Water & Air / Compounds / Clomazone

Clomazone in water and air: safety profile

Low risk

(People-specific data is limited; this page draws from human adult context.) Clomazone is an isoxazolidinone herbicide used primarily on rice, soybeans, and cotton. It acts by inhibiting carotenoid biosynthesis (DOXP pathway). EPA classified it as Group E (evidence of non-carcinogenicity for humans). Low acute mammalian toxicity: oral LD50 rat 1369 mg/kg. NOAEL 34 mg/kg/day in chronic rat study. Primary exposure is occupational; dietary exposure is minimal.

What is clomazone?

Also known as: Command, Dimethazone, FMC-57020, 2-(2-chlorobenzyl)-4,4-dimethyl-1,2-oxazolidin-3-one.

CAS number
81777-89-1
Molecular formula
C12H14ClNO2
Molecular weight
239.7 g/mol
SMILES
CC1(CON2C(=O)CCl2)c1ccccc1
PubChem CID
54778

Risk for people

Low risk

Clomazone is an isoxazolidinone herbicide used primarily on rice, soybeans, and cotton. It acts by inhibiting carotenoid biosynthesis (DOXP pathway). EPA classified it as Group E (evidence of non-carcinogenicity for humans). Low acute mammalian toxicity: oral LD50 rat 1369 mg/kg. NOAEL 34 mg/kg/day in chronic rat study. Primary exposure is occupational; dietary exposure is minimal.

Regulatory consensus

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

AgencyYearClassificationNotes
EPA2007Group E — Not carcinogenic
EU2007Approved under Regulation (EC) 1107/2009

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 you encounter clomazone

  • Agriculture
  • Water

Safer alternatives

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

  • Pendimethalin
    Trade-offs: Different mode of action (microtubule inhibition). Soil binding reduces leaching but may limit efficacy.
    Relative cost: Similar

Frequently asked questions

No FAQ entries generated.

See Clomazone in the water app

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

Open in water View raw API data

Sources (1)
  1. EPA Reregistration Eligibility Decision — Clomazone — epa

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 →