Baby Safety / Compounds / Phosmet

Is Phosmet safe for babies and kids?

High risk for kids

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

What is phosmet?

The IUPAC name is 2-(dimethoxyphosphinothioylsulfanylmethyl)isoindole-1,3-dione.

Also known as: 2-(dimethoxyphosphinothioylsulfanylmethyl)isoindole-1,3-dione, Fosmet, Decemthion, Phthalophos.

IUPAC name
2-(dimethoxyphosphinothioylsulfanylmethyl)isoindole-1,3-dione
CAS number
732-11-6
Molecular formula
C11H12NO4PS2
Molecular weight
317.3 g/mol
SMILES
COP(=S)(OC)SCN1C(=O)C2=CC=CC=C2C1=O
PubChem CID
12901

Risk for babies

High risk

Infants are acutely vulnerable to Phosmet 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

Elevated risk

Prenatal exposure to Phosmet 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

8 regulatory and scientific bodies have classified Phosmet. The classifications differ — that's the data.

AgencyYearClassificationNotes
EPA CTX / EPA OPPSuggestive Evidence of Carcinogenicity but Not Sufficient to Assess Human Carcinogenic Potential
EPA CTX / GenetoxGenotoxicity: positive (Ames: positive, 2 positive / 3 negative reports)
EPA CTX / GenetoxGenotoxicity: positive (Ames: positive, 2 positive / 3 negative reports)
EPA CTX / Skin-EyeEye Irritation: Category 2B (score: moderate)
EPA CTX / Skin-EyeSkin Irritation: Category 3 (score: moderate)
EPA CTX / Skin-EyeEye Irritation: Category 6.4A (Category 2A) (score: high)
EPA CTX / Skin-EyeSkin Irritation: Category 6.3B (Category 3) (score: moderate)
EPA CTX / Skin-EyeSkin Sensitization: Category 6.5B (Category 1) (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 phosmet

  • 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 Phosmet:

  • 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 phosmet safe for kids?

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

What products contain phosmet?

Phosmet 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 phosmet?

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 phosmet?

Phosmet has been classified by 8 agencies including EPA CTX / EPA OPP, EPA CTX / Genetox, EPA CTX / Genetox, EPA CTX / Skin-Eye, EPA CTX / Skin-Eye, 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 Phosmet in the baby app

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

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Sources (1)

  1. US EPA: Phosmet Reregistration Eligibility Decision — Dietary and Occupational Risk Assessment, Aquatic Ecological Risk, OPIDN Assessment (2001–2015) (2015) — 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 →