Bentazone

Structural formula
General
Surname	Bentazone
other names	3-Isopropyl- (1 H ) -2,1,3-benzothiadiazin-4 (3 H ) -one-2,2-dioxide
Molecular formula	C 10 H 12 N 2 O 3 S
Brief description	colorless and odorless crystals
External identifiers / databases
EC number	246-585-8
ECHA InfoCard	100.042.335
PubChem	2328
Wikidata	Q148937
properties
Molar mass	240.28 g mol −1
Physical state	firmly
density	1.41 g cm −3 (20 ° C)
Melting point	138 ° C
solubility	very bad in water (0.57 g l −1 at 20 ° C)
safety instructions
GHS hazard labeling from Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution
H and P phrases	H: 302-317-319-412
	P: 273-280-305 + 351 + 338
Toxicological data	1100 mg kg −1 ( LD 50 , rat , oral ) ; 2500 mg kg −1 ( LD 50 , rat , transdermal ) ; 5.1 mg l −1 4 h ( LC 50 , rat , inh. ) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Bentazone is a chemical compound from the group of thiadiazines .

Extraction and presentation

Bentazone can be obtained by reacting anthranilic acid with isopropylsulfamoyl chloride (obtained by reacting isopropylamine with chlorosulfonic acid ) and phosgene .

use

Bentazone is used as a contact herbicide against dicotyledonous weeds. It is absorbed through the leaves and shoots of the plants and inhibits photosynthesis in the plants. In agriculture, Bentazon is approved for the control of weeds in spring wheat , spring barley , oats, potatoes, field beans, field peas, soybeans and red clover (meadow clover). The water hazard class is bentazone at second

In 2011, around 500 tons of the active ingredient were used in the USA.

Admission

Bentazone is used as an active ingredient in plant protection products (e.g. Artett and Basagran) in many countries, including a. in Switzerland. After a decision by the EU Parliament, the approvals for pesticides containing bentazone expired in Germany and Austria.

Breakdown of bentazone in the soil

Bentazone is degraded in soils with a half-life of 8 days to N-methyl-bentazone. This is further broken down into carbon dioxide or other breakdown products, which are then mineralized. However, bentazone is very mobile in soils with a relatively low mean K _oc value of 42 cm ³ / g. The K _oc value ( sorption coefficient of organic carbon ) is reciprocal to the groundwater hazard of a substance, which is why bentazone may pose a hazard to groundwater, especially if it is used earlier or heavily. Correspondingly, the groundwater in Switzerland is contaminated with bentazone.

literature

Manfred Häfner: Strategies for the assessment of the groundwater hazard potential of plant protection products containing bentazone . State Institute for Plant Protection, Stuttgart, doi : 10.1046 / j.1439-0345.2002.02004.x

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on bentazone in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
↑ Entry on Bentazone in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Entry on bentazone. In: Römpp Online . Georg Thieme Verlag, accessed on May 2, 2014.
↑ Thomas A. Unger: Pesticide synthesis handbook . 1996, ISBN 978-0-8155-1401-5 , pp. 608 ( limited preview in Google Book search).
^ Müfit Bahadir, Harun Parlar, Michael Spiteller: Springer Umweltlexikon . Springer DE, 2000, ISBN 3-642-56998-6 , pp. 161 ( limited preview in Google Book search).
↑ List of plant protection products in Switzerland. Retrieved May 25, 2019 .
↑ Voted against re-authorization of the herbicidal active ingredient bentazone. Retrieved May 25, 2019 .
↑ Plant protection products: Basagran. Retrieved May 25, 2019 .
↑ European Food Safety Authority: Conclusion on the peer review of the pesticide risk assessment of the active substance bentazone. In: EFSA Journal 2015; 13 (4): 4077. Accessed July 31, 2019 .
↑ Plant protection products in groundwater. In: bafu.admin.ch . Retrieved November 4, 2019 .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on bentazone in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .

[CLP_100.042.335-2] Entry on Bentazone in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[roempp-3] Entry on bentazone. In: Römpp Online . Georg Thieme Verlag, accessed on May 2, 2014.

[Unger-4] Thomas A. Unger: Pesticide synthesis handbook . 1996, ISBN 978-0-8155-1401-5 , pp. 608 ( limited preview in Google Book search).

[Müfit_Bahadir,_Harun_Parlar,_Michael_Spiteller-5] Müfit Bahadir, Harun Parlar, Michael Spiteller: Springer Umweltlexikon . Springer DE, 2000, ISBN 3-642-56998-6 , pp. 161 ( limited preview in Google Book search).

[6] List of plant protection products in Switzerland. Retrieved May 25, 2019 .

[7] Voted against re-authorization of the herbicidal active ingredient bentazone. Retrieved May 25, 2019 .

[8] Plant protection products: Basagran. Retrieved May 25, 2019 .

[9] European Food Safety Authority: Conclusion on the peer review of the pesticide risk assessment of the active substance bentazone. In: EFSA Journal 2015; 13 (4): 4077. Accessed July 31, 2019 .

[10] Plant protection products in groundwater. In: bafu.admin.ch . Retrieved November 4, 2019 .