| terbacil (Ref: DPX D732) |
 |
Environmental Fate - Ecotoxicology - Human Health - A to Z Index - Home
GENERAL INFORMATION 
for terbacil
Description: A herbicide for control of annual grasses, broad-leaved weeds and some perennial weeds that is used on a range of crops including top fruit, lucerne and some herbs
Example pests controlled: Chickweed; Crabgrass; Henbit; Lambsquarter; Ruegrass; Downy brome; Yellow rocket; Speedwell; Wild mustard
Example applications: Sugarcane; Alfalfa; Fruit including peaches, blackberry, dewberry, loganberry, raspberry; Pecan nuts; Mint herbs including peppermint, spearmint; Asparagus;
Efficacy & activity: -
Availability status: Current
Introduction & key dates: 1966
EC Regulation 1107/2009 (repealing 91/414):
| Status | Not approved |
| Dossier rapporteur/co-rapporteur | Not applicable |
| Date inclusion expires | Expired |
| EU Candidate for substitution (CfS) | - |
| 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 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Also used in: Australia; USA
Chemical structure:
| Isomerism | - |
| Chemical formula | C9H13ClN2O2 |
| Canonical SMILES | CC1=C(C(=O)N(C(=O)N1)C(C)(C)C)Cl |
| Isomeric SMILES | No data |
| International Chemical Identifier key (InChIKey) | NBQCNZYJJMBDKY-UHFFFAOYSA-N |
| International Chemical Identifier (InChI) | InChI=1S/C9H13ClN2O2/c1-5-6(10)7(13)12(8(14)11-5)9(2,3)4/h1-4H3,(H,11,14) |
| 2D structure diagram/image available? | Yes |
General status:
| Pesticide type | Herbicide | |||
| Substance group | Uracil | |||
| Minimum active substance purity | - | |||
| Known relevant impurities | - | |||
| Substance origin | Synthetic | |||
| Mode of action | Selective, absorbed mainly through the roots. Inhibits photosynthesis (photosystem II). | |||
| CAS RN | 5902-51-2 | |||
| EC number | 227-595-1 | |||
| CIPAC number | 272 | |||
| US EPA chemical code | 012701 | |||
| PubChem CID | 22188 | |||
| Molecular mass (g mol-1) | 216.07 | |||
| PIN (Preferred Identification Name) | 3-tert-butyl-5-chloro-6-methylpyrimidine-2,4(1H,3H)-dione | |||
| IUPAC name | 3-tert-butyl-5-chloro-6-methyluracil | |||
| CAS name | 5-chloro-3-(1,1-dimethylethyl)-6-methyl-2,4(1H,3H)-pyrimidinedione | |||
| Other status information | - | |||
| Relevant Environmental Water Quality Standards | - | |||
| 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 |
|
|||
| 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 wettable powder. | |||
ENVIRONMENTAL FATE
for terbacil
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 710 | G4 | High | |
| Solubility - In organic solvents at 20oC (mg l-1) | 171000 | C4 - Cyclohexanone | - | |
| 53000 | C4 - Xylene | - | ||
| Melting point (oC) | 176 | L3 | - | |
| Boiling point (oC) | - | - | - | |
| Degradation point (oC) | - | - | - | |
| Flashpoint (oC) | - | - | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 7.76 X 1001 | Calculated | - |
| Log P | 1.89 | G4 | Low | |
| Bulk density (g ml-1)/Specific gravity | 1.34 | L3 | - | |
| Dissociation constant (pKa) at 25oC | 9.5 | L3 | - | |
| Note: Weak acid | ||||
| Vapour pressure at 20oC (mPa) | 0.0625 | G4 | Low volatility | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 1.30 X 10-05 | L3 | Non-volatile | |
GUS leaching potential index  |
4.70 | Calculated | High leachability | |
| SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate |
Value | 3.18 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 |
General biodegradability | - |
| Soil degradation (days) (aerobic) | DT50 (typical) | 115 | G4 | Persistent |
| DT50 (lab at 20oC) | 120 | F3 | Persistent | |
| DT50 (field) | - | - | - | |
| DT90 (lab at 20oC) | - | - | - | |
| DT90 (field) | - | - | - | |
| DT50 modelling endpoint | - | - | - | |
| Note | Best available data. Literature states DT50 50-180 days | |||
| 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 | Stable | C2 | - |
| Note | - | |||
| Water-sediment DT50 (days) | - | - | - | |
| Water phase only DT50 (days) | - | - | - | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | - | G4 | Mobile |
| Koc | 55 | |||
| Notes and range | - | |||
| Freundlich | Kf | - | - | - |
| Kfoc | - | |||
| 1/n | - | |||
| Notes and range | - | |||
| pH sensitivity | - | |||
Other known metabolites:
| Metabolite name and reference | Aliases | Formation medium / Rate | Estimated maximum occurrence fraction | Metabolising enzymes |
| 3-tert-butyl-5-acetyl-5-hydroxyhydantoin | - | Water (Photolysis) | - | - |
| 5-chloro-6-methyl-(3',5')-5'-chloro-6'-methyl-5',6'-dihydro-6',2-anhydro-3'-tert -butyluracil | - | Water (Photolysis) | - | - |
| 3-tert-butyl-6-methyluracil and 6-chloro-2,3-dihydro-3,3,7-trimethyl-5H-oxazolo (3,2a)-pyrimidine-5-one | - | Water (Photolysis) | - | - |
| 5-chloro-6-methyluracil | - | Water (Photolysis) | - | - |
| 3-tert-butyl-5-chloro-6-hydroxy-methyluracil | - | Water (Photolysis) | - | - |
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | 6 | F4 Whole fish | Low potential |
| CT50 (days) | Not available | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | > 5000 | G4 Rat | Low | |
| Mammals - Short term dietary NOEL | (mg kg-1) | - | L2 Rat, 2 year | - |
| (ppm diet) | 250 | - | ||
| Birds - Acute LD50 (mg kg-1) | > 2250 | G4 Phasianidae | Low | |
| Birds - Short term dietary (LC50/LD50) | - | - | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | > 46.2 | G4 Oncorhynchus mykiss | Moderate | |
| Fish - Chronic 21 day NOEC (mg l-1) | - | - | - | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | > 65 | 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) | 0.14 | F3 Lemna gibba | Moderate | |
| Non-target plants | - | - | - | |
| - | - | - | ||
| Algae - Acute 72 hour EC50, growth (mg l-1) | 0.042 | D4 Unknown species | Moderate | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | - | - | - | |
| Honeybees (Apis spp.) | Contact acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | > 193 | F4 Apis mellifera | Low |
| Oral acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | - | - | - | |
| Unknown mode acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | > 50 | L3 | Moderate | |
| Bumblebees (Bombus spp.) | Contact acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | - | - | - |
| - | ||||
| Oral acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | - | - | - | |
| - | ||||
| Mason bees (Osmia spp.) | Contact acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | - | - | - |
| Oral acute LD50 (worst case from 24 , 48 and 72 hour values - μg bee-1) | - | - | - | |
| Other pollinators (1) | Acute LD50 (worst case from 24 , 48 and 72 hour values - μg insect-1) | - | - | - |
| Mode of exposure | - | |||
| Other pollinators (2) | Acute LD50 (worst case from 24 , 48 and 72 hour values - μg insect-1) | - | - | - |
| Mode of exposure | - | |||
| Earthworms - Acute 14 day LC50 (mg kg-1) | > 1000 | E3 Eisenia foetida | Low | |
| 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 terbacil
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) | > 5000 | G4 Rat | Low | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | > 2000 | L3 Rabbit | - | |
| Mammals - Inhalation LC50 (mg l-1) | 4.4 | L3 Rat | - | |
| 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 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 | Genotoxic | Endocrine disrupter | Reproduction / development effects | Cholinesterase inhibitor | Neurotoxicant | |||
|
A0; B0; C0; D0; E3 | - |
|
|
- |
|||
| Respiratory tract irritant | Skin irritant | Skin sensitiser | Eye irritant | Phototoxicant | ||||
|
|
|
|
- |
|
|||
| General human health issues | Large doses may cause pallor and rapid breathing | |||||||
| Key: Genotoxicity A: Chromosome aberration (EFSA database) B: DNA damage/repair (EFSA database) C: Gene mutation (EFSA database) D: Genome mutation (EFSA database) E: Unspecified genotoxicity type (miscellaneous data source) 0: No data 1: Positive 2: Mixed/ambiguous results 3: Negative |
Key: Other : 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 |
IMDG Transport class 9 | |||
| CLP classification 2013 | Health: H302 Environment: H400, H410 |
|||
| EC Risk Classification |
Xn - Harmful: R22 N - Dangerous for the environment: R50/53 |
|||
| EC Safety Classification |
- | |||
| WHO Classification | U | - | Unlikely to present an acute hazard | |
| UN Number | 3077 | |||
| Waste disposal & packaging |
Packaging Group III (minor danger) | |||
| Language | Name |
| English | terbacil |
| French | terbacile |
| German | Terbacil |
| Danish | terbacil |
| Italian | terbacil |
| Spanish | terbacilo |
| Greek | - |
| Slovenian | terbacil |
| Polish | terbacil |
| Swedish | - |
| Hungarian | - |
| Dutch | - |
Record last updated: Saturday 29 June 2019
Contact: aeru@herts.ac.uk