Every fact on this site, with its evidence grade, its caveats, and a link to the source.
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.
What you can do / Review of other studies
Fragrance-free cosmetics and laundry products cut the main routes by which synthetic musks enter the body: skin contact and washed clothing.
Moderate evidence.
Caveats
Route inferred from exposure data; no intervention study of musk body burden. Hutter 2009 (100 Vienna adults) gives cross-sectional human support for the polycyclic musks specifically: monthly-frequency of body lotion and perfume use significantly predicted blood galaxolide/tonalide (beta=0.188-0.192, p<0.05); no cosmetics-use variable predicted nitro-musk (musk ketone/musk xylene) blood levels there. Lignell 2008 (101 Swedish mothers, milk 1996-2003) gives a second, milk-matched confirmation with per-product specificity: perfume use predicted HHCB and perfumed-laundry-detergent use predicted AHTN, but musk xylene showed no association with any product category tested. Still no before/after intervention trial for any musk, and the nitro-musk part of the action's benefit remains unverified in two independent studies now.
Source: Schmeiser 2001, International Journal of Hygiene and Environmental Health Link to this fact
What you can do / Measured in people or real products
Musk levels in blood and milk seem to track current personal-care product use rather than lifetime storage: Hutter 2009 found that how often people used perfume and body lotion significantly predicted their blood levels of the polycyclic musks (galaxolide, tonalide) in 100 adults, so choosing fragrance-free personal care and laundry products during pregnancy and breastfeeding is a plausible way to lower a mother's musk levels and, in turn, transfer to the baby.
Moderate evidence.
Caveats
Route inferred in Reiner 2007 from the absence of an age trend in milk, and now supported by direct product-use data in two independent populations and matrices: Hutter 2009 (blood, non-pregnant Vienna adults) and Lignell 2008 (101 Swedish mothers, milk itself — the exact matrix this claim concerns). Lignell 2008 found perfume-use frequency predicted HHCB and perfumed-laundry-detergent use predicted AHTN in milk, but no product-use variable predicted musk xylene, matching Hutter's blood-based polycyclic/nitro split. Still correlational and cross-sectional; no study has measured milk musk levels before and after a change in a mother's product use, and no cosmetics-use variable has ever predicted a nitro musk in either study.
Source: Reiner 2007, Environmental Science & Technology Link to this fact
What you can do / Self-reported survey
Fragrance-free policies need to cover cleaning and laundry products, not just perfume: of 60 people who react to fragranced products, 50 named cleaning products, 47 perfume, and 41 laundry products as persistent triggers.
Moderate evidence: Self-selected Canadian sample (90% female); counts of participants naming a source, not exposure measurements.
Source: Roy 2026 Link to this fact
What you can do / Review of other studies
For fragrance-allergic people, dermatologists recommend removing diffusers, scented candles, room deodorizers, incense, and wax melts, switching household cleaners, wipes, and laundry products to fragrance-free, and bringing your own shampoo to the salon and your own oil to massages.
Moderate evidence: Expert advice; the salon point rests on a single exposure keeping skin flared up to ~4 weeks (clinical observation).
What you can do / Self-reported survey
Fragrance-free health-care policies should cover cleaning and laundry products, not just staff perfume; Canadian advocates ask for exactly this, and people who react name cleaning products as their most common trigger (50 of 60).
Moderate evidence: Advocacy position plus a self-selected focus-group sample; no evidence yet that policies reduce exposure or symptoms.
What you can do / Measured in people or real products
Because galaxolide (HHCB) levels in milk tracked perfume use and tonalide (AHTN) levels tracked scented-laundry-detergent use specifically, choosing fragrance-free perfume and fragrance-free laundry detergent during pregnancy and breastfeeding are each independently plausible ways to lower the corresponding musk chemical passed to a nursing infant.
Moderate evidence.
Caveats
Correlational and cross-sectional, no before/after intervention trial; musk xylene (a nitro musk) showed no association with any product category tested, so this action would not address that compound.
Source: Lignell 2008, Environmental Science & Technology Link to this fact
What you can do / Measured in people or real products
Switching from a fragranced to a fragrance-free laundry detergent cut the fragrance chemical D-limonene coming out of the dryer vent by up to 99.7% (mean 79.1%) within one month, in real households, with no extra cost or apparent inconvenience.
Moderate evidence.
Caveats
4 households switched, D-limonene only; one household's no-product baseline (machine run with no detergent) actually rose 70.3% after the switch, which the paper attributes to residual fragrance chemicals left in the machine or clothing; no statistical testing.
Source: Goodman 2019, Air Quality, Atmosphere & Health Link to this fact
What you can do / Measured in people or real products
People with a dermatitis distributed under clothing who suspect laundry detergent can ask a dermatologist for patch testing with a 0.1% aqueous dilution of their own detergent (low enough to avoid most irritant false positives), but a single positive reaction needs further dose-response and use-testing to separate true allergy from irritation.
Moderate evidence: Based on one study's protocol; not an independently validated clinical guideline.
Source: Belsito et al. 2002, Journal of the American Academy of Dermatology Industry-funded Link to this fact
What you can do / Review of other studies
When relying on a workplace, clinic, or school's fragrance-free policy, check whether it (1) defines what's covered beyond perfume, especially cleaning and laundry products, (2) sets a default fragrance-free expectation rather than a complaint-triggered one, (3) controls what cleaning/laundry products the institution buys, and (4) names a real consequence for non-compliance — a 2026 scoping review of 63 such policies found these structural features present in well under half of cases.
Moderate evidence: Based on a gray-literature document review of North American policies; individual policies may vary, and having these features on paper does not guarantee enforcement.
What you can do / Review of other studies
If households switch from fragranced to fragrance-free laundry detergent, modeling suggests dryer-vent limonene emissions across a whole city or state could drop substantially — an estimated 1.58 tons per year for metropolitan Melbourne, or 8.66 tons per year for the state of California.
Weak evidence.
Caveats
This is a modeled extrapolation, not a measurement: it multiplies a mean vent concentration from just 2-6 households (one grab sample each) by census household counts and usage-rate assumptions, with no confidence interval or sensitivity analysis anywhere in the calculation; the Melbourne input is dominated by a single outlier household roughly 11 times the other three.
Source: Goodman, Nematollahi & Steinemann 2020/2021, Air Quality, Atmosphere & Health Link to this fact
What you can do / Measured in people or real products
Powder laundry detergents had the lowest average common-allergen count of any subgroup surveyed (0.75/product) and contained none of the preservative allergens (MI, BIT, MCI/MI, phenoxyethanol) tracked in this study; their only common allergen was fragrance, present in 3 of 4 products.
Weak evidence: Very small subgroup (n=4); one 2019 US best-seller sample, not necessarily generalizable to all powder detergents.
Information, not medical advice. See also: myths we won’t tell you.