DICHLOFLUANID

Dichlofluanid is a white to off-white crystalline powder belonging to the sulfamide class of fungicides, with molecular formula C₉H₁₁Cl₂FN₂O₂S₂, molecular weight 333.23 g/mol, CAS number 1085-98-9, EC number 214-118-7, melting point 105–106°C, density 1.55 g/cm³, and water solubility of approximately 1.3 mg/L at 20°C; it bears a dichlorofluoromethylthio (sulfenyl) moiety that confers high reactivity toward cellular thiol groups and distinguishes it structurally from the trichloromethylthio fungicides captan and folpet.
Dichlofluanid was first marketed by Bayer in 1964 under trade names Euparen and Elvaron, and has been used as a broad-spectrum protective fungicide against apple scab, gray mold, downy mildew, Botrytis, Alternaria, Sclerotinia, and Monilinia on fruits, vegetables, and ornamentals; as a wood preservative and paint undercoat biocide; and as a booster biocide in tin-free antifouling marine paints where it controls algal, weed, and animal fouling on vessels and static underwater structures.
Dichlofluanid is no longer approved for agricultural use in the European Union; it has been approved for use in antifouling products (Product Type 21) under the Biocidal Products Directive and entered Annex I for wood preservatives (Product Type 8) on 1 March 2009; it is classified under GHS with Signal Word Warning (H317 may cause an allergic skin reaction; H319 causes serious eye irritation; H332 harmful if inhaled; H400 very toxic to aquatic life) and is detectable in harbour and marina waters across many European countries.

CAS Number: 1085-98-9
EC Number: 214-118-7
Molecular Formula: C₉H₁₁Cl₂FN₂O₂S₂
Molecular Weight: 333.23 g/mol

Synonyms: Euparen, Elvaron, Eparen, Oiparen, Pecudin, Euparene, BAY 47531, Bayer 47531, B-47531, Dichlofluanide, Diclofluanide, NSC 218451, N-dichlorofluoromethylthio-N′,N′-dimethyl-N-phenylsulphamide, N-[(dichlorofluoromethyl)thio]-N′,N′-dimethyl-N-phenylsulfamide, 1,1-dichloro-N-[(dimethylamino)sulfonyl]-1-fluoro-N-phenylmethanesulfenamide, Sulfamide N-[(dichlorofluoromethyl)thio]-N′,N′-dimethyl-N-phenyl-, N,N-dimethyl-N′-phenyl-N′-[(fluorodichloromethyl)thio]sulfamide, KUE 13032C, Ku 13-032-c, DMSA impurity host, CAS 1085-98-9

Appearing as a white to off-white crystalline powder, Dichlofluanid belongs to the phenylsulfamide class of fungicides.
A reactive dichlorofluoromethylthio group gives Dichlofluanid its characteristic chemical behaviour.

On plant surfaces, Dichlofluanid forms a protective barrier that helps prevent fungal spores from establishing an infection.
Strawberries, grapes, apples, pears, vegetables, and ornamental plants have all been treated with Dichlofluanid.

Botrytis, Alternaria, Sclerotinia, and Monilinia are among the fungal genera controlled by Dichlofluanid.
Apple scab, grey mould, downy mildew, and various storage diseases can be managed with Dichlofluanid.

Formulations intended to protect timber from mould and blue-stain fungi may contain Dichlofluanid.
In paint systems, microbial deterioration of the dry coating film can be limited by Dichlofluanid.

As a booster biocide, Dichlofluanid broadens the performance of tin-free marine antifouling coatings.
Copper-based boat paints commonly combine their primary antifouling agent with Dichlofluanid.

Protection against algae and other marine fouling organisms can be extended through the addition of Dichlofluanid.
Several thiol-dependent enzyme systems involved in fungal respiration are disrupted by Dichlofluanid.

By acting at multiple biochemical sites, Dichlofluanid reduces the likelihood of resistant fungal populations developing.
Reactions with cysteine, glutathione, and other cellular thiols contribute to the biological activity of Dichlofluanid.

Under alkaline conditions, rapid hydrolysis converts Dichlofluanid into DMSA.
Acidic environments provide greater hydrolytic stability for Dichlofluanid.

Only limited dissolution occurs when Dichlofluanid comes into contact with water.
Methanol, xylene, and various organic solvents dissolve Dichlofluanid more readily than water.

Prolonged exposure to light may discolour Dichlofluanid without necessarily eliminating its biological activity.
Wettable powders, dusts, solution concentrates, and coating additives are among the available formulation forms of Dichlofluanid.

Residue testing in fruit, grapes, must, and wine commonly uses Dichlofluanid as an analytical reference standard.
Gas chromatography with electron-capture detection provides a suitable method for measuring Dichlofluanid.

Environmental monitoring in marina waters and sediments often examines both DMSA and Dichlofluanid.
Introduced commercially during the 1960s, Dichlofluanid became known through trade names such as Euparen and Elvaron.

Uses of Dichlofluanid:
Dichlofluanid has been used as a broad-spectrum protective fungicide on strawberries, grapes, apples, pears, currants, loganberries, berries, stone fruits, and ornamental plants against rust, brown spot, Botrytis cinerea, Alternaria, scab, black spot, leather rot, downy mildew, and storage diseases.
Dichlofluanid is used as a wood preservative and paint undercoat biocide, protecting timber and coated surfaces against mould, blue stain fungi, and wood-destroying organisms; it is often formulated in 50% wettable powder or 7.5% dust technical grades for surface application.
Dichlofluanid functions as a booster biocide in tin-free antifouling marine coatings, where it is incorporated into copper-based boat paints at a calculated leach rate of approximately 3.91 µg cm⁻² d⁻¹ to provide continuous broad-spectrum control of algae, barnacles, weeds, and animal fouling on vessel hulls.
Dichlofluanid is used as an analytical reference standard for the determination of residues in must and wines by gas chromatography, and in estuarine water samples as an antifouling paint booster biocide by GC and HPLC analytical procedures.
Dichlofluanid has been used as a booster biocide in aquaculture facilities and fish farming nets to control biological fouling, and as a co-biocide alongside copper compounds in coastal and marina antifouling applications where it is monitored in harbour sediments and seawater.

Benefits and Advantages of Dichlofluanid:
The monofluorodichloromethylthio moiety of dichlofluanid reacts with cellular thiol groups at a rate more than twice that of captan and folpet, conferring superior protectant fungicidal activity against a wide range of pathogens at relatively low application rates.
Unlike trichloromethylthio analogs, dichlofluanid and its bis(fluorodichloromethyl) disulfide degradate were negative for mutagenicity in S. typhimurium TA100, and dichlofluanid showed no carcinogenicity in mice at 5,000 ppm dietary levels; the fluorine substitution on the methyl thio moiety is considered responsible for this reduced genotoxic profile.
Dichlofluanid is not persistent in most soil or aquatic systems; it hydrolyses rapidly in alkaline conditions (DT50 < 10 minutes at pH 9, 22°C) and does not leach to groundwater based on its low water solubility and chemical properties, making it one of the less environmentally persistent chlorinated fungicides.
The technical purity of at least 96%, formulation flexibility as wettable powder, dust, and solution concentrate, and compatibility with copper-based antifouling systems make dichlofluanid a practical and commercially established biocide for coatings and preservation applications.

Features of Dichlofluanid:
Dichlofluanid is a white powder with a slight characteristic odour at room temperature; melting point 105–106°C (110–112°C from ethanol recrystallisation), density 1.55–1.5752 g/cm³, estimated boiling point 154°C, and flash point approximately 2–4°C.
Dichlofluanid is sparingly soluble in water (1.3 mg/L at 20°C), soluble in methanol (1.5 g/100 mL), xylene (7.0 g/100 mL), and most common organic solvents; it is unstable in alkaline media and in the presence of polysulphides, and is light-sensitive although the discolouration induced does not affect its biological activity.
The vapour pressure is 1.5×10⁻⁵ Pa at 20°C and Henry's Law constant is 2.6×10² mol/(m³·Pa) at 25°C; predicted pKa is −5.37±0.50, confirming the non-ionisable character of the molecule under relevant environmental pH ranges.
Dichlofluanid contains an unstable dichlorofluoromethylthio moiety that undergoes rapid hydrolytic and metabolic degradation in biological systems; the principal degradation product in alkaline conditions is N′,N′-dimethyl-N-phenylsulfamide (DMSA, dimethylsulfanilide), and the overall degradation route involves thiophosgene or its monofluoro analogue as short-lived intermediates.

Chemical Properties of Dichlofluanid:
Dichlofluanid has IUPAC name N-{[dichloro(fluoro)methyl]sulfanyl}-N′,N′-dimethyl-N-phenylsulfuric diamide (alternative IUPAC: N-[dichloro(fluoro)methyl]sulfanyl-N-(dimethylsulfamoyl)aniline), SMILES CN(C)S(=O)(=O)N(SC(F)(Cl)Cl)c1ccccc1, InChI=1S/C9H11Cl2FN2O2S2/c1-13(2)18(15,16)14(17-9(10,11)12)8-6-4-3-5-7-8/h3-7H,1-2H3, InChIKey WURGXGVFSMYFCG-UHFFFAOYSA-N; PubChem CID 14145, ChemSpider 13520, ECHA InfoCard 100.012.835, CompTox DTXSID5041851, UNII 76A92XU36Y, Beilstein/REAXYS 2947992, MDL MFCD00078639.
Dichlofluanid is a sulfamide in which the hydrogens on one nitrogen are replaced by two methyl groups (forming a dimethylsulfamoyl moiety) and those on the other nitrogen by a phenyl group and a [dichloro(fluoro)methyl]sulfanediyl group; it belongs to the aryl(dichlorofluoromethylthio)fungicide class and is classified as an organochlorine compound, an organofluorine compound, and a phenylsulfamide fungicide.
The fungicidal mechanism of dichlofluanid involves binding with thiol groups of enzymes involved in mitochondrial respiration; the dichlorofluoromethylthio moiety transfers to sulfur atoms of cellular thiols such as cysteine and glutathione, inhibiting multiple thiol-containing enzyme systems — a multisite mode of action that makes development of resistance unlikely under field conditions.
Dichlofluanid is hydrolysed rapidly at pH 9 (DT50 < 10 minutes at 22°C), slowly at pH 7 (DT50 > 18 hours), and is relatively stable at pH 4 (DT50 > 15 days); it reacts with glutathione and cysteine in vitro to yield DMSA and short-lived intermediate species; the monofluorodichloromethylthio moiety reacts with 4-nitrothiophenol at over twice the rate of the trichloromethylthio moiety of captan.

Production of Dichlofluanid:
Dichlofluanid is produced commercially by a two-step process: first, N,N-dimethyl-N′-phenylsulfonamide is added to toluene and treated with sodium hydride at 0–5°C for 0.5–1 hour to form a reactive intermediate; the molar ratio of sulfonamide to NaH is 1:1.0 and the mass ratio of sulfonamide to toluene is 1:6–1:8.
The reactive intermediate is then treated by dropwise addition of a 65–90% solution of dichlorofluoromethanesulphenyl chloride in toluene at room temperature for 1–2 hours; the molar ratio of sulfonamide to sulphenyl chloride is 1:0.8–1:1.4; after reaction, the mixture is water-washed, the organic phase separated, dried, and concentrated to give crude product, which is refined by recrystallisation from short-chain alcohols (methanol, ethanol, propanol, or isopropanol) at a crude-to-alcohol mass ratio of 1:2.8–1:3.2, achieving yields of up to 84%.
Dichlofluanid is commercially available at ≥96% technical purity as a white powder, formulated as 50% wettable powder or 7.5% dust, and at ≥98% analytical purity (PESTANAL grade) for use as a reference standard; storage at 2–8°C with a limited shelf life per expiry date on label.

Dichlofluanid Material Safety Data Sheet (MSDS):

Handling of Dichlofluanid:
Dichlofluanid must be handled with appropriate precautions due to its skin sensitisation potential (H317), eye irritation (H319), inhalation hazard (H332), and high aquatic toxicity (H400); dust formation must be avoided at all times, and the compound must be used only outdoors or in a well-ventilated area.
Contaminated work clothing must not leave the workplace; avoid breathing dust, fumes, gas, mist, vapours, or spray; wear protective gloves, protective clothing, and eye and face protection at all times during handling.

Dichlofluanid SDS:

Stability and Reactivity of Dichlofluanid:

Chemical stability:
Dichlofluanid is stable under recommended storage conditions at 2–8°C in a tightly closed container.
Dichlofluanid decomposes in alkaline media and in the presence of polysulphides; it is light-sensitive (discolouration on prolonged exposure, without loss of biological activity).

Reactivity:
The dichlorofluoromethylthio moiety undergoes rapid hydrolysis at alkaline pH (DT50 < 10 minutes at pH 9, 22°C) to yield N′,N′-dimethyl-N-phenylsulfamide (DMSA).
Dichlofluanid reacts exothermically with thiol-containing compounds and strong bases.

Conditions to avoid:
Alkaline conditions (rapid hydrolysis).
Prolonged exposure to light (photodegradation and discolouration).
Contact with polysulphides.
Dust formation and dispersion.

Incompatible materials:
Strong bases and alkalis.
Polysulphides.
Strong oxidising agents.
Thiol-containing reagents (rapid reaction).

Hazardous decomposition products:
N′,N′-Dimethyl-N-phenylsulfamide (DMSA) — principal hydrolysis product.
Thiophosgene and/or monofluoro thiophosgene analogue (short-lived intermediates).
Hydrogen chloride (HCl) and hydrogen fluoride (HF) upon thermal decomposition.
Sulfur dioxide (SO₂) and sulfur-containing fumes upon combustion.

Handling and Storage of Dichlofluanid:

Handling:
Use only outdoors or in a well-ventilated area; avoid dust formation at all points of handling.
Wear protective gloves, protective clothing, eye protection, and face protection.
Avoid breathing dust, fumes, gas, mist, vapours, or spray.
Do not eat, drink, or smoke in work areas.
Wash hands and skin thoroughly after handling.
Contaminated work clothing must not be taken out of the workplace.

Storage:
Store at 2–8°C in a tightly closed, clearly labelled container in a cool, dry, well-ventilated area.
Protect from light, moisture, alkaline conditions, and polysulphides.
Limited shelf life; check expiry date on label.
Dispose of contents and container through an authorised hazardous-waste facility.

First Aid Measures for Dichlofluanid:

Inhalation:
Remove the affected person to fresh air and keep comfortable for breathing.
If symptoms develop, call a poison centre or physician.

Skin contact:
If skin contact occurs, wash with plenty of soap and water.
If skin irritation or rash occurs, seek medical advice; contaminated clothing must be washed before reuse.

Eye contact:
Rinse cautiously with water for several minutes; remove contact lenses if present and easy to do, and continue rinsing.
If eye irritation persists, seek medical advice.

Ingestion:
Rinse the mouth with water; do not give anything by mouth to an unconscious person.
Call a poison centre or physician if you feel unwell.

Firefighting Measures for Dichlofluanid:

Suitable extinguishing media:
Water spray, dry chemical powder, carbon dioxide, or alcohol-resistant foam.

Specific hazards:
Dichlofluanid is a combustible solid; combustion releases hydrogen chloride, hydrogen fluoride, sulfur dioxide, and other irritating and corrosive fumes.
Flash point is approximately 2–4°C in solution formulations containing organic solvents; the pure solid does not present a significant flammability risk at ambient temperature.

Protective equipment for firefighters:
Self-contained breathing apparatus (SCBA) and full chemical-protective clothing must be used due to the release of corrosive HCl and HF fumes.

Firefighting procedures:
Collect spillage; prevent contaminated firefighting water from entering drains, sewers, or surface water (H400 — very toxic to aquatic life).
Cool exposed containers with water spray.

Accidental Release Measures for Dichlofluanid:

Personal precautions:
Avoid dust formation; avoid breathing dust and prevent contact with skin and eyes.
Wear full PPE; evacuate non-essential personnel from the release area.

Environmental precautions:
Dichlofluanid is very toxic to aquatic life (H400); prevent all release to drains, surface water, groundwater, and soil.
Collect spillage; notify environmental authorities if significant environmental contamination occurs.

Clean-up methods:
Carefully sweep or vacuum to avoid dust formation; collect in sealed, labelled, sealable containers.
Do not wash into drains; dispose of all collected waste through an authorised hazardous-waste facility.

Exposure Controls / Personal Protective Equipment for Dichlofluanid:

Engineering controls:
Provide exhaust ventilation at all points where dust may form.
Use closed handling systems where possible; emergency eyewash stations must be accessible.

Eye protection:
Chemical safety goggles and face shield; tested and approved under NIOSH (US) or EN 166 (EU).

Hand protection:
Chemically resistant gloves; inspect before use and replace if contaminated or damaged.

Skin and body protection:
Complete chemical-protective suit; clothing type selected based on concentration and amount handled.

Respiratory protection:
For dust exposures use type P95 (US) or type P1 (EU EN 143) particle respirator.
For higher protection use type OV/AG/P99 (US) or type ABEK-P2 (EU EN 143) respirator cartridges.

Hygiene measures:
Wash hands and exposed skin thoroughly after handling; do not eat, drink, or smoke in work areas; contaminated clothing must not leave the workplace.

Dichlofluanid Identifiers:
CAS Number: 1085-98-9
EC Number: 214-118-7
MDL Number: MFCD00078639
PubChem CID: 14145
ChemSpider: 13520
ECHA InfoCard: 100.012.835
CompTox (EPA): DTXSID5041851
UNII: 76A92XU36Y
Beilstein/REAXYS: 2947992
IUPAC Name: N-{[Dichloro(fluoro)methyl]sulfanyl}-N′,N′-dimethyl-N-phenylsulfuric diamide
Molecular Formula: C₉H₁₁Cl₂FN₂O₂S₂
Molecular Weight: 333.23 g/mol
Accurate Mass: 331.9623 Da
SMILES: CN(C)S(=O)(=O)N(SC(F)(Cl)Cl)c1ccccc1
InChI: InChI=1S/C9H11Cl2FN2O2S2/c1-13(2)18(15,16)14(17-9(10,11)12)8-6-4-3-5-7-8/h3-7H,1-2H3
InChIKey: WURGXGVFSMYFCG-UHFFFAOYSA-N
GHS Signal Word: Warning
GHS Hazard Statements: H317, H319, H332, H400
GHS Precautionary Statements: P261, P264, P271, P272, P273, P280, P302+P352, P304+P340, P305+P351+P338, P312, P333+P313, P337+P313, P391, P501
Rat oral LD50: 2500 mg/kg
NOEC (rat, 2yr): 500 ppm (30 mg/kg bw/day)
NOEC (dog): 1000 ppm (25 mg/kg bw/day)
EU agricultural status: Not approved (withdrawn)
EU biocidal status: Approved — Product Type 8 (wood preservatives, Annex I from 1 March 2009); Product Type 21 (antifouling) under evaluation
NACRES: NA.24
UNSPSC: 41116107

Properties of Dichlofluanid:
Physical state: Solid
Appearance: White to off-white crystalline powder
Odour: Slight characteristic odour
Molecular formula: C₉H₁₁Cl₂FN₂O₂S₂
Molecular weight: 333.23 g/mol
Density: 1.55 g/cm³ (1.5752 g/cm³ estimated)
Melting point: 105–106°C (110–112°C from ethanol)
Boiling point: ~154°C (estimated)
Flash point: ~2–4°C (solution formulations)
Vapour pressure: 1.5×10⁻⁵ Pa (20°C)
Water solubility: 1.3 mg/L (20°C) — sparingly soluble
Solubility in methanol: 1.5 g/100 mL
Solubility in xylene: 7.0 g/100 mL
Henry's Law constant: 2.6×10² mol/(m³·Pa) at 25°C
pKa: −5.37±0.50 (predicted)
Hydrolysis DT50: >15 days (pH 4); >18 hours (pH 7); <10 minutes (pH 9) — all at 22°C
Rat oral LD50: 2500 mg/kg
GHS Classification: Warning — H317, H319, H332, H400
Storage temperature: 2–8°C (limited shelf life)

Dichlofluanid Properties — Specifications:
Product name: Dichlofluanid
CAS Number: 1085-98-9
EC Number: 214-118-7
Molecular Formula: C₉H₁₁Cl₂FN₂O₂S₂
Molecular Weight: 333.23 g/mol
Technical purity: ≥96%
Analytical purity (PESTANAL): ≥98%
Appearance: White powder
Melting point: 105–106°C
Density: 1.55 g/cm³
Storage: 2–8°C; tightly closed; protected from light; limited shelf life per label
Format: Solid (neat); 50% wettable powder; 7.5% dust; solution concentrate
Techniques: HPLC, GC
Documents: CoA (Certificate of Analysis), MSDS/SDS available

Names of Dichlofluanid:
Dichlofluanid
Euparen
Elvaron
Eparen
Oiparen
Pecudin
Euparene
Diparen
BAY 47531
Bayer 47531
B-47531
Dichlofluanide
Diclofluanide
NSC 218451
KUE 13032C
Ku 13-032-c
N-dichlorofluoromethylthio-N′,N′-dimethyl-N-phenylsulphamide
N-[(dichlorofluoromethyl)thio]-N′,N′-dimethyl-N-phenylsulfamide
1,1-dichloro-N-[(dimethylamino)sulfonyl]-1-fluoro-N-phenylmethanesulfenamide
N,N-dimethyl-N′-phenyl-N′-[(fluorodichloromethyl)thio]sulfamide
Sulfamide N-[(dichlorofluoromethyl)thio]-N′,N′-dimethyl-N-phenyl-
CAS 1085-98-9