SIMAZINE

Simazine is a selective, systemic, residual s-triazine herbicide used to control germinating annual broadleaf weeds and annual grasses.
It is applied chiefly to soil before weed emergence and in early post-emergence programs permitted by the registered product label.
Its low water solubility, extremely low vapour pressure, root uptake, and residual soil activity define its formulation and field behaviour.
Commercial selection centers on technical assay, impurity profile, formulation type, particle-size control, suspension performance, storage stability, regulatory status, and destination-market documentation.

CHEMICAL IDENTITY AND COMMON NAMES

Chemically, Simazine is 6-chloro-N2,N4-diethyl-1,3,5-triazine-2,4-diamine, a symmetrical chlorinated 1,3,5-triazine bearing two ethylamino substituents.
The older term s-triazine refers to the same symmetrical 1,3,5-triazine ring system.
Simazine differs from atrazine, which contains one ethylamino and one isopropylamino substituent, and from propazine, which contains two isopropylamino groups.

Synonyms and Common Names: Simazine, Simazin, Simazina, Symazine, CAT, CDT, CET, 6-Chloro-N2,N4-diethyl-1,3,5-triazine-2,4-diamine, 6-Chloro-N,N′-diethyl-1,3,5-triazine-2,4-diamine, 2-Chloro-4,6-bis(ethylamino)-1,3,5-triazine, 2-Chloro-4,6-bis(ethylamino)-s-triazine, 2,4-Bis(ethylamino)-6-chloro-1,3,5-triazine, 2,4-Bis(ethylamino)-6-chloro-s-triazine, 4,6-Bis(ethylamino)-2-chlorotriazine, 2-Chloro-4,6-di(ethylamino)triazine, 1,3,5-Triazine-2,4-diamine, 6-chloro-N2,N4-diethyl-, 1,3,5-Triazine-2,4-diamine, 6-chloro-N,N′-diethyl-, s-Triazine, 2-chloro-4,6-bis(ethylamino)-, s-Triazine, 2,4-bis(ethylamino)-6-chloro-, 1-Chloro-3,5-bis(ethylamino)-2,4,6-triazine

TECHNICAL IDENTIFICATION

CAS Number: 122-34-9
EC / EINECS Number: 204-535-2
Index Number: 612-088-00-3
Preferred Chemical Name: 6-Chloro-N2,N4-diethyl-1,3,5-triazine-2,4-diamine
Molecular Formula: C7H12ClN5
Molar Mass: 201.66 g/mol
Chemical Class: Chlorinated s-triazine herbicide
Herbicide Mode-of-Action Group: Group 5, formerly Group C1
InChIKey: ODCWYMIRDDJXKW-UHFFFAOYSA-N
Canonical SMILES: CCNC1=NC(=NC(=N1)Cl)NCC

PHYSICAL AND CHEMICAL PROPERTIES

Appearance: White to off-white crystalline powder
Physical State: Solid
Odour: Practically odourless
Density: Approximately 1.30 g/cm³
Decomposition Temperature: 225–227 °C
Boiling Behaviour: Decomposes before boiling
Water Solubility: Approximately 5 mg/L at 20 °C and pH 7
Solubility in Acetone: Approximately 1.5 g/L at 20 °C
Solubility in Ethanol: Approximately 0.57 g/L at 20 °C
Solubility in Toluene: Approximately 0.13 g/L at 20 °C
Solubility in n-Hexane: Approximately 3.1 mg/L at 20 °C
Vapour Pressure: 8.1 × 10^-7 Pa at 20 °C
Henry's Law Constant: 5.6 × 10^-5 Pa·m³/mol at 25 °C
Log Kow: Approximately 2.3 at pH 7 and 20 °C
pKa: Approximately 1.62 at 25 °C
Acid-Base Character: Very weak base
Soil Organic Carbon Partition Coefficient: Approximately 130 mL/g
Volatility: Very low
Aqueous Hydrolysis: Half-life approximately 96 days at 20 °C and pH 7
Aqueous Photolysis: Half-life approximately 1.9 days at pH 7 under test light conditions
Representative Soil Dissipation Half-Life: Approximately 60 days under aerobic conditions and 90 days in field studies
Combustibility: Combustible solid
Dust Behaviour: Finely divided particles can form explosive mixtures with air
Chemical Stability: Stable under normal storage conditions and hydrolysed by strong acids or strong alkalis to less active hydroxy derivatives

FUNCTIONAL CHARACTERISTICS

Simazine inhibits photosynthetic electron transport at photosystem II by binding at the D1 protein acceptor site.
This blocks the formation of the energy and reducing power needed for carbon fixation, leading to chlorosis, growth cessation, tissue injury, and death in susceptible plants.

The active ingredient is absorbed mainly through roots and is transported upward in the xylem, with additional uptake through young foliage.
It is most effective during weed germination and early seedling development because moisture moves the active ingredient into the shallow root zone.

Residual performance is governed by soil moisture, texture, organic matter, pH, temperature, microbial activity, and application placement.
Adsorption becomes stronger in soils rich in clay and organic matter, while the moderate soil adsorption coefficient creates leaching potential in permeable soils and vulnerable aquifers.
Repeated use of Group 5 herbicides can select resistant weed populations, including biotypes with cross-resistance to related triazines.
Rotation and mixtures with effective herbicides from different mode-of-action groups reduce selection pressure when permitted by the registered label.

PRODUCTION AND COMMERCIAL FORMS

Simazine is manufactured by controlled nucleophilic substitution of cyanuric chloride with ethylamine in an alkaline aqueous system.
Two ring chlorine atoms are replaced by ethylamino groups, while one chlorine remains in the active molecule.
Alkali neutralizes the hydrogen chloride formed during substitution.

The reaction is strongly exothermic, and staged addition with low-temperature control supports selective substitution and safe heat removal.
The product is isolated by precipitation or crystallisation, followed by filtration, washing, drying, and milling to the required particle profile.
Process control limits unreacted cyanuric chloride, monoethylamino intermediates, over-substituted triazines, hydroxy-simazine, residual ethylamine, inorganic chloride, moisture, and cross-contamination by related triazines.

Commercial forms include technical active ingredient for formulation manufacture, wettable powder, water-dispersible granule or dry-flowable material, suspension concentrate or flowable liquid, and granules for soil application.
Established formulation concentrations include 800 g/kg wettable powder, 900 g/kg water-dispersible granule, and approximately 500 g/L suspension concentrate.
Technical active ingredient is a manufacturing material and is converted into a registered formulation before agricultural application.

APPLICATIONS AND INDUSTRIES

Simazine is used in agricultural crop protection for pre-emergence and early post-emergence control of annual broadleaf weeds and annual grasses.
Registered use patterns in jurisdictions that permit the active ingredient include corn, sugarcane, asparagus, established alfalfa, fruit and nut orchards, vineyards, berry crops, nursery stock, Christmas tree plantings, selected turfgrass, and designated non-crop areas.
The permitted crop, weed spectrum, timing, dose, soil restriction, buffer, re-entry interval, and pre-harvest interval are defined by the product registration and label in each market.

In orchards and vineyards, soil-directed treatment provides residual weed suppression beneath established perennial crops while limiting contact with sensitive foliage and fruit.
In field crops, placement before emergence targets susceptible seedlings as they establish their root systems.
In nursery, forestry, shelterbelt, and turf programs, the long soil-active period supports seasonal management of labelled annual weeds.

Simazine does not provide rapid control of well-established perennial vegetation as a stand-alone treatment.
Programs involving emerged weeds use cultivation, vegetation removal, or a compatible contact herbicide when the registered label permits the combination.

Historical and specialised uses have included algae and aquatic-weed control in managed ponds and hatchery systems.
These uses are now highly restricted because algae and other aquatic plants respond to very low concentrations of photosystem II inhibitors.

High-purity Simazine and certified standard solutions are also used in pesticide-residue analysis, environmental water and soil monitoring, method development, instrument calibration, and laboratory quality control.
Analytical reference materials are laboratory products and are not agricultural formulations.

GRADE SELECTION AND PRODUCT SUITABILITY

Technical active ingredient grade is selected for formulation manufacture through active-content assay, identity, related-substance profile, hydroxy-simazine content, moisture, acidity or alkalinity, colour, and physical form.
Milling behaviour and particle size are important when the technical material will be converted into a suspension concentrate, wettable powder, or water-dispersible granule.

Water-dispersible granules provide high active concentration, controlled dosing, reduced airborne dust, and rapid dispersion when granule disintegration and suspensibility are properly engineered.
Wettable powders offer a straightforward dispersed-solid format but require close control of wettability, dust, wet-sieve residue, and suspension stability.
Suspension concentrates support liquid metering and pumping but depend on controlled crystal size, rheology, pourability, sediment redispersibility, and protection against crystal growth.
Granular soil products require uniform active distribution, controlled granule size, low attrition, and consistent release after wetting.

Analytical grade is selected by chemical purity, chromatographic profile, certified concentration, homogeneity, stability, and metrological traceability.
Neat reference material and prepared standard solutions serve different laboratory workflows and require separate concentration and solvent specifications.

FORMULATION AND PROCESS CONSIDERATIONS

The active ingredient's water solubility is too low for practical high-strength aqueous solutions, so commercial water-based products are designed as dispersed-particle systems.
Fine milling increases available surface area and improves suspension uniformity, but excessive fines raise viscosity, dust generation, agglomeration, and handling load.

Wetters and dispersants promote initial wetting and maintain particle separation, while suspension stabilisers limit sedimentation during storage and use.
Suspension concentrates also use rheology modifiers, antifoam agents, preservatives, and freeze-thaw stabilisation as required by the formulation design.
Water-dispersible granules require a balance of binder strength, low attrition, rapid disintegration, and acceptable suspensibility after dilution.

Strongly acidic or strongly alkaline conditions accelerate conversion to hydroxy derivatives and reduce herbicidal activity.
Formulation pH, water hardness, electrolyte load, surfactant compatibility, and storage temperature therefore form part of development testing.
Continuous agitation keeps diluted wettable powders, granules, and suspension concentrates evenly dispersed during application.
Tank mixing, adjuvant selection, addition order, and spray-water requirements are governed by the registered product label.

QUALITY, SPECIFICATIONS AND DOCUMENTATION

Identity can be established by infrared spectroscopy and chromatographic retention behaviour.
Active-content assay and related substances are measured by validated gas chromatography or liquid chromatography, with mass spectrometry supporting impurity identification and low-level residue work.
Water content, particle-size distribution, bulk density, and visual appearance complete the core evaluation of technical material.

Technical Active Ingredient Controls: Identity, assay, related triazines, hydroxy-simazine, process intermediates, residual ethylamine, inorganic chloride, moisture, acidity or alkalinity, colour, and particle form
Wettable Powder Controls: Active content, wettability, suspensibility, wet-sieve residue, persistent foam, dust, moisture, and accelerated storage stability
Water-Dispersible Granule Controls: Active content, disintegration, dispersibility, suspensibility, wet-sieve residue, attrition resistance, dust, moisture, and storage stability
Suspension Concentrate Controls: Active content, particle size, viscosity, pourability, suspensibility, wet-sieve residue, pH, persistent foam, redispersibility, freeze-thaw stability, and accelerated storage stability
Granular Product Controls: Active content, content uniformity, granule-size distribution, attrition, dust, flowability, and release behaviour

A Technical Data Sheet defines the commercial form and key performance parameters.
A Safety Data Sheet provides classification, exposure controls, first aid, transport, storage, and disposal information for the supplied composition.
A Certificate of Analysis records batch-specific identity, assay, impurity, moisture, and physical-property results against the agreed specification.
Finished plant-protection products also require the destination-market label and registration documentation that defines their lawful supply and use.

SAFETY AND REGULATORY CONSIDERATIONS

European Harmonised Hazard Classification: Carcinogenicity Category 2; hazardous to the aquatic environment, Acute Category 1 and Chronic Category 1
Signal Word: Warning
H351: Suspected of causing cancer
H400: Very toxic to aquatic life
H410: Very toxic to aquatic life with long-lasting effects
Acute Oral Toxicity: Rat LD50 greater than 5,000 mg/kg for the active ingredient

Exposure controls must address inhalable dust, skin and eye contact, accidental ingestion, and repeated occupational exposure.
Airborne dust can irritate the eyes, skin, and respiratory tract.
Use closed transfer or local exhaust ventilation, chemical-resistant gloves, protective clothing, safety goggles, and suitable particulate respiratory protection for dusty operations.
Formulated products also reflect the hazards of their co-formulants.

Simazine is combustible, and suspended fine dust can ignite or explode in air.
Fire produces irritating or toxic decomposition fumes.
Water spray, foam, dry chemical powder, or carbon dioxide can be used for extinguishing, with self-contained breathing apparatus and full protective equipment for fire response.

The active ingredient is highly hazardous to algae and aquatic plants and can persist long enough to affect surface water and groundwater.
Prevent release to drains, waterways, soil outside the intended treatment area, and wastewater systems.
Spills are contained without raising dust, collected into closed labelled containers, and prevented from reaching water.

Simazine is prohibited for plant-protection applications in Türkiye and is not approved as a plant-protection active substance in the European Union or Great Britain.
Registered uses continue in other jurisdictions, including the United States and Australia, under product-specific labels and risk-mitigation conditions.
Destination-country legislation, import controls, registration status, maximum residue limits, and approved use patterns define market access.
Only the registered product label defines lawful crops, rates, timing, buffers, protective equipment, re-entry intervals, and pre-harvest intervals.

FIRST AID

Inhalation: Move the affected person to fresh air, keep at rest, and obtain medical attention for breathing difficulty or persistent symptoms.
Skin Contact: Remove contaminated clothing and wash the skin thoroughly with soap and water.
Eye Contact: Rinse cautiously with clean water for at least 15 minutes, remove contact lenses when easy to do, and obtain medical attention for continuing irritation.
Ingestion: Rinse the mouth, do not induce vomiting, and contact a poison centre or physician promptly.
Note to Physicians: No specific antidote is established, and treatment is symptomatic and supportive.

HANDLING AND STORAGE

Handle technical powder and dry formulations in closed or well-extracted equipment that prevents dust release and accumulation.
Keep ignition sources away, use dust-rated electrical equipment in powder-handling zones, and control static discharge during transfer.
Do not eat, drink, or smoke in handling areas, and wash exposed skin after work.

Store in tightly closed, correctly labelled containers in a cool, dry, well-ventilated, secure pesticide area.
Protect the product from moisture, direct sunlight, excessive heat, strong acids, strong alkalis, and strong oxidising agents.
Keep it separated from food, beverages, animal feed, seed, pharmaceuticals, and incompatible chemicals.

Collect process residues, contaminated absorbents, rinsate, and off-specification material for authorised pesticide-waste treatment.
Do not discharge residues or wash water to drains or natural water bodies.

PACKAGING AND PROCUREMENT CONSIDERATIONS

Technical powder, wettable powder, and water-dispersible granules are packed in sealed moisture-resistant lined bags, fibre drums, or compatible polymer drums that control contamination and dust.
Suspension concentrates are packed in compatible sealed polymer containers with headspace and closure systems suited to transport, agitation, and pourability requirements.
Package selection must preserve active content, moisture control, particle integrity, and formulation redispersibility throughout storage and distribution.

Transport classification is assigned from the product's physical form, composition, concentration, and package quantity.
Environmentally hazardous solid products meeting the transport criteria use UN 3077, Class 9, Packing Group III.
Environmentally hazardous liquid formulations meeting the criteria use UN 3082, Class 9, Packing Group III.
Transport Description for Qualifying Solids: Environmentally hazardous substance, solid, n.o.s.
Transport Description for Qualifying Liquids: Environmentally hazardous substance, liquid, n.o.s.

A Simazine purchasing request should identify the destination country, permitted end use, technical or formulated grade, active concentration, required quantity, packaging, delivery terms, and documentation package.
Formulation-manufacturing orders should also define assay, impurity limits, moisture, particle form, and analytical methods.
Finished-formulation orders should define active content and the relevant dispersion, suspension, wet-sieve, foam, viscosity, pourability, attrition, and storage-stability criteria.

For Simazine grade selection, specification review, documentation, packaging, and supply planning, contact Ataman Kimya at +90 216 577 10 10 or info@atamankimya.com.