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Oxadiazon

PubChem CID
29732
Structure
Oxadiazon_small.png
Oxadiazon_3D_Structure.png
Oxadiazon__Crystal_Structure.png
Molecular Formula
Synonyms
  • OXADIAZON
  • 19666-30-9
  • Ronstar
  • Oxadiazone
  • Oxydiazon
Molecular Weight
345.2 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2005-03-27
  • Modify:
    2025-01-18
Description
Oxadiazon can cause cancer according to an independent committee of scientific and health experts. It can cause developmental toxicity according to The Environmental Protection Agency (EPA).
Oxydiazon is a crystalline solid. Used as an herbicide.
Oxadiazon is an aromatic ether.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Oxadiazon.png

1.2 3D Conformer

1.3 Crystal Structures

1 of 2
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CCDC Number
Crystal Structure Data
Crystal Structure Depiction
Crystal Structure Depiction

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

5-tert-butyl-3-(2,4-dichloro-5-propan-2-yloxyphenyl)-1,3,4-oxadiazol-2-one
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

2.1.2 InChI

InChI=1S/C15H18Cl2N2O3/c1-8(2)21-12-7-11(9(16)6-10(12)17)19-14(20)22-13(18-19)15(3,4)5/h6-8H,1-5H3
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 InChIKey

CHNUNORXWHYHNE-UHFFFAOYSA-N
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.4 SMILES

CC(C)OC1=C(C=C(C(=C1)N2C(=O)OC(=N2)C(C)(C)C)Cl)Cl
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

C15H18Cl2N2O3
Computed by PubChem 2.2 (PubChem release 2021.10.14)

2.3 Other Identifiers

2.3.1 CAS

19666-30-9

2.3.2 European Community (EC) Number

2.3.3 UNII

2.3.4 UN Number

2.3.5 ChEBI ID

2.3.6 ChEMBL ID

2.3.7 DSSTox Substance ID

2.3.8 KEGG ID

2.3.9 Nikkaji Number

2.3.10 Wikidata

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • 2-(tert-butyl)-4-(2,4-dichloro-5-isopropyloxy-phenyl) delta(2)-1,3,4-oxadiazoline-5-one
  • oxadiazon
  • Ronstar

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
345.2 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
XLogP3
Property Value
4.8
Reference
Computed by XLogP3 3.0 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Donor Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Acceptor Count
Property Value
4
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
4
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
344.0694478 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
344.0694478 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
51.1 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
22
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
462
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Isotope Atom Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Covalently-Bonded Unit Count
Property Value
1
Reference
Computed by PubChem
Property Name
Compound Is Canonicalized
Property Value
Yes
Reference
Computed by PubChem (release 2021.10.14)

3.2 Experimental Properties

3.2.1 Physical Description

Oxydiazon is a crystalline solid. Used as an herbicide.
White odorless solid; [Merck Index]

3.2.2 Color / Form

White crystals
Farm Chemicals Handbook 2000. Willoughby, Ohio: Meister 2000., p. C 289
Colorless crystals
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 906

3.2.3 Odor

Odorless
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 906

3.2.4 Melting Point

90 °C
Lide, DR (ed.). CRC Handbook of Chemistry and Physics. 81st Edition. CRC Press LLC, Boca Raton: FL 2000, p. 3-235

3.2.5 Solubility

Solubility in methanol, ethanol ca 100, cyclohexane 200, acetone, isophorone, methyl ethyl ketone, carbon tetrachloride ca 600, toluene, benzene, chloroform ca 1000 (all in g/l, 20 °C)
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 906
Soluble in solvents
Farm Chemicals Handbook 2000. Willoughby, Ohio: Meister 2000., p. C 289
In water, 0.7 mg/l @ 24 °C
Yalkowsky SH, Dannenfelser RM; The AQUASOL dATAbASE of Aqueous Solubility. Ver 5. Tucson, AZ: Univ AZ, College of Pharmacy (1992)

3.2.6 Density

1.26 mg/l
Ahrens, W.H. Herbicide Handbook of the Weed Science Society of America. 7th ed. Champaign, IL: Weed Science Society of America, 1994., p. 223

3.2.7 Vapor Pressure

0.00000011 [mmHg]
1.15X10-7 mm Hg @ 22 °C
USDA; Agric Res Service. ARS Pesticide Properties Database on Oxadiazon (19666-30-9). Available from, as of Jan 3, 2001: https://www.ars.usda.gov/Services/docs.htm?docid=14199

3.2.8 LogP

log Kow = 4.80
Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 132

3.2.9 Stability / Shelf Life

Stable under normal storage conditions.
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 753

3.2.10 Collision Cross Section

182.17 Ų [M+H]+ [CCS Type: TW]

3.2.11 Kovats Retention Index

Standard non-polar
2159 , 2186.6 , 2145.1 , 2138 , 2159.6
Semi-standard non-polar
2182 , 2189 , 2198 , 2182 , 2186 , 2200 , 2187 , 2189 , 2188.3 , 2182 , 2162.5 , 2182.6 , 2193.2 , 2213.6 , 2161.3 , 2189.2
Standard polar
2948

3.3 SpringerMaterials Properties

3.4 Chemical Classes

3.4.1 Endocrine Disruptors

Potential endocrine disrupting compound
S109 | PARCEDC | List of 7074 potential endocrine disrupting compounds (EDCs) by PARC T4.2 | DOI:10.5281/zenodo.10944198

3.4.2 Pesticides

Herbicides
S69 | LUXPEST | Pesticide Screening List for Luxembourg | DOI:10.5281/zenodo.3862688
Active substance -> EU Pesticides database: Not approved
Pesticides -> Herbicides, Protox-Inhibiting
Pesticide (Oxadiazon) -> USDA PDB

4 Spectral Information

4.1 1D NMR Spectra

1D NMR Spectra

4.2 Mass Spectrometry

4.2.1 GC-MS

1 of 5
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NIST Number
125608
Library
Main library
Total Peaks
230
m/z Top Peak
175
m/z 2nd Highest
41
m/z 3rd Highest
177
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NIST Number
60221
Library
Replicate library
Total Peaks
185
m/z Top Peak
41
m/z 2nd Highest
43
m/z 3rd Highest
175
Thumbnail
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4.2.2 LC-MS

1 of 26
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Authors
Nikiforos Alygizakis, Katerina Galani, Nikolaos Thomaidis, University of Athens
Instrument
Bruker maXis Impact
Instrument Type
LC-ESI-QTOF
MS Level
MS2
Ionization Mode
POSITIVE
Ionization
ESI
Collision Energy
10 eV
Fragmentation Mode
CID
Column Name
Acclaim RSLC C18 2.2um, 2.1x100mm, Thermo
Retention Time
12.407 min
Precursor m/z
345.0767
Precursor Adduct
[M+H]+
Top 5 Peaks

345.0766 999

297.0821 732

303.0294 637

347.0739 594

305.0268 390

Thumbnail
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License
CC BY
2 of 26
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Authors
Nikiforos Alygizakis, Katerina Galani, Nikolaos Thomaidis, University of Athens
Instrument
Bruker maXis Impact
Instrument Type
LC-ESI-QTOF
MS Level
MS2
Ionization Mode
POSITIVE
Ionization
ESI
Collision Energy
20 eV
Fragmentation Mode
CID
Column Name
Acclaim RSLC C18 2.2um, 2.1x100mm, Thermo
Retention Time
12.373 min
Precursor m/z
345.0767
Precursor Adduct
[M+H]+
Top 5 Peaks

219.9556 999

303.0295 781

299.0614 611

221.9522 560

305.0264 448

Thumbnail
Thumbnail
License
CC BY

4.3 IR Spectra

4.3.1 FTIR Spectra

Technique
KBr WAFER
Source of Sample
U.S. Epa Repository, Research Triangle Park, North Carolina
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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6 Chemical Vendors

7 Agrochemical Information

7.1 Agrochemical Category

Herbicide
Pesticide active substances -> Herbicides
Herbicides
S69 | LUXPEST | Pesticide Screening List for Luxembourg | DOI:10.5281/zenodo.3862688

7.2 EU Pesticides Data

Active Substance
oxadiazon
Status
Not approved [Reg. (EC) No 1107/2009]
Date
Approval: 01/01/2009 Expiration: 31/12/2018
Legislation
2008/69/EC, 2010/39/EU, Reg. (EU) 2022/801, Reg. (EU) No 540/2011
ADI
0.0036 mg/kg bw/day [EFSA 2010]
ARfD
0.12 mg/kg bw [EFSA 2010]
AOEL
0.05 mg/kg bw/day [EFSA 2010]

7.3 USDA Pesticide Data Program

8 Pharmacology and Biochemistry

8.1 Metabolism / Metabolites

Although, examples of all oxadiazole isomers are known, only the biotransformation pathways of compounds containing 1,2,4-oxdiazole rings have been reported so far. (A15200)
A15200: Dalvie DK, Kalgutkar AS, Khojasteh-Bakht SC, Obach RS, O'Donnell JP: Biotransformation reactions of five-membered aromatic heterocyclic rings. Chem Res Toxicol. 2002 Mar;15(3):269-99. PMID:11896674

9 Use and Manufacturing

9.1 Uses

EPA CPDat Chemical and Product Categories
The Chemical and Products Database, a resource for exposure-relevant data on chemicals in consumer products, Scientific Data, volume 5, Article number: 180125 (2018), DOI:10.1038/sdata.2018.125
Sources/Uses
Used as selective pre-emergence herbicide; [Merck Index]
Merck Index - O'Neil MJ, Heckelman PE, Dobbelaar PH, Roman KJ (eds). The Merck Index, An Encyclopedia of Chemicals, Drugs, and Biologicals, 15th Ed. Cambridge, UK: The Royal Society of Chemistry, 2013.
Industrial Processes with risk of exposure
Farming (Pesticides) [Category: Industry]
For Oxadiazon (USEPA/OPP Pesticide Code: 109001) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./
U.S. Environmental Protection Agency/Office of Pesticide Program's Chemical Ingredients Database on Oxadiazon (19666-30-9). Available from, as of February 5, 2001: https://npirspublic.ceris.purdue.edu/ppis/
Herbicide
Farm Chemicals Handbook 2000. Willoughby, Ohio: Meister 2000., p. C 289
This is a man-made compound that is used as an herbicide.

9.1.1 Use Classification

Hazard Classes and Categories -> Teratogens
Herbicides
S69 | LUXPEST | Pesticide Screening List for Luxembourg | DOI:10.5281/zenodo.3862688

9.2 Methods of Manufacturing

Prepn: Brit. Pat 1,110,500 corresp to J. Metivier, R. Boesch, U.S. pat 3,385,862 (both 1968 to Rhone Poulenc).
Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 1185
1,2,4,5-Tetrachlorobenzene + isopropanol + hydrazine + pivaloyl chloride + phosgene (ether formation/amine formation/amide formation/phosgenation)
Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 655

9.3 Formulations / Preparations

USEPA/OPP Pesticide Code 109001; Trade Names: Ronstar; RP-17623; G315.
U.S. Environmental Protection Agency/Office of Pesticide Program's Chemical Ingredients Database on Oxadiazon (19666-30-9). Available from, as of February 5, 2001: https://npirspublic.ceris.purdue.edu/ppis/
Emulsifiable concentrates, granules, flowable, wettable powder
Farm Chemicals Handbook 2000. Willoughby, Ohio: Meister 2000., p. C 289
Tech. is greater than/equal to 94% pure
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium, 11 th ed., British Crop Protection Council, Surrey, England 1997, p. 906

9.4 General Manufacturing Information

Not to be used on red fescue, bentgrass turf, dichronda or centipedegrass.
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 754

10 Identification

10.1 Analytic Laboratory Methods

FDA Method 212.2. Organochlorine Residues (Nonionic) General Method for Nonfatty Foods Including Acetone Extraction, Isolation in Organic Phase, and Optional Florisil Column Cleanup.
USEPA; EMMI. EPA's Environmental Monitoring Methods Index. Version 1.1. PC# 4082. Rockville, MD: Government Institutes (1997)
FDA Method 231.1. Organophosphorous Residues General Methods for Fatty Foods Including Extraction of Fat, Acetonitrile Partition, and Florisil Column Cleanup.
USEPA; EMMI. EPA's Environmental Monitoring Methods Index. Version 1.1. PC# 4082. Rockville, MD: Government Institutes (1997)
HERL Method HERL_001. Modification of Mills, Onley, Gaither Method for the Determination of Multiple Organochlorine Pesticides and Metabolites in Human or Animal Adipose Tissue.
USEPA; EMMI. EPA's Environmental Monitoring Methods Index. Version 1.1. PC# 4082. Rockville, MD: Government Institutes (1997)
Metabolites can be determined by GLC with thermal-conductivity detection. Oxadiazon residues can be determined by GLC with electrical conductivity detection or by mass spectrometry. Residues in hops can be determined by GLC.
Ahrens, W.H. Herbicide Handbook of the Weed Science Society of America. 7th ed. Champaign, IL: Weed Science Society of America, 1994., p. 224

11 Safety and Hazards

11.1 Hazards Identification

11.1.1 GHS Classification

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Pictogram(s)
Environmental Hazard
Signal
Warning
GHS Hazard Statements

H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Precautionary Statement Codes

P273, P391, and P501

(The corresponding statement to each P-code can be found at the GHS Classification page.)

ECHA C&L Notifications Summary

Aggregated GHS information provided per 86 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown.

11.1.2 Hazard Classes and Categories

Aquatic Acute 1 (100%)

Aquatic Chronic 1 (100%)

Hazardous to the aquatic environment (acute) - category 1

Hazardous to the aquatic environment (chronic) - category 1

11.1.3 Health Hazards

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs. Fire may produce irritating, corrosive and/or toxic gases. Some liquids produce vapors that may cause dizziness or asphyxiation. Runoff from fire control or dilution water may cause environmental contamination. (ERG, 2024)

11.1.4 Fire Hazards

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, Capacitor, asymmetric, be aware of possible short circuiting as this product is transported in a charged state. Polymeric beads, expandable (UN2211) may evolve flammable vapours. (ERG, 2024)

11.1.5 Hazards Summary

The protox inhibitor herbicides (Fomesafen,Oxadiazon, Lactofen, Sulfentrazone, Carfentrazone-ethyl, Oxyfluorofen and Bifenox) can disrupt porphyrin metabolism; It has been speculated that a transient form of porphyria variegate may occur following a massive exposure or long-term exposure to lower doses. A mild eye irritant; [HSDB] An eye irritant; [eChemPortal: ERMA] An irritant; Targets the liver; [MSDSonline] See Fluthiacet-methyl.

11.1.6 Skin, Eye, and Respiratory Irritations

Slightly irritating to eyes, negligible irritant to skin.
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 754

11.2 First Aid Measures

11.2.1 First Aid

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Refer to the "General First Aid" section. (ERG, 2024)

11.3 Fire Fighting

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

CAUTION: Fire involving Safety devices (UN3268) and Fire suppressant dispersing devices (UN3559) may have a delayed activation and a risk of hazardous projectiles. Extinguish the fire at a safe distance.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam.

LARGE FIRE: Water spray, fog or regular foam. Do not scatter spilled material with high-pressure water streams. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS: Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

11.4 Accidental Release Measures

11.4.1 Isolation and Evacuation

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

11.4.2 Disposal Methods

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

11.4.3 Preventive Measures

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

11.5 Handling and Storage

11.5.1 Nonfire Spill Response

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. For Asbestos, avoid inhalation of dust. Cover spill with plastic sheet or tarp to minimize spreading. Do not clean up or dispose of, except under supervision of a specialist.

SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area.

SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2024)

11.6 Exposure Control and Personal Protection

11.6.1 Allowable Tolerances

Tolerances are established for combined residues of the herbicide oxadiazon (2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)delta2-1,3,4-oxadiazolin-5-one) and its metabolites (2-tert-butyl-4-(2,4-dichloro-5-hydroxyphenyl)delta2-1,3,4-oxadiazolin-5-one) and 2-carboxyisopropyl-4-(2,4-dichloro-5-isopropoxyphenyl)delta2-1,3,4-oxadiazolin-5 -one) in or on raw agricultural commodities as follows: 0.1 ppm in milk fat (reflecting negligible residues in milk); 0.01 ppm (negligible residue) in the meat, fat, and meat byproducts of cattle, goats, hogs, horses, and sheep.
40 CFR 180.346 (7/1/2000)

11.6.2 Personal Protective Equipment (PPE)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

11.7 Stability and Reactivity

11.7.1 Air and Water Reactions

Dust may form an explosive mixture in air.

11.7.2 Reactive Group

Azo, Diazo, Azido, Hydrazine, and Azide Compounds

Carbamates

Ethers

Aryl Halides

11.7.3 Reactivity Alerts

Explosive

11.7.4 Reactivity Profile

OXYDIAZON is a diazo compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides.

11.8 Transport Information

11.8.1 DOT Label

Class 9

11.9 Regulatory Information

California Safe Cosmetics Program (CSCP) Reportable Ingredient

Hazard Traits - Carcinogenicity; Developmental Toxicity

Authoritative List - Prop 65

Report - regardless of intended function of ingredient in the product

Status Regulation (EC)
2008/69/EC, 2010/39/EU, Reg. (EU) 2022/801, Reg. (EU) No 540/2011
New Zealand EPA Inventory of Chemical Status
Oxadiazon: Does not have an individual approval but may be used under an appropriate group standard

11.9.1 FIFRA Requirements

Tolerances are established for combined residues of the herbicide oxadiazon (2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)delta2-1,3,4-oxadiazolin-5-one) and its metabolites (2-tert-butyl-4-(2,4-dichloro-5-hydroxyphenyl)delta2-1,3,4-oxadiazolin-5-one) and 2-carboxyisopropyl-4-(2,4-dichloro-5-isopropoxyphenyl)delta2-1,3,4-oxadiazolin-5 -one) in or on raw agricultural commodities as follows: in milk fat; in the meat, fat, and meat byproducts of cattle, goats, hogs, horses, and sheep.
40 CFR 180.346 (7/1/2000)

11.10 Other Safety Information

Chemical Assessment

IMAP assessments - 1,3,4-Oxadiazol-2(3H)-one, 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-: Human health tier I assessment

IMAP assessments - 1,3,4-Oxadiazol-2(3H)-one, 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-: Environment tier I assessment

12 Toxicity

12.1 Toxicological Information

12.1.1 Toxicity Summary

'Oxadiazon is a member of the oxadiazole class of herbicides. While current data are limited, EPA has evidence that compounds within a class may share a common mechanism of toxicity. At this time, the Agency does not have sufficient data concerning common mechanism issues to determine whether or not oxadiazon shares a common mechanism of toxicity with other substances, including other oxadiazoles or other probable human carcinogens.' (L2081)
L2081: USEPA; Reregistration Eligibility Decision (RED) Database for Oxadiazon (19666-30-9). EPA 738-R-04-003 (September 2003). http://www.epa.gov/oppsrrd1/REDs/oxadiazon_red.pdf

12.1.2 EPA IRIS Information

Substance
Toxicity Summary
EPA IRIS Summary PDF (Update: Sep-30-1987 )
Critical Effect Systems

Hematologic

Hepatic

Reference Dose (RfD), chronic
5 x 10 ^-3 mg/kg-day

12.1.3 RAIS Toxicity Values

Oral Acute Reference Dose (RfDoa)(mg/kg-day)
0.12
Oral Acute Reference Dose Reference
OPP
Oral Chronic Reference Dose (RfDoc) (mg/kg-day)
0.005
Oral Chronic Reference Dose Reference
IRIS Current
Oral Slope Factor (CSFo)(mg/kg-day)^-1
0.0711
Oral Slope Factor Reference
OPP

12.1.4 EPA Human Health Benchmarks for Pesticides

Chemical Substance
Acute or One Day PAD (RfD) [mg/kg/day]
0.12
Acute or One Day HHBPs [ppb]
3400
Acute HHBP Sensitive Lifestage/Population
Females 13-49 yrs
Chronic or One Day PAD (RfD) [mg/kg/day]
0.005
Chronic or One Day HHBPs [ppb]
30
Chronic HHBP Sensitive Lifestage/Population
General Population
Cancer Quantification c (Q1) Values (CSF) [mg/kg/day]
0.0711
Carcinogenic HHBP (E-6 to E-4 ) [ppb]
0.416-41.6

12.1.5 Evidence for Carcinogenicity

Cancer Classification: Group C Possible Human Carcinogen
USEPA Office of Pesticide Programs, Health Effects Division, Science Information Management Branch: "Chemicals Evaluated for Carcinogenic Potential" (April 2006)

12.1.6 Carcinogen Classification

Carcinogen Classification
Not listed by IARC.

12.1.7 Exposure Routes

Inhalation; dermal. (L2081)
L2081: USEPA; Reregistration Eligibility Decision (RED) Database for Oxadiazon (19666-30-9). EPA 738-R-04-003 (September 2003). http://www.epa.gov/oppsrrd1/REDs/oxadiazon_red.pdf

12.1.8 Target Organs

Hematologic

Hepatic

12.1.9 Adverse Effects

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

12.1.10 Acute Effects

12.1.11 Toxicity Data

LC50 (rat) > 200,000 mg/m3
LD50 >5000 mg/kg (oral, rat) (L2081); LD50 >2000 mg/kg (dermal, rabbit) (L2081); LC50 >1.94 mg/L (inhalation, rat) (L2081)
L2081: USEPA; Reregistration Eligibility Decision (RED) Database for Oxadiazon (19666-30-9). EPA 738-R-04-003 (September 2003). http://www.epa.gov/oppsrrd1/REDs/oxadiazon_red.pdf

12.1.12 Antidote and Emergency Treatment

Skin decontamination. Skin contamination should be treated promptly by washing with soap and water. Contamination of the eyes should be treated immediately by prolonged flushing of the eyes with large amounts of clean water. If dermal or ocular irritation persists, medical attention should be obtained without delay. /Other herbicides/
U.S. Environmental Protection Agency/Office of Prevention, Pesticides, and Toxic Substances. Reigart, J.R., Roberts, J.R. Recognition and Management of Pesticide Poisonings. 5th ed. 1999. EPA Document No. EPA 735-R-98-003, and available in electronic format at: https://www.epa.gov/pesticides/safety/healthcare, p. 123
Gastrointestinal decontamination. Ingestions of these herbicides are likely to be followed by vomiting and diarrhea due to their irritant properties. Management depends on: (1) the best estimate of the quantity ingested, (2) time elapsed since ingestion, and (3) the clinical status of the subject. Activated charcoal is probably effective in limiting irritant effects and reducing absorption of most or all of these herbicides. Aluminum hydroxide antacids may be useful in neutralizing the irritant actions of more acidic agents. Sorbitol should be given to induce catharsis if bowel sounds are present and if spontaneous diarrhea has not already commenced. Dehydration and electrolyte disturbances may be severe enough to require oral or intravenous fluids. ... If large amounts of herbicide have been ingested and the patient is seen within an hour of the ingestion, gastrointestinal decontamination should be considered ... . If the amount of ingested herbicides was small, if effective emesis has already occurred, or if treatment is delayed, administer activated charcoal and sorbitol by mouth. /Other herbicides/
U.S. Environmental Protection Agency/Office of Prevention, Pesticides, and Toxic Substances. Reigart, J.R., Roberts, J.R. Recognition and Management of Pesticide Poisonings. 5th ed. 1999. EPA Document No. EPA 735-R-98-003, and available in electronic format at: https://www.epa.gov/pesticides/safety/healthcare, p. 123
Intravenous fluids. If serious dehydration and electrolyte depletion have occurred as a result of vomiting and diarrhea, monitor blood electrolytes and fluid balance and administer intravenous infusions of glucose, normal saline, Ringer's solution, or Ringer's lactate to restore extracellular fluid volume and electrolytes. Follow this with oral nutrients as soon as fluids can be retained. /Other herbicides/
U.S. Environmental Protection Agency/Office of Prevention, Pesticides, and Toxic Substances. Reigart, J.R., Roberts, J.R. Recognition and Management of Pesticide Poisonings. 5th ed. 1999. EPA Document No. EPA 735-R-98-003, and available in electronic format at: https://www.epa.gov/pesticides/safety/healthcare, p. 123
Supportive measures are ordinarily sufficient for successful management of excessive exposures to these herbicides ... . If the patient's condition deteriorates in spite of good supportive care, the operation of an alternative or additional toxicant should be suspected. /Other herbicides/
U.S. Environmental Protection Agency/Office of Prevention, Pesticides, and Toxic Substances. Reigart, J.R., Roberts, J.R. Recognition and Management of Pesticide Poisonings. 5th ed. 1999. EPA Document No. EPA 735-R-98-003, and available in electronic format at: https://www.epa.gov/pesticides/safety/healthcare, p. 124
For more Antidote and Emergency Treatment (Complete) data for OXADIAZON (6 total), please visit the HSDB record page.

12.1.13 Non-Human Toxicity Excerpts

In 2 yr feeding trials, rats and mice receiving 10 mg/kg diet showed no ill-effects.
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 754
The effects of the herbicides fomesafen oxyfluorfen, oxadiazon and fluazifop-butyl on porphyrin accumulation in mouse liver, rat primary hepatocyte culture and HepG2 cells were investigated. Ten days of herbicide feeding (0.25% in the diet) increased the liver porphyrins in male C57B1/6J mice from 1.4 : 0.6 to 4.8 : 2.1 (fomesafen) 16.9 : 2.9 (oxyfluorfen) and 25.9 : 3.1 (oxadiazon) nmol/g wet weight, respectively. Fomesafen, oxyfluorfen and oxadiazon increased the cellular porphyrin content of rat hepatocytes after 24 h of incubation (control, 3.2 pmol/mg protein, fomesafen, oxyfluorfen and oxadiazon at 0.125 mM concentration 51.5, 54.3 and 44.0 pmol/mg protein, respectively). The porphyrin content of HepG2 cells increase from 1.6 to 18.2, 10.6 and 9.2 pmol/mg protein after 24 h incubation with the three herbicides. Fluazifop-butyl increased hepatic cytochrome P450 levels and ethoxy- and pentoxyresorufin O-dealkylase (EROD and PROD) activity, oxyfluorfen increased PROD activity. Peroxisomal palmitoyl CoA oxidation increased after fomesafen and fluazifop treatment to about 500% of control values both in mouse liver and rat hepatocytes. Both rat hepatocytes and HepG2 cells can be used as a test system for the porphyrogenic potential of photobleaching herbicides.
Krijt J et al; Arch toxicol 67 (4): 255-61 (1993)
The effect of oxadiazon on hepatic peroxisome proliferation was examined both in-vivo and in-vitro. Male Sprague-Dawley-CD rats were administered 0 to 500 mg/kg of oxadiazon by oral gavage for 14 days. Male CD1 mice received 0 to 200 mg/kg of oxadiazon by oral gavage for 28 days. Male beagle dogs were treated orally with 0 or 500 mg/kg of oxadiazon for 28 days. Following the last treatment, animals were sacrificed and livers were examined via electron microscopy. Hepatocytes isolated from Sprague-Dawley-rats and human liver biopsies were cultured with 2.5x10(-5), 5x10(-5), or 10(-4) molar oxadiazon for 72 hours. Various biochemical assays were conducted. No dose dependent effects on body weight were noted among treated rodents. Dose dependent increases in liver weights and liver to body weight ratios were observed in rodents and dogs treated with oxadiazon. Oxadiazon treatment induced dose dependent peroxisome proliferation in rodent livers. Peroxisome proliferation was not induced in exposed dogs. In exposed rodents, the activities of the peroxisomal enzymes palmitoyl-CoA-oxidase and acetyl-carnitine-transferase were elevated in a dose dependent manner. In rats treated with 500 mg/kg of oxadiazon, the palmitoyl-CoA-oxidase and acetyl-carnitine-transferase activities were significantly increased to 212% and 609% of the control values, respectively. In mice treated with 200 mg/kg of oxadiazon, palmitoyl-CoA-oxidase activity was elevated to 259% of the control value and acetyl-carnitine-transferase activity was elevated to 459.5% of the control value. In cultured rat hepatocytes, oxadiazon caused dose dependent increases in palmitoyl-CoA-oxidase and acetyl-carnitine-transferase activities. The highest in-vitro oxadiazon dose induced morphological changes in rat hepatocytes. Although clofibric acid also increased peroxisomal enzyme activities in a dose dependent manner, it did not induce any morphological changes in rat hepatocytes. Neither oxadiazon nor clofibric acid significantly affected the peroxisomal enzyme activities in human hepatocytes. The authors conclude that oxadiazon causes peroxisome proliferation in rodents but not in dogs or humans.
Richert L et al; Toxicol and Applied Pharmacology 141 (1): 35-43 (1996)

12.1.14 Non-Human Toxicity Values

LD50 Rat oral (acute) >3,500 mg/kg
U.S. Environmental Protection Agency/Office of Prevention, Pesticides, and Toxic Substances. Reigart, J.R., Roberts, J.R. Recognition and Management of Pesticide Poisonings. 5th ed. 1999. EPA Document No. EPA 735-R-98-003, and available in electronic format at: https://www.epa.gov/pesticides/safety/healthcare, p. 120
LD50 Rat oral >5000 mg/kg
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 754
LD50 Rat percutaneous >2000 mg/kg
Tomlin, C.D.S. (ed.). The Pesticide Manual - World Compendium. 10th ed. Surrey, UK: The British Crop Protection Council, 1994., p. 754

12.2 Ecological Information

12.2.1 EPA Ecotoxicity

Pesticide Ecotoxicity Data from EPA

12.2.2 US EPA Regional Screening Levels for Chemical Contaminants

Resident Soil (mg/kg)
3.20e+02
Industrial Soil (mg/kg)
4.10e+03
Tapwater (ug/L)
4.70e+01
MCL (ug/L)
1.00e+03
Risk-based SSL (mg/kg)
4.80e-01
Chronic Oral Reference Dose (mg/kg-day)
5.00e-03
Volatile
Volatile
Mutagen
Mutagen
Fraction of Contaminant Absorbed in Gastrointestinal Tract
1
Fraction of Contaminant Absorbed Dermally from Soil
0.1

12.2.3 US EPA Regional Removal Management Levels for Chemical Contaminants

Resident Soil (mg/kg)
9.50e+02
Industrial Soil (mg/kg)
1.20e+04
Tapwater (ug/L)
1.40e+02
MCL (ug/L)
1.00e+03
Chronic Oral Reference Dose (mg/kg-day)
5.00e-03
Volatile
Volatile
Mutagen
Mutagen
Fraction of Contaminant Absorbed in Gastrointestinal Tract
1
Fraction of Contaminant Absorbed Dermally from Soil
0.1

12.2.4 Environmental Fate / Exposure Summary

Oxadiazon's production and use as a herbicide is expected to result in its direct release to the environment. If released to air, a vapor pressure of 1.15X10-7 mm Hg at 22 °C indicates oxadiazon will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase oxadiazon will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 16 hours. Particulate-phase oxadiazon will be removed from the atmosphere by wet and dry deposition. There is a potential for the photodegradation of oxadiazon in air; however, the rate at which this may occur is not known. If released to soil, oxadiazon is expected to have only low to slight mobility based upon reported Koc values ranging from 676 to 3,236. In laboratory studies using TLC and column leaching methods, oxadiazon was determined to be immobile in a total of six soils. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 7X10-8 atm-cu m/mole. Oxadiazon is not expected to volatilize from dry soil surfaces based upon its vapor pressure. Oxadiazon photodegrades on soil in natural sunlight with a half-life of 4.65 days. The half-life of oxadiazon in aerobic soil is reported to be 3-6 months. If released into water, oxadiazon is expected to adsorb to suspended solids and sediment based upon reported Koc values. Oxadiazon is stable to hydrolysis at neutral and acidic pHs, but degrades slowly at pH 9, with a half-life of 38 days. Oxadiazon photodegrades in water in natural sunlight with a half-life of 2.65 days. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. Biodegradation in aquatic systems is not expected to be an important environmental fate process based on its slow degradation in river die-away tests. BCF values of 24.1-708 in fish suggest that bioconcentration in aquatic organisms is low to high. Occupational exposure to oxadiazon may occur through inhalation and dermal contact with this compound at workplaces where oxadiazon is produced or used. (SRC)

12.2.5 Artificial Pollution Sources

Oxadiazon's production and use as an herbicide(1) is expected to result in its release to the environment through various waste streams(SRC).
(1) Desmurs J-R, Ratton S; Kirk-Othmer Encycl Chem Technol. 4thed. NY, NY: Wiley-Interscience 6: 156-68 (1993)

12.2.6 Environmental Fate

TERRESTRIAL FATE: Based on a classification scheme(1), reported Koc values ranging from 676 to 3,236(2-4), indicate that oxadiazon is expected to have only low or slight mobility in soil(SRC). In laboratory studies using TLC(5) and column leaching(6) methods, oxadiazon was determined to be immobile in a total of six soils. Volatilization of oxadiazon from moist soil surfaces is not expected to be an important fate process(4). Oxadiazon is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure of 1.15X10-7 mm Hg(7). Oxadiazon photodegrades on soil in natural sunlight with a half-life of 4.65 days(8). The photodegradation of oxadiazon results in three photoproducts with the loss of chlorine as the dominant process and the participation of hydroxyl(8). Biodegradation in soil is not expected to be an important fate process with a reported half-life of oxadiazon in aerobic soil of 3-6 months(9).
(1) Swann RL et al; Res Rev 85: 17-28 (1983)
(2) Kanazawa J; JARQ 17: 173-9 (1983)
(3) Kenaga EE; Ecotoxicol Environ Safety 4: 26-38 (1980)
(4) Tomlin CDS; Pesticide Manual. 11th ed p. 906 (1997)
(5) Ambrosi D, Helling CS; J Agric Food Chem 25: 215-217 (1977)
(6) Paulo, EM et al; Planta Daninha 2:111-5 (1979)
(7) USDA; Agric Res Service. ARS Pesticide Properties Database on Oxadiazon (19666-30-9). Available from, as of Dec, 2000: https://www.ars.usda.gov/Services/docs.htm?docid=14199
(8) Ying G-G, Williams B; J Environ Sci Health B34: 549-67 (1999)
(9) Ambrosi D et al; J Agric Food Chem 25: 868-72 (1977)
AQUATIC FATE: Based on a classification scheme(1), reported Koc values ranging from 676 to 3,236(2-4) indicate that oxadiazon is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(5) based upon an estimated Henry's Law constant of 7X10-8 atm-cu m/mole(SRC), estimated based on its vapor pressure, 1.15X10-7 mm Hg(6), and water solubility, 0.7 mg/l(7). According to a classification scheme(8), BCF values in the range of 24.1 to 708 measured in fish(9,10), suggests bioconcentration in aquatic organisms is low to high(SRC). Oxadiazon (1 ppm) photodegrades in water in natural sunlight with a half-life of 2.65 days(11). The photodegradation of oxadiazon results in three photoproducts with the loss of chlorine as the dominant process and the participation of hydroxyl(11). Oxadiazon is stable to hydrolysis at neutral and acidic pHs, but degrades slowly at pH 9, with a half-life of 38 days(12). Only 7% biodegradation was observed in a river die-away test using water from Ashai River, Japan after 50 days(13), suggesting biodegradation is slow in water.
(1) Swann RL et al; Res Rev 85: 17-28 (1983)
(2) Kanazawa J; JARQ 17: 173-9 (1983)
(3) Kenaga EE; Ecotoxicol Environ Safety 4: 26-38 (1980)
(4) Tomlin CDS; Pesticide Manual. 11th ed p. 906 (1997)
(5) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 4-9, 15-1 to 15-29 (1990)
(6) USDA; Agric Res Service. ARS Pesticide Properties Database on Oxadiazon (19666-30-9). Available from, as of Dec, 2000: https://www.ars.usda.gov/Services/docs.htm?docid=14199
(7) Yalkowsky SH, Dannenfelser RM; The AQUASOL DATABASE of Aqueous Solubility. Ver. 5. AZ: Univ AZ, College of Pharmacy (1992)
(8) Franke C et al; Chemosphere 29: 1501-14 (1994)
(9) Chemicals Inspection and Testing Institute; Biodegradation and bioaccumulation data of existing chemicals based on the CSCL Japan. Japan Chemical Industry Ecology - Toxicology and Information Center. ISBN 4-89074-101-1 (1992)
(10) Imanaka M et al; J Pestic Sci 6:413-7 (1981)
(11) Ying G-G, Williams B; J Environ Sci Health B34: 549-67 (1999)
(12) Tomlin CDS; Pesticide Manual. 11th ed p. 906 (1997)
(13) Imanaka M et al; J Pest Sci 10: 125-34 (1985)
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), oxadiazon, which has a vapor pressure of 1.15X10-7 mm Hg at 22 °C(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase oxadiazon is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 16 hours(SRC), calculated from its rate constant of 24.3X10-12 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). Particulate-phase oxadiazon is removed from the air by wet and dry deposition(SRC). There is the potential for the photodegradation of oxadiazon in air based upon its photodegradation in water(4); however, the rate at which this may occur is not known.
(1) Bidleman TF; Environ Sci Technol 22: 361-367 (1988)
(2) USDA; Agric Res Service. ARS Pesticide Properties Database on Oxadiazon (19666-30-9). Available from, as of Dec, 2000: https://www.ars.usda.gov/Services/docs.htm?docid=14199
(3) Meylan WM, Howard PH; Chemosphere 26: 2293-99 (1993)
(4) Ying G-G, Williams B; J Environ Sci Health B34: 549-67 (1999)

12.2.7 Environmental Biodegradation

AEROBIC: Oxadiazon, present at 100 mg/l, reached 16% of its theoretical BOD in two weeks using an activated sludge inoculum at 30 mg/l and a modified Japanese MITI test(1). In an aerobic degradation study using non-acclimated microbes in a mixed inoculum obtained from activated sludge, field soil and river sediment, oxadiazon was observed to be relatively stable to aerobic microbial degradation, with reported half-lives of 100-321 days(2). The half-life of oxadiazon in aerobic soil (loam and fine sandy loam) is reported to be 3-6 months(3). No biodegradation of oxadiazon at a concn of 0.00555 ppm occurred in Lake Kojima, Japan water samples incubated in the dark for 20 days(4). Using Ashai River, Japan water samples incubated at 10 °C, 7% biodegradation was observed after 50 days at a concn of 0.01 ppm(4).
(1) Chemicals Inspection and Testing Institute; Biodegradation and bioaccumulation data of existing chemicals based on the CSCL Japan. Japan Chemical Industry Ecology - Toxicology and Information Center. ISBN 4-89074-101-1 (1992)
(2) Kanazawa J; Environ Monit Assess 9: 57-70 (1987)
(3) Ambrosi D et al; J Agric Food Chem 25: 868-72 (1977)
(4) Imanaka M et al; J Pest Sci 10: 125-34 (1985)
ANAEROBIC: In an anaerobic degradation study using non-acclimated microbes in a mixed inoculum obtained from activated sludge, field soil and river sediment, oxadiazon was observed to be relatively stable to metabolic degradation, with reported half-lives of 107-577 days(1). Therefore, this compound is not expected to biodegrade rapidly in the environment under anaerobic conditions.
(1) Kanazawa J; Environ Monit Assess 9: 57-70 (1987)

12.2.8 Environmental Abiotic Degradation

The rate constant for the vapor-phase reaction of oxadiazon with photochemically-produced hydroxyl radicals has been estimated as 24X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 16 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Oxadiazon is stable to hydrolysis at neutral and acidic pHs, but degrades slowly at pH 9, with a half-life of 38 days(2). Oxadiazon photodegrades in natural sunlight in water (1 ppm) and on soil, with respective half-lives of 2.65 days and 4.65 days; rate differences were attributed to the attenuation of light in soil(3). The photodegradation of oxadiazon results in three photoproducts with the loss of chlorine as the dominant process and the participation of hydroxyl(3).
(1) Meylan WM, Howard PH; Chemosphere 26: 2293-99 (1993)
(2) Tomlin CDS; Pesticide Manual. 11th ed p. 906 (1997)
(3) Ying G-G, Williams B; J Environ Sci Health B34: 549-67 (1999)

12.2.9 Environmental Bioconcentration

Oxadiazon was detected in fish tissue (flesh) samples of crucian carp (Carassius cuvieri) collected from Lake Kojima in Japan at 2,4 and 9 months postapplication at concns of 0.442 ppm, 0.046 ppm and 0.017 ppm, respectively(4). At the final sampling period, the concn of oxadiazon in the surface water (0.024 ppb) was much lower than that detected in the fish samples, indicating that bioconcentration (BCF = 708 based on the point-in-time values reported) had occurred(1). In a study in which oxadiazon was introduced into a model ecosystem, adsorbed to soil (at 1 and 10 ppm), for 48 days, total residues in algae, snails and daphnids accumulated with BCFs of approximately 39-58 at both treatment rates while the respective BCFs in fish were approximately 198-248; the final concns in the water were 5.3 ppb and 44.4 ppb, respectively(2). However, in the study, only 35%, 50%, 57% and 63% of the residues recovered from the snails, fish, water and algae samples were parent oxadiazon, indicating that metabolism/degradation had occurred; the presence of the oxadiazon metabolites found in the water may have affected the bioaccumulation results(2). BCF values of 24.1-26.7 were measured in carp exposed to 40 ug/l of oxadiazon over an 8 week incubation period(3).According to a classification scheme(4), the BCF data suggests the potential for bioconcentration in aquatic organisms is low to high(SRC).
(1) Imanaka M et al; J Pestic Sci 6:413-7 (1981)
(2) Ambrosi D et al; J Agric Food Chem 26:50-3 (1978)
(3) Chemicals Inspection and Testing Institute; Biodegradation and bioaccumulation data of existing chemicals based on the CSCL Japan. Japan Chemical Industry Ecology - Toxicology and Information Center. ISBN 4-89074-101-1 (1992)
(4) Franke C et al; Chemosphere 29: 1501-14 (1994)

12.2.10 Soil Adsorption / Mobility

The Koc of oxadiazon is reported as ranging from 676 to 3236(1-3). According to a classification scheme(4), this estimated Koc value suggests that oxadiazon is expected to have only low or slight mobility in soil. In laboratory studies using TLC(5) and column leaching(6) methods, oxadiazon was determined to be immobile in a total of six soils. In a study of the adsorption of oxadiazon (concn of 0.1-100 ppm) to soil and container (potting) media, 98-99% of the applied oxadiazon was adsorbed at all treatment rates, indicating that adsorption was not dependent on concn(7).
(1) Kanazawa J; JARQ 17: 173-9 (1983)
(2) Kenaga EE; Ecotox Environ Safety 4: 26-38 (1980)
(3) Tomlin CDS; Pesticide Manual. 11th ed p. 906 (1997)
(4) Swann RL et al; Res Rev 85: 17-28 (1983)
(5) Ambrosi D, Helling CS; J Agric Food Chem 25: 215-217 (1977)
(6) Paulo, EM et al; Planta Daninha 2: 111-5 (1979)
(7) Wehtje GR et al; Hort Science 28: 126-128 (1993)

12.2.11 Volatilization from Water / Soil

The Henry's Law constant for oxadiazon is estimated as 7X10-8 atm-cu m/mole(SRC) based upon its vapor pressure, 1.15X10-7 mm Hg(1), and water solubility, 0.7 mg/l(2). This Henry's Law constant indicates that oxadiazon is expected to be essentially nonvolatile from water surfaces(3). Oxadiazon's estimated Henry's Law constant indicates that volatilization from moist soil surfaces will not occur(4). Oxadiazon is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).
(1) USDA; Agric Res Service. ARS Pesticide Properties Database on Oxadiazon (19666-30-9). Available from, as of Dec, 2000: https://www.ars.usda.gov/Services/docs.htm?docid=14199
(2) Yalkowsky SH, Dannenfelser RM; The AQUASOL DATABASE of Aqueous Solubility. Ver. 5. AZ: Univ AZ, College of Pharmacy (1992)
(3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990)
(4) Tomlin CDS; Pesticide Manual. 11th ed p. 906 (1997)

12.2.12 Environmental Water Concentrations

SURFACE WATER: Oxadiazon was detected in river water samples collected from the Koise River tributaries in Japan during a rice cultivation period between May and September 1985 at a maximum concn of 6.3 ug/l(1). Oxadiazon was not detected (detection limit = 0.01 ug/ml) in water samples (500 ml) collected monthly from the mouth of the Shinano River in Niigata Prefecture, Japan, during May to September 1996(2). Oxadiazon was detected (detection limit = 0.01 ug/l) in water samples collected from the Arno River, Italy, during 1992-1995, at yearly maximums of 0.11 ug/l in 1993 and 0.06 ug/l in 1995; oxadiazon was not detected in river water samples in 1992 or 1994(3).
(1) Iwakuma T et al; Chemosphere 27: 677-91 (1993)
(2) Tanabe A et al; J of AOAC Int 83: 61-67 (2000)
(3) Griffini O et al; Bull Environ Contam Toxicol 59: 202-209 (1997)

12.2.13 Sediment / Soil Concentrations

SEDIMENT: Oxadiazon was detected in river sediment (organic carbon contents of 0.49-4.05 mg/g) samples collected from the Koise River tributaries in Japan during a rice cultivation period between May and September 1985 at a maximum concn of 10 ug/kg during August(1).
(1) Iwakuma T et al; Chemosphere 27:677-91 (1993)

12.2.14 Atmospheric Concentrations

URBAN/SUBURBAN: Oxadiazon was not detected in the air in Kitakyashu City, Japan, an urban area 10 miles from an agricultural area, in samples collected during July 1991 and April 1992 using a single 24-hr sampling at a flow rate of 500 L/min(1).
(1) Haraguchi K et al; Atmos Environ 28: 1319-25 (1994)

12.2.15 Food Survey Values

In a 1992-1993 FDA monitoring study of oxadiazon residues in pears, the compound was not detected in any of the 710 domestic or 949 imported pear samples tested(1). Oxadiazon was not detected in a monitoring study of 6970 samples (80% domestic, 20 % foreign) of 81 commodities, including 71 pear samples, collected in Texas during 1989-1991(2).
(1) Roy RR et al; J AOAC Int 78: 930-40 (1995)
(2) Shattenberg HJ III, Hsu JP; J AOAC Int 75: 925-33 (1992)

12.2.16 Probable Routes of Human Exposure

Occupational exposure to oxadiazon may occur through inhalation and dermal contact with this compound at workplaces where oxadiazon is produced or used. (SRC)

13 Associated Disorders and Diseases

14 Literature

14.1 Consolidated References

14.2 NLM Curated PubMed Citations

14.3 Springer Nature References

14.4 Wiley References

14.5 Chemical Co-Occurrences in Literature

14.6 Chemical-Gene Co-Occurrences in Literature

14.7 Chemical-Disease Co-Occurrences in Literature

15 Patents

15.1 Depositor-Supplied Patent Identifiers

15.2 WIPO PATENTSCOPE

15.3 Chemical Co-Occurrences in Patents

15.4 Chemical-Disease Co-Occurrences in Patents

15.5 Chemical-Gene Co-Occurrences in Patents

16 Interactions and Pathways

16.1 Protein Bound 3D Structures

16.1.1 Ligands from Protein Bound 3D Structures

PDBe Ligand Code
PDBe Structure Code
PDBe Conformer

16.2 Chemical-Target Interactions

17 Biological Test Results

17.1 BioAssay Results

18 Classification

18.1 MeSH Tree

18.2 ChEBI Ontology

18.3 KEGG: Pesticides

18.4 ChemIDplus

18.5 CAMEO Chemicals

18.6 ChEMBL Target Tree

18.7 UN GHS Classification

18.8 EPA CPDat Classification

18.9 NORMAN Suspect List Exchange Classification

18.10 CCSBase Classification

18.11 EPA DSSTox Classification

18.12 EPA Substance Registry Services Tree

18.13 MolGenie Organic Chemistry Ontology

19 Information Sources

  1. Australian Industrial Chemicals Introduction Scheme (AICIS)
    1,3,4-Oxadiazol-2(3H)-one, 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-
    https://services.industrialchemicals.gov.au/search-assessments/
  2. CAMEO Chemicals
    LICENSE
    CAMEO Chemicals and all other CAMEO products are available at no charge to those organizations and individuals (recipients) responsible for the safe handling of chemicals. However, some of the chemical data itself is subject to the copyright restrictions of the companies or organizations that provided the data.
    https://cameochemicals.noaa.gov/help/reference/terms_and_conditions.htm?d_f=false
    CAMEO Chemical Reactivity Classification
    https://cameochemicals.noaa.gov/browse/react
  3. CAS Common Chemistry
    LICENSE
    The data from CAS Common Chemistry is provided under a CC-BY-NC 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc/4.0/
  4. ChemIDplus
    ChemIDplus Chemical Information Classification
    https://pubchem.ncbi.nlm.nih.gov/source/ChemIDplus
  5. EPA DSSTox
    CompTox Chemicals Dashboard Chemical Lists
    https://comptox.epa.gov/dashboard/chemical-lists/
  6. EPA Integrated Risk Information System (IRIS)
  7. EPA Safe Drinking Water Act (SDWA)
  8. European Chemicals Agency (ECHA)
    LICENSE
    Use of the information, documents and data from the ECHA website is subject to the terms and conditions of this Legal Notice, and subject to other binding limitations provided for under applicable law, the information, documents and data made available on the ECHA website may be reproduced, distributed and/or used, totally or in part, for non-commercial purposes provided that ECHA is acknowledged as the source: "Source: European Chemicals Agency, http://echa.europa.eu/". Such acknowledgement must be included in each copy of the material. ECHA permits and encourages organisations and individuals to create links to the ECHA website under the following cumulative conditions: Links can only be made to webpages that provide a link to the Legal Notice page.
    https://echa.europa.eu/web/guest/legal-notice
    3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2(3H)-one
    https://echa.europa.eu/substance-information/-/substanceinfo/100.039.272
    3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2(3H)-one (EC: 243-215-7)
    https://echa.europa.eu/information-on-chemicals/cl-inventory-database/-/discli/details/120393
  9. FDA Global Substance Registration System (GSRS)
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  10. Hazardous Substances Data Bank (HSDB)
  11. New Zealand Environmental Protection Authority (EPA)
    LICENSE
    This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International licence.
    https://www.epa.govt.nz/about-this-site/general-copyright-statement/
  12. NJDOH RTK Hazardous Substance List
  13. Risk Assessment Information System (RAIS)
    LICENSE
    This work has been sponsored by the U.S. Department of Energy (DOE), Office of Environmental Management, Oak Ridge Operations (ORO) Office through a joint collaboration between United Cleanup Oak Ridge LLC (UCOR), Oak Ridge National Laboratory (ORNL), and The University of Tennessee, Ecology and Evolutionary Biology, The Institute for Environmental Modeling (TIEM). All rights reserved.
    https://rais.ornl.gov/
  14. California Office of Environmental Health Hazard Assessment (OEHHA)
  15. ChEBI
  16. Toxin and Toxin Target Database (T3DB)
    LICENSE
    T3DB is offered to the public as a freely available resource. Use and re-distribution of the data, in whole or in part, for commercial purposes requires explicit permission of the authors and explicit acknowledgment of the source material (T3DB) and the original publication.
    http://www.t3db.ca/downloads
  17. California Safe Cosmetics Program (CSCP) Product Database
  18. EU Pesticides Database
  19. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
    LICENSE
    Copyright (c) 2022 Haz-Map(R). All rights reserved. Unless otherwise indicated, all materials from Haz-Map are copyrighted by Haz-Map(R). No part of these materials, either text or image may be used for any purpose other than for personal use. Therefore, reproduction, modification, storage in a retrieval system or retransmission, in any form or by any means, electronic, mechanical or otherwise, for reasons other than personal use, is strictly prohibited without prior written permission.
    https://haz-map.com/About
  20. CCSbase
    CCSbase Classification
    https://ccsbase.net/
  21. ChEMBL
    LICENSE
    Access to the web interface of ChEMBL is made under the EBI's Terms of Use (http://www.ebi.ac.uk/Information/termsofuse.html). The ChEMBL data is made available on a Creative Commons Attribution-Share Alike 3.0 Unported License (http://creativecommons.org/licenses/by-sa/3.0/).
    http://www.ebi.ac.uk/Information/termsofuse.html
  22. Comparative Toxicogenomics Database (CTD)
    LICENSE
    It is to be used only for research and educational purposes. Any reproduction or use for commercial purpose is prohibited without the prior express written permission of NC State University.
    http://ctdbase.org/about/legal.jsp
  23. Drug Gene Interaction database (DGIdb)
    LICENSE
    The data used in DGIdb is all open access and where possible made available as raw data dumps in the downloads section.
    http://www.dgidb.org/downloads
  24. Crystallography Open Database (COD)
    LICENSE
    All data in the COD and the database itself are dedicated to the public domain and licensed under the CC0 License. Users of the data should acknowledge the original authors of the structural data.
    https://creativecommons.org/publicdomain/zero/1.0/
  25. The Cambridge Structural Database
  26. EPA Chemical and Products Database (CPDat)
  27. EPA Pesticide Ecotoxicity Database
  28. NORMAN Suspect List Exchange
    LICENSE
    Data: CC-BY 4.0; Code (hosted by ECI, LCSB): Artistic-2.0
    https://creativecommons.org/licenses/by/4.0/
    Oxadiazon
    NORMAN Suspect List Exchange Classification
    https://www.norman-network.com/nds/SLE/
  29. EPA Regional Screening Levels for Chemical Contaminants at Superfund Sites
  30. USDA Pesticide Data Program
  31. Hazardous Chemical Information System (HCIS), Safe Work Australia
  32. NITE-CMC
    3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2(3H)-one; oxadiazon - FY2008 (New/original classication)
    https://www.chem-info.nite.go.jp/chem/english/ghs/08-mhlw-0257e.html
  33. Regulation (EC) No 1272/2008 of the European Parliament and of the Council
    LICENSE
    The copyright for the editorial content of this source, the summaries of EU legislation and the consolidated texts, which is owned by the EU, is licensed under the Creative Commons Attribution 4.0 International licence.
    https://eur-lex.europa.eu/content/legal-notice/legal-notice.html
  34. Japan Chemical Substance Dictionary (Nikkaji)
  35. KEGG
    LICENSE
    Academic users may freely use the KEGG website. Non-academic use of KEGG generally requires a commercial license
    https://www.kegg.jp/kegg/legal.html
  36. MassBank Europe
  37. MassBank of North America (MoNA)
    LICENSE
    The content of the MoNA database is licensed under CC BY 4.0.
    https://mona.fiehnlab.ucdavis.edu/documentation/license
  38. NIST Mass Spectrometry Data Center
    LICENSE
    Data covered by the Standard Reference Data Act of 1968 as amended.
    https://www.nist.gov/srd/public-law
  39. SpectraBase
  40. NMRShiftDB
  41. Protein Data Bank in Europe (PDBe)
  42. RCSB Protein Data Bank (RCSB PDB)
    LICENSE
    Data files contained in the PDB archive (ftp://ftp.wwpdb.org) are free of all copyright restrictions and made fully and freely available for both non-commercial and commercial use. Users of the data should attribute the original authors of that structural data.
    https://www.rcsb.org/pages/policies
  43. Springer Nature
  44. SpringerMaterials
    3-[2,4-dichloro-5-(1-methyl ethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2(3H)-one
    https://materials.springer.com/substanceprofile/docs/smsid_doraueezhujxwlbj
  45. Wikidata
  46. Wiley
  47. PubChem
  48. Medical Subject Headings (MeSH)
    LICENSE
    Works produced by the U.S. government are not subject to copyright protection in the United States. Any such works found on National Library of Medicine (NLM) Web sites may be freely used or reproduced without permission in the U.S.
    https://www.nlm.nih.gov/copyright.html
  49. GHS Classification (UNECE)
  50. EPA Substance Registry Services
  51. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  52. PATENTSCOPE (WIPO)
  53. NCBI
CONTENTS