| aminopyralid (Ref: XDE 750) |
 |
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SUMMARY
Aminopyralid is a pyridine carboxylic acid herbicide that is currently under approval consideration for use in the EU. It is non-volatile, highly soluble in water and, based on its chemical properties, is mobile and has a high potential for leaching to groundwater. It may be moderately persistent in soil systems but would not be expected to persistent in surface water under normal conditions. It has a low mammalian toxicity and there is some concern regarding its potential for bioaccumulation. Aminopyralid has a low to moderate toxicity to most terrestrial and aquatic species. GENERAL INFORMATION 
for aminopyralid
Description: A pyridine carboxylic acid herbicide for the long-term control of noxious and invasive broad-leaved weeds in grassland
Example pests controlled: Broomweed; Buttercups; Cocklebur; Daisy; Fleabane; Knapweed; Ragweed; Ragwort; Lambsquarter
Example applications: Rangeland; Permanent grass; Non-cropped areas including paths; roadways
Efficacy & activity: -
Availability status: Current
Introduction & key dates: 2005
EC Regulation 1107/2009 (repealing 91/414):
| Status | Approved |
| Dossier rapporteur/co-rapporteur | UK |
| Date inclusion expires | 31/12/2024 |
| EU Candidate for substitution (CfS) | No |
| 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 |
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Also used in: Australia, USA (pending)
Chemical structure:
| Isomerism | - |
| Chemical formula | C6H4Cl2N2O2 |
| Canonical SMILES | C1=C(C(=C(N=C1Cl)C(=O)O)Cl)N |
| Isomeric SMILES | No data |
| International Chemical Identifier key (InChIKey) | NIXXQNOQHKNPEJ-UHFFFAOYSA-N |
| International Chemical Identifier (InChI) | InChI=1S/C6H4Cl2N2O2/c7-3-1-2(9)4(8)5(10-3)6(11)12/h1H,(H2,9,10)(H,11,12)/f/h11H,9H2 |
| 2D structure diagram/image available? | Yes |
General status:
| Pesticide type | Herbicide | |
| Substance group | Pyridine compound | |
| Minimum active substance purity | 920 g/kg | |
| Known relevant impurities | EU dossier - None declared | |
| Substance origin | Synthetic | |
| Mode of action | Systemic, post-emergence action, absorbed by leaves and roots, some residual action | |
| CAS RN | 150114-71-9 | |
| EC number | - | |
| CIPAC number | 771 | |
| US EPA chemical code | 005100 | |
| PubChem CID | 213012 | |
| Molecular mass (g mol-1) | 207.03 | |
| PIN (Preferred Identification Name) | 4-amino-3,6-dichloropyridine-2-carboxylic acid | |
| IUPAC name | 4-amino-3,6-dichloropyridine-2-carboxylic acid | |
| CAS name | 4-amino-3,6-dichloro-2-pyridinecarboxylic acid | |
| Other status information | - | |
| Relevant Environmental Water Quality Standards | - | |
| Herbicide Resistance Classification (HRAC) | Not known | |
| Herbicide Resistance Classification (WSSA) | - | |
| Insecticide Resistance Classification (IRAC) | Not applicable | |
| Fungicide Resistance Classification (FRAC) | Not applicable | |
| Examples of recorded resistance | - | |
| Physical state | Off-white powder | |
| 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 | None | |||
| Formulation and application details | Often available as an oil in water concentrate that is mixed with water and used as a spray. | |||
ENVIRONMENTAL FATE
for aminopyralid
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 2480 | A5 | High | |
| Solubility - In organic solvents at 20oC (mg l-1) | 29200 | A5 - Acetone | - | |
| 3940 | A5 - Ethyl acetate | - | ||
| 52200 | A5 - Methanol | - | ||
| 40 | A5 - Xylene | - | ||
| Melting point (oC) | 163.5 | A5 | - | |
| Boiling point (oC) | Decomposes before boiling | A5 | - | |
| Degradation point (oC) | 334 | A3 | - | |
| Flashpoint (oC) | Not expected to self ignite; Not highly flammable | A5 | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 1.35 X 10-03 | Calculated | - |
| Log P | -2.87 | A5 | Low | |
| Bulk density (g ml-1)/Specific gravity | 1.76 | A5 | - | |
| Dissociation constant (pKa) at 25oC | 2.56 | A5 | - | |
| Note: Strong acid | ||||
| Vapour pressure at 20oC (mPa) | 2.59 X 10-09 | A5 | Low volatility | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 9.61 X 10-12 | A5 | Non-volatile | |
GUS leaching potential index  |
5.37 | Calculated | High leachability | |
| SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate |
Value | 4.99 X 10+00 | Calculated | - |
| Note | - | |||
| Potential for particle bound transport index |
- | Calculated | Low | |
| Maximum UV-vis absorption L mol-1 cm-1 | At pH 1.4 maxima = 217nm; [At pH 5 maxima = 217nm; [At pH 12.6 maxima = 220nm | A5 | - | |
| Surface tension (mN m-1) | 71.0 | A5 | - | |
Degradation:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
General biodegradability | - |
| Soil degradation (days) (aerobic) | DT50 (typical) | 35 | E4 | Moderately persistent |
| DT50 (lab at 20oC) | 55.5 | A5 | Moderately persistent | |
| DT50 (field) | 21.1 | A5 | Non-persistent | |
| DT90 (lab at 20oC) | 287.8 | A5 | - | |
| DT90 (field) | - | - | - | |
| DT50 modelling endpoint | - | - | - | |
| Note | EU dossier lab studies DT50 range 26.4-146.9 days, DT90 range 87.6-488 days, field studies DT50 range 8-35 days; Manufacturer lab data DT50 9-54 days; Other literature Lab studies range 31.5-533.2 days, 5 soils | |||
| 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 | 0.6 | E4 | Fast |
| Note | DT50: 0.6 days at pH 5. Main route of degradation on aquatic environments | |||
| Aqueous hydrolysis DT50 (days) at 20oC and pH 7 | Value | Stable | A5 | - |
| Note | Stable pH 5 to pH 9 at temps 20 and 50 DegC | |||
| Water-sediment DT50 (days) | 712 | A5 | Stable | |
| Water phase only DT50 (days) | 250 | A5 | Stable | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | - | - | - |
| Koc | - | |||
| Notes and range | - | |||
| Freundlich | Kf | 0.17 | A5 | Very mobile |
| Kfoc | 8.3 | |||
| 1/n | 0.852 | |||
| Notes and range | EU dossier Kf range 0.01-0.73 mL/g, Kfoc range 0.31-21.7 mL/g, 1/n range 0.32-1.52, Soils=8 | |||
| pH sensitivity | Adsorption higher at low pH | |||
ECOTOXICOLOGY
for aminopyralid
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | 100 | F4 | Threshold for concern |
| CT50 (days) | Not available | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | > 5000 | F4 Rat | Low | |
| Mammals - Short term dietary NOEL | (mg kg-1) | > 465 | F4 Rat | Moderate |
| (ppm diet) | > 1000 | - | ||
| Birds - Acute LD50 (mg kg-1) | > 2250 | A5 Colinus virginianus | Low | |
| Birds - Short term dietary (LC50/LD50) | - | - | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | > 100 | A5 Oncorhynchus mykiss | Low | |
| Fish - Chronic 21 day NOEC (mg l-1) | - | - | - | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | > 100 | A5 Daphnia magna | Low | |
| Aquatic invertebrates - Chronic 21 day NOEC (mg l-1) | 100 | E4 Daphnia magna | Low | |
| Aquatic crustaceans - Acute 96 hour LC50 (mg l-1) | 100 | E4 Americamysis bahia | Moderate | |
| Sediment dwelling organisms - Acute 96 hour LC50 (mg l-1) | - | - | - | |
| Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l-1) | 130 | A5 Chironomus riparius | Low | |
| Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg-1) | 46.7 | A5 Chironomus riparius | Moderate | |
| Aquatic plants - Acute 7 day EC50, biomass (mg l-1) | 88 | A5 Lemna gibba | Low | |
| Non-target plants | - | - | - | |
| - | - | - | ||
| Algae - Acute 72 hour EC50, growth (mg l-1) | 30 | F4 Pseudokirchneriella subcapitata | Low | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | - | - | - | |
| Honeybees | Contact acute 48 hour LD50 (μg bee-1) | > 6.26 | A5 | Moderate |
| Oral acute 48 hour LD50 (μg bee-1) | > 3.13 | A5 | Moderate | |
| Unknown mode acute 48 hour LD50 (μg bee-1) | - | - | - | |
| Earthworms - Acute 14 day LC50 (mg kg-1) | > 1000 | A5 | 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 | 21.5 | Mortality Dose: 0.03 kg ha-1 A5 Aphidius rhopalosiphi |
- | |
| Other arthropod (2) | LR50 g ha-1 | - | - | - |
| % Effect | 12.6 | Mortality Dose: 0.08 kg ha-1 A5 Typhlodromus pyri |
- | |
| Soil micro-organisms | Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect |
A5 Dose: 100x field rate for grassland |
- | |
| Mesocosm study data | NOEAEC mg l-1 | - | - | - |
| NOEAEC mg l-1 | - | - | - | |
HUMAN HEALTH AND PROTECTION
for aminopyralid
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 | F4 Rat | Low | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | > 5000 | A5 Rat | - | |
| Mammals - Inhalation LC50 (mg l-1) | 5.5 | A5 Rat, 4 hr | - | |
| Other Mammal toxicity endpoints | - | - | ||
| ADI - Acceptable Daily Intake (mg kg-1bw day-1) | 0.26 | A3 proposed Rabbit, SF=100 | - | |
| ARfD - Acute Reference Dose (mg kg-1bw day-1) | 0.26 | A3 proposed Rabbit, SF=100 | - | |
| AAOEL - Acute Acceptable Operator Exposure Level (mg kg-1 bw day-1) | - | - | - | |
| AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1) | 0.26 | A3 proposed Rabbit, SF=100 | - | |
| Dermal penetration studies (%) | 50 | UK ACP | - | |
| Dangerous Substances Directive 76/464 | - | - | - | |
| Exposure Limits | - | - | - | |
| Exposure Routes | Public | Low risk to bystanders | ||
| Occupational | Acceptable risk to operators with PPE/PPC Low risk to other farm workers |
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| European MRLs | Click here for the EU MRL pesticide database | |||
| Drinking Water Standards | - | - | - | |
| Drinking Water MAC (μg l-1) | 0.1 | EU Dir 89/778/EC limit; A5 Calc MAC=4260 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 | May damage the corneal resulting in permanent impairment of vision and blindness | |||||||
: 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 |
Flammable Corrosive |
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| CLP classification 2013 | Health: H302 | |||
| EC Risk Classification |
Xn - Harmful: R41 | |||
| EC Safety Classification |
- | |||
| WHO Classification | U | - | Unlikely to present an acute hazard | |
| US EPA Classification (formulation) | IV | - | Caution - Not acutely toxic | |
| UN Number | - | |||
| Waste disposal & packaging |
- | |||
| Language | Name |
| English | aminopyralid |
| French | aminopyralid |
| German | Aminopyralid |
| Danish | aminopyralid |
| Italian | aminopyralid |
| Spanish | aminopiralida |
| Greek | - |
| Slovenian | aminopiralid |
| Polish | aminopiralid |
| Swedish | aminopyralid |
| Hungarian | - |
| Dutch | - |
Record last updated: Thursday 13 September 2018
Contact: aeru@herts.ac.uk