The Applicant Guide: Completing An Application Overview For Operator And Consumer Exposure
How do I address risks to operators, bystanders and workers?
Contents
1. What data are used in the assessment of operator, bystander and worker (re-entry) exposure?
2. What applications will require an assessment of operator exposure?
3. How will the assessment of operator exposure be carried out?
a) Use of risk assessment for previously approved products
b) Use of a tiered approach
c) Personal Protective Equipment
d) Quantitative assessments of exposure
e) Changes in packaging
4. How will the assessment for amateur users of pesticides be carried out?
5. How will the bystander/resident exposure assessment be carried out?
6. How will the assessment for re-entry into treated areas be carried out?
What data are used in the assessment of operator, bystander and worker exposure?
We use data and other information to assess the risks to operators/bystanders/workers and other persons resulting from the use of the product as recommended on the label. Exposure is dependent upon many factors including formulation type, crop/situation, application rate, water volumes and methods of application. It may be possible to make a reasoned case for operator exposure based on precedent from existing or previously approved products. See Use of exposure assessment for previously approved products. In some instances you may need to compare the predicted exposure with the Acceptable Operator Exposure Level derived from data on mammalian toxicology. See Use of a tiered approach for risk assessment.
The European Commission website specifies the data requirements for products to be approved under Council Directive 91/414/EEC (see Annex III). The Plant Protection Product Regulations 2005 (PPPR)) and additional guidance in Chapter 4 of The Data Requirements Handbook may also be used to provide supplementary guidance for the assessment of operator bystander/resident and worker exposure. Specific guidance on addressing operator, bystander/resident and worker exposure for plant protection products to be considered for re-registration is available here.
Any exposure studies conducted should comply with the OECD ‘Guidance Document for the Conduct of Studies of Occupational Exposure to Pesticides during Agricultural Application’ (obtainable from OECD Environment Directorate Environmental Health and Safety Division, 2 rue Andre-Pascal, 75775 Paris, Cedex 16, France or from their website). In some circumstances it may be possible to submit a valid scientific case in lieu of data e.g. a case based on usage data for modifying the previous exposure estimates, or in other situations it may be possible to submit further toxicology data e.g. data to support an alteration to the dermal penetration figure. The exception to this would be the submission of data to address a ‘me-too’ data requirement. These data are required to ensure comparability to existing products and to ensure a comparable requirement for entry into the market as was set for the first approval holder. In this context there may be less scope for a case to be acceptable in lieu of exposure data.
What applications will require an assessment of operator exposure?
The following changes to previously considered uses may affect the operator exposure risk assessment:
- new products; or,
- increase in application rate of the active substance; or,
- change in application method; or,
- change in crop/situation; or,
- change in scale of use; or,
- increase in in-use concentration, i.e. reduction in recommended minimum water volume; or,
- change in size and or design of container; or,
- change in formulation type; or,
- change in field of use (e.g. professional to amateur); or,
- change in recommended Personal Protective Equipment (PPE); or,
- any change to the Acceptable Operator Exposure Level (AOEL), change in hazard classification or amendment to the dermal penetration values.
How will the assessment of operator exposure be carried out?
You must address the exposure to the operator in the light of the proposed use. A quantitative assessment of operator exposure should be made where the proposed use falls outside of precedent from existing or previously approved products, for example, if a different method of application is proposed. Consideration of these points may indicate the need for an operator exposure study. This section provides guidance on methods that may be used when conducting an operator exposure assessment.
Use of exposure assessment for previously approved products
It may be possible to make a reasoned case for operator exposure based on precedent from existing or previously approved products, providing that appropriate data access is obtained where necessary (to any relevant confidential toxicology and/or operator exposure data). In the case of any previously approved products, the supporting data can only be used where approval was not revoked on toxicological or operator exposure grounds. The case could be presented on the basis of comparison between the maximum active substance application rates, on condition that all other factors (e.g. water volumes, application methods, pack sizes) are comparable or, alternatively, on the basis of similar estimated exposure levels.
Use of a tiered approach for risk assessment
In the absence of any satisfactory precedents, you should follow a tiered approach.
Tier 1
An initial estimate of exposure is derived considering the relevant usage scenario and using a generic model or other appropriate method. This estimate should be compared with an appropriate AOEL. Should the exposure estimate be at, or within the AOEL, then approval may be recommended.
Tier 2
For those products that exceed the AOEL it may be possible to refine the original exposure estimate. For example, the dermal absorption figure may be refined with the provision of actual data or you can make refinements to the actual usage scenarios to more accurately reflect the proposed use of the product.
Tier 3
Should the exposure estimate still exceed the AOEL then you may need to carry out field exposure studies and/or perform biological monitoring studies under the proposed conditions of use. These studies should comply with the OECD ‘Guidance Document for the conduct of Studies of Occupational Exposure to Pesticides during Agricultural Application’. Specific exposure studies can only be used in preference to model predictions if there is evidence that they are more representative and realistic.
Personal Protective Equipment
The appropriate PPE specified for a product is determined by two separate factors.
- The hazard classification of the product. Certain toxicological classification may require specific PPE to be worn e.g. an eye irritant may necessitate the wearing of a face shield when handling the concentrate. The PPE imposed however depends upon the severity of the effects demonstrated in the toxicological tests and the risk of exposure.
- Additional PPE may be required to reduce exposure to an acceptable level when using the product according to the label recommendations (e.g. opening, mixing, loading, applying, cleaning and handling contaminated surfaces). This will be based on the operator exposure risk assessment.
We cannot recommend any approval for products used in the home garden sector for which PPE is required to ensure that risk to operators is within acceptable limits.
Quantitative assessments of exposure
Liquid formulations
The ‘Predictive Operator Exposure Model’ (POEM) may be used to estimate levels of operator exposure for pesticide products applied as sprays. Full details of this model are given in SC 8001 (1986), Martin (1990) and ‘UK Predictive Operator Exposure Model: A Users Guide 1992. POEM does, however, have its limitations; it can only be used in a limited number of application scenarios and the only PPE which can be modelled are gloves, worn during mixing and loading and/or application.
Wettable powders (WP) and water dispersible granules (WG)
For WP or WG formulations, the 75th percentile (or maximum where the datasets are small) values for dermal and inhalation exposure from the German Model, EUROPOEM database or Pesticide Handlers Exposure Database (PHED) should be used to estimate exposure during mixing and loading. The current version of ‘POEM’ incorporates these mixing and loading data, with the appropriate values taken from the different databases used to estimate exposure for mixing/loading for different formulation types and application equipment.
A guidance document is available reviewing the data currently used in UK POEM to estimate exposure to operators through inhalation or hand exposure when mixing/loading plant protection products. As well as the original POEM data used for liquid formulations, the guidance document also provides a summary of the data derived from the German model, PHED and EUROPOEM databases for mixing and loading WG and WP formulations.
Granular formulations (GR and FG)
Operator exposure data for application of granules are limited and European models are not available to estimate exposure for granule formulations. However, the Pesticide Handlers Exposure Database (PHED), developed by the US Environmental Protection Agency, National Agricultural Chemicals Association and Health Canada, has data on dermal and inhalation exposure from a large number of field studies. CRD has selected appropriate data from this database to estimate dermal and inhalational exposure for professional operators when handling and applying granular pesticides . The 75th percentile exposure values from these data subsets can be used to estimate operator exposure resulting from uses of granular formulations assuming that gloves are worn for all activities. A spreadsheet is available covering the use of granule formulations applied via tractor-mounted equipment and hand-held equipment. A summary of the selected data sets taken from the PHED to compile these exposure models is available from CRD upon request.
Alternative exposure data are available for the amateur use of granular pesticides.
Seed treatments
An exposure assessment to address the operator, bystander and worker exposure arising during the seed treatment process and the sowing of treated seed is required.
Pesticide containers: guidance on operator exposure considerations.
A guidance document is available on the specific operator exposure issues and data requirements which relate to pesticide containers. Separate guidance is available on formulation chemistry data requirements which relate to pesticide packaging.
This guidance describes:
· how different types of packaging can affect the level of operator exposure during mixing and loading operations;
· the container-related data requirements, label phrases and descriptions for notices of approval; and
· how to assess the level of operator exposure resulting from situations where a ready-to-use pesticide is applied directly from the container.
How will the assessment for amateur users of pesticides be carried out?
Guidance on predicting the exposure of amateur users applying home garden pesticides is available. It is possible in some circumstances (e.g. watering cans) to derive an estimate of exposure using POEM modified to take into account realistic usage area, work rates, application duration etc. In other situations (e.g. trigger spray packs, puffer/shaker packs, aerosols) specific models are available. Where no appropriate model is available then a case should be made considering first principles or assuming reasonable worst case scenarios.
This guidance also covers the exposure of children who may re-enter a garden soon after areas have been treated.
Approval cannot be recommended for any product used in the home garden sector where the use of personal protective equipment (PPE) is required to ensure the risk to users is within acceptable limits. The appropriate PPE specified for a product is determined by two separate factors, the hazard classification and the exposure assessment .
Limitations on the maximum pack size have now been established for Garden Pesticides. Additional guidance on packaging requirements for amateur products is available here.
How will the bystander/resident exposure assessment be carried out?
A bystander/resident exposure model is being developed. The Bystander and Residential Exposure Assessment Model (BREAM) is a Defra funded project which sets out to develop an exposure model to assess the potential exposure to pesticides for bystanders and residents. The BREAM project is due to be completed in 2010. The approaches outlined in this guidance document will be reviewed as the BREAM project progresses.
A document which describes how CRD have recently assessed bystander/resident exposure for pesticides which are of low volatility and which are typically applied as sprays either by field crop (boom) sprayers, broadcast air assisted (orchard) sprayers or hand held (knapsack) sprayers is available here.
For pesticides applied as gases and those which act through significant vapour action, for example fumigants and soil sterilants, compound specific data on residues in air during and following application are required to support approval. Applicants are invited to discuss any proposals for conducting such work with us prior to generating these data.
How will the assessment for re-entry into treated areas be carried out?
An overview of the scenarios in which post-application exposure to workers and the public may occur and guidance on how levels of exposure for these scenarios could be assessed is available here. Worked examples are included in this guidance document. With the exception of children’s exposure, the approaches described are in line with those proposed by the EUROPOEM Group.
How do I generate data on residues/consumer exposure?
What data are used in the assessment of consumer exposure?
Data on crop/animal metabolism and crop residues used to assess the risks to consumers resulting from the use of the formulation as recommended on the label, i.e. their exposure to pesticide residues from the primary and following crops, crop derivatives or livestock to which the crop has been fed. Consumer exposure is dependent on the formulation, the crop and other conditions of use.
Guidance on data requirements:
- Residues active substance data requirements for approval are given on the European Commission website for active substances; and,
- Residues formulation data requirements for approval are given on the European Commission website for the formulation; and,
- Chapter 5 of The Data Requirements Handbook.
What applications will require an assessment of consumer exposure?
New products, new uses of existing products and any changes to existing conditions of approval or other label claims/recommendation which may affect consumer exposure.
Examples of changes to existing approvals that may increase exposure include:
- crop type and whether indoor or outdoor; and,
- increased maximum rates, number of treatments, maximum total dose and latest timing; and,
- changes in formulation.
How will the assessment of consumer exposure be carried out?
Approval of new uses
You will need to address consumer exposure arising from the proposed use of the product. This can be done by either the submission of relevant metabolism/residues data or if not available, it may be possible to extrapolate residues data which support a similar use in another formulation (i.e. show that consumer exposure will be within that previously considered for another product).
Submission of new data
Where new data relating to crop residues have been submitted to support approval, the data should be summarised in the format of an OECD dossier guidelines or EC dossier guidelines Tier I Summary.
Submission of reasoned cases
This section of the Application Overview should be used where consumer exposure is being addressed by extrapolation of a previous risk assessment or a reasoned case as to why the consumer risk assessment or a data requirement need not be addressed (i.e. new data are not submitted with a Tier 1 Summary).
Extrapolation of a previous risk assessment may be most clearly presented as a tabulated comparison between the relevant conditions of use of the approved and proposed formulations, ideally in the form of a comparison as shown below. This example assumes that the proposed product contains two active substances and residues data are to be extrapolated from two products each containing one of those active substances.
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Proposed product (containing active substances 'x' and 'y'). |
Approved product (containing active substance 'x'). |
Approved product (containing active substance 'y'). |
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Crop: |
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Maximum individual dose: (g a.s./ha) |
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Latest time of application |
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Maximum number of treatments (per crop) |
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Maximum total dose (g a.s./ha/crop) |
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- Where the formulations of the proposed and approved products are different, you must explain why extrapolation of data between the formulations is acceptable (see below).
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Where the approved conditions of either of the approved products fall outside of those proposed such that the residues data are not relevant, you should address this with a reasoned case or data.
Approval for changes in formulation
Where a formulation change is requested for an existing approved product, you must address the effect on consumer exposure. The following changes will, in general, allow the previous risk consumer risk assessment to be extrapolated between different formulations. This guidance also applies to extrapolation of consumer risk assessments between different formulations as discussed in 'Approval of new uses' above.
- It is usually possible to extrapolate between different formulations of the same type where the harvest interval >14 days.
- For seed treatments and pre-crop emergence spray applications, extrapolation between all formulation types and different formulations of the same type is usually acceptable.
- For formulations which give a solid dispersion or solution in a spray tank (e.g. suspension concentrate, wettable powder, water dispersible granules, soluble concentrate, tablet, water soluble granules) and the harvest interval is >14 days, extrapolation of data between those formulation types and different formulations of the same type is usually acceptable.
- For solid formulations which are applied undiluted (e.g. granules, microgranules and fine granules) residues data between those formulation types and different formulations of the same type is usually acceptable.
Where a change falls into one of these categories, you should reference the above guidance and provide an explanation as to how the difference falls within those definitions. Any other changes should be fully addressed with reasoned cases or data.
The following extrapolations between different formulation types may not be acceptable and will be considered on a case by case basis:
- Extrapolation between emulsifiable concentrates and other formulations, other than for pre-crop emergence use. If such an extrapolation is proposed, the applicant should provide at the least a reasoned case based on comparison of the components and the conditions of use.
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Extrapolation (in either direction) between slow release formulations and any other formulation types.
Where any of these extrapolations are to be used in an application, you should reference the above guidance and provide an explanation as to how the difference falls within those definitions. Any other extrapolations should be fully addressed with reasoned cases or data.
The contents page for The Applicant Guide
Guidance documents for The Applicant Guide
The contents page for the Application Overview
General information on the Application Overview
Information on generating chemistry and toxicology data
Information on generating fate and behaviour, ecotoxicology and efficacy dataconstrution