ImpactZ

AMVAC · EPA Reg 5481-612 · Herbicide Document last checked 2026-05-30

About this product

Active ingredient Pending extraction

Manufacturer AMVAC

Category Herbicide

Full details for ImpactZ

EPA registration data Reg. 5481-612 — registry reference, signal word and status.

Applicator discussion

Nothing here is label direction — the label is the law. These are notes from other applicators, moderated before they appear. Check the labeling accompanying the product and applicable state requirements.

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According to the label From the product label

These details were extracted from this product's label PDF. The label is the law. Confirm every rate, site, restriction and safety requirement against the label before mixing or applying. Check for a state supplemental label; a product may be restricted or prohibited in a state or site even when a rate appears below. · EPA registration data for Reg. 5481-612 →

IMPACTZ is a restricted-use herbicide designed for the selective control and suppression of emerged broadleaf and grass weeds in field corn, seed corn, popcorn, and sweet corn. It contains two active ingredients: Atrazine (42.60%) and Topramezone (2.85%). The product works by inhibiting both carothenoid biosynthesis and photosynthesis II. It is applied to emerged weeds within various corn crop types. Note that this product is highly sensitive to environmental factors; it is toxic to aquatic invertebrates and should not be applied near water or in areas where surface water is present. Use caution regarding runoff, especially after rain. When handling, wear long-sleeved shirts, long pants, chemical-resistant gloves (Barrier Laminate, Butyl Rubber ≥ 14 mils, Nitrile Rubber ≥ 14 mils, Neoprene Rubber ≥ 14 mils, Natural Rubber ≥ 14 mils, Polyethylene, Polyvinyl Chloride (PVC) ≥ 14 mils, or Viton® ≥ 14 mils), and shoes socks. Avoid application if heavy rain is forecasted to prevent surface water contamination. This product is restricted to use by Certified Applicators or those under their direct supervision.

Pests covered (2)

emerged broadleaf and grass weedsBarnyardgrass, Bindweed, Broadleaf Weeds, Chickweed, Crabgrass, Dandelion, Foxtail, Goosegrass, Grasses, Johnsongrass, Purslane, Thistle

Areas treatable (1)

field corn, seed corn, popcorn, and sweet corn

How to treat each type of area 2

field corn, seed corn, popcorn, and sweet corn

emerged weeds ≤ 4 inches in size

Target pest	Location	Rate	Unit	Label notes
emerged broadleaf and grass weeds	Outdoor	8.0 fl oz per acre	fl oz per acre	Controls broadleaf weeds like Amaranth, Dandelion, and Morningglory; controls grass weeds like Barnyardgrass and Crabgrass.

emerged weeds ≤ 6 inches in size

Target pest	Location	Rate	Unit	Label notes
emerged broadleaf and grass weeds	Outdoor	10.7 – 21.4 fl oz per acre	fl oz per acre	Higher rate for larger weeds.

Mixing instructions 1

For pests	Label notes
broadleaf and grass weeds	May be tank-mixed with other herbicides for broader spectrum/residual control; follow most restrictive label directions.

Worker safety

Re-entry interval (REI) 12

PPE required Long-sleeved shirt and long pants; Chemical resistant gloves (Barrier Laminate, Butyl Rubber ≥ 14 mils, Nitrile Rubber ≥ 14 mils, Neoprene Rubber ≥ 14 mils, Natural Rubber ≥ 14 mils, Polyethylene, Polyvinyl Chloride (PVC) ≥ 14 mils, or Viton® ≥ 14 mils); Shoes socks; Chemical resistant apron when mixing/loading, cleaning up spills, or cleaning equipment.

Timing & weather

Do not apply if rain is forecasted to occur within 48 hours to prevent runoff.
Avoid application during conditions that may delay herbicide activity, such as cold temperatures or drought.

Use restrictions 5

Restricted Use Pesticide: For retail sale and use by Certified Applicators or persons under their direct supervision only.
Do not apply to water, areas where surface water is present, or to intertidal areas below mean high water mark.
Do not mix or load within 50 feet of intermittent streams and rivers, or unpoured impounded lakes and reservoirs.
Sale, use, and distribution prohibited in Nassau and Suffolk Counties of New York State.
Do not apply to terraced fields with tile outlets unless applied to a depth of 2-3 inches in the entire field.