| oryzalin (Ref: EL 119) |
 |
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SUMMARY
Oryzalin is a pre-emergence surface-applied herbicide that is not approved for use in the EU. It has a low aqueous solubility, is not volatile and, based on its chemical properties, is not expected to leach to groundwater. However, groundwater monitoring programmes have ientified it as a pollutant. It generally tends not to be persistent in soil or water systems. It has a low mammalian toxicity and is a potential carcinogen. It is moderately toxic to birds, most aquatic organisms, honeybees and earthworms. GENERAL INFORMATION 
for oryzalin
Description: A pre-emergence surface-applied herbicide used for control of annual grasses and broad-leaved weeds in fruit trees and around ornamentals
Example pests controlled: Annual grass weeds including Barnyardgrass; Pigeon grass; Crabgrass; Guinea grass; Broad-leaved weeds including Deadnettle, Fathen; Pigweeds; Nightshade
Example applications: Fruit including citrus, stone fruit, apples, pears and berries; Nuts; Vines; Christmas trees; Ornamental trees; Nursery stock
Efficacy & activity: -
Availability status: Current
Introduction & key dates: 1973
EC Regulation 1107/2009 (repealing 91/414):
| Status | Approved |
| Dossier rapporteur/co-rapporteur | Netherlands/France |
| Date inclusion expires | 31/05/2021 |
| 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
Chemical structure:
| Isomerism | - |
| Chemical formula | C12H18N4O6S |
| Canonical SMILES | CCCN(CCC)C1=C(C=C(C=C1[N+](=O)[O-])S(=O)(=O)N)[N+](=O)[O-] |
| Isomeric SMILES | No data |
| International Chemical Identifier key (InChIKey) | UNAHYJYOSSSJHH-UHFFFAOYSA-N |
| International Chemical Identifier (InChI) | InChI=1S/C12H18N4O6S/c1-3-5-14(6-4-2)12-10(15(17)18)7-9(23(13,21)22)8-11(12)16(19)20/h7-8H,3-6H2,1-2H3,(H2,13,21,22) |
| 2D structure diagram/image available? | Yes |
General status:
| Pesticide type | Herbicide | |||
| Substance group | Dinitroaniline | |||
| Minimum active substance purity | 960 g/kg | |||
| Known relevant impurities | EU dossier - N-nitrosodipropylamine 0.1 mg/kg; toluene 4g/kg | |||
| Substance origin | Synthetic | |||
| Mode of action | Selective affecting physiological growth process. Microtubule assembly inhibition. | |||
| CAS RN | 19044-88-3 | |||
| EC number | 242-777-0 | |||
| CIPAC number | 537 | |||
| US EPA chemical code | 104201 | |||
| PubChem CID | 29393 | |||
| Molecular mass (g mol-1) | 346.4 | |||
| PIN (Preferred Identification Name) | - | |||
| IUPAC name | 3,5-dinitro-N4,N4-dipropylsulfanilamide | |||
| CAS name | 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide | |||
| Other status information | Potential groundwater contaminant | |||
| Relevant Environmental Water Quality Standards | - | |||
| Herbicide Resistance Classification (HRAC) | K1 | |||
| Herbicide Resistance Classification (WSSA) | 3 | |||
| Insecticide Resistance Classification (IRAC) | Not applicable | |||
| Fungicide Resistance Classification (FRAC) | Not applicable | |||
| Examples of recorded resistance | - | |||
| Physical state | Orange crystalline 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 | No UK approval for use as a pesticide under EC Regulation 1107/2009 | |||
| Formulation and application details | Usually supplied as an aqueous suspension or wettable powder. | |||
ENVIRONMENTAL FATE
for oryzalin
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Solubility - In water at 20oC (mg l-1) | 1.13 | A5 | Low | |
| Solubility - In organic solvents at 20oC (mg l-1) | 250000 | A5 - Acetone | - | |
| 91900 | A5 - Methanol | - | ||
| 0.709 | A5 - n-Heptane | - | ||
| 1570 | A5 - Xylene | - | ||
| Melting point (oC) | 139.7 | A5 | - | |
| Boiling point (oC) | Decomposes before boiling | A5 | - | |
| Degradation point (oC) | 213 | A5 | - | |
| Flashpoint (oC) | Not expected to self ignite; Not highly flammable | A5 | - | |
| Octanol-water partition coefficient at pH 7, 20oC | P | 5.37 X 1003 | Calculated | - |
| Log P | 3.73 | G4 | High | |
| Bulk density (g ml-1)/Specific gravity | 1.2 | L3 | - | |
| Dissociation constant (pKa) at 25oC | 9.4 | A5 | - | |
| Note: Very weak acid | ||||
| Vapour pressure at 20oC (mPa) | 1.1 X 10-07 | A5 | Low volatility | |
| Henry's law constant at 25oC (Pa m3 mol-1) | 3.37 X 10-08 | A5 | Non-volatile | |
GUS leaching potential index  |
2.22 | Calculated | Transition state | |
| SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate |
Value | 1.10 X 10-01 | Calculated | - |
| Note | - | |||
| Potential for particle bound transport index |
- | Calculated | Medium | |
| Maximum UV-vis absorption L mol-1 cm-1 | Neutral solution: 208nm = 17200, 282nm = 97600, 380nm = 2690; [Acidic solution: 206nm = 17500, 282nm = 380nm = 2740; [Basic solution: 218nm = 14600, 273nm = 10100, 393nm = 2020 | A5 | - | |
| Surface tension (mN m-1) | 63.5 | A5 | - | |
Degradation:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
General biodegradability | - |
| Soil degradation (days) (aerobic) | DT50 (typical) | 44.8 | A5 | Moderately persistent |
| DT50 (lab at 20oC) | 88 | A5 | Moderately persistent | |
| DT50 (field) | 98.2 | A5 | Moderately persistent | |
| DT90 (lab at 20oC) | 559 | A5 | - | |
| DT90 (field) | 184.9 | A5 | - | |
| DT50 modelling endpoint | - | - | - | |
| Note | EU dossier lab studies DT50 range 32-456 days, DT90 range 100-1553 days, field studies DT50 range 10.9-113.2 days, DT90 range 66-376 days ; Other sources: DT50 20 days (DW4) | |||
| 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 | 0.08 | A5 | Fast |
| Note | DT50 1.4 hours sterile water, 1.6 hours river water | |||
| Aqueous hydrolysis DT50 (days) at 20oC and pH 7 | Value | Stable | A5 | - |
| Note | Stable pH 3 to pH 9 at 25 degC | |||
| Water-sediment DT50 (days) | 32.7 | A5 | Moderately fast | |
| Water phase only DT50 (days) | 5.9 | A5 | Moderately fast | |
Soil adsorption and mobility:
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Linear | Kd | 13.0 | A5 | Slightly mobile |
| Koc | 949 | |||
| Notes and range | EU dossier Kd range 5.23-25.21 mL/g, Koc range 441-1596 mL/g, Soils=12 | |||
| Freundlich | Kf | 4.93 | A5 | Slightly mobile |
| Kfoc | 724 | |||
| 1/n | 0.943 | |||
| Notes and range | EU dossier Kf range 4.83-5.04, Kfoc range 439-1008, 1/n = 0.926-0.943 | |||
| pH sensitivity | No | |||
Key metabolites:
| Metabolite | Formation medium | Estimated maximum occurrence fraction | 1107/2009 relevancy |
|
| 4-hydroxy-3,5-dinitro-benzenesulfonamide | Soil | 0.047 | Minor fraction, Relevant | |
Other known metabolites:
| Metabolite name and reference | Aliases | Formation medium / Rate | Estimated maximum occurrence fraction | Metabolising enzymes |
| 7-amino-2-ethyl-1-propyl-1H-benzimidazole-5-sulfonamide | OR-14 | Soil (Anaerobic) | Soil=0.13 | - |
| 2-ethyl-7-nitro-1-propyl-5-sulfonylamino-benzimidazole-3-oxide | OR-13 | Water (Photolysis); Groundwater | - | - |
| 3,4-diamino-5-nitrobenzensulfonamide | OR-6 | Water (Photolysis) | - | - |
| 2-ethyl-7-nitro-1hydroxy-benzimidazole-5-sulfonamide | OR-15-OH | Water (Photolysis); Groundwater | - | - |
| 2-ethyl-7-nitro-1H-benzimidazole-5-sulfonamide | OR-15 | Water (Photolysis) | - | - |
| 7-amino-2-ethyl-1H-benzimidazole-5-sulfonamide | OR-16 | Soil | Soil=0.053 | - |
| N-nitroso-N-propylpropan-1-amine | - | - | - | - |
| Property |
Value | Source/Quality Score/Other Information |
Interpretation |
|
| Bio-concentration factor | BCF (l kg-1) | 66.1 | A5 Whole fish | Low potential |
| CT50 (days) | 0.6 | - | ||
| Mammals - Acute oral LD50 (mg kg-1) | > 5000 | A5 Rat | Low | |
| Mammals - Short term dietary NOEL | (mg kg-1) | - | L2 Rat, 2 year | - |
| (ppm diet) | > 300 | - | ||
| Birds - Acute LD50 (mg kg-1) | 427 | A3 Anas platyrhynchos | Moderate | |
| Birds - Short term dietary (LC50/LD50) | > 1351 mg kg bw-1 day-1 | A5 Anas platyrhynchos | - | |
| Fish - Acute 96 hour LC50 (mg l-1) | 2.86 | A5 Oncorhynchus mykiss | Moderate | |
| Fish - Chronic 21 day NOEC (mg l-1) | 0.46 | A5 Oncorhynchus mykiss | Moderate | |
| Aquatic invertebrates - Acute 48 hour EC50 (mg l-1) | 1.02 | A5 Daphnia magna | Moderate | |
| Aquatic invertebrates - Chronic 21 day NOEC (mg l-1) | 0.36 | A5 Daphnia magna | Moderate | |
| 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) | 1.0 | A5 Chironomus riparius | Moderate | |
| Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg-1) | - | - | - | |
| Aquatic plants - Acute 7 day EC50, biomass (mg l-1) | 0.0154 | A5 Lemna gibba | Moderate | |
| Non-target plants | 26.0 | A5 Ryegrass Seedling emergence, ER50 as g/ha |
- | |
| 53.9 | A5 Lettuce Seedling emergence, ER50 as g/ha |
- | ||
| Algae - Acute 72 hour EC50, growth (mg l-1) | 18.1 | A5 Anabaena flos-aquae | Low | |
| Algae - Chronic 96 hour NOEC, growth (mg l-1) | - | - | - | |
| Honeybees | Contact acute 48 hour LD50 (μg bee-1) | 40.8 | A5 | Moderate |
| Oral acute 48 hour LD50 (μg bee-1) | 32 | A5 | Moderate | |
| Unknown mode acute 48 hour LD50 (μg bee-1) | - | - | - | |
| Earthworms - Acute 14 day LC50 (mg kg-1) | > 500 | A5 Eisenia foetida, corr | Moderate | |
| Earthworms - Chronic 14 day NOEC, reproduction (mg kg-1) | 34.3 | A5 Eisenia foetida | Moderate | |
| Other soil macro-organisms - e.g. Collembola | LR50 / EC50 / NOEC / % Effect | 2.66 | A5 Folsomia candida, 4 Week NOEC mg kg-1 | - |
| Other arthropod (1) | LR50 g ha-1 | 3852 | > A4 Aphidius rhopalosiphi |
- |
| % Effect | - | - | - | |
| Other arthropod (2) | LR50 g ha-1 | 3852 | > A4 Typhlodromus pyri |
- |
| % Effect | - | - | - | |
| Soil micro-organisms | Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect |
A5 Dose: 25.6 mg kg-1 soil, 28 days |
- | |
| Mesocosm study data | NOEAEC mg l-1 | - | - | - |
| NOEAEC mg l-1 | - | - | - | |
HUMAN HEALTH AND PROTECTION
for oryzalin
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 | A5 Rat | Low | |
| Mammals - Dermal LD50 (mg kg-1 body weight) | > 2000 | A5 Rabbit | - | |
| Mammals - Inhalation LC50 (mg l-1) | > 4.79 | A5 Rat, 4 hr (nose only) | - | |
| Other Mammal toxicity endpoints | - | - | ||
| ADI - Acceptable Daily Intake (mg kg-1bw day-1) | 0.005 | A5 | - | |
| ARfD - Acute Reference Dose (mg kg-1bw day-1) | None allocated | A5 | - | |
| AAOEL - Acute Acceptable Operator Exposure Level (mg kg-1 bw day-1) | - | - | - | |
| AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1) | 0.05 | A5 | - | |
| Dermal penetration studies (%) | 2.5-2.8 | A5 concentration dependent | - | |
| Dangerous Substances Directive 76/464 | - | - | - | |
| Exposure Limits | - | - | - | |
| Exposure Routes | Public | Very small risk of exposure of bystanders via drift | ||
| Occupational | No unacceptable risks to operators or other workers identified | |||
| 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=50 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 | Bioaccumulates Potential liver, kidney & spleen toxicant USEPA - probable human carcinogen |
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: 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 |
Not oxidising Classified as explosive category E |
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| CLP classification 2013 | - | |||
| EC Risk Classification |
Carcinogen category 3: R40 Xn - Harmful: R43 N - Dangerous for the environment: R50, R53 |
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| EC Safety Classification |
- | |||
| WHO Classification | U | - | Unlikely to present an acute hazard | |
| US EPA Classification (formulation) | III | - | Caution - Slightly toxic | |
| UN Number | Usually 3077 | |||
| Waste disposal & packaging |
- | |||
| Language | Name |
| English | oryzalin |
| French | oryzalin |
| German | Oryzalin |
| Danish | oryzalin |
| Italian | oryzalin |
| Spanish | orizalina |
| Greek | - |
| Slovenian | orizalin |
| Polish | oryzalina |
| Swedish | - |
| Hungarian | - |
| Dutch | - |
Record last updated: Thursday 23 August 2018
Contact: aeru@herts.ac.uk