NITROFEN

Nitrofen is a chlorinated nitrophenyl ether whose commercial history, photodynamic herbicidal action and long environmental legacy give it an unusually specialised procurement profile.
Once used as a contact herbicide, it is now encountered principally as an analytical reference substance, a target in residue and contamination programmes, and a controlled research chemical.
Its selection depends less on nominal assay alone than on identity traceability, light-protected presentation and a clearly defined impurity profile.

CHEMICAL IDENTITY AND COMMON NAMES

Nitrofen is the common name for 2,4-dichloro-1-(4-nitrophenoxy)benzene, a neutral diaryl ether containing two chlorine substituents and one para nitro group.
The molecule has no stereocentre and is supplied as a single constitutional compound rather than as an isomeric blend.
The spelling Nitrophen occurs as an established alternative, while the various prime-numbered diphenyl ether names describe the same substitution pattern from different ring-numbering conventions.

Nitrofen must be distinguished from other nitrophenyl ether herbicides and from chlorinated phenoxy acids, because those materials have different registry identities, toxicological profiles and analytical responses.
Historical product names and formulation codes are not chemical synonyms and are therefore excluded from the identity list.

Synonyms and Common Names: Nitrofen, Nitrophen, Nitrofene, Nitrafen, Nitraphen, Nitrochlor, Niclofen, 2,4-dichloro-1-(4-nitrophenoxy)benzene, benzene, 2,4-dichloro-1-(4-nitrophenoxy)-, 2,4-dichlorophenyl 4-nitrophenyl ether, 2,4-dichlorophenyl p-nitrophenyl ether, 2,4-dichlorophenyl para-nitrophenyl ether, ether, 2,4-dichlorophenyl p-nitrophenyl, 2,4-dichloro-4'-nitrodiphenyl ether, 2',4'-dichloro-4-nitrodiphenyl ether, 4'-nitro-2,4-dichlorodiphenyl ether, 4-nitro-2',4'-dichlorodiphenyl ether, 4-(2,4-dichlorophenoxy)nitrobenzene, 4-(2,4-dichlorophenoxy)-1-nitrobenzene, 1-(2,4-dichlorophenoxy)-4-nitrobenzene, 4-nitrophenyl (2,4-dichlorophenyl) ether, 2,4-dichlorophenyl (4-nitrophenyl) ether, 4-(4-nitrophenoxy)-1,3-dichlorobenzene, 2,4-dichloro-4'-nitrobiphenyl ether

TECHNICAL IDENTIFICATION

CAS Number: 1836-75-5
EC / EINECS Number: 217-406-0
Molecular Formula: C12H7Cl2NO3
Molar Mass: 284.09 g/mol
IUPAC Name: 2,4-dichloro-1-(4-nitrophenoxy)benzene
Chemical Class: Chlorinated nitrophenyl ether and diphenyl ether herbicide
CIPAC Number: 170
Pesticide Chemical Code: 038201
InChIKey: XITQUSLLOSKDTB-UHFFFAOYSA-N
Canonical SMILES: C1=CC(=CC=C1N+[O-])OC2=C(C=C(C=C2)Cl)Cl

STRUCTURE, LIGHT AND HERBICIDAL ACTION

Modern mode-of-action classification places Nitrofen in Group 14, formerly designated Group E, among inhibitors of protoporphyrinogen oxidase.
This enzyme catalyses the oxidation of protoporphyrinogen IX to protoporphyrin IX during chlorophyll and haem biosynthesis.
Enzyme inhibition allows protoporphyrinogen IX to accumulate and move away from its normal reaction site, where it is oxidised to protoporphyrin IX.

Protoporphyrin IX is a powerful photosensitiser.
In illuminated, oxygenated tissue it transfers energy to oxygen and generates reactive oxygen species, especially singlet oxygen.
The resulting lipid peroxidation disrupts cell membranes, causes electrolyte leakage and produces rapid bronzing, necrosis and desiccation.

This mechanism explains why light is integral to Nitrofen injury and why its action is predominantly contact-based with limited translocation.
Older descriptions often emphasised inhibition of photosynthesis, but the early biochemical event is PPO inhibition and the collapse of photosynthetic function follows oxidative membrane damage.
The distinction is important when Nitrofen is used as a comparator in herbicide mode-of-action or photochemistry research.

PHYSICAL AND CHEMICAL PROFILE

Appearance: Colourless to brown crystalline powder that darkens on exposure to light
Melting Point: 70–71 °C for pure Nitrofen and 64–71 °C for technical material
Boiling Point: Approximately 368 °C at 101.3 kPa
Density: Approximately 1.3 g/cm3
Vapour Pressure: 0.001 Pa at 40 °C
Water Solubility: Approximately 0.001 g/L at 22 °C
Solubility in Acetone: Approximately 250 g/L at 20 °C
Solubility in Benzene: Approximately 2 g/L at 20 °C
Solubility in n-Hexane: Approximately 0.28 g/L at 20 °C
Solubility in Ethanol: Approximately 0.04 g/L at 20 °C
Octanol/Water Partition Coefficient: log Kow approximately 4.6–5.5
Flash Point: Above 200 °C in a closed-cup test
Autoignition Temperature: Above 400 °C
Acid-Base Character: Neutral and essentially non-ionising under ordinary environmental conditions

The combination of milligram-per-litre water solubility and a high partition coefficient makes Nitrofen strongly lipophilic.
It dissolves readily in acetone but is poorly suited to direct aqueous formulation without an organic solvent, dispersion system or other formulation aid.
Very low vapour pressure limits evaporation from the pure solid at ambient temperature, although contaminated dust and aerosols remain important exposure routes.

The crystalline material is stable under normal dry storage but is light-sensitive, as shown by progressive darkening and photochemical transformation.
It is combustible rather than readily flammable.
Finely divided powder dispersed in air can nevertheless create an explosive dust mixture, and thermal decomposition or combustion produces corrosive chlorine-containing fumes, nitrogen oxides and carbon oxides.

LIGHT, SOIL AND SEDIMENT BEHAVIOUR

Nitrofen partitions strongly to soil organic matter, suspended solids and sediment rather than remaining dissolved in water.
Representative organic-carbon sorption coefficients of approximately 7,800–10,000 mL/g indicate very strong sorption and low dissolved-phase mobility.
Runoff containing eroded particles can still transport the compound, so low leaching potential does not equate to absence of off-site movement.

Direct hydrolysis is not a major removal pathway because the diaryl ether has no readily hydrolysable functional group.
Sunlight can drive substantial photodegradation in exposed water, generating phenolic, amino and polymeric transformation products.
Sorption, turbidity, burial and shading reduce the light available for this process and can extend persistence in soils and sediments.

Biodegradation and dissipation depend strongly on oxygen status, temperature, organic matter and flooding.
Warm flooded soils can lose Nitrofen relatively quickly, while cool or organic-rich aerobic environments can retain measurable residues for much longer periods.
This condition-sensitive behaviour is one reason that residue investigations examine the parent compound in several environmental compartments rather than relying on a single water measurement.

Measured aquatic bioconcentration factors of approximately 1,550–5,370 demonstrate high potential for accumulation in organisms.
The compound is very toxic to aquatic life and can produce long-lasting effects, making containment of powders, solutions, rinsates and contaminated solids a central handling requirement.

PRODUCTION AND THE IMPURITY QUESTION

An established synthetic route forms the diaryl ether by reacting 2,4-dichlorophenoxide with 4-chloronitrobenzene under basic conditions in a polar reaction medium.
The para nitro group activates the aryl chloride toward nucleophilic aromatic substitution, allowing the phenoxide oxygen to create the bond between the two aromatic rings.
Salt removal, washing, crystallisation and drying convert the reaction mixture into isolated Nitrofen.

Process control must separate the target compound from residual 2,4-dichlorophenol, unreacted 4-chloronitrobenzene, positional nitrodiphenyl ether isomers, bis(4-nitrophenyl) ether and other condensation by-products.
Historical technical material has also contained 2,7-dichlorodibenzo-p-dioxin at trace levels.
That dioxin impurity is analytically and toxicologically distinct from Nitrofen and cannot be characterised adequately by a routine percentage assay.

For current research and reference-material procurement, the impurity statement therefore has unusual importance.
High chemical purity, a chromatographic profile and a defined limit or result for relevant chlorinated dioxin contamination create a much more informative quality package than assay alone.

FROM FIELD HERBICIDE TO CONTROLLED REFERENCE MATERIAL

Nitrofen was formerly manufactured as technical active material and incorporated into wettable powders and emulsifiable concentrates.
Those agricultural forms belong to its historical use period and are not the normal basis of current supply in major regulated markets.

Modern demand centres on high-purity neat material, certified reference material and accurately prepared calibration solutions.
Solution presentations may use acetonitrile, cyclohexane or petroleum ether, with the solvent selected for the analytical method, working concentration and sample matrix.
Light-protective glass packaging and a solvent-compatible closure preserve composition during storage and repeated handling.

APPLICATIONS AND INDUSTRIES

Historical weed-control context

Nitrofen was used before emergence and at early post-emergence stages to control annual grasses and broadleaf weeds.
Former crop contexts included cereals, rice and other field crops as well as ornamental production.
Its rapid, light-dependent contact injury and limited translocation shaped the coverage and timing requirements of those historical applications.
This information describes legacy practice rather than a current agricultural-use recommendation.

Legacy residue and environmental monitoring

Food, feed, soil, sediment, water and biological samples are tested for Nitrofen where historical use, contaminated land, obsolete stocks or imported commodities create a residue question.
Its hydrophobicity favours organic-rich and lipid-rich matrices, while its low volatility supports chromatographic workflows based on solvent extraction and gas chromatography.
Monitoring programmes also use the compound to evaluate remediation, sediment disturbance and the movement of particle-bound contamination.

Developmental biology and congenital diaphragmatic hernia research

Nitrofen is used in controlled animal research to create an experimental model of congenital diaphragmatic hernia, pulmonary hypoplasia and associated pulmonary vascular changes.
Exposure during defined gestational windows in rodents can disrupt diaphragm and lung development, allowing researchers to study the sequence of developmental abnormalities and potential interventions.

Disturbance of retinoid biology is an important part of this model.
Nitrofen can inhibit retinaldehyde dehydrogenase activity and reduce retinoic acid formation in relevant experimental systems, but its developmental effects also involve cell death and broader signalling changes.
It is therefore a complex teratogenic research chemical rather than a clean, single-target retinaldehyde dehydrogenase inhibitor.

PPO inhibition and photochemistry research

The compound provides a historically important comparator for Group 14 herbicides, protoporphyrin IX accumulation and light-driven membrane oxidation.
Laboratory work can use it to examine the relationship between PPO inhibition, singlet-oxygen generation, lipid peroxidation and visible tissue injury.
Its defined diphenyl ether structure also supports structure-activity comparisons with related photodynamic herbicides.

Analytical reference materials and method development

Neat Nitrofen and prepared standard solutions support instrument calibration, method validation, recovery studies, proficiency work and identity confirmation.
Gas chromatography coupled to mass spectrometry is especially useful for selective residue measurement, while liquid chromatographic methods support assay and purity work.
Certified concentration, metrological traceability, stated uncertainty and solvent identity are central selection parameters for quantitative standards.

Toxicology and transformation studies

Research programmes use controlled Nitrofen material to investigate carcinogenicity, developmental toxicity, retinoid and thyroid-related pathways, metabolism and environmental transformation.
Reduction of the nitro group to an amino derivative is relevant to metabolic and degradation investigations.
These studies require a defined impurity profile because legacy technical contaminants can otherwise obscure attribution of the observed effect.

REGULATORY POSITION

Nitrofen is an obsolete pesticide active rather than a currently accepted general-purpose herbicide.
All pesticide registrations in the United States were cancelled after voluntary withdrawal began around 1980.
It is not approved as a plant-protection active substance in the European Union, and pesticide products containing it are not authorised there.

European prior-informed-consent controls apply to relevant exports for pesticide purposes.
Research and analytical supply follows the controls for hazardous chemicals and laboratory materials, while pesticide authorisation is a separate legal pathway.
This distinction directs present-day procurement toward analytical, toxicological and legacy-contamination work rather than field application.

GRADE SELECTION IS PURPOSE-DRIVEN

A neat analytical reference grade is appropriate when the laboratory will prepare its own stock solutions or needs an independent identity and purity benchmark.
Key attributes are chromatographic assay, structural identity, water and residual-solvent information, storage stability, and a transparent impurity profile.

A certified reference solution is designed for quantitative calibration.
Its useful specification includes gravimetric concentration, solvent, traceability, measurement uncertainty, homogeneity, container type and expiry period.
The solution concentration must sit within the working range of the intended detector without creating unnecessary serial dilution.

Developmental or mechanistic research calls for highly purified, reproducible material with tight control of structurally related impurities and chlorinated dioxin contamination.
Legacy technical material serves different purposes, such as historical sample characterisation or waste assessment, and is not interchangeable with a high-purity research substance.

FORMULATION, SAMPLE PREPARATION AND PROCESS CONTROL

Stock solutions are prepared in an organic solvent because water alone does not provide practical dissolution.
Acetone offers high solvating capacity, while acetonitrile and hydrocarbon solvents suit particular chromatographic systems and extraction schemes.
Glass contact surfaces and solvent-resistant closures help limit adsorption, permeation and extractable contamination.

Preparation and transfer take place under controlled light, preferably with amber vessels or an effective light barrier.
Moderate ambient-temperature mixing is preferable to unnecessary heating, and concentrated solutions remain closed when not in use to control both solvent loss and exposure.
Powder charging takes place in contained equipment with local exhaust because the low vapour pressure does not control airborne particulate risk.

Residue methods need matrix-matched recovery controls for fatty foods, soil and sediment because lipophilicity and strong sorption can reduce extraction efficiency.
Procedural blanks, fortified samples and an isotopically labelled or otherwise suitable internal standard help distinguish true loss from instrumental suppression or matrix interference.

QUALITY CONTROL AND ANALYTICAL DOCUMENTATION

Gas chromatography with flame-ionisation detection can measure bulk assay, while gas chromatography with mass spectrometric or tandem mass spectrometric detection provides greater selectivity for identity and trace residues.
High-performance liquid chromatography with ultraviolet or diode-array detection is suitable for purity profiling, and liquid chromatography with mass spectrometric detection can complement selected workflows.
Infrared spectroscopy, nuclear magnetic resonance and exact-mass data provide orthogonal confirmation of molecular identity.

Trace dioxin analysis requires a dedicated method with high chromatographic resolution and high-resolution mass spectrometric detection.
This result belongs beside the main assay when the material is intended for sensitive toxicology, developmental biology or impurity-controlled reference work.

A complete quality package identifies the test material, batch, assay method, chromatographic purity, named impurities, residual solvents, water content, storage conditions and retest or expiry date.
For a calibration solution, it also records certified concentration, solvent, uncertainty, preparation basis and homogeneity.
The Certificate of Analysis, Safety Data Sheet and Technical Data Sheet then serve distinct roles in batch release, safe handling and technical selection.

SAFETY AND OCCUPATIONAL CONTROL

Signal Word: Danger
Hazard Statements: H302, H350, H360D, H400 and H410
Acute Oral Toxicity: Category 4 and harmful if swallowed
Carcinogenicity: Category 1B and may cause cancer
Reproductive Toxicity: Category 1B and may damage the unborn child
Aquatic Hazard: Category 1 for acute and chronic effects, with very high toxicity and long-lasting impact

Occupational control treats Nitrofen as both a carcinogenic and reproductive hazard.
Ingestion, dust inhalation and skin contact with powder or solutions are the principal exposure routes, while the very low vapour pressure makes vapour from the solid a secondary concern.
Short-term exposure can irritate the skin and respiratory tract and may affect the central nervous system, while repeated exposure can affect the liver and blood.

Closed handling, a fume cupboard or contained balance enclosure, local exhaust and high-efficiency particulate capture reduce airborne exposure.
Chemical-resistant gloves, protective clothing and sealed eye protection are required for routine work.
Respiratory protection is selected for the particulate and any carrier solvent when enclosure and ventilation cannot maintain the required exposure control.

Pregnancy exposure prevention is built into access control, work assignment, training and decontamination procedures.
Eating, drinking and storage of personal items remain outside the controlled work area, and exposed surfaces are cleaned with methods that capture rather than redistribute contamination.

FIRST AID

Inhalation: Move the affected person to fresh air, keep them at rest and obtain medical attention after significant exposure or if symptoms develop.
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 assessment if irritation persists.
Ingestion: Rinse the mouth, do not induce vomiting and obtain urgent medical attention.
Note to Physicians: No specific antidote is established, so treatment is supportive with attention to neurological status and possible hepatic or haematological effects.

SPILL RESPONSE, STORAGE AND WASTE MANAGEMENT

A spill area is isolated and ventilated before collection begins.
Dry sweeping and compressed air are avoided because they disperse contaminated dust.
Powder is collected with a filtered hazardous-material vacuum or careful damp pickup, while solutions are absorbed with compatible inert material.

All recovered material, disposable protective equipment and cleaning residues are placed in sealed, labelled hazardous-waste containers.
Release to drains, surface water or soil is prevented because small quantities can create a substantial aquatic burden.
Destruction in a permitted high-temperature hazardous-waste facility with appropriate off-gas control is the preferred disposal route for Nitrofen waste.

Storage uses a tightly closed amber glass or equivalently light-protective container in a cool, dry and well-ventilated secure area.
The material is segregated from strong oxidising agents, heat and ignition sources and held within secondary containment.
An inventory and access record support the additional controls appropriate to a carcinogenic and reproductive toxicant.

PACKAGING AND PROCUREMENT CONSIDERATIONS

High-purity neat Nitrofen is normally suited to sealed amber glass vials with tamper-evident closure and protective secondary packaging.
Calibration solutions are appropriately presented in flame-sealed ampoules or solvent-compatible crimp vials that control evaporation and repeated-open exposure.
Package size is matched to realistic consumption so that long storage after opening is minimised.

An effective procurement inquiry identifies the intended analytical or research purpose, neat or solution form, required purity or certification, concentration and solvent, pack size, impurity limits, destination and documentation package.
For sensitive research, the inquiry also states the required control of 2,7-dichlorodibenzo-p-dioxin and related process impurities.
For quantitative analysis, concentration traceability and uncertainty carry more value than a broad nominal purity statement.

Ataman Kimya supports Nitrofen inquiries involving analytical or research grade selection, impurity-profile requirements, prepared standard solutions, light-protective packaging, technical documentation and supply planning.
For a product-specific discussion, contact Ataman Kimya at +90 216 577 10 10 or info@atamankimya.com