Dicofol

Structural formula
General
Surname	Dicofol
other names	2,2,2-trichloro-1,1-bis (4-chlorophenyl) ethanol; Kelthane;
Molecular formula	C 14 H 9 Cl 5 O
Brief description	colorless crystals (pure substance), viscous oil (technical product)
External identifiers / databases
EC number	204-082-0
ECHA InfoCard	100.003.711
PubChem	8268
Wikidata	Q418183
properties
Molar mass	370.49 g mol −1
Physical state	solid or liquid
density	1.45 g cm −3 for 80% viscous oil
Melting point	77.5 ° C
boiling point	180 ° C (0.13 hPa)
Vapor pressure	1.87 m Pa (20 ° C)
solubility	0.8 mg l −1 in water , 400 g kg −1 in acetone , ethyl acetate and toluene
safety instructions
H and P phrases	H: 302-312-315-317-410
	P: 273-280-501
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dicofol is an acaricide made from DDT . It acts as a contact poison against spider mites and their eggs.

history

The Rohm & Haas company first launched Dicofol in 1955. The Stockholm Convention , which came into force in 2004, restricted the use of DDT to the control of disease-carrying insects and the manufacture of dicofol. If the production takes place outside of closed systems, permits are necessary for this, as currently exist for India and China. The Chinese Ministry of the Environment decided not to extend this permit in July 2008.

Chemical properties

o , p ′ -dicofol

The technical product has a degree of purity of 95%. Of this, 80–85% is p , p ′ -dicofol and 15–20% is o , p ′ -dicofol. The remaining part of the technical product contains residues of DDT and a number of DDT analogues.

Dicofol made in China contained 114 g o , p ′ -DDT, 69 g p , p ′ -Cl-DDT, 44 g o , p ′ -DDE and 17 g p , p ′ -DDT per kilogram. From the use of Dicofol in China, a total DDT of 8770 t was extrapolated for the period from 1988 to 2002. DDT residues of the "Dicofol type" have a high o , p ′ -DDT / p , p ′ -DDT ratio.

use

Dicofol is used as an acaricide in fruit and vegetable growing, in ornamental plants and various crops. It has little effect on insects.

In Germany, Dicofol was mainly used in the cultivation of vines, hops and ornamental plants against spider mites and soft skin mites . It was usually sold as a wettable powder with an active ingredient content of 21.2% and as an emulsion spray with 42.5%.

Admission

In Germany, Austria and Switzerland, pesticides containing this active ingredient are no longer permitted. In 2008, the EU Commission decided against including Dicofol in the list of approved plant protection products because it is harmful to health, the exposure for users is regularly above the acceptable exposure and the risk assessment for consumers is not possible. The member states were obliged to revoke existing approvals by March 30, 2009.

Dicofol was nominated by the European Union for inclusion in the Stockholm Convention in 2013 and included in Annex A at the Conference of the Parties in 2019. The ban on the manufacture and use of Dicofol will come into force in the contracting states from December 2020. India, the only country in which Dicofol is still produced, announced in April 2019 that it would end production before then.

Biological importance

Mississippi alligator

After an accident during the Dicofol production, Dicofol, DDT, DDD , DDE and sulfuric acid ended up in Lake Apopka in Florida in 1980 . Within the next four years, the population of the pike alligator ( Alligator mississippiensis ) decreased by 90%. The mortality of the adult animals was clear, that of the young animals was drastically higher than in a control population. The sex ratio was shifted towards the females and changes in the hormone level and in the sexual organs of the alligators were found. In the laboratory, DDE was used to trigger a gender transition or intersexuality on the eggs of the pike alligator .

Individual evidence

↑ ^a ^b ^c ^d ^e Werner Perkow: Active substances in pesticides and pesticides , 2nd edition, 3rd supplement. Current issue March 1992, Paul Parey publishing house.
↑ ^a ^b ^c ^d Entry on Dicofol in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
↑ Entry on Dicofol 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 Dicofol. In: Römpp Online . Georg Thieme Verlag, accessed on January 3, 2015.
^ Secretariat of the Stockholm Convention: Register of Specific Exemptions , accessed on September 13, 2008.
↑ Chinese Ministry of Environmental Protection: Letter to the Secretariat of the Stockholm Convention (PDF; 226 kB), July 10, 2008.
↑ WHO / FAO Data Sheets on Pesticides, No. 81, dicofol . 1996 ( who.int [PDF]).
^ Pesticide Management Education Program (PMEP): dicofol (Kelthane) Chemical Fact Sheet 12/83 .
↑ Xinghua Qiu, Tong Zhu, Bo Yao, Jianxin Hu, Shaowen Hu: Contribution of Dicofol to the Current DDT Pollution in China . Environ. Sci. Technol. , 39 (12), 4385-4390, 2005, doi : 10.1021 / es050342a .
^ Pesticide Information Profile Dicofol at Extoxnet, as of September 1993.
↑ General Directorate Health and Food Safety of the European Commission: Entry on Dicofol in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on February 22, 2016.
↑ Decision of the Commission of September 30, 2008 on the non-inclusion of Dicofol in Annex I of Council Directive 91/414 / EEC and the revocation of the authorizations for plant protection products containing this substance (PDF) .
^ Chemicals proposed for listing under the Convention
↑ UNEP / POPS / POPRC.9 / 3 : Proposal to list dicofol in Annexes A, B and / or C to the Stockholm Convention on Persistent Organic Pollutants, 2013.
↑ 2019 Meetings of the Conferences of the Parties to the Basel, Rotterdam and Stockholm Conventions - Highlights for Monday, 29 April 2019 , ENB report, 29 April 2019.
↑ Plant protection products are banned. In: schweizerbauer.ch . April 30, 2019, accessed May 1, 2019 .
^ Advisory committee for existing substances of the Society of German Chemists : DDT and derivatives - model substances for the description of endocrine effects relevant to reproduction. BUA-Stoffbericht 216, S. Hirzel Verlag, August 1998, ISBN 3-7776-0961-7 .

[Perkow-1] Werner Perkow: Active substances in pesticides and pesticides , 2nd edition, 3rd supplement. Current issue March 1992, Paul Parey publishing house.

[Gestis-2] Entry on Dicofol in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .

[CLP_100.003.711-3] Entry on Dicofol 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-4] Entry on Dicofol. In: Römpp Online . Georg Thieme Verlag, accessed on January 3, 2015.

[5] Secretariat of the Stockholm Convention: Register of Specific Exemptions , accessed on September 13, 2008.

[6] Chinese Ministry of Environmental Protection: Letter to the Secretariat of the Stockholm Convention (PDF; 226 kB), July 10, 2008.

[7] WHO / FAO Data Sheets on Pesticides, No. 81, dicofol . 1996 ( who.int [PDF]).

[8] Pesticide Management Education Program (PMEP): dicofol (Kelthane) Chemical Fact Sheet 12/83 .

[9] Xinghua Qiu, Tong Zhu, Bo Yao, Jianxin Hu, Shaowen Hu: Contribution of Dicofol to the Current DDT Pollution in China . Environ. Sci. Technol. , 39 (12), 4385-4390, 2005, doi : 10.1021 / es050342a .

[10] Pesticide Information Profile Dicofol at Extoxnet, as of September 1993.

[PSM-11] General Directorate Health and Food Safety of the European Commission: Entry on Dicofol in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on February 22, 2016.

[12] Decision of the Commission of September 30, 2008 on the non-inclusion of Dicofol in Annex I of Council Directive 91/414 / EEC and the revocation of the authorizations for plant protection products containing this substance (PDF) .

[13] Chemicals proposed for listing under the Convention

[14] UNEP / POPS / POPRC.9 / 3 : Proposal to list dicofol in Annexes A, B and / or C to the Stockholm Convention on Persistent Organic Pollutants, 2013.

[15] 2019 Meetings of the Conferences of the Parties to the Basel, Rotterdam and Stockholm Conventions - Highlights for Monday, 29 April 2019 , ENB report, 29 April 2019.

[16] Plant protection products are banned. In: schweizerbauer.ch . April 30, 2019, accessed May 1, 2019 .

[17] Advisory committee for existing substances of the Society of German Chemists : DDT and derivatives - model substances for the description of endocrine effects relevant to reproduction. BUA-Stoffbericht 216, S. Hirzel Verlag, August 1998, ISBN 3-7776-0961-7 .