Food & Drink / Compounds / Diethyl phthalate

Diethyl phthalate in food: ingestion safety

Low risk

(People-specific data is limited; this page draws from human adult context.) Diethyl phthalate (DEP; CAS 84-66-2) is among the lowest-concern phthalate compounds in widespread use. FDA considers it safe in cosmetics and personal care products; EU Cosmetics Regulation places no concentration restriction on it. US EPA IRIS Group D (not classifiable for carcinogenicity). Unlike the restricted phthalates (DEHP, DBP, BBP, DIBP), DEP does not show significant antiandrogenic reproductive toxicity at relevant human exposure levels and is specifically excluded from EFSA's 2019 cumulative phthalate group TDI for antiandrogenic effects. Metabolized to monoethyl phthalate (MEP) — rapidly excreted in urine; short biological half-life (hours). Oral RfD 0.8 mg/kg/day. Urinary MEP is detectable in virtually all NHANES participants, reflecting widespread cosmetic and personal care exposure — at typical environmental/consumer exposure levels, no adverse health outcomes associated with DEP or MEP in epidemiological studies.

What is diethyl phthalate?

The IUPAC name is diethyl benzene-1,2-dicarboxylate.

Also known as: diethyl benzene-1,2-dicarboxylate, Ethyl phthalate, phthalic acid diethyl ester, Anozol.

IUPAC name
diethyl benzene-1,2-dicarboxylate
CAS number
84-66-2
Molecular formula
C12H14O4
Molecular weight
222.24 g/mol
SMILES
CCOC(=O)C1=CC=CC=C1C(=O)OCC
PubChem CID
6781

Risk for people

Low risk

Diethyl phthalate (DEP; CAS 84-66-2) is among the lowest-concern phthalate compounds in widespread use. FDA considers it safe in cosmetics and personal care products; EU Cosmetics Regulation places no concentration restriction on it. US EPA IRIS Group D (not classifiable for carcinogenicity). Unlike the restricted phthalates (DEHP, DBP, BBP, DIBP), DEP does not show significant antiandrogenic reproductive toxicity at relevant human exposure levels and is specifically excluded from EFSA's 2019 cumulative phthalate group TDI for antiandrogenic effects. Metabolized to monoethyl phthalate (MEP) — rapidly excreted in urine; short biological half-life (hours). Oral RfD 0.8 mg/kg/day. Urinary MEP is detectable in virtually all NHANES participants, reflecting widespread cosmetic and personal care exposure — at typical environmental/consumer exposure levels, no adverse health outcomes associated with DEP or MEP in epidemiological studies.

Regulatory consensus

5 regulatory and scientific bodies have classified Diethyl phthalate. The classifications differ — that's the data.

AgencyYearClassificationNotes
US EPA (IRIS)2009not classifiable as to human carcinogenicity (Group D); oral RfD 0.8 mg/kg/day; not a reproductive/developmental toxicant at environmentally relevant doses
EPA CTX / IRIS—D (Not classifiable as to human carcinogenicity)
EPA CTX / EPA OPP—Group D Not Classifiable as to Human Carcinogenicity
EPA CTX / Genetox—Genotoxicity: negative (Ames: negative, 0 positive / 5 negative reports)
EPA CTX / Genetox—Genotoxicity: negative (Ames: negative, 0 positive / 5 negative reports)

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter diethyl phthalate

  • Consumer Products — Plastic bottles and containers, Food packaging, Plastic toys and household items
  • Drinking Water — Leaching from plastic pipes, Migration from bottled water containers
  • Indoor Environments — Off-gassing from plastic furniture, Degradation of plastic products

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Diethyl phthalate:

  • Fragrance-free formulations
    Trade-offs: Consumer preference for scented products
    Relative cost: Lower (ingredient elimination)
  • Essential oil-based fragrances (with disclosure)
    Trade-offs: Natural does not mean safe — many essential oils are skin sensitizers
    Relative cost: 2-5× conventional

Frequently asked questions

What products contain diethyl phthalate?

Diethyl phthalate appears in: Plastic bottles and containers (Consumer products); Food packaging (Consumer products); Leaching from plastic pipes (Drinking water); Migration from bottled water containers (Drinking water); Off-gassing from plastic furniture (Indoor environments).

Why do regulators disagree about diethyl phthalate?

Diethyl phthalate has been classified by 5 agencies including US EPA (IRIS), EPA CTX / IRIS, EPA CTX / EPA OPP, EPA CTX / Genetox, EPA CTX / Genetox, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

See Diethyl phthalate in the food app

Look up products containing diethyl phthalate, compare to alternatives, and explore the full data record.

Open in food View raw API data

Sources (2)
  1. US EPA IRIS Diethyl Phthalate: Group D Not Classifiable; Oral RfD 0.8 mg/kg/day; Not Antiandrogenic; FDA Cosmetic Safety; EU Cosmetics No Restriction; EFSA Cumulative TDI Exclusion (2009) — regulatory
  2. FDA Cosmetic Ingredient Safety Diethyl Phthalate DEP: No Restriction; NHANES Urinary MEP Biomonitoring; Low Reproductive Toxicity Concern vs DEHP DBP; Not in EU Annex XVII Restrictions (2020) — regulatory

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →