Baby Safety / Compounds / Methyl parathion

Is Methyl parathion safe for babies and kids?

Severe risk for kids

Infants are acutely vulnerable to Methyl parathion due to immature acetylcholinesterase regulation, higher dermal absorption per unit body weight, and frequent floor-level exposure to residues.

What is methyl parathion?

The IUPAC name is dimethoxy-(4-nitrophenoxy)-sulfanylidene-lambda5-phosphane.

Also known as: dimethoxy-(4-nitrophenoxy)-sulfanylidene-lambda5-phosphane, Parathion-methyl, Methylparathion, Dimethyl parathion.

IUPAC name
dimethoxy-(4-nitrophenoxy)-sulfanylidene-lambda5-phosphane
CAS number
298-00-0
Molecular formula
C8H10NO5PS
Molecular weight
263.21 g/mol
SMILES
COP(=S)(OC)OC1=CC=C(C=C1)[N+](=O)[O-]
PubChem CID
4130

Risk for babies

Severe risk

Infants are acutely vulnerable to Methyl parathion due to immature acetylcholinesterase regulation, higher dermal absorption per unit body weight, and frequent floor-level exposure to residues.

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 Methyl parathion is associated with neurodevelopmental effects. Organophosphate/carbamate insecticides inhibit acetylcholinesterase, which plays a role in fetal brain development.

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

10 regulatory and scientific bodies have classified Methyl parathion. The classifications differ — that's the data.

AgencyYearClassificationNotes
IARC1983Group 2BIARC Group 2B for methyl parathion, evaluated in Monograph 30 (1983) alongside ethyl parathion and other occupational pesticide exposures. Limited evidence of carcinogenicity in humans from occupational cohort studies of insecticide applicators; limited evidence in experimental animals from rodent bioassays showing liver tumors in some studies. Methyl parathion is structurally similar to parathion (dimethyl rather than diethyl phosphorothioate ester) and has a similar AChE-inhibiting mechanism, but with slightly higher acute oral toxicity in some species and different metabolic kinetics (methyl phosphorylated AChE 'ages' more slowly than ethyl, giving a marginally wider treatment window with pralidoxime). Methyl parathion was more widely used in developing world cotton production. Cancelled in the US by 2009 (EPA reregistration ineligibility); listed under the Rotterdam Convention PIC procedure. Not re-evaluated by IARC since 1983.
EPA CTX / IARCGroup 3 - Not classifiable as to its carcinogenicity to humans
EPA CTX / EPA OPPNot Likely to Be Carcinogenic in Humans
EPA CTX / GenetoxGenotoxicity: positive (Ames: positive, 12 positive / 5 negative reports)
EPA CTX / GenetoxGenotoxicity: positive (Ames: positive, 12 positive / 5 negative reports)
EPA CTX / Skin-EyeEye Irritation: Category 2B (score: moderate)
EPA CTX / Skin-EyeSkin Irritation: Category 3 (score: moderate)
EPA CTX / Skin-EyeSkin Sensitization: Not classified (score: low)
EPA CTX / Skin-EyeEye Irritation: Category 6.4A (Category 2A) (score: high)
EPA CTX / Skin-EyeSkin Irritation: Category 6.3B (Category 3) (score: moderate)

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 methyl parathion

  • 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 Methyl parathion:

  • Physical/mechanical pest control (IPM)
    Trade-offs: More labor-intensive. May not be sufficient for severe infestations.
    Relative cost: 1.2-2×

Frequently asked questions

Is methyl parathion safe for kids?

Infants are acutely vulnerable to Methyl parathion due to immature acetylcholinesterase regulation, higher dermal absorption per unit body weight, and frequent floor-level exposure to residues.

What products contain methyl parathion?

Methyl parathion 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 methyl parathion?

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 methyl parathion?

Methyl parathion has been classified by 10 agencies including IARC, EPA CTX / IARC, EPA CTX / EPA OPP, 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 Methyl parathion in the baby app

Look up products containing methyl parathion, compare to alternatives, and explore the full data record.

Open in baby View raw API data

Sources (2)

  1. IARC Monographs Volume 30: Occupational Exposures in Insecticide Application and Some Pesticides — Parathion and Methyl Parathion Group 2B Classification (1983) (1983) — regulatory
  2. US EPA: Methyl Parathion Reregistration Eligibility Decision — Risk Assessment, Dietary and Occupational Exposure, FQPA Safety Factor, and Cancellation (2006) (2006) — 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 →