragrance allergen(s)."^[4]
• California cosmetics: since January 1, 2022, companies have reported fragrance and flavor ingredients that appear on 23 designated lists to the California Safe Cosmetics Program, along with fragrance allergens at or above 0.01% in rinse-off products and 0.001% in leave-on products.^[5]
• European Union: Regulation 2023/1545 added 56 fragrance allergens to the 24 that already had to be named on cosmetic labels. Products that do not comply could be placed on the EU market until July 31, 2026, and can stay on shelves until July 31, 2028.^[6]

What lab tests found in scented products

A University of Washington team tested 25 commonly used scented products and detected 133 different volatile organic compounds (VOCs), an average of 17 per product. Nearly a quarter of those compounds are classified as toxic or hazardous under US federal laws, and only one emitted compound was named on a product label.^[3]

A 2018 University of Melbourne study of 42 fragranced baby products, including shampoos, lotions and body washes, identified 228 different VOCs, 43 of them classified as potentially hazardous. Only 5% of the emitted compounds were disclosed on a label, safety data sheet or website. Products sold as green, organic or all-natural emitted the most common compounds at levels that were not significantly different from regular products.^[7]

In 2023 the Environmental Working Group tested 30 cleaning products and air fresheners in an air chamber and quantified 530 different VOCs, 193 of them listed as hazardous by California or European regulators. Conventional products generally emitted more VOCs than products marketed as green, and the gap was largest against the fragrance-free ones.^[8]

What fragranced products release into indoor air

Evidence: strong for the emissions and the air chemistry, which were measured in homes, an office and test chambers. The health effects of the particles that form are not yet established.

The compounds found most often in the baby product tests included limonene, acetaldehyde, ethanol, alpha-pinene and linalool.^[7] Limonene and pinene are terpenes, the compounds behind citrus and pine scents, and they react with ozone that enters buildings from outdoor air. A 2020 review by researchers at IMT Lille Douai in France describes the products of that reaction as secondary pollutants, including formaldehyde and secondary organic aerosols, which are particles that form in the air after a product is used.^[9]

Two studies from Indiana University and Purdue University measured those particles as they formed:

• Floor cleaner in an office: cleaning the floor with a commercial cleaner raised indoor terpene levels to about 100 times the outdoor level, and new particles smaller than 10 nanometers appeared within minutes. The dose reaching the respiratory tract was comparable to or higher than the dose from breathing vehicle-related aerosols.^[10]
• Scented wax melts in a test house: terpenes from the melts reacted with indoor ozone and produced nanoparticle concentrations above one million per cubic centimeter, comparable to combustion candles, gas stoves, diesel engines and natural gas engines. The authors wrote that the toxicology of these newly formed particles still needs study.^[11]
• Reed diffusers in two bathrooms: a 2023 study sampled the air around a bottled fragrance with bamboo diffuser sticks in two small student bathrooms. The main VOCs were ethanol, propylene glycol and 3-ethylbenzaldehyde, and the bathroom with less ventilation had the higher concentrations.^[12]

An Italian model-room study that compared common indoor sources recorded its two highest VOC readings from cigarette smoke (8 ppm) and a spray air freshener (10 ppm).^[13]

Laundry products and dryer vents

University of Washington researchers ran washers and dryers at two homes with a leading scented detergent and scented dryer sheets, then sampled the air leaving the dryer vent. They found more than 25 VOCs, seven of them classified as hazardous air pollutants, including acetaldehyde and benzene, which the EPA classifies as carcinogens.^[14]

Benzene in aerosol sprays

Benzene found in spray products is a separate problem from fragrance. In November 2022 the testing lab Valisure reported quantifiable benzene in 70% of the dry shampoo samples it analyzed, covering 148 batches from 34 brands, and pointed to propellants such as butane, isobutane, propane and alcohol as possible sources.^[15] Unilever had recalled Dove, Nexxus, Suave, TIGI and TRESemmé aerosol dry shampoos two weeks earlier and named the propellant as the source.^[16] Procter & Gamble recalled Old Spice and Secret aerosol antiperspirant sprays in November 2021 after detecting benzene.^[17] Both companies stated that daily exposure at the levels detected would not be expected to cause adverse health consequences, but I avoid aerosol hair and body products because of these recalls.

Health effects reported from fragrance exposure

Evidence: limited. The surveys rely on self-report, the two fertility cohorts disagree, the breast milk study measures exposure without measuring harm, and the hormone findings come from cell tests.

Headaches, breathing problems and asthma

Anne Steinemann of the University of Melbourne surveyed a nationally representative online sample of 1,136 US adults. In that survey 34.7% reported health problems such as migraine headaches and respiratory difficulties when exposed to fragranced products, and 15.1% said they had lost workdays or a job because of fragranced products at work.^[18]

A companion paper looked at the 26.8% of respondents with diagnosed asthma or an asthma-like condition. Among them, 64.3% reported one or more adverse effects from fragranced products, including respiratory problems (43.3%), migraine headaches (28.2%) and asthma attacks (27.9%).^[19]

Both papers are cross-sectional surveys by a single author, and the answers were not checked against medical records, so they measure how many people report a reaction and cannot show that fragrance caused it.

Phthalates in cologne and aftershave

Phthalates are used in personal care products, and urine tests can measure the compounds the body makes from them. In a Harvard study of 406 men, those who had used cologne or aftershave in the 48 hours before giving a urine sample had median levels of monoethyl phthalate (MEP) of 265 and 266 ng/mL, compared with 108 and 133 ng/mL in men who had not. MEP rose 33% with each additional type of personal care product used.^[20]

Two cohort studies have tested phthalate levels against time to pregnancy, and their results differ. In a Danish study of 229 women planning a first pregnancy, higher urinary MEP was associated with a 21% lower chance of conceiving in a given cycle for each one-unit rise on a log scale. The authors asked for replication in a larger and newer cohort, because women who took longer to conceive were overrepresented in their sample.^[21]

The US LIFE Study followed 501 couples. Women who did not become pregnant had higher average MEP (103.5 versus 93.8 ng/mL), but no phthalate measured in women was associated with a longer time to pregnancy in the study's fecundability models. In men, monomethyl, mono-n-butyl and monobenzyl phthalates were associated with about a 20% reduction in fecundability, the chance of conceiving in a given cycle.^[22] Both studies are based on urine measurements, which link a phthalate level to time to pregnancy without identifying the product it came from.

Synthetic musks in breast milk

Galaxolide (HHCB) and tonalide (AHTN) are synthetic musks used in perfumes and detergents. Researchers at the New York State Department of Health's Wadsworth Center found synthetic musks in most of the breast milk samples they collected in Massachusetts, with HHCB at the highest levels, up to 917 ng per gram of milk fat. They estimated that a nursing infant takes in less of these musks than of older persistent pollutants such as PCBs.^[23] Women's Voices for the Earth, the advocacy group that campaigned against galaxolide, reports the HHCB detection rate in that study as 97% of samples.^[24]

In cell-based tests at Utrecht University, HHCB and AHTN acted as antagonists at the estrogen receptor beta, the androgen receptor and the progesterone receptor, mostly at concentrations above 1 micromolar, and the authors called for more research on whether these effects occur in living animals.^[25] The EPA's own overview of endocrine disruption states that very few chemicals have been tested for their potential to interfere with the endocrine system.^[26]

A GreenScreen hazard assessment commissioned by Women's Voices for the Earth rated galaxolide Benchmark 1 and described it as persistent and highly toxic to aquatic life, and in March 2017 SC Johnson told the group it was phasing the ingredient out.^[24] In 2026 the EPA released a draft risk evaluation that describes HHCB as persistent in surface water and sediment and as bioaccumulating in aquatic organisms, but the draft's preliminary finding is that HHCB does not present an unreasonable risk to human health or the environment under the 22 uses it reviewed, and that evaluation has not been finalized.^[27]

How synthetic fragrance compares with secondhand smoke

Evidence: strong for secondhand smoke and limited for fragrance, so the comparison in this section is my opinion.

Both are chemical mixtures released indoors and breathed by people who did not choose them, but the research behind them is at very different stages.

Question	Secondhand smoke	Synthetic fragrance
What is it?	A combustion mixture from burning tobacco.	A blend of aroma chemicals whose formula is not disclosed on US labels.
Who is exposed?	Anyone sharing a room with a smoker.	Anyone sharing a room with scented products, or living downwind of a dryer vent.
What do long-term studies show?	A 14-year study of 91,540 non-smoking wives in Japan found a higher risk of lung cancer in wives of heavy smokers, and the risk rose with the amount the husband smoked.[28]	The studies cited in this article are surveys, air measurements, biomonitoring and cell tests. None of them followed people for years to compare disease rates by fragrance exposure.
What has policy done?	Scotland banned smoking in enclosed public places in 2006. Hospital admissions for acute coronary syndrome fell 17% in the 10 months that followed, and 21% among people who had never smoked.[29]	California and the EU require partial ingredient disclosure. Fragrance-free policies in workplaces and clinics are voluntary.

Secondhand smoke went from an accepted part of indoor life to a regulated exposure after studies like these accumulated. I think fragrance research is at an earlier stage, and I want to see the long-term studies done. Until they are, lowering my own exposure at home costs me very little.

Why fertility clinics ask patients to skip perfume

Evidence: moderate that air quality in the embryo lab affects IVF results, based on before-and-after lab comparisons and mouse embryo tests. No study has tested perfume by itself, and these findings concern embryos in culture dishes, so they say nothing about fragrance exposure during a pregnancy.

Some fertility clinics ask patients and staff to come in without scented products. The Pacific Centre for Reproductive Medicine in Canada describes its clinic, and especially its lab, as scent-free: staff and patients are asked to avoid perfumes, deodorants, colognes and body lotions, and staff use scent-free laundry detergent, because, in the clinic's words, scents release VOCs and exposure to them "can have an effect on the growth of embryos."^[30]

A 2021 review of embryo lab air quality gives the reasoning: eggs and embryos in culture are largely unprotected, because they lack the epithelial surfaces, immune defenses and detoxifying mechanisms of a whole body. The review lists cosmetics such as perfumes and aftershaves among the sources of VOCs in a lab, because their alcohol-based solvents evaporate. It reports a general recommendation that IVF labs keep total VOCs below 400 to 800 parts per billion, notes that one of its authors sets an alarm at 100 parts per billion in his own lab, and states that the thresholds at which VOCs harm human embryo culture have not been established.^[31]

The research behind that practice:

• 1997: embryologist Jacques Cohen's team sampled the air in IVF labs and found that VOCs built up in lab air and inside incubators, to the point that unfiltered outside air could be cleaner than filtered lab air.^[32]
• 1998: the same group detected acrolein and other aldehydes in a lab next to a newly resurfaced parking area, then added acrolein to mouse embryo cultures, where embryo growth was affected at concentrations in the low parts-per-million range.^[33]
• 2013: a clinic in Guangzhou, China compared 1,403 IVF cycles before and after upgrading its air purification. Fertilization rose from 70.1% to 83.7% and day 5 blastocyst formation rose from 41.7% to 51.1%. The paper's first sentence names perfumes alongside VOCs and microbes as things that can harm embryo development in the lab.^[34]
• 2015: the IVF program at Walter Reed National Military Medical Center moved to a new lab with better air quality while keeping its staff and protocols the same. Implantation rose from 24.3% to 32.4% and live birth rose from 31.8% to 39.3%.^[35]
• 2017: a clinic in Kolkata, India changed several things in its lab at once, including new air filtration, steel furniture in place of wood, and a rule against cosmetics such as perfume. Across 1,036 cycles, implantation rose from 31% to 42% and live birth rose from 23% to 31%.^[36]

An international expert meeting published in 2018 as the Cairo consensus produced more than 50 guideline points on lab air quality, including the control of VOCs.^[37] A Mayo Clinic review of this literature notes that most of the reports are retrospective and did not adjust for differences between patient groups.^[38] These findings concern embryos growing in a dish, and they do not show that wearing perfume affects conception or pregnancy.

Are essential oils safer than synthetic fragrance?

Evidence: strong that essential oils release terpenes and other VOCs into indoor air. The evidence on hormone effects is limited to 12 case reports and cell studies, and researchers disagree about what they show.

Pure essential oils do not contain phthalate solvents or synthetic musks, but they are concentrated terpenes, and the air chemistry described above applies to them too. The French review found that essential-oil-based cleaners and air fresheners are significant sources of terpenes indoors, and that those terpenes go on to form formaldehyde and secondary organic aerosols.^[9]

• Diffusers: a 2025 US study ran tea tree oil through an ultrasonic diffuser and a heat diffuser in a household setting. Total VOCs rose to about 10 times the background level with the ultrasonic diffuser and about 100 times with the heat diffuser. Terpene levels stayed below exposure limits with the ultrasonic diffuser, but with the heat diffuser alpha-pinene and four other compounds exceeded long-term reference levels. The authors worked for the consulting firm ChemRisk when the study was done.^[39]
• Sprays: essential-oil-based mosquito repellents produced ultrafine particles in a test chamber at an ozone level of about 17 parts per billion, which the authors describe as relevant to indoor air, at rates comparable to cooking and printing.^[40]

Lavender, tea tree and hormones

In 2007, doctors writing in the New England Journal of Medicine described three boys who developed breast tissue before puberty while using products that contained lavender and tea tree oils. The growth resolved after the products were stopped, and both oils showed estrogenic and anti-androgenic activity in human cell lines.^[41] A 2019 report added three girls and one boy exposed to lavender-fragranced products, and its authors wrote that it is unknown whether lavender oil is potent enough to cause these effects.^[42]

A 2023 review by two Cedars-Sinai physicians counted 12 such cases in total and concluded that a causal link cannot be established, because the amount of oil in the products was unknown and early breast development often goes away without any change in routine.^[43] BASF scientists tested linalool and linalyl acetate, the main components of lavender oil, in standard regulatory assays and reported no relevant estrogenic or androgenic activity, and all five authors of that paper are BASF employees.^[44] My longer article on essential oil risks and endocrine disruption goes through this research in detail, and the findings in this section are why I choose products without added essential oils.

Handmade in Montana

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How I replace fragranced products

Evidence: firsthand. These are the choices I make at home, informed by the emission studies above.

• Remove the source first: I would sooner take a scented product out of the house than try to ventilate its emissions away.
• Fragrance-free over unscented: an unscented product can still contain a masking fragrance, so I read the ingredient list for the words "fragrance" or "parfum." In the Environmental Working Group's chamber tests, fragrance-free products emitted the fewest VOCs.^[8]
• No plug-in air fresheners or diffusers: these release scent chemicals into a room for hours at a time, and the studies above measured what those chemicals form in indoor air.
• No added essential oils: they release the same family of terpenes as synthetic fragrance.
• No aerosol beauty products: the benzene recalls traced the contamination to propellant, so I skip aerosol hairspray and spray sunscreen.
• Full ingredient labels: I support full-label laws and independent product testing, because people deserve to know what is in the products they use.

How I keep my house smelling clean with four pets

Evidence: firsthand. This is my own routine and has not been tested in a study.

I clean and neutralize odors with vinegar and baking soda, and a steam mop keeps the floors shiny. HEPA filters run in most of the high-traffic rooms to help with the dust from our four pets, and my vacuum has a built-in HEPA filter too. A few times a week I open all the windows to get fresh air circulating.

I bake and cook at home every day and often have herbal infusions going in the kitchen, so the house usually smells like whatever I am making. Periodically I also burn organic white sage, which is not great for air quality, but I like the scent and view it as less bad than using synthetic fragrance or essential oils. My guide to the best indoor plants for air quality rates 16 plants for light, water and pet safety.

My fragrance-free cleaning spray recipe (makes 16 oz)

1. Fill a 16 oz spray bottle halfway with 70% isopropyl alcohol.
2. Add 2 tablespoons of castile soap.
3. Fill the rest of the bottle with distilled water.

You can infuse the water with whole herbs like mint or lemon first for a fresh scent. I use a glass spray bottle, and the spray works well on almost everything except glass, where it leaves a few streaks. For glass I use Screen Mom, a plant-based, fragrance-free cleaner that works as well as Windex in my experience.

Frequently asked questions

Is synthetic fragrance bad for you?

In a US survey, 34.7% of adults reported health problems such as migraine headaches or breathing difficulty around fragranced products, and lab studies show that scented products release VOCs that go on to form formaldehyde and nanoparticles indoors.^[18][11] The studies in this article did not follow people for years to compare disease rates, so the size of any long-term risk is not known.

What is the difference between fragrance-free and unscented?

Fragrance-free means no fragrance ingredients were added, while an unscented product may contain a masking fragrance that covers the smell of its other ingredients. On a cosmetic, the ingredient list shows the word "fragrance" or "parfum" when one was used.

Are essential oils safer than synthetic fragrance?

Pure essential oils do not contain phthalates or synthetic musks, but they release the same kinds of terpenes, which react with indoor ozone to form formaldehyde and fine particles.^[9] In a 2025 household test, a heat diffuser running tea tree oil raised total VOCs to about 100 times the background level.^[39]

Why can't you wear perfume to an IVF clinic?

Clinics ask because embryos are cultured in a lab where air quality is tightly controlled, and perfumes release VOCs as their solvents evaporate.^[30][31] Studies of lab air upgrades report higher fertilization and live birth rates afterward, though none of them tested perfume by itself.^[34][35]

Do companies have to list fragrance ingredients in the US?

A US cosmetic label can use the single word "fragrance" for the whole blend. A 2022 law directed the FDA to require labeling of specific fragrance allergens, but the proposed rule was due in June 2024 and had not been published as of October 2026.^[2] California requires partial disclosure for cleaning products and cosmetics.^[4][5]

Sources

1. International Fragrance Association (IFRA). "IFRA publishes updated global Transparency List of fragrance ingredients." Press release, April 22, 2022. https://ifrafragrance.org/latest-updates/press-releases/ifra-publishes-updated-global-transparency-list-of-fragrance-ingredients. IFRA is the fragrance industry's trade association.
2. 21 U.S.C. § 364e, Labeling. Fragrance allergen provisions added by the Modernization of Cosmetics Regulation Act of 2022. https://www.law.cornell.edu/uscode/text/21/364e
3. Steinemann AC, MacGregor IC, Gordon SM, Gallagher LG, Davis AL, Ribeiro DS, Wallace LA. Fragranced consumer products: chemicals emitted, ingredients unlisted. Environ Impact Assess Rev. 2011;31(3):328-333. doi:10.1016/j.eiar.2010.08.002. Figures as summarized by the University of Washington, October 26, 2010: https://www.washington.edu/news/2010/10/26/scented-consumer-products-shown-to-emit-many-unlisted-chemicals/
4. California Health and Safety Code § 108954 (Cleaning Product Right to Know Act of 2017). https://california.public.law/codes/ca_health_and_safety_code_section_108954
5. California Department of Public Health, California Safe Cosmetics Program. Cosmetic Fragrance and Flavor Ingredient Right to Know Act of 2020 (SB 312). https://www.cdph.ca.gov/Programs/CCDPHP/DEODC/OHB/CSCP/Pages/SB312.aspx
6. Commission Regulation (EU) 2023/1545 of 26 July 2023 amending Regulation (EC) No 1223/2009 as regards labelling of fragrance allergens in cosmetic products. https://eur-lex.europa.eu/eli/reg/2023/1545/oj
7. Nematollahi N, Doronila A, Mornane PJ, Duan A, Kolev SD, Steinemann A. Volatile chemical emissions from fragranced baby products. Air Qual Atmos Health. 2018;11(7):785-790. doi:10.1007/s11869-018-0593-1
8. Temkin AM, Geller SL, Swanson SA, Leiba NS, Naidenko OV, Andrews DQ. Volatile organic compounds emitted by conventional and "green" cleaning products in the U.S. market. Chemosphere. 2023;341:139570. doi:10.1016/j.chemosphere.2023.139570. Five of the six authors work for the Environmental Working Group, an advocacy organization.
9. Angulo Milhem S, Verriele M, Nicolas M, Thevenet F. Does the ubiquitous use of essential oil-based products promote indoor air quality? A critical literature review. Environ Sci Pollut Res Int. 2020;27(13):14365-14411. doi:10.1007/s11356-020-08150-3
10. Rosales CMF, Jiang J, Lahib A, et al. Chemistry and human exposure implications of secondary organic aerosol production from indoor terpene ozonolysis. Sci Adv. 2022;8(8):eabj9156. doi:10.1126/sciadv.abj9156
11. Patra SS, Jiang J, Liu J, Steiner G, Jung N, Boor BE. Flame-Free Candles Are Not Pollution-Free: Scented Wax Melts as a Significant Source of Atmospheric Nanoparticles. Environ Sci Technol Lett. 2025;12(2):175-182. doi:10.1021/acs.estlett.4c00986. One co-author is employed by GRIMM Aerosol Technik, an instrument manufacturer.
12. Cheng WH, Chen YC, Shih SY. Volatile Organic Compound Emissions from Indoor Fragrance Diffusers. Atmosphere. 2023;14(6):1012. doi:10.3390/atmos14061012
13. Manigrasso M, Vitali M, Protano C, Avino P. Temporal evolution of ultrafine particles and of alveolar deposited surface area from main indoor combustion and non-combustion sources in a model room. Sci Total Environ. 2017;598:1015-1026. doi:10.1016/j.scitotenv.2017.02.048
14. Steinemann AC, Gallagher LG, Davis AL, MacGregor IC. Chemical emissions from residential dryer vents during use of fragranced laundry products. Air Qual Atmos Health. 2013;6(1):151-156. doi:10.1007/s11869-011-0156-1. Figures as summarized by the University of Washington, August 24, 2011: https://www.washington.edu/news/2011/08/24/scented-laundry-products-emit-hazardous-chemicals-through-dryer-vents/
15. Valisure. "Valisure Detects Benzene in Dry Shampoo." November 1, 2022. https://www.valisure.com/valisure-newsroom/valisure-detects-benzene-in-dry-shampoo. Valisure is a private commercial testing laboratory.
16. Unilever United States. "Unilever Issues Voluntary U.S. Recall of Select Dry Shampoos Due to Potential Presence of Benzene." Company announcement, October 18, 2022. https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/unilever-issues-voluntary-us-recall-select-dry-shampoos-due-potential-presence-benzene. Company statement.
17. Procter & Gamble. "P&G Issues Voluntary Recall of Specific Old Spice and Secret Aerosol Spray Antiperspirant Products Due to Detection of Benzene." Company announcement, November 23, 2021. https://www.businesswire.com/news/home/20211123006157/en/PG-Issues-Voluntary-Recall-of-Specific-Old-Spice-and-Secret-Aerosol-Spray-Antiperspirant-Products-Due-to-Detection-of-Benzene. Company statement.
18. Steinemann A. Fragranced consumer products: exposures and effects from emissions. Air Qual Atmos Health. 2016;9(8):861-866. doi:10.1007/s11869-016-0442-z
19. Steinemann A. Fragranced consumer products: effects on asthmatics. Air Qual Atmos Health. 2018;11(1):3-9. doi:10.1007/s11869-017-0536-2
20. Duty SM, Ackerman RM, Calafat AM, Hauser R. Personal care product use predicts urinary concentrations of some phthalate monoesters. Environ Health Perspect. 2005;113(11):1530-1535. doi:10.1289/ehp.8083
21. Thomsen AML, Riis AH, Olsen J, et al. Female exposure to phthalates and time to pregnancy: a first pregnancy planner study. Hum Reprod. 2017;32(1):232-238. doi:10.1093/humrep/dew291
22. Buck Louis GM, Sundaram R, Sweeney AM, Schisterman EF, Maisog J, Kannan K. Urinary bisphenol A, phthalates, and couple fecundity: the Longitudinal Investigation of Fertility and the Environment (LIFE) Study. Fertil Steril. 2014;101(5):1359-1366. doi:10.1016/j.fertnstert.2014.01.022
23. Reiner JL, Wong CM, Arcaro KF, Kannan K. Synthetic musk fragrances in human milk from the United States. Environ Sci Technol. 2007;41(11):3815-3820. doi:10.1021/es063088a
24. Women's Voices for the Earth. "SC Johnson Announces to Eliminate Harmful Fragrance Chemical Galaxolide." Press release, March 20, 2017. https://womensvoices.org/2017/03/20/sc-johnson-announces-to-eliminate-harmful-fragrance-chemical-galaxolide/. Women's Voices for the Earth is the advocacy group that campaigned for the phase-out and commissioned the GreenScreen assessment.
25. Schreurs RHMM, Sonneveld E, Jansen JHJ, Seinen W, van der Burg B. Interaction of polycyclic musks and UV filters with the estrogen receptor (ER), androgen receptor (AR), and progesterone receptor (PR) in reporter gene bioassays. Toxicol Sci. 2005;83(2):264-272. doi:10.1093/toxsci/kfi035. Author affiliations include BioDetection Systems BV, a bioassay company.
26. US Environmental Protection Agency. "Overview of Endocrine Disruption." https://www.epa.gov/endocrine-disruption/overview-endocrine-disruption
27. US Environmental Protection Agency. Draft Risk Evaluation for 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[γ]-2-benzopyran (HHCB). EPA-740-D-26-005, public release draft, March 2026. https://www.epa.gov/system/files/documents/2026-04/01-hhcb-draft-risk-evaluation-public-release-march-2026.pdf
28. Hirayama T. Non-smoking wives of heavy smokers have a higher risk of lung cancer: a study from Japan. Br Med J (Clin Res Ed). 1981;282(6259):183-185. doi:10.1136/bmj.282.6259.183
29. Pell JP, Haw S, Cobbe S, et al. Smoke-free legislation and hospitalizations for acute coronary syndrome. N Engl J Med. 2008;359(5):482-491. doi:10.1056/NEJMsa0706740
30. Pacific Centre for Reproductive Medicine. "How Air Quality Effects In Vitro Fertilization Process." Clinic blog, July 19, 2016. https://www.pacificfertility.ca/blog/how-air-quality-effects-in-vitro-fertilization-process. Clinic statement.
31. Sciorio R, Rapalini E, Esteves SC. Air quality in the clinical embryology laboratory: a mini-review. Ther Adv Reprod Health. 2021;15:2633494121990684. doi:10.1177/2633494121990684
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