Baby Safety / Compounds / Diisooctyl phthalate (DIOP)

Is Diisooctyl phthalate (DIOP) safe for babies and kids?

Moderate risk for kids

Infants are highly exposed to Diisooctyl phthalate (DIOP) through mouthing of plastic toys, teethers, bottles, and food packaging leachates. Endocrine disruption risk is amplified during critical windows of reproductive and neurological development.

What is diisooctyl phthalate (diop)?

The IUPAC name is bis(6-methylheptyl) benzene-1,2-dicarboxylate.

Also known as: bis(6-methylheptyl) benzene-1,2-dicarboxylate, Diisooctyl phthalate, Isooctyl phthalate, Diop.

IUPAC name
bis(6-methylheptyl) benzene-1,2-dicarboxylate
CAS number
27554-26-3
Molecular formula
C24H38O4
Molecular weight
390.6 g/mol
SMILES
CC(C)CCCCCOC(=O)C1=CC=CC=C1C(=O)OCCCCCC(C)C
PubChem CID
33934

Risk for babies

Moderate risk

Infants are highly exposed to Diisooctyl phthalate (DIOP) through mouthing of plastic toys, teethers, bottles, and food packaging leachates. Endocrine disruption risk is amplified during critical windows of reproductive and neurological development.

Neonates and infants up to 12 months have incomplete blood-brain barrier development, immature Phase I/II metabolic enzymes (particularly CYP3A4, UGT1A1), and higher gastrointestinal permeability. Equivalent doses produce higher internal concentrations and longer residence times.

What to do: Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

Risk for pregnant and nursing people

Elevated risk

Prenatal exposure to Diisooctyl phthalate (DIOP) is associated with endocrine disruption affecting fetal reproductive development. Phthalates and alternative plasticizers cross the placenta and are detectable in amniotic fluid.

Suspected reproductive toxicant (GHS H361) or suspected endocrine disruptor. Precautionary approach warranted. Animal studies or limited human data suggest developmental toxicity potential.

What to do: Minimize exposure during pregnancy and lactation. Consult healthcare provider regarding specific risks. Consider alternative products with lower hazard profiles.

Regulatory consensus

1 regulatory bodyhas classified Diisooctyl phthalate (DIOP).

AgencyYearClassificationNotes
US EPA / ECHA (DIOP — diisooctyl phthalate — CAS 27554-26-3; limited individual regulatory assessment; structurally related to DEHP (both C8 phthalates) but with different branching pattern affecting metabolic activation; anti-androgenic phthalate class effects expected but species-specific and dose-dependent; no individual IRIS assessment; no ECHA SVHC listing as individual compound; not classified for carcinogenicity by IARC, NTP, EFSA, or US EPA; use declining in favor of higher-MW phthalates and non-phthalate alternatives)2020no carcinogenicity classification; C8 branched phthalate plasticizer; anti-androgenic activity expected from class; limited individual regulatory assessment; not classified by IARC, NTP, EFSA, or US EPA for carcinogenicity

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 kids encounter diisooctyl phthalate (diop)

  • 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 Diisooctyl phthalate (DIOP):

  • 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

Is diisooctyl phthalate (diop) safe for kids?

Infants are highly exposed to Diisooctyl phthalate (DIOP) through mouthing of plastic toys, teethers, bottles, and food packaging leachates. Endocrine disruption risk is amplified during critical windows of reproductive and neurological development.

What products contain diisooctyl phthalate (diop)?

Diisooctyl phthalate (DIOP) 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).

What should I do if my child is exposed to diisooctyl phthalate (diop)?

Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

See Diisooctyl phthalate (DIOP) in the baby app

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

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Sources (1)
  1. US EPA ECHA DIOP Diisooctyl Phthalate CAS 27554-26-3; C8 Branched Phthalate DEHP Structural Relative; Limited Individual Regulatory Assessment; Anti-Androgenic Class Effects Expected; No IRIS RfD; No SVHC Listing; No IARC NTP EFSA EPA Carcinogenicity Classification (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 →