| hexazinone (Ref: DPX A3674) |
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Environmental Fate - Ecotoxicology - Human Health - A to Z Index - Home
GENERAL INFORMATION 
for hexazinone
Description: A broad-spectrum herbicide used to control many annual, biennial and perennial weeds.
Example pests controlled: Grasses; Broad-leaved weeds; Woody plants
Example applications: Fruit; Sugarcane; Alfalfa; Forestry; Pastures; Rangeland; Fallow land
Availability status: Current
Introduction & key dates: 1975, USA
EC Regulation 1107/2009 (repealing 91/414):
| Status | Not approved |
| Dossier rapporteur/co-rapporteur | - |
| Date inclusion expires | Expired |
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 |
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General status:
| Pesticide type | Herbicide | |
| Substance group | Triazinone | |
| Minimum active substance purity | - | |
| Known relevant impurities | - | |
| Substance origin | Synthetic | |
| Mode of action | Non-selective with contact action, absorbed through the roots and foliage of plants. Inhibits photosynthesis (photosystem II). | |
| CAS RN | 51235-04-2 | |
| EC number | 257-074-4 | |
| CIPAC number | 374 | |
| US EPA chemical code | 107201 | |
| Chiral molecule | No | |
| Chemical formula | C12H20N4O2 | |
| SMILES | O=C1/N=C(\N(C(=O)N1C2CCCCC2)C)N(C)C | |
| International Chemical Identifier key (InChIKey) | CAWXEEYDBZRFPE-UHFFFAOYSA-N | |
| International Chemical Identifier (InChI) | InChI=1S/C12H20N4O2/c1-14(2)10-13-11(17)16(12(18)15(10)3)9-7-5-4-6-8-9/h9H,4-8H2,1-3H3 | |
| Structure diagram/image available? | Yes | |
| Molecular mass (g mol-1) | 252.31 | |
| PIN (Preferred Identification Name) | - | |
| IUPAC name | 3-cyclohexyl-6-dimethylamino-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione | |
| CAS name | 3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione | |
| Other status information | Potential groundwater contaminant; Chemical subject to PIC regulations | |
| Herbicide Resistance Classification (HRAC) | C1 | |
| Herbicide Resistance Classification (WSSA) | 5 | |
| Insecticide Resistance Classification (IRAC) | Not applicable | |
| Fungicide Resistance Classification (FRAC) | Not applicable | |
| Examples of recorded resistance | - | |
| Physical state | Colourless crystals | |
| Related substances & organisms | ||
Formulations:
| Property |
Value | |||
| Example manufacturers & suppliers of products using this active now or historically |
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| Example products using this active |
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| UK LERAP status | No UK approval for use or outside scope | |||
| Formulation and application details | Available in a variety of formulations including wettable granules, suspension concentrates and tablets. | |||
ENVIRONMENTAL FATE
for hexazinone
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 33000 | K4 | High | |
| Solubility - In organic solvents at 20oC (mg l-1) | 626000 | C4 - Acetone | - | |
| 334000 | C4 - Toluene | - | ||
| 2146500 | C4 - Methanol | - | ||
| 837000 | C4 - Benzene | - | ||
| Melting point (oC) | 113.5 | L3 | - | |
| Boiling point (oC) | Decomposes on distillation | L2 | - | |
| Degradation point (oC) | - | - | - | |
| Flashpoint (oC) | - | - | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 1.48 X 1001 | Calculated | - |
| Log P | 1.17 | P4 | Low | |
| Bulk density (g ml-1)/Specific gravity | 1.25 | L3 | - | |
| Dissociation constant (pKa) at 25oC | 2.2 | L3 | - | |
| Note: Weak base | ||||
| Vapour pressure at 25oC (mPa) | 0.03 | G4 | Volatile | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 1.10 X 10-07 | H4 | Non-volatile | |
| Henry's law constant at 20oC (dimensionless) | 8.30 X 10-11 | K3 | Non-volatile | |
GUS leaching potential index  |
4.43 | Calculated | High leachability | |
| SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate |
Value | 2.15 X 10+00 | Calculated | - |
| Note | - | |||
| Potential for particle bound transport index |
- | Calculated | Medium | |
| Maximum UV-vis absorption L mol-1 cm-1 | - | - | - | |
| Surface tension (mN m-1) | - | - | - | |
Degradation:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Soil degradation (days) (aerobic) | DT50 (typical) | 105 | L3 | Persistent |
| DT50 (lab at 20oC) | 90 | F3 | Moderately persistent | |
| DT50 (field) | - | - | - | |
| DT90 (lab at 20oC) | - | - | - | |
| DT90 (field) | - | - | - | |
| Note | Other sources: DT50 30 (sand) - 180 (clay) days (R3); General literature DT50 range 59-64 days (R3) | |||
| Plant matrix DT50 (days) | Value | 10.7 | R4 | - |
| Note | DT50 range 4.0 - 15.8 days, forest trees, leaf matrix | |||
| Aqueous photolysis DT50 (days) at pH 7 | Value | 56 | K4 | Stable |
| Note | - | |||
| Aqueous hydrolysis DT50 (days) at 20oC and pH 7 | Value | 56 | K4 | Moderately persistent |
| Note | - | |||
| Water-sediment DT50 (days) | - | - | - | |
| Water phase only DT50 (days) | - | - | - | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | - | G3 | Mobile |
| Koc | 54 | |||
| Notes and range | Other sources: Koc 610 (P3) | |||
| Freundlich | Kf | - | - | - |
| Kfoc | - | |||
| 1/n | - | |||
| Notes and range | - | |||
| pH sensitivity | - | |||
Key metabolites:
| Metabolite | Formation medium | Estimated maximum occurrence fraction | 91/414 relevancy |
|
| 3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)dione | Soil | - | ||
| 3-cyclohexyl-6-(methylamino)-1-methyl-1,3,5-triazine-2,4-(1H,3H)-dione | Soil | Major | ||
| 3-(4-hydroxycyclohexyl)-6-(methylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione | Soil | Major | ||
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | 7 | P4 | Low potential |
| CT50 (days) | Not available | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | 1690 | G4 Rat | Moderate | |
| Mammals - Short term dietary NOEL | (mg kg-1) | - | L2 Rat, 2 year | - |
| (ppm diet) | > 200 | - | ||
| Birds - Acute LD50 (mg kg-1) | > 2258 | G4 Colinus virginianus | Low | |
| Birds - Short term dietary (LC50/LD50) | - | - | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | > 320 | G4 Oncorhynchus mykiss | Low | |
| Fish - Chronic 21 day NOEC (mg l-1) | - | - | - | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | > 85 | J4 Daphnia magna | Moderate | |
| Aquatic invertebrates - Chronic 21 day NOEC (mg l-1) | > 50 | F3 Daphnia magna, LOEC | Low | |
| 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) | > 0.072 | F2 Lemna minor, 7 day | Moderate | |
| Non-target plants | - | - | - | |
| - | - | - | ||
| Algae - Acute 72 hour EC50, growth (mg l-1) | 0.0145 | F4 Pseudokirchneriella subcapitata | Moderate | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | - | - | - | |
| Honeybees | Contact acute 48 hour LD50 (μg bee-1) | - | - | - |
| Oral acute 48 hour LD50 (μg bee-1) | - | - | - | |
| Unknown mode acute 48 hour LD50 (μg bee-1) | 60 | L2 | Moderate | |
| 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 hexazinone
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) | 1690 | G4 Rat | Moderate | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | > 5000 | L3 Rabbit | - | |
| Mammals - Inhalation LC50 (mg l-1) | 7.48 | L3 Rat | - | |
| Other Mammal toxicity endpoints | - | - | ||
| ADI - Acceptable Daily Intake (mg kg-1bw day-1) | 0.05 | L3 | - | |
| ARfD - Acute Reference Dose (mg kg-1bw 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 MAC (μg l-1) | - | - | - | |
Health issues:
| Carcinogen | Mutagen | Endocrine disrupter | Reproduction / development effects | Cholinesterase inhibitor | Neurotoxicant | |||
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| Respiratory tract irritant | Skin irritant | Skin sensitiser | Eye irritant | Phototoxicant | ||||
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| General human health issues | Highly toxic | |||||||
: 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: H302, H319 Environment: H400, H410 |
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| EC Risk Classification |
Xn - Harmful: R22 Xi - Irritant: R36 N - Dangerous for the environment: R50, R53 |
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| EC Safety Classification |
S2, S60, S61 | |||
| WHO Classification | II | - | Moderately hazardous | |
| US EPA Classification (formulation) | II | - | Warning - Moderately toxic | |
| UN Number | - | |||
| Waste disposal & packaging |
- | |||
| Language | Name |
| English | hexazinone |
| French | hexazinone |
| German | Hexazinon |
| Danish | hexazinon |
| Italian | esazinone |
| Spanish | hexazinona |
| Greek | - |
| Slovenian | heksazinon |
| Polish | heksazynon |
| Swedish | - |
| Hungarian | hexazinone |
| Dutch | - |
Record last updated: Sunday 14 August 2016
Contact: aeru@herts.ac.uk