Baby Safety / Compounds / MTBE (methyl tert-butyl ether)

Is MTBE (methyl tert-butyl ether) safe for babies and kids?

Moderate risk for kids

Infants are vulnerable to MTBE (methyl tert-butyl ether) through inhalation of volatile residues in household products. Immature blood-brain barrier and higher respiratory rate per body weight amplify CNS exposure.

What is mtbe (methyl tert-butyl ether)?

The IUPAC name is 2-methoxy-2-methylpropane.

Also known as: 2-methoxy-2-methylpropane, tert-Butyl methyl ether, Methyl tert-butyl ether, MTBE.

IUPAC name
2-methoxy-2-methylpropane
CAS number
1634-04-4
Molecular formula
C5H12O
Molecular weight
88.15 g/mol
SMILES
CC(C)(C)OC
PubChem CID
15413

Risk for babies

Moderate risk

Infants are vulnerable to MTBE (methyl tert-butyl ether) through inhalation of volatile residues in household products. Immature blood-brain barrier and higher respiratory rate per body weight amplify CNS exposure.

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

Occupational and household exposure to MTBE (methyl tert-butyl ether) during pregnancy is associated with developmental toxicity. Solvents readily cross the placenta and can cause fetal growth restriction.

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

9 regulatory and scientific bodies have classified MTBE (methyl tert-butyl ether). The classifications differ — that's the data.

AgencyYearClassificationNotes
EPA CTX / IARCGroup 3 - Not classifiable as to its carcinogenicity to humans
EPA CTX / Health CanadaGroup VI: CEPA (unclassifiable with respect to carcinogenicity to humans)
EPA CTX / Health CanadaGroup VIA: CEPA (unclassifiable with respect to carcinogenicity to humans)
EPA CTX / GenetoxGenotoxicity: positive (Ames: positive, 2 positive / 18 negative reports)
EPA CTX / GenetoxGenotoxicity: positive (Ames: positive, 2 positive / 18 negative reports)
EPA CTX / Skin-EyeSkin Irritation: Skin Irrit. 2 (score: high)
EPA CTX / Skin-EyeEye Irritation: Category 2B (score: moderate)
EPA CTX / Skin-EyeSkin Irritation: Category 2 (score: high)
EPA CTX / Skin-EyeSkin Sensitization: Not classified (score: low)

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 mtbe (methyl tert-butyl ether)

  • Industrial FacilitiesManufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational EnvironmentsFactories, Warehouses, Transportation vehicles

Safer alternatives

Lower-risk approaches that achieve a similar outcome to MTBE (methyl tert-butyl ether):

  • Water-based formulations where feasible
    Trade-offs: Longer drying time. May not achieve same performance in all applications.
    Relative cost: 0.8-1.5×
  • Bio-based solvents (d-limonene, ethyl lactate)
    Trade-offs: Higher cost. Flammability concerns with some bio-solvents.
    Relative cost: 2-5× conventional

Frequently asked questions

Is mtbe (methyl tert-butyl ether) safe for kids?

Infants are vulnerable to MTBE (methyl tert-butyl ether) through inhalation of volatile residues in household products. Immature blood-brain barrier and higher respiratory rate per body weight amplify CNS exposure.

What products contain mtbe (methyl tert-butyl ether)?

MTBE (methyl tert-butyl ether) appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

What should I do if my child is exposed to mtbe (methyl tert-butyl ether)?

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 mtbe (methyl tert-butyl ether)?

MTBE (methyl tert-butyl ether) has been classified by 9 agencies including EPA CTX / IARC, EPA CTX / Health Canada, EPA CTX / Health Canada, 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 MTBE (methyl tert-butyl ether) in the baby app

Look up products containing mtbe (methyl tert-butyl ether), compare to alternatives, and explore the full data record.

Open in baby View raw API data

Sources (2)

  1. US EPA: Drinking Water Advisory: Consumer Acceptability Advice and Health Effects Analysis on Methyl Tertiary-Butyl Ether (MTBE) — Taste/Odor Threshold 20–40 μg/L, No Federal MCL Established (1997) (1997) — regulatory
  2. WHO Guidelines for Drinking-water Quality (4th edition, incorporating the 1st and 2nd addenda, 2022) — Disinfection Byproducts: THMs, HAAs, Chlorite, Bromate, Chloral Hydrate; Guideline Values and Health Basis (2022) — 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 →