Pick up a bottle of shampoo and read the ingredient list to the bottom. Most of it is named out loud: water, a cleaning agent, a thickener, a preservative. Then one word sits there by itself. Fragrance. Sometimes parfum.
That single word can cover three ingredients or fifty. Federal law does not require the company to name them on the label, and nothing on the package tells you how many there are or what they do.
This is not a loophole somebody found. It was written into the rules on purpose, and it has held for decades.
How one word ends up covering dozens of ingredients
Cosmetics sold at retail in the United States have to carry an ingredient list. The requirement comes from the Fair Packaging and Labeling Act, and the mechanics live in FDA’s labeling rules at 21 CFR 701.3. Ingredients run in descending order of how much is in the container.
Scent is the carve-out. FDA’s own cosmetic labeling guide confirms that the chemicals making up a fragrance may be declared collectively as “fragrance,” and the chemicals making up a taste as “flavor.” A masking agent, meaning something added to hide a smell rather than create one, can also be listed simply as fragrance.
The reasoning is commercial, and FDA says so. On its fragrance page, the agency explains that the labeling law cannot be used to force a company to give up trade secrets, and that scent and flavor formulas are the parts of a cosmetic most likely to qualify. A perfume accord is a recipe, and a recipe is an asset.
There is a second, much narrower door, and the contrast is instructive. A company that thinks one specific ingredient is a trade secret can petition FDA, submitting a formulation statement on Form 2512 or 2513 with its grounds for secrecy. FDA makes a tentative determination and then a final one. Only after FDA agrees may the label say “and other ingredients.” Until then, the company names the ingredient like everybody else.
Fragrance skips all of that. No petition, no review, no agency decision. It is simply allowed.
One more piece of context reframes everything above. FDA does not approve cosmetics before they go on sale. The company carries the legal responsibility for safety and labeling, and the agency acts afterward, when something goes wrong.
Which rules apply to which products
The category a product falls into decides which rulebook it gets, and the categories do not line up with the way anybody shops. Shampoo, lotion, deodorant, makeup and perfume are cosmetics, so the FDA rules above apply. A household cleaner is not a cosmetic, is not regulated as one, and is not required to carry the kind of full ingredient list a cosmetic carries. Two bottles bought on the same trip can tell you completely different amounts about themselves, and nothing on either label explains why.
Where cleaning product ingredient disclosure does exist here, it has come from state legislatures rather than Congress. California’s Cleaning Product Right to Know Act of 2017 is the statute most often cited. This article does not summarize its provisions, because the statute text could not be verified while the article was written, and a secondhand paraphrase of a disclosure law is worth very little. Read the current text in the California Health and Safety Code if the details matter to you, paying attention to what it requires on a package versus on a company website. That distinction is usually where the information sits.
It helps to sort every scent-related term into one of four boxes.
Defined in regulation. The ingredient declaration on a cosmetic is a real rule with a citation behind it.
A government certification program. Voluntary to join, strict once you do. EPA’s Safer Choice label and its fragrance-free notation both work this way.
A private certification. Run by industry or a nonprofit. EPA’s disclosure guidance for Safer Choice partners points companies toward the International Fragrance Association’s list of fragrance materials. That association is a trade body, not a regulator.
Defined by nobody. “Clean scent,” “natural fragrance,” “unscented” and “hypoallergenic” all live here.
Where the cosmetics law stands as of October 2026
Congress rewrote large parts of federal cosmetics authority in the Modernization of Cosmetics Regulation Act of 2022, usually shortened to MoCRA. It is the biggest change in this area in generations, and it is still being installed.
Here is what FDA’s MoCRA page described as operating when it was last updated on August 10, 2026. Manufacturers must register their facilities and renew every two years. The responsible person for a product must list it with FDA, ingredients included, and update that listing annually. Serious adverse events must be reported within 15 business days. Companies must keep records substantiating safety, and FDA can get at those records, suspend a registration, and order a recall.
Now the part this article turns on. MoCRA directs FDA to issue requirements for labeling fragrance allergens. As of that August 2026 update, FDA’s MoCRA page showed no proposed rule and no final rule on fragrance allergens, and FDA’s cosmetics labeling hub has no page on the subject. Good manufacturing practice regulations are also still pending, and a proposed rule on testing talc for asbestos went out in December 2024 and was withdrawn in November 2025.
So the honest answer, dated October 2026: the fragrance allergen labeling requirement exists in the statute and does not yet exist as anything you can read off a bottle. That may well change, and FDA’s MoCRA page is where it will show up first. That is a better place to check than any article, this one included.
What scented products do to indoor air
EPA reports that concentrations of many volatile organic compounds run consistently higher indoors than outdoors, by as much as ten times. Scented products are one contributor among many, and nobody should read them as the whole story.
The more interesting chemistry starts after the molecules leave the bottle. A great many fragrance ingredients are terpenes, a family of compounds built by plants. Limonene is the citrus-peel one. Linalool turns up in lavender and in an enormous number of soaps. Terpenes react readily with ozone, which drifts indoors from outside and is also produced by some electrical equipment.
A 2015 review in the Journal of Toxicological Sciences by Kim and colleagues set out the consequence: components released by air fresheners can react with ozone to produce secondary pollutants including formaldehyde, secondary organic aerosol and ultrafine particles. The scent you bought is a reagent, not the end of the chemistry.
Now the honest limits. Peder Wolkoff’s review of indoor air pollutants in offices, in the International Journal of Hygiene and Environmental Health, found that ozone-initiated terpene reactions become a concern where ozone is enriched and limonene elevated, partly because of the formaldehyde they generate. The same review reported that the aerosol particles formed appear not to produce airway effects by themselves, and that the gaseous products are the part that matters. The chemistry is established. The concentration at which it becomes a health problem in an ordinary living room is not pinned down, and most of what circulates online about it sits in the preliminary tier rather than the settled one.
Air fresheners get their own paragraph because they are sold as though they fix something. A plug-in, a spray or a gel removes nothing from the air. It adds molecules that change what your nose reports about the molecules already there. Ventilation moves air out and filtration captures particles, and other articles in this library cover both. An air freshener does neither. If a room smells bad, the smell is information, and masking it throws the information away while adding to the load.
Unscented and fragrance-free mean different things
On a shelf these two words look interchangeable. They are not.
Fragrance-free is a claim about what went in: no fragrance was added. Unscented is a claim about what comes out: the product does not smell of anything in particular. FDA states the difference plainly, warning that a product labeled unscented may contain fragrance ingredients added specifically to mask the odor of the other ingredients. A raw surfactant blend can smell unpleasant. Covering that up is a normal formulation decision, and the thing doing the covering is fragrance.
Neither word is defined in federal regulation for cosmetics, so neither is a promise. There is one place where fragrance-free carries a defined meaning backed by review, and it is a government certification program rather than a law. Under EPA’s Safer Choice Standard, a product may carry a fragrance-free notation only after EPA reviews the ingredients to confirm the product contains no fragrance materials. EPA also addresses the obvious workaround, though not with a flat ban. A chemical recognized as having dual functionality, meaning one intentionally used as a solvent and also as a fragrance, is ineligible for a product seeking the fragrance-free certification. EPA says it works with manufacturers case by case to decide whether a chemical has that dual role.
What EPA asks of the fragranced products it does certify shows what disclosure looks like when somebody requires it. Safer Choice criteria bar listed carcinogens, mutagens and reproductive toxicants, listed persistent and bioaccumulative compounds, and listed respiratory sensitizers from fragrance use. The program’s disclosure guidance requires that dermal sensitizers above 0.01 percent, which is 100 parts per million, appear on the label itself no matter where the rest of the disclosure lives.
One caution before you go label-reading: the absence of the word “fragrance” does not guarantee the absence of fragrance chemicals, because FDA’s rules also permit a company to list scent components individually by name.
Fragrance allergy and the hypoallergenic problem
Fragrance chemicals are among the most common causes of allergic contact dermatitis, the itchy and often delayed rash that appears where a product touched you. This is established, not speculative, and the numbers come from clinics that test for it.
The North American Contact Dermatitis Group patch tests patients at a dozen or so centers across the United States and Canada against a standard panel of 80 allergens. In the 2021 to 2022 cycle, reported in the journal Dermatitis, 3,056 patients were tested and 72 percent had at least one positive reaction. Hydroperoxides of linalool registered 10.1 percent, ahead of cobalt. In the 2019 to 2020 cycle, fragrance mix I was positive in 12.8 percent of 4,121 patients and hydroperoxides of linalool in 11.1 percent.
Hold those numbers next to the word on the front of the package. A product can say hypoallergenic and mean nothing at all by it, because no federal standard defines the term. FDA is unusually blunt about this, stating that “The term means whatever a particular company wants it to mean.”
The history explains why nobody has fixed it. FDA issued a final rule on June 6, 1975 that would have allowed the word only where testing showed a significantly lower rate of skin reactions than comparable products. Two cosmetics companies sued. A district court sided with FDA, and the appeals court struck the rule down, finding FDA had not shown consumers understood the word the way the rule defined it. Nothing has replaced it.
There is a structural reason this persists. FDA points out that it does not have the same legal authority to require allergen labeling for cosmetics that it has for food. The peanut warning on a cookie box and the silence about fragrance allergens on a lotion are not an inconsistency. They are two different statutes.
Essential oils are fragrance chemicals too
Here is the correction that trips up the most people. Limonene and linalool, the two names that keep surfacing in the patch test data, are not synthetic laboratory inventions. They are among the most abundant components of citrus and lavender oils and occur throughout the plant kingdom.
They also oxidize. Left in contact with air, terpenes form hydroperoxides, and it is the hydroperoxides rather than the fresh molecules that patch test panels use as the allergens. An opened bottle that has sat for a year is chemically a different mixture from a new one. The 2021 to 2022 report found that positive reactions to hydroperoxides of limonene rose significantly compared with the previous cycle.
None of this says anything about whether an essential oil does or does not do something therapeutic. That is a separate question and this article is not answering it in either direction. The narrow chemical point stands on its own: “natural” describes where a molecule came from, not how your skin or your airway will respond to it. A terpene pressed from a peel and the identical terpene made in a reactor are the same molecule.
When a recurring rash is worth a clinic visit
A rash that keeps returning in the same place, that maps to where you apply something, or that settles on the eyelids, neck and sides of the face is worth taking to a clinician rather than solving by trial and error in the shower.
Patch testing is the actual test. A dermatologist applies small amounts of standardized allergens to the back, leaves them for roughly two days, and reads the skin more than once afterward. It names the specific chemical, which is the only thing that lets you avoid it reliably. Switching brands until something works is slower and often fails, because the same allergens appear across brands and across whole product categories.
Different situation, different response: swelling of the lips, tongue or throat, or trouble breathing, is not contact dermatitis. That is an emergency and 911 is the right call.
Laundry, workplaces and shared air
Scented laundry products are an unusual exposure because the product does not stay in the laundry room. It leaves on the fabric by design and goes wherever the fabric goes. Our article on laundry products covers softeners, dryer sheets and scent boosters as products. What belongs here is what the rules above mean for them: a scent booster and a perfume are governed differently, disclose different amounts, and may well share ingredients.
Survey work gives some sense of how people experience this. In a national online survey of 1,137 US adults published in Air Quality, Atmosphere and Health, Anne Steinemann found that among respondents reporting a medically diagnosed asthma or asthma-like condition, 28.9 percent reported health problems from scented laundry products coming out of a dryer vent and 41.0 percent from air fresheners. An earlier survey by the same researcher found 34.7 percent of a nationally representative sample of US adults reporting health problems from fragranced products, and 15.1 percent saying they had lost workdays or a job over fragranced product exposure at work.
Be precise about what that evidence is. These are self-reported symptoms collected online, not clinical measurements. They are strong evidence that a great many people believe scented products affect them, and weak evidence about mechanism, dose or severity. Treat them as a map of experience rather than a measurement of harm.
That work is the backdrop to fragrance-free policies, which some workplaces, hospitals, schools and conference organizers now have. They typically ask staff and visitors not to wear scented personal products, and sometimes extend to what the building itself buys.
The argument for them is about shared air. In a building with one ventilation system, one person’s product becomes everyone’s exposure, and there is no respirator anyone is going to wear to a meeting. For a colleague whose asthma is triggered reliably, the alternative to a policy is often leaving the room.
The argument against is practical. The policies are awkward to enforce, they depend on judgment calls about what counts as scented, they can create friction between coworkers, and the supporting data is largely self-reported. They also tend to overlook the fragrance already in the hand soap and the surface cleaner a facilities department buys in bulk. Both arguments are sound at once, which is why organizations land in different places. It is a management question, not a scientific one.
Read the back of the package
Stop treating the words on the front of a package as information, and start reading the list on the back. A short routine for something you are about to buy, or something you suspect:
- Look for “fragrance” or “parfum” on the ingredient list. If it is there, scent was added, in an amount the label will not tell you.
- Check whether scent chemicals are named individually instead. Linalool, limonene, citronellol, geraniol and eugenol are fragrance ingredients listed one by one.
- Read “unscented” as a statement about smell and nothing more. Read “hypoallergenic,” “clean,” “natural” and “dermatologist tested” as undefined.
- For fragrance-free with something behind it, look for a certification whose criteria you can pull up and read, such as EPA’s Safer Choice fragrance-free notation.
- If you react to something, keep the package. The ingredient list is what a clinician will ask for, and a patch test is what names the culprit.
The gap this article describes is real and it is not closing quickly, but the practical consequence is narrow. On a scented product, the label tells you that scent was added and nothing about what the scent is. Everything else you might want to know has to come from a certification you can look up, a statute you can read, or a test done on your own skin.
Sources
- U.S. Food and Drug Administration. “Fragrances in Cosmetics.” fda.gov
- U.S. Food and Drug Administration. “Modernization of Cosmetics Regulation Act of 2022 (MoCRA).” fda.gov
- U.S. Food and Drug Administration. “Hypoallergenic Cosmetics.” fda.gov
- U.S. Food and Drug Administration. “Cosmetics Labeling Guide.” fda.gov
- U.S. Food and Drug Administration. “Cosmetics Labeling.” fda.gov
- U.S. Environmental Protection Agency. “What are volatile organic compounds (VOCs)?.” epa.gov
- U.S. Environmental Protection Agency. “Safer Choice Criteria for Fragrances.” epa.gov
- U.S. Environmental Protection Agency. “Safer Choice Criteria for Fragrance-Free Products.” epa.gov
- U.S. Environmental Protection Agency. “Safer Choice and Design for the Environment (DfE) Standard.” epa.gov
- U.S. Environmental Protection Agency. “Safer Choice Ingredient Communication and Disclosure Guidance.” epa.gov
- PubMed. “Houle MC, et al. “North American Contact Dermatitis Group Patch Test Results: 2021-2022.” Dermatitis, 2025. PubMed. DOI: 10.1089/derm.2024.0474.” doi.org
- PubMed. “DeKoven JG, et al. “North American Contact Dermatitis Group Patch Test Results: 2019-2020.” Dermatitis, 2023. PubMed. DOI: 10.1089/derm.2022.29017.jdk.” doi.org
- PubMed. “Kim S, et al. “Characterization of air freshener emission: the potential health effects.” The Journal of Toxicological Sciences, 2015. PubMed. DOI: 10.2131/jts.40.535.” doi.org
- PubMed. “Wolkoff P. “Indoor air pollutants in office environments: assessment of comfort, health, and performance.” International Journal of Hygiene and Environmental Health, 2013. PubMed. DOI: 10.1016/j.ijheh.2012.08.001.” doi.org
- PubMed. “Steinemann A. “Fragranced consumer products: exposures and effects from emissions.” Air Quality, Atmosphere & Health, 2016. PubMed. DOI: 10.1007/s11869-016-0442-z.” doi.org
- PubMed. “Steinemann A. “Fragranced consumer products: effects on asthmatics.” Air Quality, Atmosphere & Health, 2018. PubMed. DOI: 10.1007/s11869-017-0536-2.” doi.org