Body & Beauty / Compounds / Diisodecyl phthalate (DIDP)

Diisodecyl phthalate (DIDP) on your skin: a safety profile

Low risk

(People-specific data is limited; this page draws from human adult context.) Diisodecyl phthalate (DIDP; CAS 26761-40-0) presents a low risk to human adults at current dietary and environmental exposure levels. The EFSA TDI of 150 μg/kg bw/day provides a substantial margin above estimated human daily intakes from food, indoor dust, and consumer product migration in adults. DIDP's high molecular weight and lower dermal absorption compared to shorter-chain phthalates reduces exposure from skin contact. DIDP biomonitoring urinary metabolites (monoisodecyl phthalate; MiDP and related oxidized metabolites) are detectable in general population urine, confirming real-world exposure, but at concentrations generally below EFSA TDI thresholds. The more stringent cumulative group TDI (50 μg TEQ/kg bw/day) applies to the DEHP/DBP/BBP/DIBP grouping; DIDP is not included in this 4-phthalate group, though regulatory consideration of a broader phthalate cumulative assessment including DIDP and DINP is ongoing.

What is diisodecyl phthalate (didp)?

The IUPAC name is bis(8-methylnonyl) benzene-1,2-dicarboxylate.

Also known as: bis(8-methylnonyl) benzene-1,2-dicarboxylate, DIISODECYL PHTHALATE, Palatinol Z, di-isodecyl phthalate.

IUPAC name
bis(8-methylnonyl) benzene-1,2-dicarboxylate
CAS number
26761-40-0
Molecular formula
C28H46O4
Molecular weight
446.7 g/mol
SMILES
CC(C)CCCCCCCOC(=O)C1=CC=CC=C1C(=O)OCCCCCCCC(C)C
PubChem CID
33599

Risk for people

Low risk

Diisodecyl phthalate (DIDP; CAS 26761-40-0) presents a low risk to human adults at current dietary and environmental exposure levels. The EFSA TDI of 150 μg/kg bw/day provides a substantial margin above estimated human daily intakes from food, indoor dust, and consumer product migration in adults. DIDP's high molecular weight and lower dermal absorption compared to shorter-chain phthalates reduces exposure from skin contact. DIDP biomonitoring urinary metabolites (monoisodecyl phthalate; MiDP and related oxidized metabolites) are detectable in general population urine, confirming real-world exposure, but at concentrations generally below EFSA TDI thresholds. The more stringent cumulative group TDI (50 μg TEQ/kg bw/day) applies to the DEHP/DBP/BBP/DIBP grouping; DIDP is not included in this 4-phthalate group, though regulatory consideration of a broader phthalate cumulative assessment including DIDP and DINP is ongoing.

Regulatory consensus

3 regulatory and scientific bodies have classified Diisodecyl phthalate (DIDP). The classifications differ — that's the data.

AgencyYearClassificationNotes
ECHA SVHC / EFSA (DIDP — diisodecyl phthalate — REACH SVHC candidate list — reproductive toxicant Category 1B (Repr. 1B; may damage fertility or the unborn child); EFSA 2019 Group TDI established for DEHP, DBP, BBP, DIBP mixture of 4 phthalates at 50 μg TEQ/kg bw/day; DIDP separately assessed with TDI of 150 μg/kg bw/day; no carcinogenicity classification by IARC, NTP, or US EPA; EU REACH Annex XIV authorization list evaluation ongoing for DIDP/DINP group)2019no carcinogenicity classification; ECHA SVHC candidate — reproductive toxicant Cat 1B; EFSA TDI 150 μg/kg bw/day; high-molecular-weight phthalate plasticizer; anti-androgenic at high doses; EU REACH restrictions on use in child-care articles and sensitive applications
EPA CTX / Genetox—Genotoxicity: negative (Ames: negative, 0 positive / 1 negative reports)
EPA CTX / Genetox—Genotoxicity: negative (Ames: negative, 0 positive / 1 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 diisodecyl phthalate (didp)

  • 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
  • Fragrance — perfume, cologne, scented personal care products, household fragrance products, candles
    Identified in Fragrance Ingredient Safety Priority Research database (2,325 ingredients)

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Diisodecyl phthalate (DIDP):

  • DINCH or citrate esters (ATBC)
    Trade-offs: May require reformulation. Higher cost.
    Relative cost: 1.2-2×

Frequently asked questions

What products contain diisodecyl phthalate (didp)?

Diisodecyl phthalate (DIDP) 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 diisodecyl phthalate (didp)?

Diisodecyl phthalate (DIDP) has been classified by 3 agencies including ECHA SVHC / EFSA (DIDP — diisodecyl phthalate — REACH SVHC candidate list — reproductive toxicant Category 1B (Repr. 1B; may damage fertility or the unborn child); EFSA 2019 Group TDI established for DEHP, DBP, BBP, DIBP mixture of 4 phthalates at 50 μg TEQ/kg bw/day; DIDP separately assessed with TDI of 150 μg/kg bw/day; no carcinogenicity classification by IARC, NTP, or US EPA; EU REACH Annex XIV authorization list evaluation ongoing for DIDP/DINP group), 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 Diisodecyl phthalate (DIDP) in the body app

Look up products containing diisodecyl phthalate (didp), compare to alternatives, and explore the full data record.

Open in body View raw API data

Sources (1)
  1. EFSA 2019 DIDP TDI 150 μg/kg bw/day; ECHA SVHC Repr 1B Reproductive Toxicant REACH Candidate; High-MW Phthalate PVC Plasticizer; Anti-Androgenic Leydig Cell Effects; Cumulative Group TDI DEHP DBP BBP DIBP Excludes DIDP; EU Toys Child-Care Articles Restriction (2019) — 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 →