Baby Safety / Compounds / Fonofos

Is Fonofos safe for babies and kids?

Severe risk for kids

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

What is fonofos?

The IUPAC name is ethoxy-ethyl-phenylsulfanyl-sulfanylidene-lambda5-phosphane.

Also known as: ethoxy-ethyl-phenylsulfanyl-sulfanylidene-lambda5-phosphane, Dyfonate, DYPHONATE, Difonate.

IUPAC name
ethoxy-ethyl-phenylsulfanyl-sulfanylidene-lambda5-phosphane
CAS number
944-22-9
Molecular formula
C10H15OPS2
Molecular weight
246.3 g/mol
SMILES
CCOP(=S)(CC)SC1=CC=CC=C1
PubChem CID
13676

Risk for babies

Severe risk

Infants are acutely vulnerable to Fonofos 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 Fonofos 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

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

AgencyYearClassificationNotes
IARC1983Group 2BIARC Group 2B for fonofos, evaluated in Monograph 30 (1983) on occupational exposures in insecticide application and some pesticides. Limited evidence in humans from occupational cohort studies of insecticide applicators; limited evidence in experimental animals from chronic bioassays. Fonofos is an organophosphonate soil insecticide with high acute mammalian toxicity (rat oral LD50 approximately 8–16 mg/kg, WHO Class Ia — extremely hazardous). It was used as a soil-incorporated granule for control of corn rootworm, wireworms, and other soil-dwelling pests in corn and soybean production. EPA cancelled US food uses of fonofos by 2001 due to unacceptable dietary and occupational risks under FQPA review; it is no longer in registered agricultural use in the US. IARC has not re-evaluated since 1983.
EPA CTX / EPA OPPGroup E Evidence of Non-carcinogenicity for Humans
EPA CTX / GenetoxGenotoxicity: negative (Ames: negative, 0 positive / 4 negative reports)
EPA CTX / GenetoxGenotoxicity: negative (Ames: negative, 0 positive / 4 negative reports)
EPA CTX / Skin-EyeSkin Irritation: 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 fonofos

  • 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 Fonofos:

  • 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 fonofos safe for kids?

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

What products contain fonofos?

Fonofos 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 fonofos?

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 fonofos?

Fonofos has been classified by 5 agencies including IARC, EPA CTX / EPA OPP, EPA CTX / Genetox, EPA CTX / Genetox, 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 Fonofos in the baby app

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

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Sources (2)

  1. IARC Monographs Volume 30: Occupational Exposures in Insecticide Application and Some Pesticides — Fonofos Group 2B Classification (1983) (1983) — regulatory
  2. US EPA: Fonofos Reregistration Eligibility Decision — Group 2B Carcinogenicity, Dietary and Occupational Risk, Groundwater Contamination, and Cancellation (2001) (2001) — 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 →