Please note: these minutes are the final version as agreed at the 279th meeting of the ACP held on 12 October 2000
The Advisory Committee on Pesticides provides independent advice to Ministers on matters relating to the regulation and use of pesticides, including applications for approval of new products and reviews of existing approvals. It usually meets in closed session (because of intellectual property and commercial secrecy considerations) approximately eight times a year in York. This was the first meeting open to the public.
Chairman: Prof. D Coggon
Deputy Chairman: Prof. A Boobis
Members: Dr N Bateman, Mrs S Owen, Prof. R Smith, Dr A Carter, Dr C Soutar, Mrs E Brown, Prof. G Edwards Jones, Mr J Orson, Prof. G Matthews, Mr C Stopes, Dr P McElhatton
Minister of State for Agriculture: Baroness Hayman
Assessors: Dr A D Martin (Pesticides Safety Directorate (PSD)), Dr R Abel (Department for Environment Transport and the Regions (DETR)), Dr C Griffiths (Scottish Agricultural Science Agency (SASA)), Dr J Norman (Food Standards Agency (FSA)), Dr S Smith (Health and Safety Executive (HSE))
Advisers: Dr K Wilson (PSD), Mr R Davis (PSD), Mr J A Bainton (PSD), Ms A Brazier (HSE)
Secretariat: Mr M Oliver (PSD) Secretary, Ms J Reeves (PSD) Co-ordinator,
Mrs S Rambridge (PSD) Deputy Co-ordinator, Mr J McDonald (PSD) Assistant Co-ordinator, Ms F Harrison (PSD) Minutes
Technical Secretariat: Mrs J Wilder (PSD), Dr J O’Hara (HSE)
A full list of attendees is available.
1.1 The Chairman welcomed everyone to the first open meeting of the Advisory Committee on Pesticides. He informed the meeting that the Government were keen to open their Advisory Committees to the public. Although much of the business of the ACP was highly technical and a small part also subject to legal constraints because of commercial secrets, the ACP had agreed that it was a good idea to hold an open meeting to enable the wider public an insight into their work.
1.2 The Chairman recognised that, as this was the first open meeting, the format might not be optimal, and indicated that the Committee would welcome any comments or suggestions for improvements. He envisaged that there would be an open meeting each year, possibly arranged to coincide with the publication of the ACP Annual Report.
2. Introduction from Baroness Hayman, Minister of State (Lords) for Agriculture
2.1 Noting that this meeting was the first open meeting of the ACP, Baroness Hayman stressed the importance Ministers placed on openness. It was important to challenge what really needed to be done in private and to create new communication channels and build confidence by showing there was nothing to hide. Closed doors create mistrust and lead to public unease as to how committees operate. While it was not appropriate to have every meeting of the ACP open to the public there was much of today’s meeting that could be done openly.
2.2 She wished to record her thanks to the Committee, for the way in which they had responded to the request for more openness and for their work as members of the ACP, which was not an insubstantial task. She thanked them for the time and energy they devoted to this difficult job.
2.3 Baroness Hayman reported that the regulatory system for pesticides was not a simple one but it was robust. However, this did not mean it could not be improved. Pesticide use was allowed only if there were good grounds, backed by scientific evidence, for considering that any risks associated with handling and using products were at an acceptable level. She went on to define ‘acceptable risk’ in this context as meaning that the approved use should not cause any identified adverse effect in users of the pesticide, or bystanders, or consumers of foods derived from treated crops. In the environment it was important that non-target wildlife populations were not adversely affected.
2.4 Baroness Hayman assured the meeting that the six Ministers and the Food Standards Agency (who jointly take decisions on pesticides) take their responsibilities in this area very seriously and do ask questions and seek further advice from Committees on particular issues in helping to formulate their views.
2.5 In concluding, Baroness Hayman confirmed there would be an annual open meeting of the ACP and possibly specific meetings on particular topics. Broader issues, which are not based on confidential information, will be discussed. The last two items on today’s agenda were examples of such issues which otherwise could have gone to an ordinary, closed meeting. She hoped this meeting would be part of the whole process of greater public access to information on pesticides and decision making in government.
3. Agenda Item 1: A Guide to Pesticide Regulation in the UK and the Role of the Advisory Committee on Pesticides (ACP)
3.1 The Chairman introduced this new publication from the ACP, commenting that although those from the pesticide industry were already aware of the scientific evaluation undertaken for each pesticide, others might not be quite so familiar with the process.
3.2 A huge amount of data were examined for each pesticide, and human and environmental risk assessments were prepared. The guide sought to explain the principles behind these.
3.3 The Chairman hoped the guide to pesticide regulation would be helpful in increasing general knowledge and aiding greater understanding of the minutes of ACP meetings published on the web. Copies of the guide to pesticide regulation were available by post from the ACP secretariat and would also shortly be available via the PSD website.
3.4 The guide will be updated periodically and any suggestions for improvements should be sent to PSD. The ACP will try to take any comments into account when the guide is next revised.
3.5 In inviting questions from the audience, the Chairman suggested that if anyone had questions on specific pesticide products these should be put in writing and he would deal with them as soon as possible.
3.6 There was some concern over the requirement for ticket admission to the open meeting and a feeling that saying the public may be overwhelmed by the complexity of the issues was condescending.
3.7 Baroness Hayman replied that she personally was sometimes overwhelmed by the complexity and commented that with very technical issues it was a challenge to open up the process effectively to all those with a legitimate interest.
3.8 The Chairman agreed that input from the public is important but noted that making things open involved much extra work and therefore it would take time to build up a system and get it working properly. The open meeting was by ticket only to assist with practical arrangements such as what size of venue to book. Baroness Hayman added that the meeting had been nationally advertised, and all who requested a ticket had received one.
3.9 The use of epidemiological data was discussed in the particular context of the influence of environmental exposure to hormone disrupting compounds. Committee members clarified that epidemiological methods were most powerful in examining large proportionate differences in risk, but were generally of rather limited value for the identification of small increases in the risk of relatively frequent diseases. For new pesticides, there are no epidemiological data available, and therefore the Committee's risk assessment must be based on animal toxicological data. Expert judgement was needed in deciding how far findings in animals could be extrapolated to humans.
3.10 The scope for GPs to detect and report adverse effects of pesticides was also queried. Members clarified that such reporting was most likely to be effective in identifying acute (ie relatively immediate) effects where the link to pesticide exposure could be made more easily and with greater confidence than for effects which took some years to develop. It was confirmed that the Committee had good links with Dept of Health, which provided advice to the Committee both directly and via its own expert committees.
3.11 The pace of the current review of older pesticides was questioned, and the Chairman agreed that the review programme currently underway was not going as quickly as they would wish. However, it was important to balance the desire to complete reviews rapidly against the need to ensure that the scientific assessment of risk was reliable and thorough. The reviews of older pesticides were prioritised so that those used on a large scale, or which had particular safety concerns were examined first.
3.12 One person noted that he was aware of an increase in hypothyroidism which he suggested might be linked to trends in agricultural systems. It was suggested that perhaps the website could be used for a two-way debate on particular issues, such as this. Members had not previously come across reports of a rise in hypothyroidism, and asked for further details outside the meeting so that, if appropriate, the matter could be followed up.
3.13 Surprise was expressed at the statement on page 28 of the Guide to Pesticide Regulation, that toxic interactions between pesticides were not already assessed. The Chairman reported that toxicologists have been concerned for some time that combined exposures to more than one pesticide, particularly to pesticides with a similar mode of action or metabolism, were not taken into account in risk assessment. However, he noted that the safety factors for individual pesticides were so large that there was unlikely to be a problem in practice. Professor Boobis added that the methodology to assess risks from combinations of pesticides was very complex and had not yet been fully developed.
3.14 Concern was expressed that the regulatory system did not positively require safer application systems to be used. Professor Matthews informed the meeting that he had been appointed to the Committee to address aspects of operator safety and application methods. He said that operators were trained and he believed that with developments such as use of closed transfer systems and patch spraying, exposure to pesticides was being reduced. He too was concerned that the mergers of many agrochemical companies was likely to result in a reduction in the number of people involved in development of new application techniques. The Chairman added that some initiatives on the application of pesticides do come from the Committee and cited Local Environmental Risk Assessments For Pesticides (LERAPS) as an example.
3.15 Greater clarity in labelling particularly for the home garden sector was requested. The Chairman appreciated that a different style of labelling was needed for amateur users and Dr Carter reminded the meeting that there was a review of pesticide product labelling underway to which the ACP have input.
3.16 Questions were asked about the extent of assessment required for pesticides that were already approved elsewhere in Europe or for other purposes in UK such as food grade materials. The Chairman explained that there is now an EC system for the regulation of pesticides. However the final decision on approval of a pesticide still needs to be taken in each Member State as the crop/situation in which the product is used and the ecological impact may differ in each country. With regard to food grade chemicals, he would expect that the consumer risk assessment would be acceptable, as this would have been assessed in relation to a food use. He noted that the environmental risk of spraying such a chemical would not have been evaluated before and therefore data on the chemical would still need to be examined.
3.17 The Committee was asked how much control they had regarding the research budget. The Chairman noted that he had met with the Chief Scientist of the Ministry of Agriculture, Fisheries and Food (MAFF) and the Committee had input into the research funded by MAFF. He said that the Health and Safety Executive (HSE) also funded research projects. Baroness Hayman explained that in the case of research on organophosphates (OPs), an Inter-Departmental Working Party was established to ensure that Government Departments were not working in isolation and research was financed jointly by the Department of Health, MAFF and the Department of Environment. She added that she had found the meeting extremely interesting and was sorry that she could not stay for the rest of the afternoon.
4. Agenda Item 2: Future Developments of Exposure Models to Calculate Potential Intakes of Pesticide Residues by UK Consumers
4.1 PSD introduced this paper. The assessment of consumer exposure forms a vital part of the process in approval and regulation of pesticides. The paper outlined the current state of development of models to assess both chronic and acute exposure and proposed some further developments to take account of both additional information on diets and developments in modelling acute exposure.
4.2 Professor Boobis commented that there were international developments regarding the derivation of the acute reference dose (ArfD) and PSD agreed citing, in particular, the Joint Meeting on Pesticide Residues (JMPR) work to determine the most appropriate toxicological study to use in setting an ARfD. Professor Boobis supported PSD’s comment that it was appropriate to do an initial comparison perhaps using the Acceptable Daily Intake (ADI) to see if an ARfD was needed.
4.3 Dr Bateman questioned if cooking was taken into account in the modelling. PSD stated that the need for processing data depended on the properties of the pesticide. For example, if an oil soluble pesticide was in the commodity then it might transfer to cooking oil. If a raw commodity contributed a high proportion of consumer intake then processing data would be required to refine the calculations.
4.4 Mrs Owen noted the information regarding the vegetarian diet and asked about children's diets. PSD confirmed that there were already data available for children and infants diets.
4.5 Professor Edwards-Jones who had used modelling in economics stated that those models had been validated and asked if the consumer models were similarly validated. PSD confirmed that the Food Standards Agency validated the point estimates and for the probabilistic models, all inputs had to be validated in order for the outcome to be validated. PSD continued that the output of point estimates could be compared with the output from the probabilistic models and that data from the Pesticide Residues Committee (PRC) could be used to validate the models. The Chairman added that when reviewing a pesticide active substance, it was possible to include all dietary sources of the active in the estimation of exposure. However, for new active substances it was more difficult. PSD continued that for a new active substance approval is usually sought initially for a food staple that would contribute the most to the diet. If the estimated exposure is low e.g. 10% of ADI, then no further assessment is needed when uses are extended to other crops. If however, the contribution is greater than 50% of the ADI then additional work is required.
4.6 Mrs Brown questioned the meaning of the phrase 'mathematical algorithms for stochastic modelling' (page 3 of the paper). PSD replied that it was the way in which distributions were combined e.g. food consumption with body weights of 1½. -4½ year old children. The Chairman added that algorithms are a set of rules.
4.7 Discussion was then opened to the audience.
4.8 The possibility of children being exposed to the same pesticide from other sources as well as food residues was raised. The Chairman confirmed that the Committee would note whether a pesticide was used in the home, e.g. to control ants, as well as in agriculture. He said the margins of safety were large. However, models for assessment of such exposure were an area for future development, along with those addressing combinations of different pesticides.
4.9 It was queried whether pesticides used on items of animal feed (such as sugar beet tops and pulp) were considered in the human risk assessment. PSD reported that the residues in the sugarbeet and in the pulp are examined and then the transfer to animal tissues calculated from animal feeding studies. These data were required for each pesticide intended for use on crops fed to animals.
4.10 The extent of liaison on pesticide matters with the Environmental Protection Agency (EPA) in the USA was queried. The Chairman said the Committee does take note of the EPA's actions and members of the Committee also meet scientists from other organisations at conferences. PSD confirmed that there was contact through the Organisation for Economic Co-operation and Development (OECD) on the harmonisation of pesticide regulation. In addition, PSD access the EPA website and a member of PSD had recently visited the EPA. HSE were also active members of the OECD and their staff had also visited the EPA.
4.11 Noting the proposals in the paper, explanation was sought on ‘development of guidelines for sensitivity analysis’. PSD explained that a set of rules are currently followed in assessing the sensitivity of the models used, but that these were not made available as formal guidelines and therefore the paper was asking if they should be developed as such. The Chairman confirmed that the sensitivity of the models is dependent on the input parameters and there was a need to specify what is required as a minimum.
4.12 Reassurance was sought on the extent to which ‘binge eaters’ were covered by the modelling. An example was given of a person who eats about 3 lettuce each week. PSD confirmed that the extreme consumers modelled represented about three times the average consumption of each commodity. The Chairman also noted that PSD had taken the lead internationally in assessing the variability of pesticide residues arising from individual food items from a treated crop.
4.13 The Committee then considered the specific proposals made in the paper. With regard to proposal (b), Professor Boobis clarified that the vegetarian diets were already included in the consumption data used for the general population. This proposal suggested they be considered additionally as a separate group.
4.14 Professor Boobis sought clarification of proposal (c). PSD explained that the UK model used the 97.5th percentile as an extreme consumption figure. Unlike EUROPOEM for estimating operator exposure, there is no harmonised European model for assessing consumer exposure. Therefore, as a one off exercise, a comparison of the UK consumption data with those from other Member States was suggested. By exploring where any differences occurred and why they were occurring, it would be possible to consider the need to incorporate data from other Member States in our own risk assessments, perhaps to better reflect some ethnic diets.
4.15 The meeting was reminded of the pesticide carbendazim, which had been detected in yams, and noted that some ethnic communities in UK might consume yams at high levels. The Committee commented that residues in yams were a matter for the Pesticide Residue Committee (formerly the Working Party on Pesticide Residues) rather than the ACP, because yams are not grown in UK. PSD recalled the incident referred to and said that they had obtained published data on the likely levels of consumption of yams by ethnic communities in order to estimate exposure to the pesticide. The calculations had shown that the risk from the consumption of the yams was acceptable.
4.16 The Committee recommended that :
a) Models should continue to be updated as new consumption data become available;
b) New adult vegetarian consumption data should be compared with standard adult consumption data; if important differences in estimated pesticide intakes are seen, intakes by adult vegetarians should be modelled routinely.
c) Consumer intake models from other member states should be compared with the UK standard models to identify any significant differences.
d) IUPAC's deliberations on the appropriateness of the variability factor should be presented to the ACP.
e) Further work should be undertaken in the development of probabilistic models for assessing consumer exposure.
f) Guidelines for validation and sensitivity analysis of probabilistic models should be developed.
g) Methods for determining cumulative exposure should be developed, validated using practical examples, and presented to the ACP.
4.17 It was pointed out that more informed debate could have taken place if the papers had been circulated to the public in advance of the meeting. The Committee noted this comment for future open meetings.
5. Agenda Item 3: Research into Smoke Generators - Proposals for Estimating Human Exposures
5.1 HSE introduced this paper, which was a brief summary of an HSE research project into smoke generators. A company, Octavius Hunt, had supported the research project by providing advice and smoke generator products. The research had investigated the release of the smoke and pesticide concentrations in the air and in surface deposits. The information had been used to develop models to estimate exposure for people re-entering the space once treated.
5.2 HSE explained that smoke generators were used when other pesticide products were unsuitable; for example, in a very large or complex space such as a grain store or in a situation where liquid spray might cause damage, such as a highly decorated interior. Operators ensured that the space was reasonably well sealed from air leaks, ignited the devices and left the enclosure as the smoke dispersed.
5.3 HSE noted that the model was based on relatively simple calculations and assumptions and further work would be necessary to refine it.
5.4 HSE apologised to Members for an error on the front page of the document, where it was proposed that workers should ‘confirm’ that areas were free of smoke, rather than ‘certify’, as had been stated.
5.5 Dr Bateman noted from the study that approximately 62-82% of the pesticide had been lost when burned, whereas the model used a value of 50%. HSE confirmed that the study had indicated losses around the figures stated but that a default 50% loss was considered to be a conservative value. Dr Bateman observed that there appeared to be no information on the products of the burning process or how these might vary from one pesticide to another. He asked whether it would be possible to use a pesticide less prone to thermal degradation. HSE stated that two pesticides and a red dye had been used in the study. One pesticide, dicloran, burned at a high temperature and the other, permethrin, at a lower temperature. Members agreed that approval holders would need to provide information on substances produced on combustion of the pesticide active substance.
5.6 Professor Boobis noted that the model was stated to predict air concentrations ‘irrespective of ventilation’ and questioned whether this was the case. He believed that the model identified values that could be assumed in the absence of other data. The Chairman asked that the statement be reworded and HSE agreed that it would be amended to indicate that the prediction was a proposed default value.
5.7 Professor Boobis noted that the presence of bats would need to be taken into account when treatments were being considered.
5.8 The Chairman commented that the apparently low level of deposition on horizontal downward facing and vertical surfaces might have implications for the efficacy of timber treatments. He noted that two model values were given for air and surface levels of pesticide and asked which were to be used. HSE replied that the greater of the two values should be used in a conservative approach. The Chairman suggested that further research was needed to confirm the linear relationship of air and surface concentrations with the amount of applied product.
5.9 Discussion was then opened to the audience.
5.10 The protection provided from respiratory protective equipment (RPE) was queried. HSE explained that equipment providing less than face filter protection 2 (FFP2) should not be considered appropriate RPE. For RPE of FFP2, a protection factor of 10 could be expected.
5.11 It was emphasised that priority should be given to determining the identity of the products produced on combustion of the pesticide active substance. The Chairman re-iterated that this information would be needed for individual active substances.
5.12 It was noted that reducing human exposure by ventilation would result in exposure of the environment. Could the research be extended to estimate the pesticide lost to the environment? HSE agreed that it should be possible to make a worst case assumption that windows etc. had been left open during release of the smokes. It should then be possible to predict the outdoor air concentrations downwind and the likely concentrations reaching bystanders and the environment. The Chairman added that the ACP took account of loss to, and possible impact on, the environment when considering all evaluations of pesticide products.
5.13 Discussion on the extent to which the ACP investigated other less toxic alternatives to specific pesticides was requested. The Chairman noted that toxicity was not one-dimensional in that it was necessary to consider effects on users, consumers and the environment. An individual’s view of the overall toxicity of a pesticide thus depended to an extent on their value judgements. He continued that neither the UK nor EC legislation relating to pesticides allowed for comparative assessments but that the current system required each pesticide to meet stringent criteria. However, it was also important that the best pesticide for each situation was chosen and used in the correct way. Groups such as the Pesticides Forum were seeking to address this and the ACP participates in these processes. It was suggested that it would be interesting to hear at a future open meeting about the Committee’s views regarding use of the least toxic alternatives. Dr Bateman re-iterated that, unless the law was amended, pesticide legislation did not allow the Committee to consider less toxic alternatives. However it was noted that under the Control of Substances Hazardous to Health (COSHH) Regulations, a worker first had to decide if a pesticide was needed and, if so, to ensure the risks to operators and bystanders were acceptable.
5.14 The issue of lack of choice and information for individuals about the pesticides used in their school/workplace was raised. The Chairman agreed that in some circumstances the risk to someone re-entering an area during or shortly after treatment could be significant. However, the professional operator had a duty of care to prevent entry by others into treated areas until they were satisfied that the area could be entered safely. If treatment had been carried out a considerable time before allowing re-entry and by scientific criteria the risk to people and animals was close to zero, then from a safety point of view it was not necessary to provide information. If the surface or air residues remaining on re-entry presented an unacceptable risk then the use of the smoke would not be approved. However, there was a broad general issue regarding the provision of information following the use of all chemicals.
5.15 In response to final questions on the paper, HSE added that all the smokes measured had been particulate, apart from permethrin, which had been partly in the vapour form. The temperature reached inside the smoke generator as it burned was not measured, it was estimated at between 300 and 400°C. The smoke plume temperatures were measured; one that ignited reached more than 900°C.
5.16 The Committee recommended :
a) Proposals for modelling the levels of airborne pesticide after firing the smoke device, and for estimating the deposits on surfaces from settled smoke should be accepted for regulatory purposes on a provisional basis, pending the completion of research on modelling ventilation when smoke is settling;
b) The proposal for calculating the reductions in pesticide smoke concentrations in air at various rates of passive ventilation should be accepted until computer models have been developed;
c) To ensure a ‘safe system of work’, the conditions of approval for smoke generators should include a stipulation that professional workers undertaking smoke treatments ventilate treated enclosures at the end of the treatment period and confirm these free of pesticide smoke;
6. Meeting Close
6.1 The Chairman thanked all for their contributions saying that this had been a very constructive debate. A number of useful points had been raised and he asked those present to write in with any further suggestions.
6.2 The meeting closed at 4.30pm.