Frequently asked questions on the assessment of the health risk of glyphosate

Following oral administration, around 20% of glyphosate is absorbed from the gut and almost completely excreted within 7 days. The acute toxicity (one-time application) of glyphosate was low via oral, dermal or inhalative routes of exposureClose dialogexposureExposureTo glossary in animal experiments and in all tested species. Glyphosate was not irritating to rabbit skin and proved negative in all tests for skin sensitisation. However, glyphosate acid is irritating to the eyes.

With repeated administration of glyphosate in doses above the NOAEL (no observed adverse effect level), changes were observed in the salivary glands along with effects on liver and appendix; in addition, irritant effects on the mucous membrane were observed in the gastrointestinal tract and in the urinary bladder as well as cataracts of the eyes. In all studies, a definite NOAEL, in other words a maximum dose at which no damaging effects to health occurred, could be determined.

Studies on rats and rabbits showed that glyphosate is not to be classified as reprotoxic or developmentally toxic based on the legal provisions of the CLP in Europe. Anomalies occurred in the offspring in isolated cases following the administration of very high doses to pregnant rabbits. However, since these effects were limited to doses at which the rabbits already exhibited clear symptoms of poisoning and mortalityClose dialogmortalityMortalityTo glossary, these findings were - in line with internationally accepted assessment principles - not considered to indicate any risk for developmental disorders in humans.

It is not only the experts in the EU who agree in the EFSAshort forEuropean Food Safety Authority Conclusion that glyphosate is detrimental to neither the reproduction nor the development of mammals including humans. This view is shared by the Joint Meeting on Pesticide Residues (JMPR) of the WHO and the Environmental Protection Agency (EPA) in the US.

Even if it is possible in principle to detect certain developmental toxicity effects of chemical substances in experiments on frog or chicken embryos, these are nevertheless not validated as test systems in the human toxicological testing of active ingredients of pesticides and other chemicals. This means that they have not been verified with regard to the informational value, practicability and reproducibility of the results, nor have they been recognised by the EU and other international organisations (such as the OECD). For this reason, the findings of such studies are of only limited use for the purpose of health risk assessment.

As regards the studies conducted by Professor Carrasco (University of Buenos Aires) with frog or chicken embryos, it must be taken into account that the test substances were administered directly to the progeny, i.e. by mixing them into the culture medium or through injection into the chicken eggs. The guidelines for toxicity testing of chemicals stipulate, however, that the test substance must be administered to the females orally, via the skin or by inhalation; i.e., the offspring is exposed through the passage of the test substance through the placenta.

Glyphosate is an approved active substance in herbicides and agents used for desiccation (pre-harvest treatment), and residues in foods and feed are therefore admissible if they are below the permitted maximum residue level. This means that humans and animals may ingest small amounts of glyphosate via food and feed. As glyphosate is rapidly excreted once again by the body, it is to be expected that traces of the active substance can be detected in the urine of humans and animals. The glyphosate concentrations detected in urine to date do not, however, indicate that the exposure of users or consumers to glyphosate represents any risk to their health.

On this matter, BfRshort forGerman Federal Institute for Risk Assessment has published an overview based on evaluation of studies in Europe and the USA in which urine samples were analysed for glyphosate residues (http://link.springer.com/article/10.1007%2Fs00003-014-0927-3#page-1).

Due to the residues in their feed, farm animals may excrete higher amounts of glyphosate in their urine than humans. This is the finding of tests on German and Danish dairy cows. The low volume of data that is currently available shows here as well, that the estimated intake was well below the concentrations that caused effects in toxicological studies and that therefore no risk to health is assumed to exist.

On the question of glyphosate detected in urine, we also refer you to the response to the parliamentary question in the German Bundestag parliament on 1 July 2013.

External Link:http://dip21.bundestag.de/dip21/btd/17/142/1714291.pdf

On 25 June 2015, the "Bündnis 90/Die Grünen" parliamentary party reported that a laboratory had found the active pesticide substance glyphosate in 16 breast milk samples and described the findings as "a matter of grave concern". A large number of mothers were understandably worried about this study.

The test laboratory used the so-called ELISA test as a detection method to analyse the 16 breast milk samples for the presence of glyphosate. The glyphosate concentrations in the samples were reported to have been between 0.21 and 0.43 ng/mL. However, the manufacturer of the ELISA test specifies a sensitivity of only 75 ng/mL for the detection of glyphosate in milk using this method. Moreover, the positive findings in breast milk were not confirmed by independent analysis. BfRshort forGerman Federal Institute for Risk Assessment therefore expressed doubts regarding the reliability of the results and commissioned its own study in order to achieve valid findings. Neither did the available data indicate whether the test had been validated in advance for all analysed matrices (breast milk, urine). This would have been necessary to allow any robust statements. The levels measured in breast milk are therefore neither an indication for accumulation of the active substance in the body nor for a risk to health.

Every assessment of risks is generally based on use of a product or substance for the intended purpose or on foreseeable use. It goes without saying that misuse, negligent use or incorrect use can result in risks that cannot be assessed. This is why the government has put various checks in place in the area of pesticides. Monitoring of use for intended purpose is not the job of BfRshort forGerman Federal Institute for Risk Assessment as a risk assessment authority, however. This is the responsibility of the competent management authorities. In this case, the German Plant Protection Act (PflSchG) stipulates that this is the job of the regional state authorities. In the event of non-compliance with the provisions, Art.short forarticle 13 of the PflSchG provides for appropriate penalties and fines. The PflSchG also stipulates that use over large areas may only be carried out by qualified experts who can provide proof of proficiency and who regularly have to undergo suitable further training.

To ensure that use of these products in the private sphere is for the intended purpose and in the proper manner, the PflSchG stipulates mandatory advice for customers by dealers selling pesticides. The supervisory authorities monitor trade compliance with this stipulation. In addition, the guidelines for use and the full assessment reports can be found on the website of the Federal Office of Consumer Protection and Food Safety (BVLshort forGerman Federal Office of Consumer Protection and Food Safety).

External Link:http://www.bvl.bund.de/DE/04_Pflanzenschutzmittel/01_Aufgaben/02_ZulassungPSM/02_Zulassungsberichte/psm_zulassungsberichte_node.html

ADIshort forAcceptable Daily Intake stands for Acceptable Daily Intake and indicates the amount of a substance that a consumer can ingest daily over an entire lifetime without any recognizable health risk. The ADIshort forAcceptable Daily Intake value is used to assess the chronic risk.

AOELshort forAcceptable Operator Exposure Level stands for Acceptable Operator Exposure Level and represents the exposure level for operators during the application of plant protection products below which no recognizable health risk is to be expected.

In the context of the renewal procedure for glyphosate, numerous toxicological studies were submitted and evaluated, which exceeded by far the required number of animal experiments and were not available for the first approval. The ADIshort forAcceptable Daily Intake and AOELshort forAcceptable Operator Exposure Level values were derived during the re-evaluation of glyphosate by taking into consideration all available studies and information.

The acute reference dose (ARfDshort forAcute Reference Dose) is defined as the quantity of a substance in food that a consumer can ingest in the course of one day spread over one or more meals without any appreciable health risk. Thus, the ARfDshort forAcute Reference Dose represents a threshold value for the health risk assessment with respect to short-term exposure for consumers.

In the context of the renewal procedure for glyphosate, all available toxicological studies were reviewed in terms of harmful effects after a single or short-term exposure. It was observed that in the developmental toxicity studies serious effects can occur in the rabbit dams at relatively low doses (mortality and post-implantation loss from 100 mgshort formilligram/kgshort forkilogram bw/day). For this reason, an ARfDshort forAcute Reference Dose of 0.5 mgshort formilligram/kgshort forkilogram bw was derived. This value is based on a NOAEL (No Observed Adverse Effect Level) of 50 mgshort formilligram/kgshort forkilogram bw, that is, the dose at which no toxic effects were observed, and an assessment factor of 100.

BfRshort forGerman Federal Institute for Risk Assessment is currently in the process of assessing the German food monitoring data from the past six years in order to be able to make statements about average user exposure to pesticide residues. The assessments have not been completed and therefore results are not yet available. BfRshort forGerman Federal Institute for Risk Assessment intends to publish the data as soon as the project is completed.

The assessments conducted so far have shown that across all food categories which have been tested as part of the food monitoring programme over the last six years, just under 1400 samples have been tested for glyphosate. To make a reliable statement about the exposure of the German population to glyphosate, this number of samples is to be regarded as too low. Overall, residues were detected in less than 4 % of the tested samples. Based on these 24 findings, glyphosate exposure amounts to less than 1 % of the ADIshort forAcceptable Daily Intake value. ADIshort forAcceptable Daily Intake stands for “Acceptable Daily Intake” and indicates the amount of a substance which a consumer can absorb on a daily basis without appreciable health risks. The ADIshort forAcceptable Daily Intake value is used to assess the chronic risk of consumers.