Don’t take our word for it. Here’s every fact on this site, with its evidence grade, its caveats, and a link to the source, so you can check us.
We start you on the strong ones: findings that have been replicated or come from one large, well-controlled study. Moderate and weak facts are here too, labeled for what they are. Use “Link to this fact” to share a single card.
Green, natural and unscented / Measured in people or real products
In 14 of 17 'alternative' (mostly green-marketed) products that contained fragrance chemicals, the label never mentioned fragrance.
Moderate evidence: Mostly natural terpenes at low levels; single products from one retailer.
Source: Dodson 2012, Environmental Health Perspectives Link to this fact
Green, natural and unscented / Measured in people or real products
Products labeled 'green,' 'natural' or 'non-toxic' released hazardous chemicals too, with no significant difference from ordinary ones in a test of 25 best-sellers.
Moderate evidence: 11 vs 14 products; underpowered; list-membership counts; small sample (11 vs 14 products, p>0.30): a null result, not proof of equality.
Source: Steinemann 2011, Environmental Impact Assessment Review Link to this fact
Green, natural and unscented / Measured in people or real products
Baby products labeled green, organic, or natural released no fewer chemicals than regular ones (398 vs 286 detections), and 20 of 21 in each group released at least one chemical classed as potentially hazardous.
Moderate evidence: Headspace counts, not concentrations; agrees with Lin 2020 and Steinemann 2011.
Source: Nematollahi 2018, Air Quality, Atmosphere & Health Link to this fact
Green, natural and unscented / Measured in people or real products
Plant-derived scent chemicals drove the particle bursts, so a 'natural' citrus or pine scent is not automatically cleaner to breathe.
Moderate evidence: No unscented comparison in this study.
Green, natural and unscented / Measured in people or real products
In a test of 79 US feminine hygiene products, labels such as organic, natural, or for sensitive skin did not predict lower levels of volatile chemicals.
Moderate evidence: Product content, not exposure; small subgroups.
Source: Lin 2020, Environment International Link to this fact
Green, natural and unscented / Lab study (cells or chemistry)
'Natural' scent is not biologically inert: essential oils such as lavender and tea tree are chemical mixtures, and in lab tests they acted on estrogen and androgen receptors.
Moderate evidence: Shows biological activity, not harm at use levels.
Source: Henley 2007, New England Journal of Medicine Link to this fact
Green, natural and unscented / Lab study (cells or chemistry)
Natural does not mean hormonally inert: the hormone-active chemicals tested here are ordinary constituents of lavender and tea tree essential oils, not synthetic fragrance chemicals.
Moderate evidence: Cell assays only, at concentrations far above plausible human exposure; whole-animal guideline tests of the two main lavender constituents were negative.
Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact
Green, natural and unscented / Lab study (cells or chemistry)
Terpenes do not behave alike: alpha-terpineol and terpinen-4-ol were the most hormone-active of the eight essential-oil chemicals tested, while eucalyptol was inactive on both the estrogen and the androgen receptor.
Moderate evidence: Receptor assays only; eucalyptol is separately reported to inhibit the steroid-synthesis enzyme CYP17A1, which this study did not test.
Source: Ramsey 2019, The Journal of Clinical Endocrinology & Metabolism Link to this fact
Green, natural and unscented / Review of other studies
Essential oils oxidize in air into the same allergens as synthetic fragrance, and 'natural' cosmetics routinely carry fragrance allergens: 91% of 'natural' perfumes on the Danish market contained at least one target fragrance sensitizer (chemical analysis, 1996) — but only 35% of the other 'natural' cosmetics (shampoos, creams, lotions) in the same study did, at far lower concentrations — and 82 of 100 European natural-brand products checked in 2013-15 listed at least one allergen on the label.
Moderate evidence.
Caveats
91%/35% is Rastogi 1996's own perfume-vs-other-cosmetics split, now confirmed by reading the primary directly (a review had dropped the perfume qualifier and stated 91% as if it covered 'natural cosmetics' generally; corrected 2026-09-27). Rastogi 1996 also found synthetic-only fragrance chemicals (hydroxycitronellal, alpha-hexylcinnamic aldehyde) in some 'natural' products, at concentrations that in one case (6.04% hydroxycitronellal) exceeded the level shown to sensitize 36% of volunteers in patch testing. 82/100 is Klaschka 2016's independent label analysis (10 products from each of 10 brands, not representative, declarations only). The oxidation half rests on Karlberg/Bråred Christensson primaries, not on these surveys. Single small studies (n=42 and n=100), not replicated across labs, so strength stays moderate per the grading rule.
Source: Pastor-Nieto 2021 (Rastogi 1996; Klaschka 2016), Current Treatment Options in Allergy Link to this fact
Green, natural and unscented / Review of other studies
In 1999 a dermatologist listed ten US "fragrance-free" skin products that named fragrance chemicals in their own ingredient lists, including a "fragrance-free" cleansing bar containing rose, rosewood, cedarwood, and almond oils; one manufacturer admitted the benzaldehyde in its fragrance-free product was there to mask an unpleasant smell.
Moderate evidence.
Caveats
Ten named examples from 1999 labels, not a systematic survey; formulations have likely changed since. Masking is one manufacturer's admission and remains unquantified across products.
Source: Scheinman 1999, Journal of the American Academy of Dermatology Link to this fact
Green, natural and unscented / Review of other studies
Essential oils are complex mixtures of hundreds of components whose composition varies by producer, plant origin, climate, and extraction method, so a product labeled as containing 'lavender oil' or 'tea tree oil' does not guarantee a fixed chemical composition or a fixed level of biological activity.
Moderate evidence: Stated as general essential-oil chemistry background in this review; not measured for any specific consumer product here.
Source: Ramsey 2020 (YJBM), Yale Journal of Biology and Medicine Link to this fact
Green, natural and unscented / Measured in people or real products
A headspace test of the fragranced and fragrance-free versions of the same detergent brand found 34 volatile chemicals in the fragranced version but only 7 in the fragrance-free version, and no fragrance terpenes (such as D-limonene or linalool) at all in the fragrance-free version.
Moderate evidence: Single product pair tested (one Australian brand); presence/absence only, not a full quantitative comparison.
Source: Goodman 2019, Air Quality, Atmosphere & Health Link to this fact
Green, natural and unscented / Measured in people or real products
In the same test house and wax warmer, an unscented wax melt produced no significant terpene release and no measurable nanoparticle formation, showing that the fragrance chemicals — not the melted wax itself — are what drives the particle-forming reaction.
Moderate evidence: A single unscented product tested as one control condition; supports the mechanism but is not itself a survey of unscented products generally.
Source: Patra et al. 2025, Environmental Science & Technology Letters Link to this fact
Green, natural and unscented / Measured in people or real products
Not all fragrance-based odor masking works the same way: Iso E Super, a common deodorant fragrance chemical that barely blocked the malodor receptors in lab dish tests, still reduced how strong a sulfur malodor smelled to people, but less effectively than beta-ionone, suggesting this masking runs mainly through the brain blending two smells together rather than through receptor blocking.
Moderate evidence: Central-processing explanation is the authors' inference from a negative in-vitro result, not directly tested; based on the same single-lab, single-cohort study.
Source: Fukutani et al. 2023, Current Biology Industry-funded Link to this fact
Green, natural and unscented / Measured in people or real products
Ethanol, linalool, and D-limonene, common fragrance and solvent terpenes found in both synthetic and "natural" scented products, were the single most-listed chemicals overall (about 27%, 16%, and 12% of products respectively) in a database of over 7,000 Korean household chemical products, ahead of synthetic fragrance aldehydes like hexyl cinnamaldehyde (about 8%).
Moderate evidence: Ingredient-list prevalence, not measured air or dermal exposure; does not distinguish products marketed as "natural"/"green" from conventional ones.
Source: Lee & Ji 2022, Ecotoxicology and Environmental Safety Link to this fact
Green, natural and unscented / Government agency
Because the EU's expanded fragrance-allergen list includes most of the chemicals that make up common essential oils (lavender, citrus, rose, patchouli, and more), a product marketed as 'natural' or 'essential-oil-based' is not exempt from fragrance-allergen labeling and may in fact trigger more individual allergen declarations than a synthetic-fragrance product.
Moderate evidence.
Caveats
This is an inference from the regulation's own entry list (natural oils named by species as fragrance-allergen entries), not a product-testing study; see our existing natural-cosmetics label surveys for empirical confirmation of a related pattern.
Source: Regulation (EU) 2023/1545 Link to this fact
Green, natural and unscented / Measured in people or real products
In a chamber test of 30 US cleaning products and air fresheners, fragrance-free green cleaners gave off significantly fewer volatile chemicals than conventional ones: about 500 vs 4,700 ug/m3 total on average (approx., read from Fig. 4A), and about 6 vs 46 distinct VOCs per product (approx., read from Fig. 4D).
Moderate evidence.
Caveats
EWG-authored (advocacy nonprofit that ranks cleaners and licenses EWG VERIFIED to cleaner makers); Skyline Foundation grant; unblinded; 7 fragrance-free vs 14 conventional products, one product per brand, single lab; green products also applied less product per use; chamber concentration, not personal exposure. Group means are read from Fig. 4.
Green, natural and unscented / Other evidence
None of 150 "Clean" textured-hair products at a Los Angeles Target listed a chemical on Target's own exclusion list, yet "clean" did not mean fragrance-free: 14.6% listed sulfates and 27% phenoxyethanol.
Moderate evidence.
Caveats
Label reading only. Target's list excludes SLES, not all sulfates, and phenoxyethanol and isothiazolinones were not on it; results for phthalates and formaldehyde are not reported in the text.
Source: Madrid Larrañaga 2026, Journal of Exposure Science & Environmental Epidemiology Link to this fact
Information, not medical advice. See also: myths we won’t tell you.