| diclobutrazol (Ref: PP296) |
 |
Environmental Fate - Ecotoxicology - Human Health - A to Z Index - Home
SUMMARY
Dichloburazol is a discontinued fungicide that is not approved for use in the EU. It has a low aqueous solubility and is volatile. There are significant gaps in reported fate data. Dichlobutrazol has a low mammalian toxicity but is moderately toxic to fish. It is relatively non-toxic to honeybees. GENERAL INFORMATION 
for diclobutrazol
Description: A discontinued fungicide that was mainly used to control mildews on a range of crops
Example pests controlled: Powdery mildew; Apple mildew; Rust; Scab
Example applications: Cereals; Vines; Coffee; Apples & pears; Curcubits
Efficacy & activity: -
Availability status: Obsolete
Introduction & key dates: 1979, first reported
EC Regulation 1107/2009 (repealing 91/414):
| Status | Not approved |
| Dossier rapporteur/co-rapporteur | Not applicable |
| Date inclusion expires | Not applicable |
| EU Candidate for substitution (CfS) | Not applicable |
| Listed in EU database | Yes |
Approved for use (
) or known to be used (
) in the following European countries: 
AT |
BE |
BG |
CY |
CZ |
DE |
DK |
EE |
EL |
ES |
FI |
FR |
HR |
HU |
IE |
IT |
LT |
LU |
LV |
MT |
NL |
PL |
PT |
RO |
SE |
SI |
SK |
UK |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Chemical structure:
| Isomerism | Diclobutrazol is a molecule with two chiral centres. The technical material is an isomeric mixture. |
| Chemical formula | C15H19Cl2N3O |
| Canonical SMILES | CC(C)(C)C(C(CC1=C(C=C(C=C1)Cl)Cl)N2C=NC=N2)O.CC(C)(C)C(C(CC1=C(C=C(C=C1)Cl)Cl)N2C=NC=N2)O |
| Isomeric SMILES | CC(C)(C)[C@H]([C@@H](CC1=C(C=C(C=C1)Cl)Cl)N2C=NC=N2)O.CC(C)(C)[C@@H]([C@H](CC1=C(C=C(C=C1)Cl)Cl)N2C=NC=N2)O |
| International Chemical Identifier key (InChIKey) | PLPRPHZNQBHGSP-DZYJZKBLSA-N |
| International Chemical Identifier (InChI) | InChI=1S/C15H19Cl2N3O/c1-15(2,3)14(21)13(20-9-18-8-19-20)6-10-4-5-11(16)7-12(10)17/h4-5,7-9,13-14,21H,6H2,1-3H3 |
| 2D structure diagram/image available? | Yes |
General status:
| Pesticide type | Fungicide, Other substance | |||
| Other constituent type | Bactericide, Wood preservative | |||
| Substance group | Conazole | |||
| Minimum active substance purity | - | |||
| Known relevant impurities | - | |||
| Substance origin | Synthetic | |||
| Mode of action | Systemic, absorbed through leaves, stem and roots and translocated. Known to block fungal sterol biosynthesis. | |||
| CAS RN | 75736-33-3 | |||
| Alternative/old CAS RN | 66345-62-9 | |||
| EC number | 266-324-1 | |||
| CIPAC number | 421 | |||
| US EPA chemical code | - | |||
| PubChem CID | 53309 | |||
| Molecular mass (g mol-1) | 328.24 | |||
| PIN (Preferred Identification Name) | rac-(2R,3R)-1-(2,4-dichlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pentan-3-ol | |||
| IUPAC name | (2RS,3RS)-1-(2,4-dichlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pentan-3-ol | |||
| CAS name | (αR,βR)-rel-β-[(2,4-dichlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol | |||
| Other status information | Should not be used on solanaceous crops - phytotoxic. | |||
| Relevant Environmental Water Quality Standards | - | |||
| Herbicide Resistance Classification (HRAC) | Not applicable | |||
| Herbicide Resistance Classification (WSSA) | Not applicable | |||
| Insecticide Resistance Classification (IRAC) | Not applicable | |||
| Fungicide Resistance Classification (FRAC) | 11 | |||
| Examples of recorded resistance | - | |||
| Physical state | Off-white coloured crystalline solid | |||
| Related substances & organisms | - | |||
Formulations:
| Property |
Value | |||
| Example manufacturers & suppliers of products using this active now or historically |
|
|||
| Example products using this active |
|
|||
| UK LERAP status | No UK approval for use as a pesticide under EC Regulation 1107/2009 | |||
| Formulation and application details | Usually formulated as a suspension concentrate. | |||
ENVIRONMENTAL FATE
for diclobutrazol
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 7.1 | L3 | Low | |
| Solubility - In organic solvents at 20oC (mg l-1) | - | - | - | |
| Melting point (oC) | 148 | V3 | - | |
| Boiling point (oC) | - | - | - | |
| Degradation point (oC) | - | - | - | |
| Flashpoint (oC) | - | - | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 6.46 X 1003 | Calculated | - |
| Log P | 3.81 | L3 | High | |
| Bulk density (g ml-1)/Specific gravity | 1.25 | L3 | - | |
| Dissociation constant (pKa) at 25oC | <2 | L3 | - | |
| Note: Basic | ||||
| Vapour pressure at 20oC (mPa) | 0.0027 | L3 | Low volatility | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 1.25 X 10-04 | L3 | Non-volatile | |
GUS leaching potential index  |
- | - | - | |
| SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate |
Value | - | - | - |
| Note | - | |||
| Potential for particle bound transport index |
- | - | - | |
| Maximum UV-vis absorption L mol-1 cm-1 | - | - | - | |
| Surface tension (mN m-1) | - | - | - | |
Degradation:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
General biodegradability | - |
| Soil degradation (days) (aerobic) | DT50 (typical) | 7 | L3 | Non-persistent |
| DT50 (lab at 20oC) | - | - | - | |
| DT50 (field) | - | - | - | |
| DT90 (lab at 20oC) | - | - | - | |
| DT90 (field) | - | - | - | |
| DT50 modelling endpoint | - | - | - | |
| Note | Data scant. Literature suggests DT50 is around a week | |||
| Dissipation rate RL50 on plant matrix | Value | - | - | - |
| Note | - | |||
| Dissipation rate RL50 on and in plant matrix | Value | - | - | - |
| Note | - | |||
| Aqueous photolysis DT50 (days) at pH 7 | Value | - | - | - |
| Note | - | |||
| Aqueous hydrolysis DT50 (days) at 20oC and pH 7 | Value | - | - | - |
| Note | - | |||
| Water-sediment DT50 (days) | - | - | - | |
| Water phase only DT50 (days) | - | - | - | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | - | - | - |
| Koc | - | |||
| Notes and range | - | |||
| Freundlich | Kf | - | - | - |
| Kfoc | - | |||
| 1/n | - | |||
| Notes and range | - | |||
| pH sensitivity | - | |||
ECOTOXICOLOGY
for diclobutrazol
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | - | - | - |
| CT50 (days) | - | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | > 4000 | L3 Rat | Low | |
| Mammals - Short term dietary NOEL | (mg kg-1) | - | - | - |
| (ppm diet) | - | - | ||
| Birds - Acute LD50 (mg kg-1) | > 9461 | L3 Anas platyrhynchos | Low | |
| Birds - Short term dietary (LC50/LD50) | - | - | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | > 23.9 | L3 Oncorhynchus mykiss | Moderate | |
| Fish - Chronic 21 day NOEC (mg l-1) | - | - | - | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | 9.3 | L3 Daphnia magna | Moderate | |
| Aquatic invertebrates - Chronic 21 day NOEC (mg l-1) | - | - | - | |
| Aquatic crustaceans - Acute 96 hour LC50 (mg l-1) | - | - | - | |
| Sediment dwelling organisms - Acute 96 hour LC50 (mg l-1) | - | - | - | |
| Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l-1) | - | - | - | |
| Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg-1) | - | - | - | |
| Aquatic plants - Acute 7 day EC50, biomass (mg l-1) | - | - | - | |
| Non-target plants | - | - | - | |
| - | - | - | ||
| Algae - Acute 72 hour EC50, growth (mg l-1) | - | - | - | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | - | - | - | |
| Honeybees | Contact acute 48 hour LD50 (μg bee-1) | 0.05 | L3 | High |
| Oral acute 48 hour LD50 (μg bee-1) | 0.05 | L3 | High | |
| Unknown mode acute 48 hour LD50 (μg bee-1) | - | - | - | |
| Earthworms - Acute 14 day LC50 (mg kg-1) | - | - | - | |
| Earthworms - Chronic 14 day NOEC, reproduction (mg kg-1) | - | - | - | |
| Other soil macro-organisms - e.g. Collembola | LR50 / EC50 / NOEC / % Effect | - | - | - |
| Other arthropod (1) | LR50 g ha-1 | - | - | - |
| % Effect | - | - | - | |
| Other arthropod (2) | LR50 g ha-1 | - | - | - |
| % Effect | - | - | - | |
| Soil micro-organisms | - | - | - | |
| Mesocosm study data | NOEAEC mg l-1 | - | - | - |
| NOEAEC mg l-1 | - | - | - | |
HUMAN HEALTH AND PROTECTION
for diclobutrazol
General:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Threshold of Toxicological Concern (Cramer Class) |
High (class III) | - | - | |
| Mammals - Acute oral LD50 (mg kg-1) | > 4000 | L3 Rat | Low | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | > 1000 | V3 Rat | - | |
| Mammals - Inhalation LC50 (mg l-1) | - | - | - | |
| Other Mammal toxicity endpoints | - | - | ||
| ADI - Acceptable Daily Intake (mg kg-1bw day-1) | - | - | - | |
| ARfD - Acute Reference Dose (mg kg-1bw day-1) | - | - | - | |
| AAOEL - Acute Acceptable Operator Exposure Level (mg kg-1 bw day-1) | - | - | - | |
| AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1) | - | - | - | |
| Dermal penetration studies (%) | - | - | - | |
| Dangerous Substances Directive 76/464 | - | - | - | |
| Exposure Limits | - | - | - | |
| Exposure Routes | Public | - | ||
| Occupational | - | |||
| European MRLs | Click here for the EU MRL pesticide database | |||
| Drinking Water Standards | - | - | - | |
| Drinking Water MAC (μg l-1) | - | - | - | |
Health issues:
| Carcinogen | Mutagen | Endocrine disrupter | Reproduction / development effects | Cholinesterase inhibitor | Neurotoxicant | |||
|
- |
- |
- |
|
|
|||
| Respiratory tract irritant | Skin irritant | Skin sensitiser | Eye irritant | Phototoxicant | ||||
- |
|
- |
|
- |
|
|||
| General human health issues | No further information available | |||||||
: Yes, known to cause a problem
: No, known not to cause a problem
: Possibly, status not identified
- : No data found
Handling issues:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| General |
No information available | |||
| CLP classification 2013 | Health: H319 Environment: H411 |
|||
| EC Risk Classification |
Xi - Irritant: R36 N - Dangerous for the environment: R51, R53 |
|||
| EC Safety Classification |
S2, S26, S61 | |||
| WHO Classification | O | - | Obsolete substance | |
| US EPA Classification (formulation) | No consensus across products or no products available | - | - | |
| UN Number | - | |||
| Waste disposal & packaging |
- | |||
TRANSLATIONS
for diclobutrazol
| Language | Name |
| English | diclobutrazol |
| French | - |
| German | - |
| Danish | - |
| Italian | - |
| Spanish | - |
| Greek | - |
| Slovenian | - |
| Polish | - |
| Swedish | - |
| Hungarian | - |
| Dutch | - |
Record last updated: Thursday 31 May 2018
Contact: aeru@herts.ac.uk