Baby Safety / Compounds / Guaiacol (2-methoxyphenol)

Is Guaiacol (2-methoxyphenol) safe for babies and kids?

Moderate risk for kids

Infants are more vulnerable to Guaiacol (2-methoxyphenol) 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 guaiacol (2-methoxyphenol)?

The IUPAC name is 2-methoxyphenol.

Also known as: 2-methoxyphenol, guaiacol, o-Methoxyphenol, 2-Hydroxyanisole.

IUPAC name
2-methoxyphenol
CAS number
90-05-1
Molecular formula
C7H8O2
Molecular weight
124.14 g/mol
SMILES
COC1=CC=CC=C1O
PubChem CID
460

Risk for babies

Moderate risk

Infants are more vulnerable to Guaiacol (2-methoxyphenol) 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

Context-dependent

Prenatal exposure to Guaiacol (2-methoxyphenol) through personal care products may affect fetal development. Some fragrance chemicals are sensitizers or endocrine-active compounds with transplacental transfer.

No specific reproductive toxicity data identified, but pregnancy-specific safety data is limited for most chemicals. Precautionary minimization of exposure is recommended.

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 Guaiacol (2-methoxyphenol).

AgencyYearClassificationNotes
FDA1965GRASGRAS food flavoring — smoke/vanilla component

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 guaiacol (2-methoxyphenol)

  • 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 Guaiacol (2-methoxyphenol):

  • Vanillin
    Trade-offs: Alternative fragrance ingredient; individual safety profile should be assessed per IFRA standards; sensitization potential varies by compound; patch testing recommended for sensitive individuals.
    Relative cost: 1.2-2×
  • Ethyl vanillin
    Trade-offs: Alternative fragrance ingredient; individual safety profile should be assessed per IFRA standards; sensitization potential varies by compound; patch testing recommended for sensitive individuals.
    Relative cost: 1.2-2×

Frequently asked questions

Is guaiacol (2-methoxyphenol) safe for kids?

Infants are more vulnerable to Guaiacol (2-methoxyphenol) 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 guaiacol (2-methoxyphenol)?

Guaiacol (2-methoxyphenol) 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 guaiacol (2-methoxyphenol)?

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 Guaiacol (2-methoxyphenol) in the baby app

Look up products containing guaiacol (2-methoxyphenol), compare to alternatives, and explore the full data record.

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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 →