Ddt in Dicofol

DDT IN DICOFOL

Authors : E.J. van de Plassche, A.M.G.R. Schwegler, M. Rasenberg and G. Schouten

CONTENTS

Page

1 INTRODUCTION 1

2 PRODUCTION OF DICOFOL 2 2.1 Method of synthesis of dicofol 2 2.2 Production within the UN-ECE 2 2.3 Production outside the UN-ECE 2

3 REGULATIONS WITH RESPECT TO THE TECHNICAL SPECIFICATIONS OF COMMERCIAL DICOFOL 3

4 CONCLUSION 4

5 REFERENCES 5

APPENDIX 1 6

1 INTRODUCTION

The Protocol to the 1979 Convention on Long-Range Transboundary Air Pollution on Persistent Organic Pollutants states in Annex II that the use of DDT is restricted to: S for public health protection from diseases such as malaria and encephalitis; S as a chemical intermediate to produce dicofol.

The Protocol requirements with respect to the first restriction are discussed elsewhere. In relation to the use of DDT (cas number: 50-29-3) as feedstock for the production of dicofol (cas number: 115-32-2) the Protocol states that ”such use shall be reassessed no later than two years after the data of entry into force of the present Protocol”.

This document describes the current use of DDT as feedstock for the production of dicofol. It should be stated that the Protocol has not yet entered into force.

A questionnaire was sent out by the UN-ECE secretariat by the end of 2001 to obtain information. The questions and the responses are summarised in Appendix 1. In total 24 parties to the LRTAP Convention responded to the questionnaire. Information was also retrieved via literature search and contacts with producers of dicofol.

2 PRODUCTION OF DICOFOL

2.1 Method of synthesis of dicofol

Dicofol - the active ingredient being a mixture of approximately 80% p,p’-dicofol and 20% o,p’-dicofol - is produced by hydroxylation of DDT as emulsifiable concentrate and wettable powder formulations. This implies that: S a producer can purchase DDT and use DDT as a feedstock or starting material to produce dicofol; S a producer can make DDT as an intermediate or precursor in house first and subsequently produce dicofol from DDT. The advantage of this method is that it elimi- nates the need to transport DDT itself. DDT was first synthesized in research on dyes as early as 1874 by Ziedler. DDT as an insecticide was discovered by P.H. Müller working at J.R. Geigy in 1939. DDT is produced from chloral (trichloraceticaldehyde), monochlorobenzene and oleum (fuming sulphuric acid: sulphuric(VI)acid containing an excess of sulphur trioxide).

2.2 Production within the UN-ECE

From the information obtained via the questionnaire it was concluded that dicofol is produced only by Montecinca,S.A. in Barcelona, Spain under contract to Dow Agro- Sciences (prior owner being Rohm and Haas). Dicofol made and sold by Dow AgroSciences carries the trademark KELTHANE®. Their production route involves the in house production of DDT as a precursor from trichloraceticaldehyde, monochlorobenzene and oleum.

Based on other sources two other producers within the UN-ECE were found: - in Spain dicofol is probably also produced by Mariano Fernendez Tarrats (source: HPV-LPV database, European Chemicals Bureau). No information could be obtained on the production process. In Italy dicofol is imported but not produced by SipCAM SpA. - in Israel Makhteshim-Agan is probably producing dicofol (source: Internet). No information on the production process could be obtained.

Based on the information received, it can be concluded that within the UN-ECE region dicofol is produced by certainly one and maybe two other companies. For one company it is known that DDT is produced as an on-site intermediate in order to make dicofol. For the other two companies no information is available.

2.3 Production outside the UN-ECE

In China dicofol is produces by the Yangzhou Pesticide Factory which reports production quantities of 2000 ton dicofol per year (source: Internet). Production is also reported by Hindustan Insecticide Ltd., New Delhi (India). No information on the production process used in China or India could be obtained.

According to Dow AgroSciences dicofol is also produced in Brazil. No information on the production process could be obtained.

3 REGULATIONS WITH RESPECT TO THE TECHNICAL SPECIFICATIONS OF COMMERCIAL DICOFOL

In several countries or international organisations commercial dicofol has to meet stan- dards with respect to: S the minimum content of the p,p'-isomer; S the maximum content of DDT and related substances (abbreviation: DDTr). Dico- fol produced from DDT contains some DDT and DDT analogues, o,p’-and p,p’- isomers, DDD, DDE and Cl-DDT. Up to 18 impurities of dicofol have been reported.

The following (inter)national regulations excist: S EU Council Directive 79/117/EEC prohibits use and marketing of products containing less than 78% p,p’-dicofol or more than 1 g/kg (equal to 0.1%) of DDTr; S FAO Specification 123/TC/S/F (1992) requires DDTr to be less than 0.1%; S the limit of 0.1% of DDTr is also in place in the USA and Canada. According to information from Dow AgroSciences this limit applies also in Japan, Australia and Argentina. Information from other countries is not available.

The critical issue is if dicofol is purified to meet the stringent specifications set in many, but no all countries worldwide. KELTHANE® produced by Dow AgroSciences is purified on-site to meet the 0.1% DDTr limit. The DDTr content of 'raw' dicofol produced by Dow AgroSciences and employed as feedstock for purification is unknown, but any manufac- turing wastes - including those containing DDTr - are destroyed through appropriate techniques like high-temperature incineration.

As stated in chapter 2 no information could be obtained from other producers - in or outside the UN-ECE - on the production process of dicofol. Subsequently, the content of DDTr in commercial dicofol made by these producers is unknown. A content of 3.5% DDTr of dicofol produced by a company in India has been reported, however.

4 CONCLUSION

Based on the information received it can be concluded that within the UN-ECE region dicofol is produced by certainly one and maybe two other companies. Dicofol is also produced outside the UN-ECE region. For Dow AgroSiences in Spain it is known that DDT is produced as a site-limited intermediate which is used as feedstock to produce dicofol. For the other companies no information is available.

The way of production used by Dow AgroSciences proves that DDT is not an essential component in order to make dicofol. The allowed use of DDT as feedstock is from a technical point of view therefore no longer necessary. Socio-economic considerations like unfair trade issues may lead to the decision to maintain the exempted use of DDT for the production of dicofol in the Protocol. This discussion is outside the scope of the present dossier, however.

5 REFERENCES

Anonymous (2000). Pesticide Information Profiles. EXTOXNET, Extension Toxicology Network. http://ace.orst.edu/info/extoxnet/pips/dicofol.htm.

Council Directive 90/533/EEC of 15 October 1990 amending the annex to Directive 79/117/EEC prohibiting the placing on the market and use of plant protection products containing certain active substances. Official Journal L 296, 27/10/1990, p. 63.

E-mail from K. Racke (Dow AgroSciences) to E. van de Plasssche (Royal Haskoning) 29 May 2002.

Racke, D.R. (2002). Dow AgroSciences' Comments on "Information dossier on DDT used for the production of Dicofol, Final Report, 26 April 2002" prepared by Ministry of VROM/DGM.

Appendix 1

Information obtained via the questionnaire sent out by the UN- ECE Secretariat.

Table 1: Questions and responses with respect to the use of DDT as feedstock for the production of dicofol.

UN-ECE mem- Is dicofol produced in your Is DDT used for the produc- What other production proc- Is the amount of DDT in commercial dicofol What is the actual amount of ber state country? tion of dicofol? ess is used? regulated? DDT in commercial dicofol? Albania Armenia No production No information on use available. Austria No production Belgium No production Bosnia & Herzegovina Bulgaria Canada No production Use is allowed, amount of DDT is regulated (max 0.1 %) Croatia No production Dicofol is included in Poison list, but as a product it is not registered. Active substance is still in official Poison list, but product made with this active substance has no use licence because of unacceptable toxicology and metabolic problems. Procedure for removing active substance from the Poison list is in progress. Cyprus Czech Republic No production Denmark No production Estonia Finland No production Former Yugo- slav Republic of Macedonia France No production Concentration DDT is regulated to be < 0.1 %. Georgia No production Dicofol is not used for (agricultural or) any pur-

UN-ECE mem- Is dicofol produced in your Is DDT used for the produc- What other production proc- Is the amount of DDT in commercial dicofol What is the actual amount of ber state country? tion of dicofol? ess is used? regulated? DDT in commercial dicofol? poses, it is not included in the list of substances allowed for the use, there is no traditional use among parties involved (custom, distribution, storage, end-use) Germany No production Dicofol is no longer used for agricultural pest control since 1992. Other application areas as well as amounts are not known. Greece Hungary Iceland Ireland Israel Italy No production, Dicofol is imported as raw material and is used after purification for the formulation of products containing dicofol. Kazakhstan No production No regulation for the maximum amount of DDT in Dicofol. Latvia No production No use Luxembourg Monaco, Prin- No production cipality of Netherlands No production Use is banned Norway No production No use Poland No production Dicofol is banned from use Portugal Republic of No production Dicofol not included in register of permitted sub- Moldova stances for use in agriculture, including individual

ing. (SO3 and H2SO4) Maximum amount of DDT (and related com- pounds) in commercial dicofol < 1 g/kg. Sweden No production No use Switzerland No production There is no registration of dicofol in Switzerland. It means that this product is not used or produced. Turkey Turkmenistan Ukraine United King- “No information that dicofol is Dicofol is used at 1ton per year. Importers of dicofol were re- dom produced in the UK” luctant to disclose typical analysis. United States No production Use is allowed, amount of DDT is regulated (max 0.1 %) Uzbekistan Yugoslavia