Baby Safety / Compounds / Captan

Is Captan safe for babies and kids?

Elevated risk for kids

(Babies-specific data is limited; this page draws from human pregnant context.) Prenatal exposure to Captan may affect fetal development through endocrine disruption pathways. Several fungicide classes (azoles, dicarboximides) interfere with steroid biosynthesis.

What is captan?

The IUPAC name is 2-(trichloromethylsulfanyl)-3a,4,7,7a-tetrahydroisoindole-1,3-dione.

Also known as: 2-(trichloromethylsulfanyl)-3a,4,7,7a-tetrahydroisoindole-1,3-dione, Aacaptan, Orthocide, Merpan.

IUPAC name
2-(trichloromethylsulfanyl)-3a,4,7,7a-tetrahydroisoindole-1,3-dione
CAS number
133-06-2
Molecular formula
C9H8Cl3NO2S
Molecular weight
300.6 g/mol
SMILES
C1C=CCC2C1C(=O)N(C2=O)SC(Cl)(Cl)Cl
PubChem CID
8606

Risk for babies

Elevated risk

Prenatal exposure to Captan may affect fetal development through endocrine disruption pathways. Several fungicide classes (azoles, dicarboximides) interfere with steroid biosynthesis.

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.

Risk for pregnant and nursing people

Elevated risk

Prenatal exposure to Captan may affect fetal development through endocrine disruption pathways. Several fungicide classes (azoles, dicarboximides) interfere with steroid biosynthesis.

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

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

AgencyYearClassificationNotes
US EPA1999B2US EPA IRIS classification of captan as Group B2 (probable human carcinogen) based on sufficient evidence of carcinogenicity in experimental animals — gastrointestinal tract tumors (duodenal adenocarcinomas) in mice at high doses in chronic bioassays, and renal tubular tumors in some rat studies. The carcinogenic mechanism in mice involves local cytotoxicity to the duodenal epithelium from captan metabolites (tetrahydrophthalimide, thiophosgene-like reactive intermediates) generated in the gastrointestinal lumen; this mechanism may be operative at high doses rather than at low environmental exposures. IARC evaluated captan in Monograph 30 (1983) and classified it as Group 3 (not classifiable as to human carcinogenicity), based on inadequate evidence in humans and limited evidence in animals available at that time. EPA's B2 classification reflects additional animal carcinogenicity data available after the IARC evaluation. The degree to which high-dose mouse GI tumor findings are relevant to human risk at typical agricultural exposure levels is debated; EPA's linear low-dose extrapolation from animal tumor data generates cancer slope factors used for risk assessment of dietary residue exposure.
IARC1983Group 3IARC Monograph 30 (1983) evaluated captan and assigned Group 3 based on inadequate evidence in humans and limited evidence in experimental animals available at the time. This classification predates EPA's subsequent animal bioassay data showing GI tumors in mice. IARC has not re-evaluated captan since 1983.
EPA CTX / NIOSHpotential occupational carcinogen
EPA CTX / IARCGroup 3 - Not classifiable as to its carcinogenicity to humans
EPA CTX / EPA OPPLikely to be carcinogenic to humans following prolonged, high-level exposures causing cytotoxicity and regenerative cell hyperplasia in the proximal region of the small intestine (oral exposure) or the respiratory tract (inhalation exposure), but not like
EPA CTX / CalEPAKnown human carcinogen
EPA CTX / GenetoxGenotoxicity: positive (Ames: positive, 27 positive / 5 negative reports)
EPA CTX / GenetoxGenotoxicity: positive (Ames: positive, 27 positive / 5 negative reports)
EPA CTX / Skin-EyeEye Irritation: Eye Dam. 1 (score: very high)
EPA CTX / Skin-EyeSkin Sensitization: Skin Sens. 1 (score: high)
EPA CTX / Skin-EyeEye Irritation: Category 1 (score: very high)
EPA CTX / Skin-EyeSkin Irritation: Category 2 (score: high)
EPA CTX / Skin-EyeSkin Sensitization: Category 1 (score: high)
EPA CTX / Skin-EyeEye Irritation: Eye Dam. 1 (score: very high)
EPA CTX / Skin-EyeSkin Sensitization: Skin Sens. 1 (score: high)
EPA CTX / Skin-EyeEye Irritation: Category 8.3A (Category 1) (score: very high)
EPA CTX / Skin-EyeSkin Sensitization: Category 6.5B (Category 1) (score: moderate)
EPA CTX / Skin-Eyeskin irritation: in vivo: Moderate or Mild Irritation (score: moderate)
EPA CTX / Skin-Eyeeye irritation: in vivo: Corrosive or Irritation Persists for > 21 days (score: very high)
EPA CTX / Skin-Eyeskin sensitisation: in vivo (non-LLNA): High Frequency of Sensitization (score: high)

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 captan

  • 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 Captan:

  • 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

What products contain captan?

Captan appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

Why do regulators disagree about captan?

Captan has been classified by 20 agencies including US EPA, IARC, EPA CTX / NIOSH, EPA CTX / IARC, EPA CTX / EPA OPP, 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 Captan in the baby app

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

Open in baby View raw API data

Sources (2)

  1. US EPA IRIS: Captan — Cancer Classification B2 (Probable Human Carcinogen), Cancer Slope Factor, and Chronic Reference Dose (1999) (1999) — regulatory
  2. US EPA: Captan Registration Eligibility Decision — Dietary Risk Assessment, Occupational Exposure, Ecological Risk, and Reregistration Eligibility (2004) (2004) — 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 →