Outdoor & Yard / Compounds / Alachlor

Alachlor in the yard and garden

Elevated risk for your yard

Alachlor is a chloroacetanilide herbicide widely used on corn and soybeans. EPA classified it as Group B2 (probable human carcinogen) based on nasal turbinate tumors and stomach tumors in rats. Banned in the EU since 2006 (Commission Decision 2006/966/EC). In the US, EPA established an MCL of 2 ppb in drinking water. Primary exposure routes: occupational (applicators), dietary residues, and contaminated groundwater. Alachlor is metabolized to 2,6-diethylaniline (DEA) and alachlor ESA, both detected in groundwater across the US Corn Belt.

What is alachlor?

Also known as: Lasso, Metachlor, Alanox, 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide.

CAS number
15972-60-8
Molecular formula
C14H20ClNO2
Molecular weight
269.77 g/mol
SMILES
CCc1cccc(c1N(COC)C(=O)CCl)CC
PubChem CID
2078

Risk for people, pets,

Elevated risk

Alachlor is a chloroacetanilide herbicide widely used on corn and soybeans. EPA classified it as Group B2 (probable human carcinogen) based on nasal turbinate tumors and stomach tumors in rats. Banned in the EU since 2006 (Commission Decision 2006/966/EC). In the US, EPA established an MCL of 2 ppb in drinking water. Primary exposure routes: occupational (applicators), dietary residues, and contaminated groundwater. Alachlor is metabolized to 2,6-diethylaniline (DEA) and alachlor ESA, both detected in groundwater across the US Corn Belt.

Regulatory consensus

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

AgencyYearClassificationNotes
EPA1998Group B2 — Probable human carcinogen
EU2006Banned — not approved 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 your yard encounter alachlor

  • Agricultural Water
  • Food
  • Soil

Safer alternatives

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

  • S-metolachlor
    Trade-offs: Same chloroacetanilide class but lower application rate and reduced groundwater contamination. Not classified as carcinogen.
    Relative cost: Similar
  • Acetochlor
    Trade-offs: Similar efficacy; conditional registration with monitoring requirements.
    Relative cost: Similar

Frequently asked questions

Is alachlor safe for your yard?

Alachlor is a chloroacetanilide herbicide widely used on corn and soybeans. EPA classified it as Group B2 (probable human carcinogen) based on nasal turbinate tumors and stomach tumors in rats. Banned in the EU since 2006 (Commission Decision 2006/966/EC). In the US, EPA established an MCL of 2 ppb in drinking water. Primary exposure routes: occupational (applicators), dietary residues, and contaminated groundwater. Alachlor is metabolized to 2,6-diethylaniline (DEA) and alachlor ESA, both detected in groundwater across the US Corn Belt.

See Alachlor in the outdoor app

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

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Sources (2)
  1. EPA Reregistration Eligibility Decision — Alachlor (1998) — epa
  2. IARC Monograph Vol. 79 — Some Thyrotropic Agents (2001) — iarc

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 →