topramezone (Ref: BAS 670 H) ** Translations

---

Environmental Fate - Ecotoxicology - Human Health - A to Z Index - Home

SUMMARY

Topramezone is a post-emergence herbicide currently being evaluated for use within the EU. It is highly soluble in water, non-volatile but, based on its chemical properties, has a high risk of leaching to groundwater. It can be persistent in both soil and aquatic systems. It is moderately toxic to mammals but a low potential for bioaccumulation. It is classified as an irritant. It is moderately toxic to birds, honey bees, earthworms, fish and aquatic invertebrates.

GENERAL INFORMATION
for topramezone

Description: A post-emergence herbicide for broad-leaved weeds and grasses used mainly on corn

Example pests controlled: Giant foxtail; Broad-leaved signal grass; Crabgrass; Goosegrass; Woolly cupgrass; Shattercane; Johnsongrass; Barnyardgrass

Example applications: Field corn (grain, silage, seed); Sweetcorn; Popcorn

Efficacy & activity: -

Availability status: Current

Introduction & key dates: 2006

EC Regulation 1107/2009 (repealing 91/414):

Status	Pending
Dossier rapporteur/co-rapporteur	France
Date inclusion expires	-
EU Candidate for substitution (CfS)	No data
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

Chemical structure:

Isomerism	None
Chemical formula	C16H17N3O5S
Canonical SMILES	CC1=C(C=CC(=C1C2=NOCC2)S(=O)(=O)C)C(=O)C3=CNN(C3=O)C
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	IYMLUHWAJFXAQP-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C16H17N3O5S/c1-9-10(15(20)11-8-17-19(2)16(11)21)4-5-13(25(3,22)23)14(9)12-6-7-24-18-12/h4-5,8,21H,6-7H2,1-3H3
2D structure diagram/image available?	Yes

General status:

Pesticide type	Herbicide
Substance group	Benzoylpyrazole
Minimum active substance purity	970 g/kg
Known relevant impurities	EU dossier - None declared
Substance origin	Synthetic
Mode of action	Systemic, highly selective, rapidly absorbed and translocated
CAS RN	210631-68-8
EC number	-
CIPAC number	800
US EPA chemical code	123009
PubChem CID	11302979
Molecular mass (g mol-1)	363.39
PIN (Preferred Identification Name)	[3-(4,5-dihydro-1,2-oxazol-3-yl)-4-(methanesulfonyl)-2-methylphenyl](5-hydroxy-1-methyl-1H-pyrazol-4-yl)methanone
IUPAC name	[3-(4,5-dihydro-1,2-oxazol-3-yl)-4-mesyl-o-tolyl](5-hydroxy-1-methylpyrazol-4-yl)methanone
CAS name	[3-(4,5-dihydro-3-isoxazolyl)-2-methyl-4-(methylsulfonyl)phenyl](5-hydroxy-1-methyl-1H-pyrazol-4-yl)methanone
Other status information	PAN Bad Actor
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	White crystalline solid
Related substances & organisms	-

Formulations:

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Avmac BASF Bayer CropScience
Example products using this active	Pylex BAS 670 00H Armezon
UK LERAP status	No UK approval for use as a pesticide under EC Regulation 1107/2009
Formulation and application details	Formulations include suspension concentrates.

ENVIRONMENTAL FATE
for topramezone

Property		Value	Source/Quality Score/Other Information	Interpretation
Solubility - In water at 20oC (mg l-1)		100000	A5	High
Solubility - In organic solvents at 20oC (mg l-1)		10000	A5 - Acetone	-
		10000	A5 - Toluene	-
		10000	A5 - n-Heptane	-
		10000	A5 - Ethyl acetate	-
Melting point (oC)		220.9	A5	-
Boiling point (oC)		-	-	-
Degradation point (oC)		300	A5	-
Flashpoint (oC)		Not expected to self ignite; Not highly flammable	A5	-
Octanol-water partition coefficient at pH 7, 20oC	P	3.02 X 10-02	Calculated	-
	Log P	-1.52	A5	Low
Bulk density (g ml-1)/Specific gravity		1.406	A5	-
Dissociation constant (pKa) at 25oC		4.06	A5	-
		Note: Weak acid
Vapour pressure at 20oC (mPa)		1.10 X 10-09	A5	Low volatility
Henry's law constant at 25oC (Pa m3 mol-1)		7.13 X 10-14	A5	Non-volatile
GUS leaching potential index		4.75	Calculated	High leachability
SCI-GROW groundwater index (μg l-1) for a 1 kg ha-1 or 1 l ha-1 application rate	Value	3.65 X 10+00	Calculated	-
	Note	-
Potential for particle bound transport index		-	Calculated	Medium
Maximum UV-vis absorption L mol-1 cm-1		207nm = 27077, 272nm = 8601, 300nm = 5800, 410nm = 96	A5	-
Surface tension (mN m-1)		69.0	A5 at 20oC, 1% solution	-

Degradation:

Property		Value	Source/Quality Score/Other Information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT50 (typical)	218	A5	Persistent
	DT50 (lab at 20oC)	218	A5	Persistent
	DT50 (field)	26.1	A4	Non-persistent
	DT90 (lab at 20oC)	763	A5	-
	DT90 (field)	529	A4	-
	DT50 modelling endpoint	-	-	-
	Note	EU dossier lab studies DT50 range 85-357 days, DT90 range 283-greater than 1000 days; field studies DT50 range 10.8-69.3 days, DT90 range 184-greater than 1000 days. Other studies: Lab DT50 range 125-495 days, field studies range 3-29 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	Stable	A5	-
	Note	Data for sterile buffer solution at pH 5 and pH9, slow degradation in natural water DT50 72 days continuous irradiation
Aqueous hydrolysis DT50 (days) at 20oC and pH 7	Value	Stable	A5	-
	Note	Stable pH 5 to pH 9at 25 degC, 30 days
Water-sediment DT50 (days)		77.5	A5	Moderately fast
Water phase only DT50 (days)		9.5	A5	Moderately fast

Soil adsorption and mobility:

Property		Value	Source/Quality Score/Other Information	Interpretation
Linear	Kd	-	P4	Moderately mobile
	Koc	171
	Notes and range	Canadian dossier gives Koc range 38-303 mL/g
Freundlich	Kf	1.78	A5	Moderately mobile
	Kfoc	93
	1/n	0.86
	Notes and range	EU dossier Kf range 0.165-6.33, Kfoc range 15.0-296.7 mL/g, 1/n range 0.786-0.923
pH sensitivity		Adsorption stronger on more acidic soils

Key metabolites:

Metabolite		Formation medium	Estimated maximum occurrence fraction	1107/2009 relevancy
3-(4,5-dihydro-isoxazol-3-yl)-4-methanesulfonyl-2-methyl-benzoic acid (Ref: M670H05)		Soil	0.192	Major fraction, Relevant
(3-cyano-4-methanesulfonyl-2-methyl phenyl)(5-hydroxy-1-methyl-1H-pyrazol-4-yl)methanone (Ref: M670H01)		Soil	-	Minor fraction, Not relevant
6-(5-hydroxy-1-methyl-1H-pyrazol-4-yl)carbonyl)-5-methyl-2,3-dihydro-4H-1-benzothiopyran-4-one (Ref: M670H10)		Soil	-	Minor fraction, Not relevant

Other known metabolites:

Metabolite name and reference	Aliases	Formation medium / Rate	Estimated maximum occurrence fraction	Metabolising enzymes
(Ref: M670H02)	hydroxy topramezone	Plant; Animal	-	-
(Ref: M670H03)	topramezone des-N-methyl	Plant	-	-
(Ref: M670H04)	demethyl hydroxy topramezone	Animal	-	-
(Ref: M670H08)	topramezone methyl ketone	Plant	-	-

ECOTOXICOLOGY
for topramezone

Property		Value	Source/Quality Score/Other Information	Interpretation
Bio-concentration factor	BCF (l kg-1)	0.3	A5	Low potential
	CT50 (days)	Not available		-
Mammals - Acute oral LD50 (mg kg-1)		> 2000	A5 Rat	Low
Mammals - Short term dietary NOEL	(mg kg-1)	0.5	P4 Rat	High
	(ppm diet)	-		-
Birds - Acute LD50 (mg kg-1)		> 2000	A5 Colinus virginianus	Low
Birds - Short term dietary (LC50/LD50)		> 1085 mg kg bw-1 day-1	A5 Colinus virginianus	-
Fish - Acute 96 hour LC50 (mg l-1)		> 100	A5 Oncorhynchus mykiss	Low
Fish - Chronic 21 day NOEC (mg l-1)		0.01	P4 Oncorhynchus mykiss	Moderate
Aquatic invertebrates - Acute 48 hour EC50 (mg l-1)		> 100	A5 Daphnia magna	Low
Aquatic invertebrates - Chronic 21 day NOEC (mg l-1)		97.5	P4 Daphnia magna	Low
Aquatic crustaceans - Acute 96 hour LC50 (mg l-1)		-	-	-
Sediment dwelling organisms - Acute 96 hour LC50 (mg l-1)		-	-	-
Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l-1)		-	-	-
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg-1)		-	-	-
Aquatic plants - Acute 7 day EC50, biomass (mg l-1)		0.009	A5 Lemna gibba	High
Non-target plants		46.1	A5 Onion Seedling emergence, ER50 as mL product/ha (BASS 670 00 Conc 336 g/L)	-
		17	Ar Buckwheat Vegetative vigour, ER70 as mL product/ha (BASS 670 00 Conc 336 g/L)	-
Algae - Acute 72 hour EC50, growth (mg l-1)		17.2	A5 Pseudokirchneriella subcapitata	Low
Algae - Chronic 96 hour NOEC, growth (mg l-1)		3	P4 Pseudokirchneriella subcapitata	Low
Honeybees	Contact acute 48 hour LD50 (μg bee-1)	> 100	A5	Low
	Oral acute 48 hour LD50 (μg bee-1)	> 72.05	A5	Moderate
	Unknown mode acute 48 hour LD50 (μg bee-1)	-	-	-
Earthworms - Acute 14 day LC50 (mg kg-1)		> 1000	A5 Eisenia foetida	Low
Earthworms - Chronic 14 day NOEC, reproduction (mg kg-1)		0.672	A5 Eisenia foetida	Moderate
Other soil macro-organisms - e.g. Collembola	LR50 / EC50 / NOEC / % Effect	37.2	A5 Folsomia candida, NOEC mg kg-1	-
Other arthropod (1)	LR50 g ha-1	100	>, Mortality A5 Aphidius rhopalosiphi, adult	-
	% Effect	-	-	-
Other arthropod (2)	LR50 g ha-1	105	Mortality A5 Typhlodromus pyri	-
	% Effect	-	-	-
Soil micro-organisms		Nitrogen mineralisation: No significant adverse effect Carbon mineralisation: No significant adverse effect	A5 Dose: 0.67 mg kg-1 soil, 28 days	-
Mesocosm study data	NOEAEC mg l-1	-	-	-
	NOEAEC mg l-1	-	-	-

HUMAN HEALTH AND PROTECTION
for topramezone

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)		> 2000	A5 Rat	Low
Mammals - Dermal LD50 (mg kg-1 body weight)		> 2000	A5 Rat	-
Mammals - Inhalation LC50 (mg l-1)		> 5.4	A5 Rat, 4 hr (head & nose)	-
Other Mammal toxicity endpoints		-		-
ADI - Acceptable Daily Intake (mg kg-1bw day-1)		0.001	A5	-
ARfD - Acute Reference Dose (mg kg-1bw day-1)		0.001	A5	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg-1 bw day-1)		-	-	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg-1bw day-1)		0.0006	A5	-
Dermal penetration studies (%)		-	-	-
Dangerous Substances Directive 76/464		-	-	-
Exposure Limits		-	-	-
Exposure Routes	Public	Negligible risk to bystanders
	Occupational	Possible risk on re-entry of sprayed areas
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=12 μg l-1	-

Health issues:

Carcinogen	Mutagen	Endocrine disrupter	Reproduction / development effects	Cholinesterase inhibitor	Neurotoxicant
	-	-			-
Respiratory tract irritant	Skin irritant	Skin sensitiser	Eye irritant	Phototoxicant
-		-		-
General human health issues		Eye, liver, kidney, pancreas, and thyroid toxicant USEPA - possible human carcinogen at high doses

: 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 explosive or oxidising IMDG Transport Code is usually 9
CLP classification 2013		None allocated at this time
EC Risk Classification		Reproduction risk category 2: R61 N - Dangerous for the environment: R50/53
EC Safety Classification		S45, S53, S60, S61
WHO Classification		NL	-	Not listed
US EPA Classification (formulation)		No consensus across products or no products available	-	-
UN Number		Usually 3077
Waste disposal & packaging		Packaging Group III (minor danger)

TRANSLATIONS
for topramezone

Language	Name
English	topramezone
French	-
German	Topramezone
Danish	topramezone
Italian	topramezone
Spanish	topramezona
Greek	-
Slovenian	topramezon
Polish	topramezone
Swedish	-
Hungarian	-
Dutch	topramezone

---

Record last updated: Wednesday 30 May 2018
Contact: aeru@herts.ac.uk