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.
Children and pregnancy / Measured in people or real products
Pregnant women who had used perfume or cologne in the past day had 167% higher urine levels of MEP, the breakdown product of the fragrance solvent diethyl phthalate (DEP), than women who hadn't (177 women, Boston).
Strong evidence.
Caveats
Exposure marker, not health outcome; independently replicated in two further US cohorts with overlapping confidence intervals: Parlett 2013 (2.92x, postpartum, SFF multi-site) and Just 2010 (2.3x, 95% CI 1.6-3.3, pregnant, NYC minority cohort, with a dose-response and a null personal-air DEP association pointing to a dermal exposure route).
Source: Braun 2014, Journal of Exposure Science and Environmental Epidemiology Link to this fact
Children and pregnancy / Review of other studies
A 2018 US EPA systematic review found robust evidence that two common phthalates, DEHP and DBP, are linked to male reproductive harm (lower sperm quality; shorter anogenital distance in baby boys exposed before birth) at everyday exposure levels.
Strong evidence: Associations graded by protocol; DEHP/DBP are mainly plasticizers, not fragrance ingredients; no meta-analysis.
Source: Radke 2018 (US EPA), Environment International Link to this fact
Health effects / Review of other studies
In the same EPA review, diethyl phthalate (DEP), the phthalate used in fragrance, had only 'slight' evidence of male reproductive effects, the weakest of six phthalates, even though people are exposed to it the most.
Strong evidence: Use to set the record straight, not to accuse fragrance; 'slight' is not 'none' (more high-confidence studies needed).
Source: Radke 2018 (US EPA), Environment International Link to this fact
Hidden ingredients / Measured in people or real products
In lab tests of 213 US household and personal-care products, not one label listed a phthalate, yet the phthalate DEP, a common fragrance solvent, turned up in half of the pooled conventional product samples.
Strong evidence: Products bought 2007-08; composited samples; content not dose.
Source: Dodson 2012, Environmental Health Perspectives Link to this fact
Hidden ingredients / Review of other studies
US law does not require the individual chemicals in a fragrance to be listed, so a shopper cannot tell from the label whether a scented product contains diethyl phthalate.
Strong evidence: Regulatory background statement, as of 2013.
Source: Parlett 2013, Journal of Exposure Science and Environmental Epidemiology Link to this fact
Hidden ingredients / Advocacy group testing
Ingredient labels cannot show what is inside 'parfum': a 2010 Canadian cosmetics survey had to leave out diethyl phthalate, a common fragrance solvent, because 'short of a laboratory analysis, there's no way to know'.
Strong evidence: Illustrative quote; for measured prevalence cite Dodson 2012 (DEP in 21/42 conventional composites, no label listed a phthalate).
Hidden ingredients / Measured in people or real products
Health Canada's own testing of 252 Canadian cosmetic and personal care products found the fragrance solvent DEP in 70% of fragrance products, at levels up to 2.6% by weight, yet every DEP-positive product was labeled only with the generic term "parfum" — never DEP or any phthalate.
Strong evidence.
Caveats
N=252 individually tested products, Canadian market, 2007-08; detection frequency is lower than two smaller earlier surveys (Hubinger & Havery 2006, EWG 2002) found for fragrances specifically.
Source: Koniecki 2011, Environmental Research Link to this fact
What you can do / Review of other studies
Choosing fragrance-free personal care products is a reasonable way to cut DEP exposure, since DEP is used as a fragrance solvent; label reading alone will not catch phthalates.
Strong evidence: Reasoned advice; not tested as an intervention in this paper.
Source: Crinnion 2010, Alternative Medicine Review Link to this fact
Information, not medical advice. See also: myths we won’t tell you.