Technical Factsheet on: SIMAZINE
List of Contaminants
As part of the Drinking Water and Health pages, this fact sheet is part of a larger publication:
National Primary Drinking Water Regulations
Drinking Water Standards
MCLG: 0.004 mg/L
MCL: 0.004 mg/L
HAL(child): 1 - to 10-day: 0.07 mg/L; Longer-term: 0.07 mg/L
Health Effects Summary
Acute: EPA has found simazine to potentially cause the following health effects from acute exposures at
levels above the MCL: weight loss, changes in blood.
Drinking water levels which are considered "safe" for short-term exposures: For a 10-kg (22 lb.) child
consuming 1 liter of water per day, up to a 7-year exposure to 0.07 mg/L.
Chronic: Simazine has the potential to cause the following health effects from long-term exposures at
levels above the MCL: tremors; damage to testes, kidneys, liver and thyroid; gene mutations.
Cancer: There is some evidence that simazine may have the potential to cause cancer from a lifetime
exposure at levels above the MCL.
Usage Patterns
Simazine is a pre-emergence herbicide used for control of broad-leaved and grassy weeds on a variety of
deep-rooted crops such as artichokes, asparagus, berry crops, broad beans, citrus, pome and stone fruits
orchards, and others. It is also used on non-crop areas such as farm ponds, fish hatcheries, etc.
Its major use is on corn where it is often combined with AAtrex. Other herbicides with which simazine is
combined include: paraquat, on apples, peaches; Roundup or Oust for noncrop use; Surflan on
Christmas trees; Dual on corn and ornamentals. The amount of simazine used annually in the USA was
estimated in 1985 to be 4.8 billion pounds.
Release Patterns
Simazine may be released into the environment via effluents at manufacturing sites and at points of
application where it is employed as a herbicide.
Since simazine is not a listed chemical in the Toxics Release Inventory, data on releases during its
manufacture and handling are not available.
Environmental Fate
If released to water, simazine is not expected to adsorb to sediment and suspended particulate matter, or
to volatilize. Persistence depends upon many factors including degree of algae and weed infestation.
Simazine residues may persist up to 3 years in soil under aquatic field conditions. Dissipation of simazine
in pond and lake water was variable, with half-lives ranging from 50 to 700 days. Slow biodegradation of
simazine may occur in water based upon the slow biodegradation observed in soil. Simazine is fairly

resistant to hydrolysis. However, chemical hydrolysis of simazine may be more important environmentally
than biodegradation at low pH or when various catalysts are present.
If released to soil, the mobility of simazine will be expected to vary from slight to high in soil-types ranging
from clay soils to sandy loams soils, respectively, based upon soil column, soil thin-layer chromatography,
and Koc experiments. Therefore, it may leach to groundwater; adsorption of simazine in soil has been
observed to increase as titratable acidity, organic matter and, to a lesser extent, clay content of the soil
increased. Simazine may be susceptible to slow hydrolysis in soil based upon reported half-lives for
degradation (purportedly mainly soil catalyzed hydrolysis) of simazine in two soil 45 and 100 days.
Simazine can be utilized by certain soil microorganisms as a source of energy and mineralization. No
degradation of simazine was detected in a soil suspension test without the addition of glucose as an
energy source suggesting that degradation of simazine in these soil experiments was due to co-
metabolism. Reported persistence of simazine in soil varies from a half-life of <1 month to no degradation
being observed in 3.5 months. Simazine is not expected to volatilize from near surface soils or surfaces
under normal environmental conditions.
If released to the atmosphere, simazine is expected to exist almost entirely in the particulate phase.
Vapor phase reactions with photochemically produced hydroxyl radicals in the atmosphere may be
important (estimated half-life of about 2.8 hr). Photolysis may be an important removal mechanism in the
Simazine has a low potential to bioaccumulate in fish. BCFs: 0.76-0.95, green sunfish ; <1, bluegill
sunfish; 5, bluegill sunfish; 2, catfish. Other BCF values up to 55 have been reported in the literature.
The most probable exposure should be occupational exposure which may occur through dermal contact
or inhalation at places where simazine is produced or used as a herbicide.
Chemical/ Physical Properties
CAS Number: 122-34-9
Color/ Form/Odor: White powder
M.P.: 225 C B.P.: N/A
Vapor Pressure: 6.1x10-9
Octanol/Water Partition (Kow): Log Kow = 2.18
Density/Spec. Grav.: 1,3g/ml at 20 C
Solubility: 5 mg/L of water at 20 C; Soluble in water
Odor/Taste Thresholds: N/A
Soil sorption coefficient: Koc =135 (measured); slight to high mobility in soil, depending upon other factors
Henry's Law Coefficient: 4.63x10-10 atm-cu m/mole
Bioconcentration Factor: BCF <10 in fish; not expected to bioconcentrate in aquatic organisms.

Trade Names/Synonyms: Aktinit; Batazina; Bitemol; CAT(Herbicide); CDT; Cekuzina-S; Geigy 27,692;
Gesatop; Herbazin; Herbex; Hungazin; Premazine; Primatol S; Pricep; Printop; Radocon; Simadex;
Tafazine; Zeapur; 2-chloro-4,6-bis(ethylamino)-1,3,5-Triazine
Other Regulatory Information
Monitoring For Ground/Surface Water Sources:
Initial Frequency- 4 quarterly samples every 3 years
Repeat Frequency- If no detections during initial round:
2 quarterly per year if serving >3300 persons;
1 sample per 3 years for smaller systems
Triggers - Return to Initial Freq. if detect at > 0.00007 mg/L
Reference Source Method Numbers
EPA 600/4-88-039 505; 507; 508.1; 525.2
Treatment- Best Available Technologies:
Granular Activated Charcoal
For Additional Information:
EPA can provide further regulatory and other general information:
EPA Safe Drinking Water Hotline - 800/426-4791
Other sources of toxicological and environmental fate data include:
Toxic Substance Control Act Information Line - 202/554-1404
Toxics Release Inventory, National Library of Medicine - 301/496-6531
Agency for Toxic Substances and Disease Registry - 404/639-6000
National Pesticide Hotline - 800/858-7378