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Pesticide Safety Directorate actions, information and comments

NB: The PSD is now  the Chemicals Regulations Directorate (CRD)


The Pesticide Safety Directorate has undergone reorganisation and from 1 April 2009 is known as the Chemicals Regulations Directorate. Click here for their website.


Click here for information about the 'new' directorate.


Click here for advice on use of chemicals by the home gardener



Taken from the Hansard 6 July 2009  click here (Near the bottom of the page)



Mr. Clappison (Shadow Minister, Work & Pensions; Hertsmere): To ask the Secretary of State for Environment, Food and Rural Affairs what recent assessment he has made of the effects on agricultural production of the use of (a) Aminopyralid and (b) manure containing Aminopyralid; what recent representations he has received on such use; whether he plans to relicense Aminopyralid; and if he will make a statement. [283464]

Please note links below are no longer available

Dan Norris (Parliamentary Under-Secretary, Department for Environment, Food and Rural Affairs; Wansdyke): Aminopyralid is known to be a useful herbicide for control of broadleaved weeds in high production grassland.

The Advisory Committee on Pesticides (ACP) considered applications for approval of two aminopyralid products for use on grassland at their 337(th) and 338(th) meetings on 12 May and 30 June 2009.

The minutes of the 337(th) meeting can be found on the ACP website and the minutes of the 338(th) meeting will be posted there in due course:

DEFRA has received a number of representations from individuals and allotment organisations concerned about the possibility of manure containing aminopyralid becoming available to gardeners. The applications for approval of these new products include tighter restrictions than previous approvals and the company concerned has plans for a stewardship programme to ensure that the risk of aminopyralid containing manure entering the supply chain is minimised.

Ministers will consider whether the issues raised have been adequately addressed and approvals can be granted when advice is received from the ACP.


As usual my comments are in green


23 July 2008:

Dow have now indicated that they are withdrawing products which contain aminopyralid from sale and PSD is formally suspending their authorisations whilst they investigate the options for preventing a recurrence of this problem.  Click here to see blog posting

At this point aminopyralid products have been withdrawn by the manufacturer only on a temporary basis, however it needs to be appreciated that herbicides that contain this ingredient will have been used already this year. According to available information the herbicides used this year could be affecting our supply of manure for at least two more years and probably for longer than that depending on how manure is stored prior to distribution. It is therefore, crucial that you only buy your manure from trusted sources - that is from sources who know exactly what has been used on the product from the very beginning of the chain of supply. farmers have been advised to store unused supplies.


24 July 2008 Latest PSD update

The PSD advise a regular visits are made to their web site where updates will be posted. Updates are listed on the left of the screen.

  • Latest PSD update: Partial quote:
  •  Dates are not precise but after purchasing in January 2008 and digging in or rotavating during February-March, various crops were planted in April. Samples of the remaining manure, treated soil, and affected potatoes and tomatoes were taken in July and analysed by the government’s Central Science Laboratory.

Crop samples of potatoes and tomatoes contained trace amounts of aminopyralid. The levels were below the Limit of Quantification (LOQ) of 0.02 mg per kilogram. The LOQ is the lowest level at which quantifiable residues can be measured.

The unused manure sampled in January still had trace residues below the LOQ.

It was not possible to find aminopyralid in the treated soil taken. This reflects the bacterial decomposition that begins to act on the pesticide after free aminopyralid is released from plant material in the manure in the first few weeks after digging in.

  • PSD will continue to investigate this matter and hold further discussions with the main data holder, Dow. This action will help to decide whether, and if so, under what conditions the suspension of aminopyralid products can be lifted.
  • PSD update: Partial quote:PSD has already confirmed that using manure, which may contain residues of aminopyralid, does not have implications for human health. However, in response to the concerns of allotment holders and leisure gardeners about damage believed to result from these residues, PSD has been in contact with Dow AgroSciences Limited, the approval holder and data owner for the majority of aminopyralid products approved in the UK. Dow AgroSciences have asked for their approvals to be modified whilst the situation is under investigation. PSD has accepted this and amended the approval of all products containing aminopyralid to suspend the approval for sale, supply, and use with immediate effect whilst further investigations are undertaken. Storage is unaffected and it remains legal and safe for these products to be stored by anyone.
  • Earlier Pesticide Safety Directorate Update. This update contains sections on Information about aminopyralid, Safety information and Action being taken. Two section are worth quoting here:"Based on reasonable worst case assumptions: that cattle are only fed grass, or silage made from grass, treated with aminopyralid; that vegetables are grown in soil mixed with manure produced from the animals; and that all the aminopyralid released from the manure is taken up into the plants; the highest residues would not be a concern for health, so vegetables should be safe to eat"."It would appear that the label precautions concerning the use of manure may not always have been followed when manure has been supplied to allotment holders and gardeners. PSD is urgently investigating the problem. A key issue in the investigation will be whether the conditions of use regarding manure are sufficient, or sufficiently well known, to prevent a recurrence".


In response to an email from Eileen one of our visitors the PSD had this to say:

The PSD responses are in black and the questions/issues that I think the response raises are in green.

  1. The evidence that the crop damage has been caused by aminopyralid is, so far, mainly circumstantial, despite the number of enquiries we have received.  We are now in the process of having samples analysed to confirm that aminopyralid is actually present where crop damage has been reported.  Much of the damage reported is consistent with the known effects of aminopyralid, but because a number of other causes, including other herbicides, might produce similar effects, we are working to confirm that we are actually dealing with the right problem.

Where are the samples coming from we haven’t been asked have you? The RHS also said that sampling was inconclusive due to the very small amounts of residue and also the way in which the residue is released over time. If the damage could be caused by something else – what else and also how can we be advised that crops should be safe to eat if it is not proven what is in the soil?

  1. As far as we are aware, most of the manure implicated in crop damage on allotments and in gardens has been obtained direct from farms or stables, rather than as a packaged product from garden centres.  While this does not significantly alter the problem that people are experiencing, it does add a slightly different emphasis to our investigations.
    We have had several people emailing the web site to say commercial packaged manure was suspected if you suspect such a produce then make sure that you let the PSD and DOW know.
  2. We have recently met with Dow to see what further information and data they might be able to provide to assist us in our investigations.  While our own initial assessment indicated that consumption of crops from affected plants should not carry a risk to health, evaluation of the additional information from Dow now indicates that the highest levels of aminopyralid residues in the manure would not give rise to health concerns and that crops from affected plants should be safe to eat.  We fully expect the results of the sampling to confirm this.
    But earlier they say that it may not be aminopyralid that is causing the problem and the PSD update seems to suggest that the tests have been already carried out. If so what tests have been done and what are still to be done?
    Reply from PSD to above question was: The situation has now changed in that we have better data on the levels of aminopyralid that may occur in manure. We have been able to use this data to provide reassurance that any residues in affected crops are unlikely to cause health problems. In this respect it is not that new toxicity tests have been done - the toxicity of aminopyralid is already well understood. What has changed is our understanding of the likely intake from produce grown on affected soil.

4. PSD actually has no powers to regulate manure, even if it contains pesticide residues.  Our powers relate to the regulation of pesticide approvals and to the use of a pesticide according to its approval and do not cover the subsequent use of treated material such as aminopyralid-treated grass.
So who does regulate anyone? There seems to be a worrying implication below.


From a regulatory point of view, the law is not particularly clear about the supply of farmyard and stable manure to allotments and gardeners. The disposal of farmyard manure is covered by agricultural waste regulations, which are administered by the Environment Agency.  However, where manure is used on agricultural land, it is not treated as waste, and although allotments are not agricultural land, the manure is being used for a similar purpose, so this is something of a grey area.  On the other hand, manure from commercial stables appears to be covered by waste management regulations, which are also administered by the Environment Agency, but, again, the supply of stable manure to allotments also appears to be something of a grey area.


Allotments and gardens seem totally unprotected – can anyone provide manure treated with anything and no-one seems responsible for investigating when things go wrong?


Assuming aminopyralid is present in the manure, it will probably have been applied to the original grass in 2006 or 2007.  Most of the aminopyralid that will be used this year has probably already been used, and had probably already been used before it became apparent that there was a problem with manure so even if the products were removed from the market now, treated grass is almost certainly in the system.  However, a lot of work has been done by a wide range of groups - from Dow themselves to various Government Departments and Agencies to organisations involved in gardening and allotment growing - to try and publicise the problem and provide information about it.  This should mean that not just users but others involved elsewhere in the use of treated grass and in the supply of manure will be much more aware of the potential problems and will act accordingly.


There still seems to be many people just stumbling across information when browsing the Internet - we have had lots of emails saying they were totally unaware of the problem. Also what about those without Internet access.


I can assure you that we are taking this problem very seriously and are investigating in some detail.  However, it would be inappropriate to comment on the possible outcomes of our investigations until those investigations are complete.  But now that more information is becoming available we will be updating the information on our website - as and when we can to ensure that anyone dealing with this problem is kept up to date with developments.  You may therefore wish to keep a watching brief on the site.


Questions and responses from an email conversation that I had with the PSD

The PSD responses are in black and the questions/issues that I think the response raises are in green.


1. Why does there appear to be nothing in place to regulate the use of a licensed product - no-one accepts responsibility for tracing the source of the misuse of this chemical?


There has been statutory control of pesticides since 1986 under which pesticides must be approved before they can be legally advertised, sold, supplied, stored or used. These are primarily the Food and Environment Protection Act 1985 (as amended by subsequent  legislation), the Control of Pesticides Regulations 1986 (as amended), the Plant Protection products Regulations 2005 (as amended), and the Biocidal Products Regulations 2001 (as amended). Prior to 1986, there  was a voluntary industry-run scheme which dates back to 1957, and  which followed on from an earlier scheme which began in the 1940s. These regulations control the use of approved products quite strictly and the use of an unapproved pesticide or the use of an approved  pesticide other than in line with its approval and the label  instructions constitutes breaches of the regulations. In addition,  users are required by law to take all reasonable precautions when using pesticides to protect the health of people, animals and the  environment. Advice to users on how to meet their legal  responsibilities under pesticide legislation is provided in the  statutory 'Code of Practice for Using Plant Protection Products'. However, the current problem does not result from the misuse of aminopyralid but from the use of the treated grass but this is not  covered by the legislation which regulates the approval and use of the product.


My point here is that there seems no system in place to track where things have gone wrong. There may well be strict regulations but is there a system of monitoring that the regulations are followed. It would appear from emails that I have received in confidence that at least one person affected went back to the farm and it was confirmed that aminopyralid had been used - it may not have been misused on the field but the person who had sprayed had supplied resulting manure - he hadn't read the label.


Where legislation exists it usually includes provision for monitoring and enforcement - there is, after all, no point in introducing legislation if it cannot be enforced - even if this can only happen after an event or incident.  However, legislation usually includes some sort of statement of its scope so that it is clear whether and where the legislation applies and if something is outside the scope of the legislation, the legislation, and therefore any monitoring and enforcement, cannot apply, however much it might be useful for it to do so. Sometimes, the application of legislation can be tricky and the Law of Unintended Consequences can sometimes come into play.  According to the Environment Agency website - (link now unavailable) 20/1387827/1226419/?lang=_e

And (link now unavailable)

pdf - manures and slurries are not waste if used on agricultural premises.  But allotments and gardens are not agricultural premises so, in theory, the supply of manure to allotments and gardens would appear to make that manure an agricultural waste and subject to the waste regulations.  But if the regulations are applied, then the manure might have to be disposed of as a waste material and might no longer be available for use on allotments and gardens, or perhaps allotment sites would have to be registered as waste disposal sites.  Aminopyralid residues notwithstanding, this would probably not be generally considered to be a good thing. If you've already discussed the problem with the EA and they have decided that it falls outside their remit, it is possible that no specific legislation applies.


2. Safety relies on someone reading, (in fact being able to read and understand) a label on a bottle and effectively passing information down a chain of supply - no paperwork is needed just word of mouth.


We are in the process of considering whether the aminopyralid approvals need modifying in order prevent a recurrence of the problem  in future. Incidentally, UK pesticides regulations actually require that anyone using a pesticide in the course of business or employment must be competent to perform the duties required by that business or employment. It is arguable that someone who cannot read and understand the label would have some difficulty in demonstrating that they are therefore competent to use a pesticide.


This takes me back to my comment above - who monitors that an individual is competent.


Anyone using any of the aminopyralid product such as Forefront would be required to hold a Certificate of Competence (with certain very limited exceptions), and since the training for the Certificate includes a written test, it is unlikely that someone who could not read would be able to pass the test.


3. No testing appears to have been carried out prior to licensing as to the safety of eating accidentally contaminated crops - at best now advice is contradictory. The PSD state that crops affected should be safe to eat if the manure is contaminated with aminopyralid but say evidence is circumstantial and there may be other causes.


If by testing you mean trials involving the consumption by humans of crops containing pesticide residues, then this does not happen. There are significant ethical issues involved in any medical trial involving human subjects and other ways are usually found to obtain the required information. With pesticides, studies are done, usually on rats, to determine the toxicity of a pesticide, and on crops to determine the likely residues that will be present in the crops. It is then possible to extrapolate from these results to carry out a consumer risk assessment. If you would like further information on this aspect of pesticide regulation and assessment, you might find the applicant Data Requirements Handbook of interest: please see this will give you an indication of the range and scale of data required to support an application for the approval of a pesticide. Based on the information we now have, we consider that if aminopyralid is present in the manure at the highest possible level that could result from use of aminopyralid products, the level of aminopyralid present in the crops should be well below the levels at which we might expect a risk to health to occur and therefore any crops grown in the  manure should be safe to eat. Where we have said that the evidence is circumstantial, this is actually in respect of the presence of aminopyralid in the manure, and not in respect of the crops being safe to eat. When we say that the evidence is circumstantial, we don't mean that it is questionable or untrue; we simply mean that while we have evidence of the use of an aminopyralid product on grass which was fed to animals which produced manure which was used on allotments where crops showed signs of damage consistent with the known effects of aminopyralid, we have no definite, explicit evidence that aminopyralid is in the manure and cannot therefore exclude the possibility that something else might have caused the crop damage, even though the use of aminopyralid means that it is highly likely that aminopyralid is in the manure because there is a known route by which it can end up there.


I don't expect testing to be done on humans but when I first enquired about this I was told by the chemical company that no testing had been done for the scenario that we were facing. Official advice was to dig in crops and not to eat them. Then in restudying data the advice changed. I would have expected that investigation of data would have already been carried out prior to the herbicide being authorised as at that point it must have been acknowledged that there was a chance of the chemical entering the food chain. The initial advice caused upset to people who had already consumed crops without realising that they could be contaminated. It also caused people do destroy crops that they are now advised should be safe.  I also wonder why the wording is not IS safe to eat rather than should be.


The aminopyralid products met the terms of the approval process and the potential effects on certain crops was recognised at this stage. However, as the approval process allows for, information came to light which led to us reviewing the situation.  As part of this review, we obtained further information to clarify specific points and it was on the basis of our assessment of this further information that we amended our advice. I should emphasise that while we have said that crops from affected plants should be safe to eat, this does not mean that anyone with affected crops must eat them; it means that if they do or have done so, we would not expect them to come to any harm. The reason for saying "should be safe" rather than "is safe" is that "is safe" implies a categorical (that is, absolute) assurance that no harm will come to anyone under any circumstances and it is simply just not possible to guarantee this, not just with pesticide use but in any situation in life. There is always a risk in every situation; the challenge is to try and manage the situation to ensure that any risks are acceptable.


4. The opinions on whether testing of soil samples and plant material is viable or even effective is again contradictory. We are told testing is being done but are not sure what is being tested. At best it would appear that due to the small amounts of herbicide likely to  be in the manure and the complex way in which residues are released -  testing cannot rule out its presence just at best confirm it.


We have been currently looking at two sampling sites where we have an explicit link between manure (known to have come from a farm using a Dow aminopyralid product) and allotment grown crops with exposure symptoms. These have been selected to give us the best chance of relating any residues we find to inputs and thus improving our risk assessment and hopefully being able to provide further reassurance to consumers. The samples depend on what is available at the sites but include soil/manure and plants. And the results might do little more than simply confirm that aminopyralid is present, but that will place us in a better position than simply assuming it is present.


5. We are told that the supply of manure to allotments and gardens is a grey area - in effect anyone can deliver manure containing anything to us for use on our food crops.


This does not mean there is no regulation or that no legislation exists which might cover this situation. While the disposal of manure from farms and stables is regulated by the Environment Agency, the provision of goods and services which should cover the supply of manure to allotment users will be covered by trading standards and consumer protection legislation. In general, if someone is supplying a product, then that product must be fit for its purpose, so if a supplier was to claim that the manure was free of aminopyralid and it subsequently transpired that aminopyralid was present and it caused damage to crops, that is likely to provide the basis for an extremely good case against the supplier. See also the response to point 8 below.


I have contacted Trading Standards, and the Environment Agency and it is from these sources that I was told of the grey area. Trading standards would cover if a commercial product stated it was organic and proved to be contaminated with herbicide but not 'raw' manure. Both agencies explored this scenario in detail before coming up with the answer that it was not within their remit.


This probably means that any 'regulation' of manure supply will be dependent on self-regulation combined with action in the civil courts where such self-regulation fails.  You should, of course, seek clarification and advice on this from a suitably qualified source - I note you refer on your website to advice provided by the National Association of Allotment and Leisure Gardeners on seeking compensation.


6. Contaminated manure even appears to have been supplied by organic farms and seems to have found its way into commercially bagged manure/compost.


We have had one or two reports of this but no confirmed evidence. The testing we have been undertaking is in the context of carrying out a risk assessment of the problem rather than a risk assessment of every affected allotment, and we have no remit to carry out general or quality assurance testing on behalf of the manure supply industry.


Isn't it difficult to provide confirmed evidence? By one or two do you mean that literally? In answers to questions in Parliament Mr Woolas states that PSD have about 90 complaints. However when I complained it was on behalf of 12 people not just me. Other allotments have sent in maybe one complaint on behalf of many. Your website seems to put people off making a complaint as it says that a user should be reasonably certain (very difficult) and if so contact DOW for advice. It doesn't ask for a report to be made to PSD. I think the numbers affected by this problem are underestimated.


Yes, I do mean literally one or two reports of problems resulting from the use of commercially bagged compost/manure.  The 90 complaints that Mr Woolas refers to is also literally that: we have a record of some 90 enquiries or reports on different aspects of the one problem.  In many cases, we are aware that the enquirer has contacted us on behalf of one or more other people, or even on behalf of an entire allotment society, but that is still only considered to be a single enquiry.  The number of people involved does not actually materially alter the problem as far as pesticide regulation is concerned, but simply the extent of it (that is not intended to deny or diminish the problems that any individual has experienced), so there has been no over-riding need to identify exactly how many individuals have been affected. Almost certainly, no one has a clear idea of how many individuals have been affected by this. The problem has been reported in many different directions and some of these reports will have been forwarded on to other organisations so there may be many cases of duplication. If anything, because you have been pulling together information on the problem, you probably have a better idea of the numbers involved than anyone else.By asking people to be reasonably certain that aminopyralid is involved, we were trying to avoid getting into a situation where any crop damage whatsoever was simply being blamed on aminopyralid.  The reason for expecting that someone with a problem of crop damage on their allotment would be reasonably certain that aminopyralid was involved was that if it wasn't then the advice we and Dow were providing would be invalid or ineffective and possibly even detrimental and we had no wish to make the problem worse.  And we weren't expecting users to carry out some sort of analysis but it did seem at least possible that they might be able to confirm that aminopyralid had been used by contacting the manure supplier.


7. We don't know whether at any point fruit and vegetables supplied by the retail trade have been affected.


We have not, as yet, had any reports of aminopyralid residues in foods supplied by the retail trade but if aminopyralid is detected in samples of food then we would make an assessment of any risks to health based on the levels of aminopyralid present. In any case, many suppliers and retailers in the food industry already carry out their own residue testing as part of ensuring that the commodities they supply meet the requirements of Food Safety legislation.


8. We are told that in order to avoid a repeat of the problem we should only obtain manure from trusted sources. Due to the intricacy of the chain of supply and how this contamination can enter the chain - this is impossible. Anyone misusing either by design or accident is unlikely to be traceable and therefore educated or prosecuted.  Apparently farmers were 'educated' in the use of the herbicide last year when problems were cause to commercial crops but it would appear the lessons were not learned.


It is probably impossible, as you say, for an end user to determine what might have gone into any manure they obtain. However, a degree of self-regulation does appear to be developing within the manure supply industry and we are aware that producers of commercially-packaged manure are beginning to require their manure producers to guarantee that Forefront has not been used on anything fed to the animals. It therefore looks likely that in future, a user should be able to ask for some sort of guarantee from a manure supplier that the manure does not contain pesticides, veterinary medicines, chemicals or any other contamination. If the supplier is unable to provide such a guarantee, then the user will have the option of taking their custom elsewhere.  While this will probably not, on its own, entirely eliminate the problem, it will be a significant step forward from the current situation.


Is a degree of self regulation adequate though? I have read that one commercial supplier is asking stables to sign to say that no aminopyralid products have been used but that depends on the stable being able to trace back through the chain of supply and get accurate answers. Wouldn't a more significant step be to require an article of provenance to be kept whereby the use of any chemical was listed as the product was passed down the chain. This is something that is already used in other industries. It also of course relies on the end user - i.e. the general public - knowing what to ask or look for.


It is a little difficult to estimate how effective self-regulation might be, but it is clearly in everyone's interest that it works.  I can understand that there is some interest in introducing some sort of statutory control but this would not be straightforward. New legislation is not introduced overnight. Even secondary legislation implemented under Statutory Instruments can take 2 or 3 years to draw up and introduce, assuming that the political will is there in the first place and Ministers agree it is required. The quick introduction of legislation in response to a high-profile incident is by no means the norm and, as has often been observed, a quick fix rarely satisfies anyone. And with the devolution of various powers and responsibilities, including some related to pesticides, to the Scottish Government, Welsh Assembly Government and Northern Ireland Executive, it would require implementing in all 4 countries of the UK in order to avoid a repeat of the problem as the result of cross-border trading within the UK. And that, of course, says nothing about the movement of animal feed across Member State borders within the EU. These days, introducing new legislation is a serious undertaking. There is also the question of proportionality. The problem caused by the manure is a specific one resulting from a specific set of circumstances. The introduction of a general solution which would have an effect on all farm pesticide use might well be considered to be disproportionate to the problem it is intended to solve.  Nor would it cover all situations which might lead to the introduction of herbicide or other residues into manure, and I've already referred to the Law of Unintended Consequences. And, as you touch upon, whatever system develops or is introduced, it still requires the end user to take some responsibility for ensuring that the manure or compost they obtain is suitable for their purposes.


9. If aminopyralid isn't the cause of the crop failures is there any other chemical that could have the same effect?


PSD have no evidence that any other active ingredient causing the same symptoms.


Responses from Phil Woolas to a letter that I sent recently to Mary Creagh MP


In many ways I am amazed that no-one anticipated this scenario before a licence was given and that the only safety net is down to a farmer reading a label correctly. Surely given human nature it could have been anticipated that a proportion of users would not follow label instructions. In the event for the problem to be as widespread as it has been this must be what a significant proportion of users must have done or they at least failed to pass on important information to those who have either contracted them to spray or supply them with materials. The question – “What if ...?” should surely have been considered.


The possibility that crops could be affected by contaminated manure was anticipated as it was known that aminopyralid would remain tightly bound to plant material in manure. Data was therefore provided to, and assessed by, the PSD to show what crops might be affected by residues arising from the application of manure or ploughing in grassland for following crops.  As a result, the restriction that manure should not be applied to those sensitive crops was added to the label. Following label instructions is a legal requirement and failure to comply with the conditions of use is a prosecutable offence. I do not think it could reasonably have been foreseen that so many farmers would appear to have been unaware of the restriction, or to have disregarded it.

Follow-up question that this raises

Does anyone know of anyone who has actually been prosecuted for misuse? As far as I am aware no-one seems interested in tracking down misuse - if this is the case the threat of prosecution is hardly a deterrent.



I applaud what the chemical company has done by voluntarily withdrawing the product even on a temporary basis. It is worrying, however, that it is the chemical company and not our government departments that is taking the initiative.


PSD must operate within the law and regulatory decisions must have a clear legal basis. When the approvals of these products were amended to prevent sale and use, there was no direct evidence that aminpoyralid was the causal agent. The suspicion that aminopyralid was involved was based on symptoms of crop damage which could have resulted from other causes. By that stage, however, PSD had evaluated additional which confirmed that, if aminopyralid was the cause, it would not have implications for consumer health. In these circumstances any action by PSD which did not have a clear legal basis could have led to legal action by the approval holder. It was therefore better and more effective to work with the approval holder to seek a voluntary change in the approval status of the affected products.



The Pesticide Safety Directorate issue updates on their website but do all farmers read these and if so how often?  How else do they find out that a product has had its licence withdrawn? I understand that some farmers are still unaware that this is the case for products containing aminopyralid. So will some continue to use aminopyralid based products unwittingly?


The season of use of these products had at that stage passed and it is unlikely that farmers would have continued to use these products after their use was suspended. Moreover, relatively few farmers buy products direct from the approval holder; most; obtain products from a small number of distributors who do read regulatory updates. The manufacturer, Dow AgroSciences, has contacted distributors to take back any stocks they may have and to contact the farmers to whom they have sold supplies. Farmers and distributors do not, in any case, hold large stocks because of the cost, and these products are thus only in the system to the extent that they have already been used in 2008. This may still have a potential impact on manure sold into 2009.

Follow-up question that this raises

If manure is stored in piles for a time before being delivered to gardeners etc. I would guess that the effects of spraying in 2008 will affect gardeners for longer than just 2009. As I understand it when manure is stored in piles the chemical can take several years to break down.



A number of people suspect that contamination was introduced to their soil through bagged commercial products which would come under Trading Standards remit but proving that contamination exists in such products is practically impossible. As I understand it there are no tests yet available that could categorically come to a definite conclusion. At best they could only detect that aminopyralid residue was present not that it definitely wasn’t.


Establishing whether manure or compost might be contaminated is indeed difficult. Sensitive chemical tests do exist for aminopyralid which are capable of detecting as little as 10 to 20 millionths of a gram of the substance in a kilogram of plant material, soil or manure. However, these tests are highly complex and expensive and some plant species, particularly legumes are sensitive to even lower levels (aminopyralid is after all a selective herbicide used to control broad leaved plant species). This means that chemical analysis is unlikely to be an effective way of monitoring residues and it may be less selective but more sensitive bioassay would be helpful to allotment holders to check for any residues in manure.



From DOW’s website I understand that in the near future DOW is looking to apply for licence to use aminopyralid products on food cereals crops. Should this licence be granted then the problem will be compounded as straw products will also be affected by residues.


The investigation that is currently being undertaken by PSD will be looking at how the difficulties that have arisen for gardeners and allotments holders may be dealt with and prevented in the future before re-instating the product authorisations. Should Dow AgroSciences apply for use of aminopyralid on cereals, they will have to address all the appropriate data requirements, as well as any relating specifically to this issue.

Response 2:

A key issue in their (DOW) consideration will be whether the conditions of use regarding manure are sufficient, or sufficiently well known. PSD is the European Community's rapporteur for aminopyralid under Directive 91/414/EEC and has sought information from other member States who may have experienced similar problems. These findings will be taken into account when the Community considers whether this substance should be approved for use more widely.

(For those of you - like me - who wondered what rapporteur meant in this context - it means that the PSD prepares the report on aminopyralid for the EU)

Responses from Huw Irranca- Davies (Phil Woolas' replacement) to a follow up-letter that I sent recently to Mary Creagh MP received 8 November 2008

Follow-up question

Does anyone know of anyone who has actually been prosecuted for misuse? As far as I am aware no-one seems interested in tracking down misuse - if this is the case the threat of prosecution is hardly a deterrent.

Response to follow up

There is a real difficulty in showing unequivocally that damage or even slow growth is directly linked to a particular source. Additionally there is the question of whether the supply was made knowing that the manure contained aminopyralid. It might also be necessary to prove that at the time of planting there was indeed sufficient aminopyralid present in the treated soil. Given that aminopyralid is quickly broken down by soil bacteria, it might be difficult to extrapolate back to the time of damage if no aminopyralid could be found in the treated soil at the time of the investigation.


So this is a law that it is impossible to enforce and consequently offers no protection nor provides a deterrent against misuse. The statement that aminopyralid quickly breaks down in the soil leads to a false sense of security. In an area of soil containing contaminated manure it can take at least a year for all the affected material to break down thus releasing aminopyralid into the soil. It is only then that it takes a short time (assumed to be about three weeks) for the aminopyralid to be broken down. Consequently aminopyralid is being released into the soil over an extended period of time which causes problems thought at least one growing season. As I understand it from the PSDs own website tests have been carried out that have confirmed the presence of aminopyralid.



Mr Woolas confirms that manure affected by aminopyralid could be in the system and be used by gardeners and allotment holders during the next year (I would argue that the effects could be longer). In this case many gardeners and allotment holders could experience the same problems as they have faced this year due to ignorance of the problem. A group of us have been trying our utmost to publicise the problem with limited success. National papers and TV seem to have been the most reluctant to give any publicity to the issue and where they have the editing has omitted very important facts. What is the PSD DEFRA or any government agency doing to publicise the problem and try to inform gardeners that care should be taken when obtaining manure or indeed compost.


PSD has also been alert to this possibility and published guidance on its website to cover all aspects of the situation. Dow, the company holding the current suspended approvals for aminopyralid-containing products has also been active in this respect, as has the RHS. As the approvals have already been suspended, this will prevent further supply and use. If the approvals are re-instated (and this is by no means certain), there will need to be some form of Product Stewardship to maintain effective communication about the disposal and possible use of manure containing aminopyralid.

Follow-up comment

I doubt whether gardeners in general will pick up on information provided by these sources, my reference was to more popular media publicity. Prevention of further use of the chemical isn't the issue but prevention of further use of contaminated manure by ordinary gardeners especially in light of the fact that gardening magazines and programmes still mention the use of manure with no warning to take care that the supply hasn't been contaminated.



It also seems that there is no real regulation regarding the supply of materials to gardeners or allotments holders and that even the term organic has very little meaning when applied to gardening products.


Inevitably this position arises because of the very varied and often informal way in which manure is traded, often by farm-gate sale. Arguably it is simply not possible to monitor such complex arrangements comprehensively. Recognising these factors, we believe that the only practical way of trying to prevent a recurrence would be to strength the label advice and warning, if the suspended approval were to be reinstated.

Follow up comment

The response is only relating to manure supplied direct from a farm but there is no reason why commercial products should seemingly be unregulated. This doesn't address the issue that organic doesn't mean anything when applied to commercially produced garden products. Also the strengthening of warning on a label doesn't achieve anything if someone doesn't read the label and if there are no consequences for failing to do so. It also doesn't prevent a new batch of chemicals causing the same problems.


Letter received from Huw Irranca-Davies 19 December.


I accept that the chemical aminopyralid isn't a risk to human health and also that the product has been temporarily withdrawn. However, one aspect that has been mentioned to me by a professional gardener of some standing is the fear that a chemical may be safe on its own but is it safe when combined in a cocktail of other chemicals. In a typical manure pile where silage/bedding has been sourced from different places it is probable that a whole raft of chemicals are present. So combined are they still safe? I also think that our experiences with this particular chemical could be replicated with some other product so rather than it being the chemical that has caused our current problems I feel that it is the process of authorisation that requires strengthening.


Without some more specific information on the chemicals that may be present, I cannot comment. However, at a general level the PSD, through the Independent Advisory Committee on Pesticides has considered the matter. The ACP reported in the early 1990s that interactions of pesticides and other chemicals were at worst additive rather than synergistic. This conclusion was supported by a later literature covering the possible synergistic effects of mixtures of pesticides.

Follow up comment

The chemicals used now would not have been considered in any 1990 investigation. In the 1990s the effects that we have suffered would have been unthinkable.



 The question about publicity really referred to publicising to the general gardening public, and not the professionals, that there was a need to take care when obtaining manure. Such people are unlikely to visit the PSD or DOW websites (until our problem I had no idea that either even existed!) and they are also unlikely to stumble across the problem on the RHS website unless they are looking for it. If you don't know that a problem exists then you don't look for information about it. Gardeners are accidentally stumbling across the information on our website when they are searching for a supplier of manure and are unaware that they need to be vigilant. Then there is a mass of gardeners out there who don't have Internet access.  Maybe some form of leafleting at garden suppliers/nurseries/garden centres could help? I  know that the chemical will not be used again until/if the product is reinstated but it was used to spray fields this year and so potentially contaminated manure will be out there waiting for some poor unsuspecting grower to spread it on his soil. Information states that in a stacked manure heap the chemical can persist for over a year maybe several as it is trapped until the microbes in the soil effect decomposition.


You suggest that more could be done to safeguard against the possibility of manure produced this year being inadvertently supplied or obtained. PSD has tried hard to publicise the issue through its website, by replying to enquiries via its Information Section, and being interviewed on Gardeners' Question Time. However your point is well made and I will ask PSD to take forward your proposal for leafleting garden centres.

Follow up comment

The answering of queries and the interview on GQT was not initiated by PSD it was as a result of other people making the approaches, therefore they haven't really been proactive in their attempts at publicity other than use of their website. The leafleting will be a good move but in many ways will be too late for many gardeners and should have happened much earlier.



In response to the point that it is difficult to prosecute any misusers as it is difficult to detect who they are, I have to say that there is no point having a law if it can't be enforced as it offers neither protection nor deterrent. As far as I am aware according to the PSD website tests have been carried out that prove aminopyralid to be present in some material that has been tested. Is it true that not even one misuser has been identified and if not prosecuted then at least given a strong warning.  Mr Irranca-Davies states that the only practical way to prevent a recurrence is to strengthen the label's advice and warnings. How does this help if users are not actually reading the label? If it is difficult to prove that users have misused the product or that it is present in manure, if it is difficult to identify who has misused the product, if it has been impossible to take anyone to task for misuse on this occasion then how will this be possible if the label advice is strengthened? How will this improve anything?


I previously set out the practical problems liable to be encountered in controlling the supply of raw manure and you rightly say there is no point in an unenforceable law. My position was that it would be difficult (although not impossible) to take regulatory action and that reducing the risk of a recurrence through, amongst other methods, strengthened label advice would be better.

Follow-up comment

Doesn't really answer the question



The statement that aminopyralid breaks down quickly in soil is misleading. It implies that a short time after applying the manure to the soil everything is well again. This is not the case. As the manure in the soil decomposes aminopyralid is released and it is only then that it breaks down (after we are told) about three weeks. However, the manure causes problems for a very long period of time i.e. until all the plant material in the manure has decomposed. As each particle of plant material in the manure decomposes it releases a new burst of aminopyralid. Granted a very tiny amount but enough to kill, deform or stunt sensitive plants. We planted tomato plants in soil that had had manure applied several months before. For a couple of months they grew well and suddenly became deformed. Even a year after applying the manure we have small clumps of manure intact that has not yet decomposed and so aminopyralid could still be present in these clumps to cause us problems next season depending on the rate of decomposition over winter.


You query the rate of decline of aminopyralid in treated soil and at what time it might be safe to plant, citing your own experiences. It is true that after digging-in or rotavating the soil, the released aminopyralid will reach a maximum concentration, probably within a matter of weeks, and decline through bacterial action. However, because of the large number of variables in any given case (origin of manure, time of purchase, soil type, method and extent of incorporation etc.) it is not possible to predict accurately the rate of decline. More important o know at what reduced concentration it would be safe to plant and there are as yet no specific studies to address this point. Since chemical analysis is expensive and impractical for an allotment holder, the best action would be to use a simple bio assay of suspect soil. This would involve planting out crops known to be sensitive in small plots of treated soil and checking germination and growth over time. PSD would be happy to provide advice on this method.

Follow-up comment

I still think to state that aminopyralid breaks down in a matter of weeks is misleading! Other gardeners' comments on using bio-assay tests would be interesting - personally  think it is impractical. May as well just plant in the soil and see what happens after all there isn't any real alternative as if you try the bio-assay methods, by the time you get some sort of result it may be too late to plant crops anyway. Email to let me know what you think and I may publicise your comment.






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Our Plot at Green Lane Allotments Blog  | A Gardener's Weather Diary  | School Vegetable Patch Website


© Our Plot on Green Lane Allotments - Please email me if you wish to use any of this site's content