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Swedish experience of chemical substitution

In the last ten years, Swedish regulators have demonstrated their commitment to reducing the risks of pesticide use, and have become pioneers in the use of comparative assessment. Their aim is to avoid authorising or using a pesticide of concern for which less risky substitutes are available. Peter Bergkvist of the Swedish Chemicals Inspectorate (KEMI) reports.

In 1991, an international meeting on pesticide regulation, held in Sweden , concluded that ‘The present use of agricultural pesticides is often not optimal either from a sustainable agricultural point of view, or from an environmental, occupational or public health point of view.’ An ambitious plan was formed and is being implemented by regulators significantly to improve systems for the authorisation and use of pesticides by 2011.
    Comparative assessment and substitution are used in their simplest forms in everyday life: as humans, we select the least risky course of action and substitute an alternative without thinking about it. This principle has now been adopted by regulators in the approval of pesticides and other chemicals.
    It is essential to build confidence among all stakeholders – farmers, consumers, agrochemical supply companies, environmental organisations and others – in the regulatory system, and its implementation of sustainable pesticide use policies. An effective and transparent implementation of the precautionary principle is essential, and the use of comparative assessment and substitution when appropriate is a necessary part of this. Where no suitable alternatives exist, a suitable phase-out period must be built in to give time for agricultural producers to adapt.
    Regulators do not need new systems which complicate what they already have to do, and comparative assessment also allows swift decision-making without a loss of quality or predictability. 

The role of science in policy
Many of today’s pesticides are acceptable in terms of health and environmental effects and merit approval. However, some pesticides are of high or very high concern, and if we were to approve a health-threatening pesticide today that became the equivalent of a persistent organic pollutant (POP) tomorrow, the approval system would be discredited.
    Science cannot easily serve policy issues, and society tends to push scientists and their managers to come up with simplistic solutions, which exaggerate scientific influence in a problem. When this occurs, non-experts including citizens and politicians, tend to develop unrealistic expectations about what science can deliver.
    Science cannot deliver safety for health or the environment: only political and regulatory decisions can do that, taking scientific uncertainties into account. A trustworthy system does not ‘over-sell’ science. Policy-makers need to face up to the value judgements that must be made in pesticide regulation. There is no point in asking for more data if it is not likely to change the decision. Endless scientific data will not solve policy issues; instead, scientific uncertainty must be taken into account in the formulation of policy.
    Comparative assessment is the precautionary principle in practice: it offers alternative solutions, in a transparent way, where there is uncertainty over the potential risks of pesticides. The precautionary principle should be used when emerging problems, such as endocrine-disrupting chemicals, create uncertainty, and when trigger-values for substances of high concern are exceeded. Although the principle is mentioned in the preamble of Directive 91/414, there is a clear need to amend the text to allow the principle to be implemented. There is also a need to more clearly shift the burden of proof onto those who want to market these products.

Three hypothetical examples illustrate the way KEMI implements comparative assessment

Example 1
There is an application for substance A to be used as a herbicide for spring application in cereals. It is:

  • Highly mobile
  • Persistent
  • Very toxic to several aquatic organisms
  • The exposure to non-target plants, aquatic ecosystems and groundwater could be considerable.

Three other herbicides belonging to the same chemical group are on the market with significantly better properties. It is possible to reject the approval of substance A.

Example 2
Substance B is used as a herbicide in carrots, onions, beans, cereals. It is:

  • Persistent
  • Bioaccumulating
  • Volatile
  • Very toxic to different aquatic organisms

Other herbicides on the market have significantly better properties for all crops except carrots, onions and beans. Therefore authorisation is given only for carrots, onions and beans until better chemical or non-chemical alternatives are available.

Example 3
In reviewing existing sugar-beet herbicides containing the same active ingredient, four out of six are based on an organic solvent D. The remaining two are instead based on an oil-miscible flowable concentrate containing vegetable oil.
    Solvent D is known to be a severe irritant to the skin, eyes, nose and throat of exposed workers. Therefore re-approval of the four solvent D based products are rejected.

The Swedish model
Sweden’s chemical inspectors, KEMI, provide the best working model for comparative assessment. It is based on the view that it is difficult to quantify potential risks in absolute terms, but they can easily be compared and ranked. Our system operates through the use of cut-off criteria and products with similar uses are ranked using key endpoints.
    There are three main situations in which comparative assessment comes into play in the Swedish system: during a review; in considering a new product; when a new product may displace an existing product or products. If substitution is to be implemented, the alternative product must present significantly less risk to health or the environment; it must be sufficiently effective against the target organisms; it must not impose any significant economic or practical disadvantages on the user, and must be available and applicable for the use intended.
    Resistance management must be carefully considered, particularly if there are few alternatives, before comparative assessment is required. The alternatives must be appropriate in all the relevant situations. Finally, the level at which substitution should take place – active ingredient, product, advisor, or farmer – and the scope for defining the riskiest use-areas for substitution must be considered.
    Regulators have to consider a number of factors when applying comparative assessment. The difference in risks between a proposed product and those already available has to be significant to justify a refusal on the grounds of comparative assessment. If it is not possible to decide which is the least dangerous substance, comparative assessment cannot be used. Regulators have to identify all or some of the alternatives, and if there is only one, the possibilities for substitution are reduced. If there are so few alternatives on the market that the development of resistance can be anticipated, comparative assessment cannot be applied. If only some of the uses are covered by the alternatives, this is defined as partial substitution.
    Consideration needs to be given as to what level substitution is applied to: active ingredient, product, advisor (the extension service) level, or at farmer level. 
    The most hazardous or risky products, in the ‘red’ zone, are phased out because of their unacceptability; products in the ‘amber’ zone are subject to comparative assessment and substitution using a phase out period, usually five years, to be replaced with less hazardous products in the ‘green’ zone. It is possible for a manufacturer to reformulate a product or amend rules for good agricultural practice (GAP) to reduce the ranking and thus allow continued sale on the market.
    The system has been operating for ten years now and a substantial number of substances and products have been removed through the adoption of comparative assessment. KEMI believe comparative assessment could include both product and active ingredient. However to make substitution an effective regulatory instrument, comparative assessments should primarily be used at product level. The question ‘Are there any safer alternative options?’ is always considered when we evaluate any pesticide.
    KEMI also believe that it is important for key stakeholders to be involved in regulatory implementation, as this can encourage adoption of further voluntary measures. For example, the island of Gotland has a sensitive limestone geology, to which sulfonyl-urea based herbicides pose a particularly high risk. The agrochemical marketing companies and farmers on the island agreed voluntarily that these products were not used.
    Comparative assessment has the potential to be a valuable tool for risk reduction in the European Union. It gives signals to manufacturers about which are the highest risks to be avoided where possible – provided there are alternatives available. 

Edited presentation to the Pesticide Challenge conference, November 2003, Peter Bergkvist, Swedish Chemicals Inspectorate (KEMI),,

[This article first appeared in Pesticides News No. 58, December 2002, pages 14-15]

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