DIURON

Diuron is a synthetic substituted phenylurea used primarily as a residual herbicide and, in separate industrial contexts, as a material preservative and an accelerator for latent epoxy-curing systems.
In biochemical research it is commonly called DCMU and used as a selective inhibitor of photosynthetic electron transport.
Agricultural, biocidal, epoxy, research, and analytical uses require distinct purity, particle-size, formulation, documentation, and regulatory profiles, making the intended application central to product selection.

CHEMICAL IDENTITY AND COMMON NAMES

Diuron is the ISO common name for 3-(3,4-dichlorophenyl)-1,1-dimethylurea.
Its structure contains a 3,4-dichlorophenyl group attached to a dimethyl-substituted urea group.
The abbreviation DCMU derives from dichlorophenyl dimethylurea and is especially common in photosynthesis research.
Diuron must be distinguished from its transformation products 3-(3,4-dichlorophenyl)-1-methylurea, 3-(3,4-dichlorophenyl)urea, and 3,4-dichloroaniline, which are separate chemical identities.

Synonyms and Common Names: Diuron, Diuron (ISO), DCMU, 3-(3,4-Dichlorophenyl)-1,1-dimethylurea, 1-(3,4-Dichlorophenyl)-3,3-dimethylurea, 1,1-Dimethyl-3-(3,4-dichlorophenyl)urea, N'-(3,4-Dichlorophenyl)-N,N-dimethylurea, N-(3,4-Dichlorophenyl)-N',N'-dimethylurea, N,N-Dimethyl-N'-(3,4-dichlorophenyl)urea, Urea, N'-(3,4-dichlorophenyl)-N,N-dimethyl-, Urea, 3-(3,4-dichlorophenyl)-1,1-dimethyl-, 3,4-Dichlorophenyldimethylurea

TECHNICAL IDENTIFICATION

CAS Number: 330-54-1
EC / EINECS Number: 206-354-4
Molecular Formula: C9H10Cl2N2O
Molar Mass: 233.09 g/mol
CIPAC Code: 100
EU Index Number: 006-015-00-9
InChIKey: XMTQQYYKAHVGBJ-UHFFFAOYSA-N

PHYSICAL AND CHEMICAL PROPERTIES

Appearance: White crystalline solid or powder
Physical State: Solid
Odour: Odourless
Melting Point: 158–159 °C
Density: Approximately 1.48–1.50 g/cm³ at 20 °C
Water Solubility: Approximately 42 mg/L at 25 °C
Solubility in Acetone: Approximately 53.6 g/L at 25 °C
Solubility in Xylene: Approximately 1.33 g/L at 25 °C
Vapour Pressure: 1.15 × 10⁻³ mPa at 20 °C
Log Kow: Approximately 2.68–2.87
Ionic Character: Non-ionic
Ionisation: No relevant acid-base dissociation under normal environmental pH conditions
Volatility: Very low
Stability: Stable under normal dry storage conditions
Thermal Behaviour: Decomposes on strong heating

The combination of low water solubility and moderate lipophilicity favours adsorption to organic matter while still permitting transport in water containing suspended soil or sediment.
Strong heating can generate carbon oxides, nitrogen oxides, hydrogen chloride, and other halogen-containing decomposition products.

FUNCTIONAL CHARACTERISTICS

In susceptible plants, Diuron is absorbed principally through the roots and is transported upward in the xylem, with more limited uptake through foliage.
It binds at the plastoquinone QB site of the photosystem II D1 protein and blocks electron transfer from photosystem II to the plastoquinone pool.
The resulting interruption of ATP and reducing-power formation stops carbon fixation, produces chlorosis, and ultimately kills actively photosynthesising tissue.
Diuron belongs to current HRAC/WSSA Group 5, corresponding to legacy HRAC Group C2.

Low volatility supports residual activity without significant loss by evaporation.
Soil moisture moves the active substance into the germination zone, while adsorption, dose, placement, soil texture, organic matter, rainfall, and crop tolerance determine the depth and duration of weed control.

In paints, coatings, and antifouling systems, inhibition of photosynthesis suppresses algae and other photosynthetic fouling organisms at exposed surfaces.
Material-preservative performance also depends on uniform dispersion, controlled release from the film, and compatibility with the binder and other active ingredients.

In dicyandiamide-cured epoxy formulations, Diuron functions as a substituted-urea accelerator for dicyandiamide (DICY) rather than as the principal curing agent.
Heating generates catalytic activity that promotes epoxy and dicyandiamide reaction pathways, reducing the temperature or time needed to reach cure while retaining useful one-component storage latency.
Particle size, dispersion quality, accelerator concentration, resin chemistry, fillers, and the dicyandiamide ratio directly influence cure onset, gel time, conversion, and storage stability.

PRODUCTION AND COMMERCIAL FORM

A common industrial route converts 3,4-dichloroaniline to 3,4-dichlorophenyl isocyanate and then reacts the isocyanate with dimethylamine to form Diuron.
Purification, washing, drying, and controlled milling establish the final assay, impurity profile, moisture content, and particle-size distribution.

Technical Diuron is supplied as a crystalline powder for further formulation.
Herbicidal forms include wettable powders, water-dispersible granules, suspension concentrates, and granules designed for controlled application and dispersion.
Material-preservative and antifouling uses employ powders or formulated dispersions compatible with the coating system.
Epoxy-accelerator material is commonly offered as a fine or micronised powder to support homogeneous incorporation into resin compounds.
High-purity reagent material, neat reference standards, and certified standard solutions serve research and analytical laboratories.

APPLICATIONS AND INDUSTRIES

AGRICULTURAL WEED CONTROL

Where registered, Diuron provides pre-emergence and early post-emergence control of susceptible annual grasses and broadleaf weeds, with residual activity in the treated soil layer.
Established crop contexts include cotton, sugarcane, citrus, pineapple, asparagus, vineyards, orchards, and selected berry crops.
Application rate, crop stage, soil placement, soil texture, organic matter, rainfall, irrigation, and rotational restrictions are defined by the authorised use pattern for each crop.

In cotton production, specific Diuron use patterns serve as harvest aids to promote defoliation and prepare the crop for mechanical harvest.
This use requires application timing and rate control that are distinct from soil-residual weed-control programs.

Non-crop applications include vegetation management on industrial land, rights-of-way, utility sites, road and rail corridors, and drainage or irrigation banks where such uses are authorised.
Higher residual rates can provide broad vegetation suppression, so containment of treated soil and protection of adjacent desirable plants are important operational controls.

PAINTS, COATINGS, ADHESIVES, AND SEALANTS

Diuron is used as a mildewcide and material preservative in authorised paints, stains, coatings, adhesives, and sealants.
It helps protect susceptible products and dry films from biological deterioration when its concentration, particle size, dispersion, and compatibility are matched to the formulation.

In authorised marine and protective antifouling coatings, Diuron can function as a booster biocide against algae and other photosynthetic fouling organisms.
The coating matrix regulates delivery to the wetted surface, linking efficacy and environmental release to binder chemistry, film thickness, service conditions, and active loading.

AQUATIC ALGAE CONTROL

Registered algaecide formulations are used in defined commercial fish-production systems, aquaria, and containerised ponds.
Because aquatic plants and algae are highly sensitive to Diuron, dose, water volume, exposure period, discharge restrictions, and treatment interval are tightly controlled by the authorised label.

EPOXY RESINS, ADHESIVES, COMPOSITES, AND ELECTRICAL MATERIALS

Diuron is an effective latent accelerator for one-component epoxy systems cured with dicyandiamide.
It is used in structural and heat-curing adhesives, prepregs, composite laminates, powder coatings, electrical laminates, circuit-board materials, moulding compounds, and encapsulation systems.
The accelerator enables lower-temperature or shorter cure cycles than unaccelerated dicyandiamide while preserving workable storage latency before heat activation.

Micronised grades facilitate uniform distribution and faster activation in highly filled or film-forming formulations.
Excessive accelerator loading or an overly reactive particle-size profile can shorten storage life, making cure response and latency part of the same grade-selection decision.

PHOTOSYNTHESIS RESEARCH

DCMU is used as a selective photosystem II inhibitor in plant, algal, cyanobacterial, and chloroplast research.
It supports investigations of photosynthetic electron transport, chlorophyll fluorescence, oxygen evolution, photoprotection, and the separation of photosystem I and photosystem II responses.
Experimental work uses controlled concentrations because inhibition depends on organism, exposure time, cell density, illumination, and solvent content.

ANALYTICAL TESTING

High-purity Diuron standards support residue, environmental, water, soil, food, coating, and formulation analysis.
Separate reference materials for 3-(3,4-dichlorophenyl)-1-methylurea, 3-(3,4-dichlorophenyl)urea, and 3,4-dichloroaniline are used when methods must quantify transformation products as well as the parent compound.

GRADE SELECTION AND PRODUCT SUITABILITY

Technical pesticide material is selected by active-content assay, water content, free dimethylamine salts, 3,4-dichloroaniline, insoluble matter, colour, and process-related trace impurities.
One established technical-material specification sets a minimum declared Diuron content of 95%, free amine salts not exceeding 0.4% of the Diuron content when expressed as dimethylamine hydrochloride, and water not exceeding 1.0%.
Control of chlorinated aniline and chlorinated azo or azoxy trace impurities is especially relevant to toxicological, regulatory, colour, and downstream-formulation requirements.

Wettable powder grades are designed for wetting, suspensibility, and dilution in the spray tank but require effective dust control during handling.
Water-dispersible granules reduce loose powder exposure and must disintegrate rapidly into a stable suspension.
Suspension concentrates provide a pre-dispersed liquid form and are assessed for active-content uniformity, pourability, viscosity, sedimentation, redispersibility, wet-sieve residue, and storage stability.
Granular products support targeted soil placement and require control of granule strength, dust, active-content distribution, and release behaviour.

Epoxy-accelerator grades require close control of assay, melting range, moisture, free amines, 3,4-dichloroaniline, colour, and particle-size distribution.
Fine and micronised grades improve dispersion and cure response in one-component systems, while the selected D10, D50, and D90 profile helps balance reactivity against storage latency.
Application testing commonly measures gel time, differential scanning calorimetry cure onset and peak, degree of cure, glass-transition temperature, adhesion, and aged storage stability.

Material-preservative grades are evaluated for active content, particle size, dispersion quality, binder compatibility, film colour, storage stability, and release characteristics.
The active concentration and authorised claim must match the product category and destination market.

Research reagent grades prioritise chemical purity and a defined impurity profile.
Certified reference materials additionally require assigned purity or concentration, metrological traceability, uncertainty, solvent identity for solutions, container integrity, and a defined validity period.

FORMULATION AND PROCESS CONSIDERATIONS

Diuron's low water solubility means that agricultural formulations normally deliver finely divided solid particles rather than a true aqueous solution.
Wettable powders, water-dispersible granules, and suspension concentrates require sufficient agitation to maintain uniform distribution during dilution and application.
Sieves, filters, and spray nozzles must be matched to the particle-size profile to prevent blockage without removing active material from the spray suspension.

Moist soil supports movement into the weed-germination zone after application.
Coarse, low-organic-matter soils provide less adsorption and a narrower margin for crop selectivity, while clay and organic matter increase binding and can reduce immediately available active concentration.
Runoff, erosion, and drainage controls are particularly important before heavy rainfall or irrigation because transported soil and suspended sediment can carry Diuron beyond the treated area.

For paints and coatings, the powder should be dispersed sufficiently to remove agglomerates and distribute the active substance throughout the film without damaging the binder system.
Addition order, dispersant choice, milling energy, film pH, co-biocide compatibility, pigment volume, and binder hydrophobicity affect stability and surface delivery.
Formulation work should include storage, film-performance, leaching, efficacy, and regulatory-dose evaluation under the intended service conditions.

In epoxy compounds, Diuron and dicyandiamide are dispersed uniformly into the resin while avoiding process temperatures that initiate premature reaction.
Moisture control, shear history, milling temperature, filler surface chemistry, and accelerator concentration affect both cure consistency and shelf stability.
Gel-time and thermal-analysis profiles establish a production cure window for the complete resin, hardener, accelerator, filler, and additive package.

Laboratory stock solutions for photosynthesis studies are commonly prepared in acetone or another compatible organic solvent before dilution into the test medium.
The final solvent concentration is kept consistent across treated and control samples so that biological responses reflect DCMU exposure rather than the carrier solvent.

QUALITY, SPECIFICATIONS AND DOCUMENTATION

High-performance liquid chromatography is suitable for Diuron assay and for separation of major aromatic-urea transformation products.
Impurity profiling can combine chromatographic methods with targeted analysis for 3,4-dichloroaniline, free amine salts, residual solvents, and chlorinated trace impurities.
Water is commonly measured by a selective moisture method, while particle size is assessed by laser diffraction or wet-sieve testing as appropriate to the grade and product form.

A Technical Data Sheet describes the commercial form, key physical properties, grade characteristics, and processing information.
A Safety Data Sheet communicates hazard classification, exposure controls, first aid, transport, storage, spill response, and disposal requirements.
A Certificate of Analysis records the batch-specific results for the agreed specification, such as identity, assay, moisture, impurity limits, appearance, and particle size.

For formulated pesticides, useful release tests include active content, suspensibility, dispersibility, wetting time, wet-sieve residue, persistent foam, pH, redispersibility, pourability, and accelerated-storage behaviour as applicable.
For epoxy applications, the specification should connect chemical and particle-size data with cure-response tests performed in a representative resin system.
For analytical standards, certificate values must clearly identify whether the assigned value is chromatographic purity, mass fraction, or solution concentration.

SAFETY AND REGULATORY CONSIDERATIONS

The current European Union harmonised classification identifies Diuron as Carcinogenicity Category 1B with hazard statement H350, which means that it may cause cancer.
It is also classified as Specific Target Organ Toxicity following repeated exposure, Category 2, with hazard statement H373 for potential damage to the blood system through prolonged or repeated exposure.
Its environmental classification is Aquatic Acute Category 1 with H400 and Aquatic Chronic Category 1 with H410, reflecting very high toxicity to aquatic life and long-lasting effects.
This classification has applied since 1 September 2025 and assigns acute and chronic M-factors of 100.
The applicable signal word is Danger.

Repeated occupational exposure can damage red blood cells and produce methaemoglobinaemia or haemolytic anaemia.
Possible systemic signs include cyanosis, headache, dizziness, weakness, shortness of breath, and unusual fatigue.
Exposure control therefore focuses on enclosed transfer, dust suppression, local exhaust ventilation, hygiene, and personal protective equipment selected for the operation.

Diuron and its transformation products can persist in soil, sediment, and water, while photosynthetic aquatic organisms are particularly sensitive.
Product, contaminated wash water, firefighting water, and collected spill material must be kept out of drains, surface water, and untreated wastewater systems.

Diuron is not approved as an active substance for plant-protection products in the European Union, and its previous approval expired on 30 September 2020.
This plant-protection status is separate from the assessment and authorisation of biocidal products, material preservatives, and other industrial uses.
Agricultural, aquatic-algaecide, antifouling, and material-preservative uses are governed by the active authorisation, approved product label, use rate, worker-protection measures, residue conditions, and environmental controls in the destination jurisdiction.

FIRST AID

Inhalation: Move the exposed person to fresh air, keep them at rest, and obtain medical attention if breathing difficulty or systemic symptoms occur.

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 persistent irritation.

Ingestion: Rinse the mouth, do not induce vomiting, and obtain immediate advice from a poison centre or physician.
Do not give anything by mouth to an unconscious person.

Note to Physicians: Monitor the complete blood count, red-cell integrity, methaemoglobin, oxygenation, and liver, spleen, and kidney function based on the clinical presentation.
Treatment is supportive, with management of clinically significant methaemoglobinaemia performed by medical professionals under established clinical protocols.

HANDLING AND STORAGE

Use closed or contained transfer wherever practical and avoid generating or breathing dust.
Provide local exhaust at charging, milling, blending, sampling, and packaging points.
Wear chemical-resistant gloves, protective clothing, and safety goggles, and use respiratory protection selected from the exposure assessment when ventilation does not adequately control airborne material.
Wash thoroughly after handling and keep work clothing separate from food, drink, and personal items.

Store Diuron in tightly closed, correctly labelled containers in a cool, dry, well-ventilated, secure area.
Protect it from moisture, direct sunlight, excessive heat, strong acids, strong bases, and strong oxidising agents.
Segregate it from food, beverages, animal feed, medicines, and incompatible chemicals.
Control access to trained personnel and maintain containment suitable for a substance highly toxic to aquatic life.

For a spill, isolate the area, stop the release when this can be done safely, and prevent entry to drains or waterways.
Collect dry solid with low-dust methods, a suitable filtered vacuum, or careful dampening, and place the recovered material in a sealed labelled container for authorised disposal.
Avoid sweeping methods that disperse airborne dust.

Use extinguishing media appropriate to the surrounding fire.
Firefighters require self-contained breathing apparatus and full protective clothing because heated Diuron can release toxic and corrosive decomposition products.
Contain contaminated firefighting water for controlled disposal.

Dispose of Diuron, contaminated absorbents, obsolete pesticide material, and unrinsed packaging through an authorised hazardous-waste or pesticide-waste route.
Never discharge product residues or equipment rinsate into drains, soil, surface water, or untreated wastewater.

PACKAGING AND PROCUREMENT CONSIDERATIONS

Dry technical and accelerator grades are packaged in tightly sealed, moisture-resistant lined bags, fibre drums, or compatible polymer drums selected to protect the powder and contain dust.
Suspension concentrates and formulated dispersions require chemically compatible leak-resistant containers with headspace and closure systems suited to the liquid product.
Analytical standards are supplied in small sealed containers or ampoules that protect identity, concentration, and stability.

Transport Name: Environmentally hazardous substance, solid, n.o.s. (Diuron)
UN Number: UN 3077
Transport Hazard Class: 9
Packing Group: III

Liquid formulations and mixtures are assigned transport status from their complete composition, physical form, concentration, package size, and destination rules.

A precise Diuron procurement request identifies the intended herbicidal, material-preservative, epoxy, research, or analytical application.
It should also state the required assay, impurity limits, particle-size distribution, formulation type and concentration, package format, order quantity, destination market, and required Technical Data Sheet, Safety Data Sheet, and Certificate of Analysis.
For regulated uses, the request should include the authorised product category and destination jurisdiction so that grade, formulation, labelling, packaging, and documentation align with the intended supply route.

Contact Ataman Kimya to discuss Diuron grade selection, specifications, particle-size profile, application requirements, documentation, packaging, and supply planning.
Telephone: +90 216 577 10 10
Email: info@atamankimya.com