What is Glufosinate-ammonium?

Glufosinate-ammonium is a vitally important crop protection tool that farmers in around 80 countries have used safely for 30 years to control weeds in over 100 crops. It is one of the most effective herbicides available for treating weeds in orchards, vineyards and other herbicide-resistant LibertyLink crops such as soybeans, corn, canola or cotton. Crucially, its distinguishing chemistry and ‘mode of action’ help farmers avoid weed resistance .

What alternatives to using Glufosinate-ammonium does the farmer have?

Glufosinate-ammonium is an essential tool for farmers to maintain an economically viable business while maintaining healthy crops. Alternative chemical treatments can be used in some circumstances but these often affect whole plants rather than just the part of the plant with which they come into contact, which would harm the crop. Alternative chemical treatments also tend to have a smaller spectrum of control. Using mechanical weed control methods is usually considerably more costly and not always feasible.

Does Glufosinate-ammonium pose risks to human health?

Glufosinate-ammonium has been the choice of farmers for 30 years in around 80 countries. During this period it has been evaluated by multiple independent regulatory authorities worldwide on a regular basis and certified as safe in use when used according to label instructions. Bayer supports various product stewardship initiatives which instruct farmers on how to use the product correctly.

Is Glufosinate-ammonium toxic? If so, is it safe for use?

In the European Union, Glufosinate-ammonium is classified for presumed human reproductive toxicity, based on laboratory studies – for example, on rats – at doses impossible under realistic and responsible conditions of use. Glufosinate-ammonium is not classified for carcinogenic or endocrine disrupting effects.

Glufosinate-ammonium has been used safely for 30 years, on more than 100 crops in around 80 countries worldwide, and to-date, there are no known cases of harm to humans when applied according to labelled instructions. This reflects, firstly, that the dosage stipulated is far lower than the relevant safety thresholds, ensuring a wide margin of safety for workers and others near the farm during and after application. It also reflects the existing use of various measures – ranging from training on how to apply the product in line with the specific soil and weather conditions of the farm, to use of technologies to reduce exposure.

Furthermore, residues of Glufosinate-ammonium on food, if present, are at levels far lower than safety threshold limits; an average person would have to consume more than 250 apples in a single day in order to breach the toxicological safety threshold limits.

Is Glufosinate-ammonium considered as an endocrine disruptor? Does it cause cancer?

Based on all the available information and studies, Glufosinate-ammonium shows no evidence of being an endocrine disruptor. Additionally, it is not classified as carcinogenic. The herbicide is safe to consumers, operators and the environment when used according to label instructions.

Is Glufosinate-ammonium present in our food?

The exposure of consumers to residues of Glufosinate-ammonium via food is estimated based on the results of field residue trials conducted according to worst-case assumptions, including the highest authorized application rates and the shortest authorized pre-harvest intervals. Based on these tests, any traces of Glufosinate-ammonium that may remain on crops and that are ingested directly by humans or indirectly as a result of consuming meat and milk from animals that have fed on such crops are limited at stricter levels than defined toxicological safety thresholds. Therefore, they do not pose a health risk. For example, an average person would have to consume more than 250 apples in a single day in order to breach the toxicological safety threshold limits.

How safe is Glufosinate-ammonium to the environment?

Glufosinate-ammonium has been rigorously tested through lengthy trials for environmental safety over the course of 30 years. When label instructions are followed, it is safe to use. The herbicide is not significantly active in soil and is rapidly degraded by micro-organisms in the soil, making water contamination very unlikely. Risk to birds, bees, aquatic organisms, earthworms and other soil organisms is also very unlikely when the product is used according to label instructions.

How are herbicides, including Glufosinate-ammonium, tested for safety during the product development stage?

Before a herbicide is allowed on the market, the manufacturer must perform a thorough safety assessment. This is a long and comprehensive process that involves many tests and field trials. If a chemical is found to be an efficient weed control agent, it is then screened for its safety in relation to humans, animals, and the environment. Toxicological tests and environmental assessments examine any potential risks to health and the effects on soil, water and air. Controlled field trials conducted in close-to-real-farm conditions take worst case scenario levels of exposure into account to determine high safety margins. All data are presented to the relevant regulatory authorities who review the findings, and make a decision regarding the authorization of the product. This decision is based on a comprehensive scientific peer-reviewed analysis.

What is the current status of registration of Glufosinate-ammonium in the EU?

The current EU registration for Glufosinate-ammonium is valid until 31 July 2018. 

Is Glufosinate-ammonium mentioned on the list of candidates for substitution in Europe?

Glufosinate-ammonium is mentioned on the list of candidates for substitution published by the European Commission under Regulation 1107/2009 in January 2015. The list does not question the safety of the active substance, which has already passed the strict EU evaluation criteria and is approved for safe use. The listing means that products containing Glufosinate-ammonium will be required to go through comparative assessment by Member States, meaning they will be compared with adequate alternative solutions (chemical and non-chemical) already available to farmers. The products will be (re)authorized if there are no significantly safer alternatives, or if the substitution would present unacceptable consequences. The list will not apply to applications for the authorization of plant protection products submitted before 1 August 2015.


The sun rises on crop diversity

Maize (corn) monocultures are a common sight on Hungary’s Northern Great Plain. But as with any monoculture herbicide resistance is always a potential danger. In 2010 Istvan Szolomajer discovered Panicum riparium growing on his fields. Initially, Istvan and his fellow farmers used ALS inhibitors to control this weed, but after several years of application, there was strong evidence of an emerging resistance problem. Istvan’s solution to the resistance problem was to replace maize monoculture with crop diversity – changing from monocot to dicot crops and from spring to winter crops, for example. This year, he has been growing sunflowers on 100 ha, winter wheat on 50 ha, and maize on most of the remaining 200 ha under cultivation. This crop diversity has brought Istvan welcome relief from resistant Panicum riparium. Close cooperation with Bayer staff in Hungary has been a crucial factor in Istvan’s diversity strategy.

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