Some idiot on our allotment recently used a paraquat-based weedkiller to clear part of his plot. A LOT of this drifted on to neighbouring plots severely affecting plants there. Question: can any of these be eaten if they survive? What effect does paraquat have on soil and crops planted there in the short, medium and long term?
Can anybody out there who has had similar problems on their allotments tell me whether the individuals using these chemicals were ever thrown out of the association or chucked off by the Council? The damage done on our site has been considerable and we are considering taking this action.
Paraquat weedkiller
Moderators: KG Steve, Chantal, Tigger, peter, Chief Spud
It won't do you any harm on the crops but give them a thorough wash It does no further harm once it goes onto the soil. The real dange is eating/drinking the raw weedkiller as there is no antidote but the usual packeted stuff is not very strong nevertheless it is best to avoid that. Some people were getting the farm concentrate from farmers in unmarked bottles, that always was taboo and very dangerous left around. The new formulation Weedol 2 now has no paraquat in it, only the diquat.
Allan
Allan
Last edited by Allan on Mon Jun 05, 2006 8:21 am, edited 1 time in total.
Hi Barry,
Paraquat no longer has a licence to be used in UK by anybody. The use-up period expired in, I think, April 2004 so that person is in breach of the law.
However that doesn't answer your question and the answer is that it will have no long term lasting effects on the soil but no planting up should be done for at least 6 weeks. If in doubt carry out a Cress Test.
Paraquat no longer has a licence to be used in UK by anybody. The use-up period expired in, I think, April 2004 so that person is in breach of the law.
However that doesn't answer your question and the answer is that it will have no long term lasting effects on the soil but no planting up should be done for at least 6 weeks. If in doubt carry out a Cress Test.
JB.
Can you quote where you got the "six weeks" from?
I have just got this from Paraquat Information Centre and I always took it that it was inactive as soon as it was incorporated in the soil, a sort of chemical flamegun effect.Not that I am allowed to use it now!
Quote"
Paraquat is inactive in soil - When paraquat residues come into contact with the soil the paraquat active ingredient rapidly becomes adsorbed and strongly bound to clay and organic matter in the soil. It becomes biologically inert and as a result it cannot be taken up by plant roots or other organisms. Paraquat does not sterilize the soil and it cannot be released or re-activated by the application of water or other agrochemicals."
Also, from an old box of Weedol sachets which contained paraquat and diquat.
"Weedol has no harmful effects on the soil. Fresh plantings and seed sowings can be made as soon as the spray has dried"
It seems to me that the ban was imposed not because of danger to humans in usage but in the few cases, albeit some lethal, where the concentrate was misused.
I have just got this from Paraquat Information Centre and I always took it that it was inactive as soon as it was incorporated in the soil, a sort of chemical flamegun effect.Not that I am allowed to use it now!
Quote"
Paraquat is inactive in soil - When paraquat residues come into contact with the soil the paraquat active ingredient rapidly becomes adsorbed and strongly bound to clay and organic matter in the soil. It becomes biologically inert and as a result it cannot be taken up by plant roots or other organisms. Paraquat does not sterilize the soil and it cannot be released or re-activated by the application of water or other agrochemicals."
Also, from an old box of Weedol sachets which contained paraquat and diquat.
"Weedol has no harmful effects on the soil. Fresh plantings and seed sowings can be made as soon as the spray has dried"
It seems to me that the ban was imposed not because of danger to humans in usage but in the few cases, albeit some lethal, where the concentrate was misused.
Hi Allan,
The same is said about Roundup but would you plant immediate after using it. Of course you wouldn't!
It is a general precaution when using weedkillers of any description. It is always better to err on the side of caution.
The person that has used it on Barry's Allotment is obviously a bit of a prat to spray when there was the remotest possibility of spray-drift.
It's not so much the spray as the sprayer.
I think that that person should be taken to task by the allotment committee and if that doesn't have the desired effect then it should be put in the hands of the site owners.
The same is said about Roundup but would you plant immediate after using it. Of course you wouldn't!
It is a general precaution when using weedkillers of any description. It is always better to err on the side of caution.
The person that has used it on Barry's Allotment is obviously a bit of a prat to spray when there was the remotest possibility of spray-drift.
It's not so much the spray as the sprayer.
I think that that person should be taken to task by the allotment committee and if that doesn't have the desired effect then it should be put in the hands of the site owners.
JB.
Hi,
Would be interested in the 6-week comment also. I'm no herbicide expert (just opinionated!).
I have a suspicion that it will depend on the solution/formulation that the paraquat is delivered in (i.e. what else is in there). Since paraquat kills only what it comes ito contact with it may be that some formulations contain other herbicides that kill roots as well. These may well reside in the soil as active for some time.
Another thought is that there are harmful 'buffer' compounds in the formulation which ensure that, once in solution, the paraquat remains active until it comes into contact with something else.
From very sketchy memory (I'll do some research) I think paraquat irreversibly damages fat (lipid) molecules in cell walls
Thought you'd like the chemical name....
N,N'-dimethyl-4,4'-bipyridinium dichloride
Interestingly, having sprayed large tracts of illegally grown south american 'weeds', a batch of paraquat contaminated wacky-backy arrived in the USA. This however was thought not to present any health risks since the burning made the active ingredient 'harmless' even to those who 'accidentally inhaled'!
Off to look in my dad's shed for evidence!
Loz
Would be interested in the 6-week comment also. I'm no herbicide expert (just opinionated!).
I have a suspicion that it will depend on the solution/formulation that the paraquat is delivered in (i.e. what else is in there). Since paraquat kills only what it comes ito contact with it may be that some formulations contain other herbicides that kill roots as well. These may well reside in the soil as active for some time.
Another thought is that there are harmful 'buffer' compounds in the formulation which ensure that, once in solution, the paraquat remains active until it comes into contact with something else.
From very sketchy memory (I'll do some research) I think paraquat irreversibly damages fat (lipid) molecules in cell walls
Thought you'd like the chemical name....
N,N'-dimethyl-4,4'-bipyridinium dichloride
Interestingly, having sprayed large tracts of illegally grown south american 'weeds', a batch of paraquat contaminated wacky-backy arrived in the USA. This however was thought not to present any health risks since the burning made the active ingredient 'harmless' even to those who 'accidentally inhaled'!
Off to look in my dad's shed for evidence!
Loz
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Mr Potato Head
Paraquat poisoning is nasty stuff. We're taught (I'm a volunteer medic) that it's one of the only things you shouldn't adminster oxygen for - as it accelerates the effects. Either way you'll die in a very nasty fashion... Sadly, for a while, it was the suicide method of choice for lonely farmers! 
Useful link
Inchem
and a 'positive spin' from the producers...
http://www.paraquat.com/
Useful link
Inchem
and a 'positive spin' from the producers...
http://www.paraquat.com/
Can anybody confirm that paraquat is actually banned for use on allotments in the UK? This is very important, since the individual spraying with this has been told off before. I need a concrete internet page or press report that says that it cannot be used. Cannot find anything myself using a search engine.
Thanks!
Thanks!
-
Chantal
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I can only find references to it NOT being banned when the EU had the chance back in 2003. However, if you email Pesticide Action Network (PAN) UK, I'm sure they'll advise you. admin@pan-uk.org
Chantal
I know this corner of the earth, it smiles for me...
I know this corner of the earth, it smiles for me...
I have found the same as you, Chantal. All info points to the fact that it is not banned in the UK. Below are quotes taken from this link - http://www.pan-uk.org/pestnews/actives/paraquat.htm
'Regulatory status
Finland and Sweden banned paraquat because of its high toxicity.
Austria banned because of high toxicity and high frequency of poisonings(32).
Hungary severely restricted because accidental poisoning rate was unacceptably high(33).
Norway voluntary cancellation.
Limited registration in Germany. Concern with residues in soil has led to registration for field crop applications only once every four years, and only in areas at risk from erosion.
US Restricted use pesticide - purchase and use only by certified applicators.
Europe Under EC Registration Directive 91/414 the UK will review paraquat on behalf of Member States by mid 1997(34).'
Further and from the same site, 'In the UK there are no such restrictions and Pathclear and Weedol are allowed for amateur use in household gardens.'
' Zeneca markets paraquat as Gramoxone for agricultural use in formulations ranging between 24-36% active ingredient and for home and garden use under the trade names Weedol and Pathclear...'
'Regulatory status
Finland and Sweden banned paraquat because of its high toxicity.
Austria banned because of high toxicity and high frequency of poisonings(32).
Hungary severely restricted because accidental poisoning rate was unacceptably high(33).
Norway voluntary cancellation.
Limited registration in Germany. Concern with residues in soil has led to registration for field crop applications only once every four years, and only in areas at risk from erosion.
US Restricted use pesticide - purchase and use only by certified applicators.
Europe Under EC Registration Directive 91/414 the UK will review paraquat on behalf of Member States by mid 1997(34).'
Further and from the same site, 'In the UK there are no such restrictions and Pathclear and Weedol are allowed for amateur use in household gardens.'
' Zeneca markets paraquat as Gramoxone for agricultural use in formulations ranging between 24-36% active ingredient and for home and garden use under the trade names Weedol and Pathclear...'
The cow is of the bovine ilk
One end is moo, the other, milk.
One end is moo, the other, milk.
First, there is no doubt that the paraquat-based formulations are now illegal.Was it really paraquat or the new formulation of Weedol i.e. Weedol 2 which is perfectly legal or it wouldn't be on sale. Whatever it was should have been put on with a droplet pattern such as from a sprinkler close to the ground, not from a "sprayer" if other allotments were to be considered,and only in conditions of no wind.
In the days, rather years, when I used paraquat-based Weedol I found no after-effects on subsequent crops so it is wrong to dismiss the manufacturers instructions. Admittedly I wouldn't personally have sown or planted the same day but I do give credibility to a science-based instruction rather than to scaremongering, I have never seen any untoward after-effects.
All this is academic if paraquat is no longer used unless the new formulation is to be treated as identical in its effects.
To deal with Johnboy's remarks about when I would sow or plant immediatelyafter use, yes I have done in the past, I will do, I have to do or sacrifice all the plants that I have ready to go out. There is never anything like six weeks grace between clearing the ground and needing to get the plants in. If you will recall the current season, previously the ground was hard and unworkable, then there were two days between the deluges when treatment of weeds was possible and I just had to do it with chemicals. Now the weeds are dead I can burn off and then cultivate.
Allan
In the days, rather years, when I used paraquat-based Weedol I found no after-effects on subsequent crops so it is wrong to dismiss the manufacturers instructions. Admittedly I wouldn't personally have sown or planted the same day but I do give credibility to a science-based instruction rather than to scaremongering, I have never seen any untoward after-effects.
All this is academic if paraquat is no longer used unless the new formulation is to be treated as identical in its effects.
To deal with Johnboy's remarks about when I would sow or plant immediatelyafter use, yes I have done in the past, I will do, I have to do or sacrifice all the plants that I have ready to go out. There is never anything like six weeks grace between clearing the ground and needing to get the plants in. If you will recall the current season, previously the ground was hard and unworkable, then there were two days between the deluges when treatment of weeds was possible and I just had to do it with chemicals. Now the weeds are dead I can burn off and then cultivate.
Allan
Okay, had another look and here may be the info you need, Barry - http://www.pesticides.gov.uk/fg_leraps.asp?id=1198 I suppose withdrawl timetable applies to the UK?
I have also checked my box of Pathclear and it does not contain paraquat.
I have also checked my box of Pathclear and it does not contain paraquat.
The cow is of the bovine ilk
One end is moo, the other, milk.
One end is moo, the other, milk.
Yes, that's exactly how I see it Barry. This link explains the withdrawal significance more clearly, in the event you need it - http://www.garden-care.org.uk/withdrawn.asp
Quote:
'In addition since 1991 there has been an ongoing review of all garden (and agricultural chemicals) by the EU. This has resulted in and will continue to result in a number of products being revoked from use.
This means that after a certain date a product can no longer be sold and furthermore from a further date the product can no longer be used by the consumer. The product must then be disposed of safely.'
Quote:
'In addition since 1991 there has been an ongoing review of all garden (and agricultural chemicals) by the EU. This has resulted in and will continue to result in a number of products being revoked from use.
This means that after a certain date a product can no longer be sold and furthermore from a further date the product can no longer be used by the consumer. The product must then be disposed of safely.'
The cow is of the bovine ilk
One end is moo, the other, milk.
One end is moo, the other, milk.