Baby Safety / Compounds / 4-tert-Butylphenol

Is 4-tert-Butylphenol safe for babies and kids?

Very high risk for kids

Infants are more vulnerable to 4-tert-Butylphenol than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

What is 4-tert-butylphenol?

Also known as: p-tert-Butylphenol, Butylphen, 4-(1,1-Dimethylethyl)phenol, 4-t-Butylphenol.

IUPAC name
4-tert-butylphenol
CAS number
98-54-4
Molecular formula
C10H14O
Molecular weight
150.22 g/mol
SMILES
CC(C)(C)C1=CC=C(C=C1)O
PubChem CID
7393

Risk for babies

Very high risk

Infants are more vulnerable to 4-tert-Butylphenol than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

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

Very high risk

Prenatal exposure to 4-tert-Butylphenol through personal care products may affect fetal development. Some fragrance chemicals are sensitizers or endocrine-active compounds with transplacental transfer.

Known reproductive toxicant (GHS H360) or confirmed endocrine disruptor. Placental transfer is presumed. Fetal exposure during critical developmental windows may cause structural malformations, growth restriction, or functional deficits.

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

Regulatory consensus

3 regulatory and scientific bodies have classified 4-tert-Butylphenol. The classifications differ — that's the data.

AgencyYearClassificationNotes
EDC Assessment2024Suspected endocrine disruptor
ECHA2019SVHC_EDCSVHC — endocrine disrupting properties (environment)
EU_REACH2014CoRAPCoRAP evaluation completed — ED ENV + ED HH unresolved

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 4-tert-butylphenol

  • Personal Care — essential oils, oral care, antiseptics
  • Food — spice flavoring (thymol, carvacrol)
  • 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 4-tert-Butylphenol:

  • Exposure reduction / process substitution
    Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.
    Relative cost: 1.2-2×

Frequently asked questions

Is 4-tert-butylphenol safe for kids?

Infants are more vulnerable to 4-tert-Butylphenol than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

What products contain 4-tert-butylphenol?

4-tert-Butylphenol appears in: essential oils (Personal care); oral care (Personal care); spice flavoring (thymol, carvacrol) (Food); perfume (Fragrance); cologne (Fragrance).

What should I do if my child is exposed to 4-tert-butylphenol?

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.

Why do regulators disagree about 4-tert-butylphenol?

4-tert-Butylphenol has been classified by 3 agencies including EDC Assessment, ECHA, EU_REACH, 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 4-tert-Butylphenol in the baby app

Look up products containing 4-tert-butylphenol, compare to alternatives, and explore the full data record.

Open in baby View raw API data

Sources (1)
  1. PubChem Compound Database (2026) — database

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 →