Diethyl Phthalate (DEP)
Diethyl phthalate (DEP) is a phthalate that dissolves fragrance in perfumes and scented products and makes the scent last longer. It is permitted in cosmetics in the EU and is not in the same class as banned phthalates such as DBP and DEHP. Even so, because the effects of phthalates on the hormone system are being studied, it makes sense to be cautious, especially with inhalation from air fresheners and continuous exposure.
Risk range
1 is the lowest and 10 the highest risk. The range depends on the amount used, whether the product is rinsed off and how it is used. The Temiz İçerik app uses the same ranges.
It is present at low levels within fragrance; leave-on perfumes and lotions are close to the upper end of the range.
The range is higher for air fresheners and spray odour neutralisers because it spreads into the air, is inhaled and creates continuous exposure in enclosed spaces.
What is diethyl phthalate and what is it used for?
Phthalates are a family of chemicals derived from phthalic acid. While those with large molecules (such as DEHP) are used to soften plastic, the small-molecule diethyl phthalate works more as a solvent and fixative: it dissolves fragrance molecules, slows their evaporation and makes the scent last longer. In some products it is also used as a denaturant to make alcohol undrinkable.
Which products contain it?
- Perfumes, deodorants and scented body lotions
- Air fresheners, spray odour neutralisers and scented candles
- Some nail polishes and hairsprays
- Scented detergents and fabric softeners
It is not always listed separately on the label; it can often stay hidden under the heading “Parfum” or “Fragrance”. So it is not always possible to tell from the label whether it is present in scented products.
Is it harmful? The scientific assessment
The EU's scientific committee concluded that DEP is safe at current levels of use in cosmetics, and the substance is not banned in cosmetics in the EU. DEP is also not among the phthalates classified in the EU as toxic for reproduction (CMR).
By contrast, some phthalates such as dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) have been banned in cosmetic products in the EU because they may harm the reproductive system; they are also restricted in toys and childcare articles. Turkish cosmetics legislation is aligned with these bans.
Human studies have reported associations between phthalate metabolites measured in urine and certain hormonal and developmental outcomes; however, these studies do not prove cause and effect, and the results are not consistent. Because the scientific debate is ongoing, experts recommend reducing unnecessary exposure.
Why be more careful with air fresheners?
We spray perfume onto the skin a few times; an air freshener, on the other hand, releases substances into the air of an enclosed space for hours. This means phthalates and other volatile fragrance ingredients can be breathed in continuously. This is why, in the app, DEP is rated in a higher range in the cleaning/household products category.
Who should be careful?
- Pregnant women: The debate about phthalates focuses on the developmental period; fragrance-free products may be preferable.
- Parents of babies and young children: Not using air fresheners continuously in children's rooms is a good habit.
- People with asthma or fragrance sensitivity: Air fresheners can make symptoms worse regardless of phthalates.
What to do when you see it on a label
Seeing DEP in a fragranced cosmetic is not, on its own, a cause for alarm. If you want to reduce exposure, you can choose products labelled “phthalate-free” or fragrance-free, and choose regular ventilation instead of air fresheners. For allergens in scented products, see also the fragrance page.
Frequently asked questions
Is diethyl phthalate banned?
No. It is permitted in cosmetics in the EU and Türkiye. The phthalates that are banned are those classified as harmful to the reproductive system, such as DBP and DEHP.
If the label doesn't mention phthalates, is the product phthalate-free?
Not always. DEP can be included under the heading “Parfum/Fragrance”. For certainty, look for a “phthalate-free” claim.
Is it harmful to use air fresheners?
There is no proven harm from occasional use. However, continuous use in an enclosed space means long-term exposure to various volatile substances; ventilation is a better alternative.
Sources
Updated: 2026-10-11 · How we score
This page is for general information and is not personal medical advice. Warnings on the product label and the advice of a health professional always come first.