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Report on the Health Effects of Selected Pesticide Coformulants

1 Introduction

1.1 Aim of the project

The purpose of the project is to compile and evaluate the available toxicological information on selected coformulants in pesticide formulations in order to assess their adverse health effects. This report is aimed at creating a basis for discussion on whether a revision of the approval scheme for pesticides, as proposed by the Bichel-Committee in their report, is needed (Bichel Committee 1999b).

1.2 Background

Concern in the Danish Parliament on the increasing pesticide pollution, especially of the ground water, resulted in 1998 in the appointment by the Minister of the Environment and Energy of a committee of independent scientists from research, agriculture, green organisations, consumer organisations, food and agrochemical industry, trade unions and relevant ministries. The task of the committee was to analyse the consequences of different scenarios for partial or total phasing out of pesticides in the agricultural industry in relation to the present socio-economic factors related to production and use of pesticides.

This main committee, “the Bichel-Committee”, and its four sub-committees on agriculture; on production, economics and employment; on health and environment; and on legislation, respectively, presented the result of their work in 1999 in four sub-committee reports and a main report. The main report evaluated the consequences, with respect to manufacturing, economy, legislation, health, employment and environment, of the production achieved by the agricultural industries to date. The sub-committees performed cost-benefit assessments of different scenarios for the total and partial phasing-out of pesticides (Bichel Committee 1999a). Based on the report from the subcommittee on health and the environment, the Bichel-Committee expressed concern that coformulants in some cases were more acutely toxic than the active ingredients (e.g., organic solvents) and that some of them were included in the Danish EPA List of undesirable substances (Miljøstyrelsen 1998). The Bichel-Committee recommended that the approval system should be extended so that the requirements on coformulants would approach the requirements set on the active ingredients of pesticides. The committee also recommended that consideration be given to ban all carcinogenic coformulants (MST 1999a).

1.3 Definitions

An existing industrial chemical is a chemical substance or preparation (containing more than one chemical substance) used for general purposes in industry and households, which was present on the market in the EU in  September 1981, when the EINECS-list¹ was formed. These chemicals are not subject to a specific approval procedure, as e.g. for pesticides. Industrial chemicals marketed later than September 1981 are subject to a notification procedure and are referred to as new substances. Many coformulants are existing industrial chemicals.

A pesticide is a plant protection product or a biocide. It is composed of one or more active ingredients and a number of coformulants.

A plant protection product is a pesticide used for pest control (herbicide, insecticide or fungicide) in agriculture, gardening or in forestry.

A biocide is a pesticide used for fungus, bacteria or insect control in non-agricultural use. Examples of biocides are rat-controlling products, mosquito-repellents, disinfection products and wood-protection products.

The active ingredient is the biologically active chemical in a pesticide, which has the actual controlling effect.

A coformulant, also called “inert” or auxiliary substance is a chemical substance, which is added to the active ingredient(s) in a pesticide to obtain better technical affinity of the product to the intended use of the pesticide. Coformulants include carrier substances, solvents, surfactants, dispersing agents, adhesives, absorption-promoting agents, antioxidants, bactericides, dyes, fillers, and perfume.

1.4 Scope

Coformulants include a large number of different chemicals that have various technical and physico/chemical properties in relation to their function in the pesticide formulation. In Denmark, 488 different substances are used as coformulants (Miljøstyrelsen 2003). These chemicals can be expected to have various toxicological profiles, some of them harmless (e.g., water) and some with serious toxicological properties (e.g., the organic solvent isophorone, which is a suspected carcinogen). Coformulants represent 69 % by weight of the pesticides sold in Denmark (1997-figure), corresponding to about 10000 tonnes (MST 1999b).

Therefore, even a minor toxicological concern could become significant in relation to the high amounts of coformulants used in pesticides. A detailed risk assessment would require specific exposure data in order to relate hazard and exposure. However, it is very difficult to obtain data on exposure. The widespread use and handling of pesticides mean that exposure to pesticides and thereby to coformulants may be high in some situations. Furthermore, a large number of coformulants are also marketed as industrial chemicals and thus may contribute to human exposure.

1.5 Existing regulation

1.5.1 Approval procedure

1.5.1.1 Active ingredients

In Denmark, pesticides are regulated by the Statutory Order from the Ministry of the Environment on Pesticides (Miljø- og Energiministeriet 1998) under the Chemical Substance Act. This statutory order is based on the EU directive 91/414/EC on plant protection products (EEC 1991). According to this legislation, all pesticides marketed in Denmark must be approved by the Danish Environmental Protection Agency before their marketing and use in Denmark. The information required to fulfil a request for approval of a pesticide includes the composition of the product. On the active ingredient, a range of analytical methods; data on physico-chemical, toxicological, ecotoxicological properties; and data on environmental fate are mandatory. The toxicological requirements for the active ingredient include studies on acute toxicity, skin and eye irritation, skin sensitisation, short-term and long-term toxicity as well as specific end-points including, toxicity to reproduction, mutagenicity and carcinogenicity. Also metabolism studies on the active ingredient are required. For some of the end-points, studies in two different animal species must be conducted. The studies must comply with specific guidelines (OECD or EU-guidelines) and for toxicological end-points, be performed according to the rules of Good Laboratory Practice. The data requirements on the active ingredient are described in Annex 5.1 and 5.3 to the statutory order on pesticides. (Miljø- og Energiministeriet 1998).

1.5.1.2 Coformulants

The data requirements of the approval scheme also include some toxicological end-points for the pesticide formulations, namely acute toxicity, and skin and eye irritation. The applicant must therefore also provide test results on the specific pesticides for these end-points. Some indications on the acute toxicity and irritative potential of the coformulants used can be derived from this information. However, no information on long-term effects of the coformulants can be derived from these mandatory studies. Coformulants are not themselves at present subject to approval, as there are no specific demands by the authorities for toxicological documentation specifically related to the chemical substances added to the active ingredient in order to produce pesticide formulations. However, the precise composition of the pesticides must be known, so that all component substances can be identified. On this basis, the Danish EPA always requires data sheets containing brief information on physico-chemical and toxicological properties of the coformulants to the extent to which they have been studied (Miljø- og Energiministeriet 1998). A coformulant with a known serious long-term effect present in a pesticide above a certain percentage will trigger classification of the pesticide. Such a classification of the pesticide will entail exposure and risk assessment of the pesticide product with respect to its intended use. On this basis, the Danish EPA can refuse or withdraw approval of a pesticide because of adverse effects of a coformulant, even if the active ingredient is without alarming effects.

1.5.2 Classification and labelling

1.5.2.1 Substances

The rules on classification and labelling of chemical substances are laid down in directive 67/548/EEC (EEC 1967), which is implemented in Denmark by the statutory order from the Ministry of the Environment on classification, packaging, marketing and sales of chemicals (Miljøministeriet 2002a) and in the statutory order from the Ministry of the Environment on the list of dangerous substances (Miljøministeriet 2002b). Classification of a substance consists of a categorisation in classes of danger and so-called risk phrases (R-phrases) describing the intrinsic physico-chemical, toxicological and ecotoxicological hazards of a chemical, and is performed end-point by endpoint. It is performed according to specified criteria based on human as well as animal data, the latter referring to EU guidelines (Annex V to directive 67/548/EEC) and, for pesticides, also other internationally accepted guidelines (Annexes II and III to directive 91/414). Based on recommendations from an EU-group of experts, approximately 7000 chemical substances have until now been classified by the EU-Commission (Annex I to EU-directive 67/548/EEC).

1.5.2.2 Preparations

Preparations are classified according to the directives 88/379/EEC and 1999/45/EC (EEC 1988, EC 1999). Preparations are classified either on the basis of tests performed on the pesticide itself, following the same criteria for classification as for the substances, or by a calculation method taking into account the toxicity and the percentage of each ingredient in the preparation.

1.5.2.3 Classification of pesticides

According to the provisions of the legislation on pesticides, active ingredients and pesticide products are to be classified according to the rules of the classification directives 67/548/EEC (EEC 1967) and 88/379/EEC (EEC 1988). The national authorities classify the active ingredient and the pesticide product on basis of the information available. Thus, the classification of the active ingredient reflects the physico-chemical hazards, and the dangers to human health and to the environment covered by the data requirements. With respect to the pesticide product, classification for health effects will always reflect the toxicological effects of the coformulants with respect to acute toxicity and local irritation, which are the end-points where data are required for the pesticide product. Classification of the pesticide product will reflect long-term and specific effects caused by coformulants if the coformulants are adopted on the list of dangerous substances (Miljøministeriet 2002b).

1.5.2.4 Future regulation

No EU rules have applied hitherto for the classification with respect to specific effects or long-term effects of pesticide formulations. In Denmark, the Danish EPA has practised to classify pesticides for all end-points as non-pesticide preparations, i.e. on the basis of available toxicological information on the ingredients in the pesticide. From July 2004, this practise will be implemented with the new preparations directive 1999/45/EC (EC 1999) in the whole of the EU. The classification of the pesticide product will take into account the known toxicological properties of the coformulants and thus indirectly indicate toxicological effects of the coformulants, if they are expressed in the pesticide classification. However, the classification rules being based on available documentation, the classification of a pesticide containing coformulants where no data are available for a specific end-point will be incomplete.

1.5.3 Safety data sheets

A general requirement exists for every pesticide containing dangerous substances that a safety data sheet must be available at the workplace. The safety data sheet contains information on composition, health and  environmental effects of the pesticide, and first aid measures. However, no testing requirements are laid down in the safety data sheet regulation, which means that they are produced on the basis of available toxicological information.

1.6 Lack of data

The EU Commission has shown that data availability on High Production Volume Chemicals (over 1000 tonnes per manufacturer/importer per year in the EU) in the IUCLID database² was low, e.g., 14% having the minimum information for risk assessment and 21 % having no test data at all on human or environmental toxicity (Allanou et al. 1999). The Danish EPA has investigated the availability of data publicly available in RTECS³. The survey revealed an even lower data availability, as acute toxicity data were available for 13.4 % of the around 100000 industrial substances on the EU market (excluding New Notified substances and Pesticide substances), mutagenicity data for 3.9 %, data for toxicity to reproduction for 2.5 %, and data for carcinogenicity for 1.8 % of the substances (Miljøstyrelsen 2001).

1.7 Related projects

1.7.1 Pilot project on coformulants in herbicides

A pilot project from 1991 under the pesticide research programme was conducted on data availability and toxicity data screen of approved herbicides (Miljøstyrelsen 1992). Based on data from the PROBAS⁴, the study showed that 8571 tonnes herbicides were used in 1990, of which 37 % (3176 tonnes) were coformulants. Of the 105 coformulants identified, 36 substances were present in more than 3 herbicides. Confidentiality rules established for the reporting from chemical companies to the Danish Product Register mean that the identity of substances used in 3 products or less may not be made publicly available. Data on these coformulants were scarce, with only a few references in RTECS², HSDB⁵, the list of dangerous substances, the KRAN-lists⁶ and/or IARC⁷-cancer classification list. For 7 out of 9 substances used in over 100 tonnes, no data were found. The few substances where some documentation was found were listed as toxic, neurotoxicants, reproductive toxicants, allergens, and/or carcinogens. The project concluded that there was limited toxicological information available for the main part of coformulants in herbicides. The available documentation indicated that the coformulants were not toxicologically insignificant. Some of them even had serious toxicological effects (Miljøstyrelsen 1992). The above pilot project calls for an investigation of the toxicology of coformulants, not only in herbicides, but also in all types of pesticides. This information is called for as a basis for evaluating the need to adjust the existing approval system.

1.7.2 Nordic project on coformulants in plant protection products

A Nordic project “Auxiliary substances in plant protection products - their impact on health and environment” was launched in 2000. This project aims at establishing an overview on pesticide coformulants used in the Nordic countries, and create a negative list on substances with known toxicological and ecotoxicological properties and a list of substances to be further investigated for adverse health and environmental effects. The Nordic project will include summaries for health and environmental effects for 22 coformulants and is expected to be finalised in June 2003 (Nordic Council of Ministers 2003, in press). The Danish EPA is represented in the steering committee of the Nordic project, ensuring correlation between the Nordic and the Danish project and that there is no duplication of work in these projects.

______________________________________________________________
¹ EINECS: European Index of Existing Chemical Substances: list of 100 116 chemical substances on the market in the European Union in september 1981, based on notifications from the chemical industry.
² IUCLID database. International Uniform Information Database on High Production Volume Chemicals - reported by the European Industry in the frame of the EU Existing Chemicals Risk Assessment Programme.
³ Registry of Toxicity of Existing Chemical Substances: Database on toxicological references on chemicals. Contains information on ca. 160.000 substances.
⁴ PROBAS: Database on chemical products notified to the Danish Product Register
⁵ HSDB: Hazardous Substance Data Base
⁶ KRAN- lists: 4 lists from the Danish National Occupational Institute identifying carcinogens (K), reprotoxicants (R), sensitiseres (A) and neurotoxicants (N).
⁷ IARC: International Agency for Reasearch on Cancer. WHO research organ.

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