Detailed record of discussion
Chairman: Professor J G Ayres
Deputy Chairman: Dr D Osborn (Chaired item 12 onwards).
Members: Ms A Baker, Prof C Brown, Mr J Clarke, Prof G Hawksworth, Prof C V Howard, Ms R Howell, Dr A Leake, Prof L Maltby, Dr M McPherson, Prof P Matthiessen,
Prof C Ockleford, Dr H Rees, Dr V K Tohani.
Assessors: Ms G Asbury (FSA), Mr T Davis (PSD).
Advisers: Mr J Battershill (HPA), Dr J Best (EN), Mr R Davis (PSD), Dr S Kinghorn-Perry (HSE), Dr B Maycock (FSA), Dr E Pemberton (EA), Dr K Wilson (PSD).
Secretariat:Ms J Wilder (PSD) Secretary, Mrs R Brown (PSD) Minutes secretary, Mr P Fisher (PSD)Minutes secretary.
Other attendees:Mr M Curtis (PSD), Mr J Dale(PSD), Dr I Dewhurst (PSD), Mr P Hamey (PSD), Mrs C Hetherton (PSD), Dr J Hingston (PSD). Mrs E Hives (PSD), Mr S Hoy (PSD),
Dr P Johnson (PSD), Mrs E Jenkins (PSD), Ms C Kennedy (PSD),Mrs S Mattock (PSD),Dr J O’Leary Quinn (PSD), Mr D Richardson (PSD), Mr S Samuels (PSD), Mrs R Savege (PSD),
Miss T Ware (PSD).
1.1 Apologies were received from: Dr J Cherrie, Prof D Colman, Dr C Elcombe, Dr R Waring, Dr M Camlin (DARDNI), Mr S Dyer (DH), Ms L George (NAWAD), Dr C Griffiths (SASA)
2.1 The Chairman reminded Members of the confidentiality of the papers and their discussions. If Members believed that they had a commercial or financial interest in any of the items being discussed, they should declare their interest as soon as the meeting moved on to that agenda item. They would then not take part in the discussion, nor would they be involved in any decision taking, unless invited to do so by the Chairman.
2.2 The Chairman welcomed four new ACP members, Ms Baker, Prof Brown, Prof Matthiessen and Prof Ockleford .
4.Agenda item 1:4.1a) 322nd Meeting: Minutes [ACP 1 (323/2007)]
Agreed subject to correction of a minor typographical error.
4.2 b) 322nd Meeting: Detailed record of discussion [ACP 2(323/2007)]
Agreed as drafted.
4.3 c) Record of the Open Meeting 13 November 2006[ACP 16 (323/2007)]
The Chairman indicated he would send some amendments to the secretariat for the section outlining his talk. Subject to these changes the record was agreed.
4.4 d) Draft Question and Answer for Open Meeting [ACP 20 (323/2007)]
Members agreed the draft answer captured the discussion at the meeting well and agreed to publication as drafted.
5. Agenda Item 2: Secretary’s report [ACP 3 (322/2006)]
5.1 The Secretary to the Committee reported that no recommendations had been made since the previous meeting.
6. Matters arising
6.1 a) Ethaboxam [ACP 14 (323/2007)]
6.1.1 Members considered the recent advice received from the Committee on Mutagenicity (COM). The COM had advised that the applicant should undertake two further studies, an in vitro study to clarify dose response and to identify an appropriate NOEL for aneugenicity and an in vivo study examining dose response and possible site of contact activity. Written comments from absent members confirmed their agreement to the suggested studies and members present at the meeting were all in agreement that the applicant should be asked to undertake these two studies.
6.1.2 Members heard that a recently published paper suggested that interpretation of possible effects of aneuploidy should include the possibility that they could act to suppress tumours. (Ref: Weaver, Silk, Montagna, Verdier-Pinard and Cleveland, Cancer Cell 11, 25-36). Members heard that whilst there are relatively few aneugenic substances, these are associated with a range of in vivo effects. Members agreed that having considered the COM advice it could be published as usual on the COM website.
6.2 b) Application for UK provisional approval (Control of Pesticides Regulation (COPR))for Cyd-X containing Cydia pomonella Granulovirus (CpGV) [ACP 18 (323/2007)]
6.2.1Cydia pomonella Granulovirus (CpGV) is a new biopesticide formulated as Madex, a suspension concentrate formulation for use on apple and pear. The target pest organism is codling moth.
6.2.3 Members had sought expert advice from outside the Committee before finalising their advice on approval, and specific experts had responded giving detailed responses to the questions that had been raised by the ACP at the previous meeting.
6.2.4 Members were reassured by the expert advice noting that most of their concerns had been addressed. The environmental risk assessment was accepted and as the virus was confirmed to be very host specific members confirmed that there was no need for any additional ecotoxicology data.
6.2.5 Members noted the inclusion of a section on exposure assessment. Estimates indicated exposure to both the virus and extraneous material remaining following manufacture would be very low. As the product was to be classified as a sensitiser, operators would be required to use protective clothing. Members discussed the possibility of also requiring respiratory protective equipment (RPE) as there was no information at present as to the possibility of the product containing respiratory pathogens. Members noted that there were no reports of humans having been affected following application of the product and concluded that following 30 years of use elsewhere in the world it was likely that any serious problems would have been reported in the literature. Members therefore proposed adding some additional species (including some common respiratory pathogens) to the quality control screening for microbial contamination already undertaken. Provided the batches were manufactured to an appropriate standard they concluded that RPE would not be required.
6.2.6 Finally, Members reconsidered the resistance management strategy at the request of the applicant. They concluded that there is a high risk of resistance developing so it was important that an appropriate strategy be introduced. The standard approach to resistance management for codling moth was to vary the mode of action used to control alternate generations of the pest. Given that relevant experts advised there are a maximum of two generations a year in the UK, the strategy of three applications per year to control a single generation was appropriate.
6.2.7 Members concluded that in the light of the expert advice received they could advise Ministers that this product was suitable for approval for use in the UK.
6.3 c) Other matters arising [ACP 13 9323/2007)]
6.3.1 The Secretary outlined the state of play on a number of matters arising from earlier meetings.
6.3.2 It was agreed that an outline of a proposed paper on economics should be circulated to Members for comments and suggestions.
6.3.3 Particular points raised were as follows: Members noted the suggestion that the Medical and Toxicology panel hold a meeting to consider endocrine changes in mammalian metabolism and asked that this meeting extend to ecotoxicological aspects if possible
6.3.4 Members noted that the minutes of discussion when considering the request to hold meetings in open session could have been phrased in a more positive manner which would better reflect the committees’ positive approach to what is a difficult issue
7. Resistance implications of insecticide mixtures [ACP 19 (323/2007)]
7.1 The Committee discussed this paper outlining the efficacy principles to be considered in the development of formulated mixtures containing more than one insecticide. Members recalled that there is already guidance available considering the approach to risk assessment of formulations containing more than one active substance, and agreed that this document provided a sound basis for the development of guidance for applicants to consider in efficacy dossiers for mixed insecticide formulations. It was particularly helpful that the principles it encompassed had been confirmed with other experts in resistance management.
7.2 Members then discussed whether the use of combinations of insecticides was likely to result in the use of reduced dose rates as was seen with some fungicides and herbicides. It was concluded that the main purpose of such mixtures seemed to be to broaden the spectrum of activity rather than to reduce the dose applied. Pesticides Usage Survey Group (PUSG) data indicated that whereas about 50% of the full dose is commonly used in fungicides, the comparable figure was about 80% for insecticides. The one area where dose rate applied was more variable was in top fruit where the dose applied is adjusted to the size of tree canopy in order to deliver a uniform dose on the leaves. It remained important that all recommended doses had to be supported by dose justification data. Members suggested that the section of the document considering the possible impact on dose would need some modification and they agreed to provide specific written comments
7.3 Members noted that formulated mixtures might also result in less than optimal timing of application for each of the specific target pests.
7.4 Members were concerned that this guidance should be seen as a need to justify the formulated mixes rather than precluding their approval and stressed that it was important that the UK regulatory system did not impose unnecessary additional constraints in comparison with other EU member states. With this in mind the committee were informed that PSD intended to discuss the guidance with the EPPO resistance panel and with efficacy evaluators in other member states.
7.5 Members noted the need for further development of the draft before publication as a guide, and recommended that in addition to discussion with the EPPO Resistance Panel, the paper should also be discussed with CPA and NFU. It was agreed that it would also be desirable for the farming community to consider the principles when preparing tank mixes of more than one insecticide and this should also be considered in the wider communication of the principles.
Action: Members to provide specific comments
8. Value of the mouse toxicity study to pesticide risk assessments [ACP 12 (323/2007)]
8.1 Members heard that the value to risk assessment of the mouse chronic toxicity study was being considered in the International arena
8.2 Members considered this initial assessment of the extent to which the mouse chronic carcinogenicity data for new and existing compounds evaluated in the European Union had been valuable in the risk assessment.
8.3 Members asked whether there was a possibility that key findings such as tumours might be missed if there had only been a rat study available. Members noted the written comments supplied indicating that it was rare for the mouse study to drive the risk assessment, and their attention was drawn to a similar review undertaken by the Committee on Carcinogenicity on 1997/98 The COC review had considered around 1300 substances using the Gold Carcinogen Potency Database to identify chemicals and 76 potential mouse specific carcinogens had been identified as requiring some further consideration. Following a more detailed consideration of the toxicology data on these substances 13 were considered to be genuine mouse-specific carcinogens. Eight of these had inadequate genotoxicity data, but it was noted pesticides were subject to rigourous genotoxicity testing. Neither of the two genotoxic mouse-specific carcinogens identified were pesticides. Two out of five mouse specific carcinogens that were were not genotoxic were pesticides (dieldrin and captan). The relevance of these data for human health risk assessment could be assessed from data on carcinogenic mode of action.
8.4 The Committee therefore asked for further information on findings of shorter term studies in the small number of substances where it seemed there were possible mouse specific effects. It was suggested examination of 90 day studies might indicate the target organ for example. This examination might help to identify whether there are indicators in short term studies as to when a chronic mouse study would be particularly valuable.
Action: PSD to examine the data further
8.5 It was clarified that one of the main reasons this issue is under consideration is to try and reduce the use of laboratory animals. With this in mind members considered the possibility of using a whole lifetime protocol which used fewer animals in each study. Members heard that there was difficulty in keeping sufficient animals alive over the already prolonged period of 2 years for rats and 18 months plus for mice to produce a valid study. In addition it had proved almost impossible to identify compound induced effects from the confounding ‘natural’ levels of effects in the whole lifetime studies, and for this reason such protocols were not recommended for regulatory purposes
8.6 Members agreed that this paper would form a useful contribution to the on-going international discussion about mouse chronic studies, and confirmed that current plans to produce a poster for a conference should go ahead.
9. Report from PIAP [ACP 17 (323/2007)]
9.1 Members considered the Pesticides Incidents Report (PIAP) and agreed that, as in previous years, some additional information such as comparison with pesticide usage data would be helpful.
9.2 It was agreed that the Chairman should write outlining the issues to the PIAP Chairman and inviting him to the ACP to discuss the issues raised.
10.Draft Annual Report [ACP 15 (323/2007)]
10.1 Members considered the first draft of the ACP Annual Report for 2006, and considered the format adopted for its publication. It was agreed that although the current report may be unattractive to lay readers, it is acceptable in delivering a report of the work of the Committee. Members agreed however, that future format should be reviewed as part of a wider communication strategy to be developed by the Chairman, lay members and secretariat.
Action: Chairman lay members and secretariat
10.2 Members were asked to confirm their personal details and interests were correctly presented in the draft report and to notify the secretariat of any other changes required.
11. Aquatic risk assessment for the re-registration of products containing Isoproturon [ACP 9 (323/2007)]
11.1 Mr Clarke and Prof Brown both declared non-personal specific interests in this item and thus only responded to questions from the Chair.
11.2 Members observed that the papers presented included notifications from three companies for the re-registration of products containing isoproturon following completion of the European review. Each notifier had adopted a slightly different approach to meeting the requirement for consideration of the risk to surface waters. Members heard that PSD had completed the necessary risk assessments in all other areas and had confirmed they were in compliance with the Uniform Principles for assessment of Plant Protection Products.
11.3 Members also noted that the Environment Agency had drawn attention to the Water Framework Directive. Environmental Quality Standards (EQS) were being set under this directive for a number of substances including isoproturon. Based on current monitoring data, isoproturon will fail the proposed EQS at between 5 and 10 % of sites. Member States are legally required to show progressive reduction towards compliance with the EQS by 2015. Members therefore agreed to concentrate upon the scientific risk assessment in the formation of advice at this time.
11.4 Members considered first the ecotoxicology studies that had been provided and the derivation of appropriate regulatory endpoints from these higher tier studies. They confirmed that the endpoints proposed from the mesocosm study and the lower limit HC5 were both appropriate and were concluded to be protective.. They confirmed that the rationale for providing studies on aquatic plants and algae under conditions of low light and temperature was sensible as these were similar to conditions during the winter months. However they noted that the ability of such studies to detect effects on growth was low as the test species were not really growing under the conditions of the test. Nonetheless there were signs of effects in the study. There was also evidence of recovery when the test species were placed in clean water. However the total single exposure and recovery period in the study lasted only 14 days. Evidence from surface water monitoring indicated multiple exposures were likely over a 3-4 month period which included spring when growth was faster as well as during winter. For these reasons members concluded that the results from the low light and temperature study were not appropriate for use in this risk assessment.
11.5 Members agreed that a 5m buffer zone looked likely to be sufficient to protect the aquatic environment from spray drift for some of the products, but this had no impact on contamination via drainflow. The risk assessment indicated unacceptable effects on aquatic organisms (plants, algae and invertebrates) were likely from the estimated concentrations predicted to occur via drainflow.
11.6 Members therefore examined the derivation of predicted environmental concentrations from drainflow produced by the three notifiers. Attempts to combine modelling with monitoring data were applauded. However each of the approaches adopted by the notifiers suffered from some shortcomings.
11.7 In the first approach, the risk assessment was based upon an acute effects concentration, thus the selection of exposure concentrations from a chronic time period was not appropriate. In addition there was concern expressed about the suitability of the soil series used in the lysimeter study to represent drained soils. Additionally, the use of an overall 75th percentile concentration was not considered adequately precautionary.
11.8 In the second the input variables that were selected for the drainage model did not calibrate well with concentrations that might be expected on the basis of UK field monitoring. The draft PSD assessment included a good critique of this study.
11.9 The ACP confirmed that the approach adopted in the third case was the most valid, but the selection of the three less vulnerable soils did not necessarily represent the worst case since collectively these soils only represented approximately 75% of the cereal growing area .
11.10 Overall the Committee agreed that there was thus a good rationale to support the use of the approach that had previously been adopted by PSD. Members agreed that the concept of ‘scenario years’ was an attempt to take a realistic approach. However there was some uncertainty about how best to use it in developing advice because knowledge of ecological communities is limited. For example there is a need to consider recovery and whether a ‘one-off’ event had important longer term environmental consequences. Members therefore agreed to ask the Environmental Panel to consider the resilience of ecological communities as a generic issue, however they agreed that these discussions were not likely to change the conclusions reached on isoproturon.
Action: Environmental panel
11.11 Members next considered whether there was any evidence that the predicted effects were being seen in the field, as isoproturon has been in use for many years on a large scale as it is widely used for weed control in cereals. They reviewed an extensive Environment Agency database which shows that isoproturon contamination of UK rivers is very widespread, both temporally and spatially, and frequently exceeds concentrations that pose a risk to aquatic life. The situation in headwater streams (which are not routinely monitored by the EA) is likely to be even worse due to the reduced opportunity for dilution and degradation. Members had checked the published literature ahead of the meeting. They commented that effects in the field would be difficult to measure due to the large number of factors affecting growth in the environment. However one study had identified pollution induced community tolerance (Ref: Dorigo, U., Bourrain, X., Berard, A. and Leboulanger, C. (2004). Seasonal changes in the sensitivity of river microalgae to atrazine and isoproturon along a contamination gradient. Science of the Total Environment318, 101-114.). In this study a community of periphyton from a river had been grown on a slide and then tested for their tolerance to a number of substances in the laboratory. In theory the population should be less sensitive in laboratory tests if the sensitive populations had been removed by exposure in the field. Whilst it was possible that there was some cross-over of effect from atrazine in this study, there was some evidence that periphyton sensitive to isoproturon had been removed from the population of the river sampled. Whilst members agreed that this study could not be relied upon alone, taken together with the database provided for the review it did provide some supportive evidence that the effects predicted in the risk assessments were probably taking place in the field.
11.12 Members heard isoproturon is a very important herbicide in agriculture. It is used mainly in the autumn as part of the strategy to control blackgrass in cereals, where it offers an alternative mode of action to use in the management of resistance in this weed. Members heard it is also important to farmers for control of annual meadow grass and some broadleaved weeds such as mayweed. Although there are a few alternatives to isoproturon, these too are also undergoing review in Europe, so their availability is uncertain in the medium term. It is thus likely that the alternative compounds would increase in use if isoproturon was not available and these compounds might not present a better risk profile. Members were concerned that the substance by substance approach to the review programme might result in the removal of compounds leaving possibly the least favoured molecule in terms of overall risks as the sole means of control in such scenarios. (This would obviously depend upon the order of the review programme). They noted that whilst at present this was the way in which the programme was required to operate, it was a generic concern that they wished to draw to Ministers attention.
11.13 Members concluded that as the risk to the aquatic environment was unacceptable, but the use was clearly very important it was necessary to consider what, if any, measures might be taken to manage the risk.
11.14 Members noted that PSD was funding some R&D (PS2218) on ‘targeted mitigation systems for transport of pesticides in drainflow’ and asked whether this research was currently indicating any possible ways forward for risk mitigation for drainflow. Members heard that the study was currently at the end of year 2 of a 3 year programme. To date year 1 had been very dry so in fact there had been overall low flow rates but a greater degree of transport in coarser textured soils. Results analysed from year 2 so far indicated a possible weak relationship between concentrations in drainflow and the clay content of soil. This R&D supported the possibility that vulnerable soils might be able to be identified, although further work was still required on this project. Members considered whether it was possible to restrict the use of isoproturon on such soils, allowing continued use elsewhere.
11.15 Members considered also whether it would be possible to put in place appropriate enforcement and monitoring systems to check compliance with restrictions of this type. It was suggested that the soil and crop protection plans now required under cross compliance and the entry level stewardship schemes might be developed to provide for this possibility, but further research would be necessary.
11.16 Members heard that one member’s farm consists of around 800 acres and includes about 8 different soil types to manage. In addition members heard that such a restriction would not be particularly helpful to farmers, because the main use of isoproturon was on the heavier land which was more likely to be subject to losses via drainflow.
11.17 Overall members concluded that the risk assessments indicated a risk to the aquatic environment from the currently approved use of isoproturon. They could not therefore recommend that these uses be re-registered in the UK. The ACP is aware of the importance of isoproturon to UK agriculture and have considered the possibility of managing the risk. They concluded that it is unclear at present as to how to mitigate drainflow. Considerable further research is required and it is not clear that this would result in a practical outcome. They agreed to prepare written advice for Ministers to this effect.
12. Battery Operated Ready to Use containers for the Home Garden Market [ACP 6 [323/2007)]
At this point in the meeting the Chairman had to leave and the deputy chairman took the chair.
12.1 The Committee discussed recent innovations in packaging design in the ready to use home/garden pesticide market. When considering recent Human Health Incident Surveys in September, the ACP had noted the number of incidents involving children gaining access to home garden pesticides, and had stressed the need for particular care in storage and use.
12.2 Members assessed three battery operated containers, and considered that all were potentially attractive to children, and expressed concern about the effectiveness of safety catches.
12.3 The Committee was advised that one of the three containers presented was already available in the retail market, and Members considered it inequitable to allow that to remain available, while recommending that others should not be used.
12.4 Members noted the detailed examination of the incidents data presented which indicated that overall incidents were very low and that no incidents had yet been reported arising from these containers. However given the relatively short period such containers had been available it was unlikely that they would feature in reports yet, and the Committee was aware that whilst the various reporting schemes were the best data available they might not cover all incidents.
12.5 Members also heard the view expressed that these containers offered benefits to elderly or frail gardeners. Members discounted this because handling a 5l container would not be easy for frail people.
12.6 Members therefore agreed that advice should be given that the existing container should be withdrawn from sale, and approval for others refused.
13. Date of Next Meeting
13.1 20th March 2007 at the National Railway Museum, York
14. Any Other Business
14.1 The Secretary reported that the detailed record of discussion of the 320th meeting of the ACP has been published on the ACP website.
14.2 Members were advised of two Position Papers for the First UK Approval for the use of Isoxflutole and Imazamox.
J G Ayres