At a glance
| Chemical family | Phthalate ester plasticizer |
| CAS number | 117-81-7 |
| Classification | IARC Group 2B (possibly carcinogenic to humans); EPA Toxic Substances Control Act prioritized chemical; CPSC restricted to <0.1% in children's products |
| Where you encounter it | Vinyl mattress covers, vinyl crib mattress covers, PVC flooring and wallpaper, medical tubing, food packaging films, personal care products, house dust |
| Sleep micro environment relevance | Off-gasses from vinyl covers continuously; emission rate increases >10× from 25°C to 35°C — meaning a body-warmed mattress emits substantially more DEHP than a room-temperature one; the metabolite MEHP is also excreted in sweat at higher concentrations than in urine |
| Activated carbon capture | High — β-cyclodextrin polymer (host-guest chemistry), granular activated carbon, and activated carbon fiber cloth all adsorb DEHP effectively |
What it is
DEHP is a colorless, oily liquid used as a plasticizer to make rigid PVC into the flexible vinyl that appears in a wide range of consumer and industrial products. It is not chemically bonded to the polymer matrix — it sits between the polymer chains as a softening agent — which means it migrates out of the product over time through evaporation, abrasion, and contact with skin or other materials. This migration is what creates the exposure pathway. A vinyl cover at the point of manufacture and the same cover after five years of use have substantially different DEHP loads, with the difference distributed across air, dust, skin, and adjacent materials.
The compound has been the subject of extensive biomonitoring because its primary metabolite, MEHP (mono(2-ethylhexyl) phthalate), is excreted in urine and is one of the most reliable indicators of human phthalate exposure. The CDC's NHANES program has detected DEHP metabolites in the urine of essentially every American tested for decades. The European Chemicals Agency added DEHP to the Authorisation List under REACH in 2011, requiring specific authorization for its continued use in the EU — a regulatory designation reserved for substances of very high concern. In the US, the Consumer Product Safety Commission restricted DEHP to less than 0.1% by weight in children's toys and child-care articles under the CPSIA in 2008.
In a sleep-environment context, the most important property of DEHP is its temperature-dependent volatility. Phthalates have low vapor pressures at room temperature but emit significantly more rapidly when warmed. A body-warmed mattress is a meaningfully different emission source than a chamber-test certification would suggest.
How it gets to the bedroom
From vinyl mattress and crib covers
A 2015 study by Boor and colleagues measured phthalate emissions from vinyl crib mattress covers under controlled chamber conditions and found that gas-phase phthalate concentrations rose more than 10× when temperature was raised from 25°C to 35°C. One vinyl cover in the study contained 125.7 mg/g DEHP — over 12% of the cover by weight. Peer-reviewed — Boor 2015, PMID 25419579 Body temperature is approximately 37°C, and the surface of a mattress in contact with a sleeping person reaches the upper end of that emission range continuously for 7–9 hours per night.
From house dust
DEHP is detected in over 98% of US house dust samples. Peer-reviewed Dust accumulates on bedding, carpets, and soft furnishings. Children's exposure is particularly elevated because of more time spent on the floor, higher hand-to-mouth contact, and breathing closer to dust-reservoir surfaces. The 2015 Boor study specifically flagged children sleeping in small, poorly ventilated rooms as the highest-exposure scenario for phthalate inhalation. Peer-reviewed
From your own sweat
A 2012 study by Genuis and colleagues found MEHP — the DEHP metabolite — in the sweat of all 20 participants tested, at concentrations more than twice as high as in urine. Peer-reviewed — Genuis 2012, PMC3504417 DEHP itself appeared in sweat samples even in participants where it was not detected in serum, indicating that the body mobilizes stored DEHP through sweat. The practical implication for the sleep environment: even if your mattress is phthalate-free, you may be depositing your own DEHP metabolites onto bedding through perspiration during sleep.
From personal care products
DEHP and related phthalates are sometimes used as fragrance carriers in personal care products. Application to skin before bed transfers residue to pillows, sheets, and pajamas — a pathway documented for DEP (diethyl phthalate) and inferred for DEHP based on shared product use patterns. Inferred from the documented DEP residue pathway and shared product context
From PVC flooring and wallpaper
PVC building materials in the room itself emit DEHP into indoor air. The combined load — mattress cover + dust + flooring + wallpaper — is what produces the bedroom-level concentrations measured in residential air quality studies.
What the research says
Documented health effects
DEHP and its metabolites have been studied extensively for reproductive and developmental effects. The strongest evidence base concerns male reproductive development: prenatal exposure to phthalates including DEHP has been associated with shortened anogenital distance, altered hormone levels, and other markers of disrupted androgen signaling in male infants. Peer-reviewed The "phthalate syndrome" in animal models — a constellation of male reproductive tract malformations following prenatal DEHP exposure — is well documented at occupationally relevant exposure levels.
DEHP is classified by IARC as Group 2B (possibly carcinogenic to humans) based on evidence of liver tumors in rodent studies and limited evidence in humans. The compound is also on California's Proposition 65 list as a reproductive toxicant.
Bedroom-specific evidence
The 2015 Boor study established the temperature-dependence of emission rates from vinyl covers and specifically modeled exposure scenarios for infants and children sleeping on vinyl-covered crib mattresses. The modeled inhalation dose at body-temperature emission rates exceeded the EPA reference dose for DEHP in the modeled infant exposure scenario. Peer-reviewed This study is one of the more direct mattress-specific exposure assessments in the published literature.
For parents of infants and young children
Infants and children are the population for whom DEHP exposure has the strongest documented health concern, both because of developmental window vulnerability and because their per-body-weight exposure is higher than adults. The Boor study, the EPA's TSCA risk evaluation, and the CPSC restrictions all reflect this elevated concern. The specific question of whether crib mattress DEHP exposure crosses thresholds of meaningful developmental concern in a typical residential setting depends on ventilation, cover composition, and individual room conditions that vary substantially. Inferred from documented exposure thresholds and emission data
What helps reduce exposure
Avoid vinyl mattress covers, especially on crib mattresses. Vinyl covers are the highest-emission DEHP source in most bedrooms. Untreated cotton, wool, polyethylene-blend covers, and TPU (thermoplastic polyurethane) covers without phthalate plasticizers reduce or eliminate this pathway. Check the manufacturer's disclosure; "phthalate-free" claims should be verified against third-party testing where possible.
For crib mattresses specifically: prioritize disclosure. Manufacturers including Naturepedic, My Green Mattress, and several others publish complete material disclosures for crib mattresses. The Boor 2015 study made specific recommendations for parents of infants regarding cover material selection.
Ventilate the room with fresh air. Phthalate concentrations in indoor air are reduced by air exchange. HVAC recirculation does not dilute phthalates; actual outdoor air infiltration does. Brief daily window-opening, especially in warmer months when vinyl emission rates are higher, is the documented mitigation. Peer-reviewed
Wash bedding regularly. Bedding accumulates phthalates from both ambient air and the sleeper's own sweat (MEHP). Weekly washing reduces the deposited load on the surface in contact with skin. This does not address the mattress itself but reduces the dermal-contact dose from accumulated residues.
Reduce dust accumulation. HEPA-filtered vacuuming, regular wet-mop of hard surfaces, and washing soft furnishings reduce the dust reservoir of DEHP and other SVOCs. Dust is the primary exposure pathway for non-mattress sources of DEHP in the bedroom.
What does NOT help
- "BPA-free" and "non-toxic" labels do not necessarily mean phthalate-free. Different chemical class; different regulatory framework; different disclosure requirements.
- CertiPUR-US certification does not cover phthalates in mattress covers — only the polyurethane foam component. A CertiPUR-US-certified mattress can have a PVC-and-DEHP-containing waterproof cover. See our piece on what CertiPUR-US actually tests for.
- Air purifiers without VOC-rated activated carbon do not meaningfully reduce gas-phase DEHP. HEPA captures particles; phthalate vapor passes through. Activated carbon rated for SVOC capture is the relevant filtration class.
- Heating the room to "off-gas" the mattress before use makes things worse, not better. Higher temperature increases emission rate; the mattress doesn't run out of DEHP, it just emits it faster.
Open research questions
- The specific cumulative DEHP exposure over a typical mattress lifespan (8–10 years) under continuous body-warmed conditions, versus the chamber-test emission rates used in regulatory assessment. Speculation — the chamber data exists; the in-use lifetime calculation has not been published
- The capture efficiency of activated carbon fiber cloth at the sleep-surface interface for DEHP under body-heat conditions. This is one of the chamber-test protocols proposed in Embr's research program. Speculation — the broader activated-carbon-phthalate adsorption chemistry is documented; the sleep-surface application has not been measured
- The contribution of the sleeper's own sweat-mediated MEHP deposition to bedding DEHP-equivalent loads, particularly in shared sleeping arrangements (co-sleeping infants, partners). Speculation — the Genuis 2012 sweat finding establishes the pathway exists; the bedding-load quantification has not been done
Citations
- International Agency for Research on Cancer. DEHP (Group 2B). IARC Monographs. Peer-reviewed
- Consumer Product Safety Improvement Act of 2008 (CPSIA), Section 108 — phthalate restrictions in children's products. Regulatory
- European Chemicals Agency. DEHP Authorisation List entry. Regulatory
- Boor BE, Liang Y, Crain NE, Järnström H, Novoselac A, Xu Y (2015). Identification of Phthalate Plasticizers, Flame Retardants and Unreacted Isocyanate Monomers Present in Polyurethane Foam Mattresses. Environmental Science & Technology Letters. PMID 25419579 Peer-reviewed
- Genuis SJ, Beesoon S, Lobo RA, Birkholz D (2012). Human Elimination of Phthalate Compounds: Blood, Urine, and Sweat (BUS) Study. PMC3504417 Peer-reviewed
- EPA. Risk Evaluation for Di-ethylhexyl Phthalate under TSCA. Regulatory
- CDC. National Health and Nutrition Examination Survey (NHANES) — Phthalate Metabolite Biomonitoring. Peer-reviewed
- California Office of Environmental Health Hazard Assessment. Proposition 65 listing — DEHP. Regulatory
Frequently asked questions
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Is DEHP in my mattress?
Possibly, depending on the cover material. DEHP is most commonly used in vinyl (PVC) mattress covers and crib mattress covers. Mattresses with cotton, wool, polyethylene, or TPU covers without PVC vinyl coating typically do not contain significant DEHP. The law tag on the mattress and the manufacturer's material disclosure are the most reliable indicators. Boor 2015 specifically documented one vinyl crib cover containing 125.7 mg/g DEHP by weight.
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Why does body heat matter for DEHP?
Phthalate emission rates increase substantially with temperature. The Boor 2015 study measured a more-than-tenfold increase in DEHP gas-phase emissions from vinyl covers when temperature rose from 25°C to 35°C. Body surface temperature against a mattress reaches approximately 36–37°C. The certification tests typically used to evaluate mattresses run at room temperature, which underestimates the in-use emission rate.
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Is DEHP banned in children's products?
In the United States, DEHP is restricted to less than 0.1% by weight in toys and child-care articles under the Consumer Product Safety Improvement Act of 2008. Regulatory The restriction applies to toys and articles "designed or intended primarily for children three years of age or younger" plus some additional categories. Crib mattresses are in a regulatory gray zone — they have not been universally treated as restricted under the CPSIA, and disclosure of DEHP-containing covers is inconsistent.
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Does washing remove DEHP from bedding?
Partially. Washing reduces accumulated phthalate residues on bedding surfaces but does not remove DEHP from the underlying mattress cover. Washing helps for the dermal-contact dose from accumulated residues; it does not address the emission rate of the cover itself.
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Are there phthalate-free mattress covers?
Yes. Polyethylene-coated covers, TPU (thermoplastic polyurethane) covers without phthalate plasticizers, untreated cotton, and wool are all phthalate-free options. Specific brands disclosing complete material composition include Naturepedic, My Green Mattress, Avocado, and several others. "Phthalate-free" claims should be verified through specific testing certification (OEKO-TEX, GOTS, GOLS, MADE SAFE) rather than marketing language alone.
Related compounds
Embr Sleep is a sleep environment company researching and addressing the chemistry of the bedroom. Our work on phthalates focuses on capture at the sleep-surface interface under body-heat conditions — work that is in research and product development.
Last reviewed 2026-05-15. If you find a factual error, contact us.