Outdoor & Yard / Compounds / Simazine

Simazine in the yard and garden

Moderate risk for your yard

GHS Warning classification.

What is simazine?

The IUPAC name is 6-chloro-2-N,4-N-diethyl-1,3,5-triazine-2,4-diamine.

Also known as: 6-chloro-2-N,4-N-diethyl-1,3,5-triazine-2,4-diamine, Gesatop, Princep, Simanex.

IUPAC name
6-chloro-2-N,4-N-diethyl-1,3,5-triazine-2,4-diamine
CAS number
122-34-9
Molecular formula
C7H12ClN5
Molecular weight
201.66 g/mol
SMILES
CCNC1=NC(NCC)=NC(Cl)=N1
PubChem CID
5216

Risk for people, pets,

Moderate risk

GHS Warning classification.

Regulatory consensus

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

AgencyYearClassificationNotes
EPA CTX / IARC—Group 3 - Not classifiable as to its carcinogenicity to humans
EPA CTX / EPA OPP—Not Likely to Be Carcinogenic in Humans
EPA CTX / Genetox—Genotoxicity: negative (Ames: None, 1 positive / 5 negative reports)
EPA CTX / Genetox—Genotoxicity: negative (Ames: None, 1 positive / 5 negative reports)

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 your yard encounter simazine

  • Agricultural Products — Treated grains and legumes, Crop residues
  • Drinking Water — Municipal water supplies in agricultural regions

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Simazine:

  • 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 simazine safe for your yard?

GHS Warning classification.

What products contain simazine?

Simazine appears in: Treated grains and legumes (Agricultural products); Crop residues (Agricultural products); Municipal water supplies in agricultural regions (Drinking water).

Why do regulators disagree about simazine?

Simazine has been classified by 4 agencies including 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 Simazine in the outdoor app

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

Open in outdoor View raw API data

Sources (3)
  1. PubChem Compound CID 5216 — database
  2. EPA CompTox Chemicals Dashboard — DTXSID4021268 — epa
  3. ATSDR Toxicological Profile — CAS 122-34-9 — reference

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 →