Pesticide Assessment Report

1. Summary of subject pesticide

(1) Nonproprietary name of active ingredient
Glyphosate (ISO common name)
Glyphosate- isopropylammonium (ISO common name)
Glyphosate- ammonium (ISO common name)
Glyphosate- potassium (ISO common name)

(2) Chemical name
Glyphosate



Glyphosate-isopropylammonium

Glyphosate- ammonium

Glyphosate-potassium


(3) Molecular formula
Glyphosate: C₃H₈NO₅P

Glyphosate- isopropylammonium: C₆H₁₇N₂O₅P

Glyphosate- ammonium: C₃H₁₁N₂O₅P

Glyphosate- potassium: C₃H₇KNO₅P

(4) Molecular weight
Glyphosate: 169.1

Glyphosate isopropylammonium: 228.2

Glyphosate ammonium: 186.1

Glyphosate potassium: 207.2

(5) Structural formula


Glyphosate potassium

Glyphosate ammonium

Glyphosate isopropylammonium

Glyphosate

2. Summary of assessment of glyphosate (1)

Assessment of the Effect of Food on Health regarding “Glyphosate” (CAS No. 1071-83-6) [glyphosate-ammonium (CAS No. 40465-66-5), glyphosate-isopropylammonium (CAS No. 38641-94-0) and glyphosate-potassium (CAS No. 70901-12-1)] was performed using various documents.

Study results used in assessment included animal metabolic fate (rat and rabbit), plant metabolic fate (soybean, grape, etc.), residues in crops, subacute toxicity (rat, mouse and dog), chronic toxicity (dog), combined chronic toxicity/carcinogenicity (rat), carcinogenicity (mouse), 2-generation reproduction (rat), developmental toxicity (rat and rabbit), and genotoxicity.
From the results of toxicity studies, the effects of glyphosate treatment were observed mainly in the gastrointestinal tract (diarrhea, soft stool, etc.) and body weight (reduced weight gain ). No carcinogenicity, reproductive effect, teratogenicity or genotoxicity was observed.
From the results of various studies, the definition of residue: substance for dietary exposure evaluation in agricultural commodities was established as glyphosate (parent compound only).
The acceptable daily intake (ADI) of 0.75 mg/kg body weight/day was established based on developmental toxicity in rabbits at 75 mg/kg body weight/day, which was the lowest no-observed-adverse-effect-level (NOAEL) among the test results, divided by the safety factor 100.
It was judged that there was no need to establish the acute reference dose (ARfD) because the lowest no-observed-adverse-effect-level concerning the toxic effect that may be caused by single oral treatment, etc. with glyphosate was 1,000 mg/kg body weight obtained in acute toxicity in mice, which was not less than the cutoff (500 mg/kg body weight).

3. Summary of assessment of glyphosate (2)

Assessment of the Effect of Food on Health regarding “Glyphosate” (CAS No. 1071-83-6) [glyphosate-potassium (CAS No. 70901-12-1)] was performed using various documents.

Study results used in assessment included animal metabolic fate (rat), plant metabolic fate (paddy rice, lemon, etc.), residues in crops, etc., subacute toxicity (rat and dog), subacute neurotoxicity (rat), chronic toxicity (rat and dog), combined chronic toxicity/carcinogenicity (rat and mouse), 2-generation reproduction (rat), developmental toxicity (rat and rabbit), and genotoxicity.
From the results of toxicity studies, the effects of glyphosate treatment were observed mainly in body weight (reduced weight gain) and the liver (elevated ALT and ALP , etc.). No neurotoxicity, carcinogenicity, reproductive effect, teratogenicity or genotoxicity was observed.
The definition of residue: substances for dietary exposure evaluation in agricultural commodities were established as glyphosate and N-acetylglyphosate.
The lowest no-observed-adverse-effect-level among the toxicity test results was 81.3 mg/kg body weight/day in the 90-day subacute toxicity test in rats, in which the lowest observed adverse effect level was 414 mg/kg body weight/day. On the other hand, in the 2-year combined chronic toxicity/carcinogenicity test in rats which was a longer test, the no-observed-adverse-effect-level was 121 mg/kg body weight/day, and the lowest observed adverse effect level was 361 mg/kg body weight/day. The difference came fromthe difference in dose setting, and as a result of investigation of the resulting toxicity observations, etc., it was considered to be appropriate to use 121 mg/kg body weight/day which was the result of the longer test as the no-observed-adverse-effect-level in rats. In addition, the no-observed-adverse-effect-level of 100 mg/kg body weight/day in the developmental toxicity test in rabbits was the lowest no-observed-adverse-effect-level in animals other than rats, and this was used as the basis and was divided by the safety factor 100 to give 1 mg/kg body weight/day, which was established as the acceptable daily intake (ADI).
It was judged that there was no need to establish the acute reference dose (ARfD) because the lowest no-observed-adverse-effect-level concerning the toxic effect that may be caused by single oral treatment, etc. with glyphosate was 1,000 mg/kg body weight obtained in the acute neurotoxicity test in rats, which was not less than the cutoff (500 mg/kg body weight).

4. Summary of assessment of glyphosate (3)

Assessment of the Effect of Food on Health regarding “Glyphosate” (CAS No. 1071-83-6) [glyphosate-isopropylammonium (CAS No. 38641-94-0)] was performed using various documents.

Study results used in assessment included animal metabolic fate (rat), plant metabolic fate (rice, apple, etc.), residues in crops, etc., subacute toxicity (rat, mouse and dog), subacute neurotoxicity (rat), chronic toxicity (dog), combined chronic toxicity/carcinogenicity (rat), carcinogenicity (mouse), 2-generation reproduction (rat), developmental toxicity (rat and rabbit), and genotoxicity.
From the results of toxicity studies, the effects of glyphosate treatment were observed mainly in the gastrointestinal tract (diarrhea, intestinal dilation, intestinal mucosal hypertrophy, etc.), the kidney (renal tubular degeneration, etc.), the liver (elevated ALP, liver cell hypertrophy, etc.) and the blood (reduced RBC, etc.). No neurotoxicity, carcinogenicity, reproductive effect, teratogenicity, or genotoxicity that was a problem in the body was observed.
The definition of residue: substance for dietary exposure evaluation in agricultural commodities was established as glyphosate (parent compound only).
The lowest no-observed-adverse-effect-level among the toxicity test results was 100 mg/kg body weight/day in the 90-day subacute toxicity test (1) in rats, the 90-day subacute toxicity test and the 1-year chronic toxicity test in dogs, and this was used as the basis and was divided by the safety factor 100 to give 1 mg/kg body weight/day, which was established as the acceptable daily intake (ADI).
It was judged that there was no need to establish the acute reference dose (ARfD) because the lowest observed adverse effect level concerning the toxic effect that may be caused by single oral treatment, etc. with glyphosate was 5,000 mg/kg body weight obtained in the acute toxicity test in rats and mice, which was not less than the cutoff (500 mg/kg body weight).

5. Summary of assessment of glyphosate (4)

Assessment of the Effect of Food on Health regarding “Glyphosate” (CAS No. 1071-83-6) [glyphosate-isopropylammonium (CAS No. 38641-94-0)] was performed using various documents.

Study results used in assessment included animal metabolic fate (rat), plant metabolic fate (rice, apple, etc.), fate in soil and in water, residues in crops, subacute toxicity (rat, mouse and dog), chronic toxicity (dog), combined chronic toxicity/carcinogenicity (rat), carcinogenicity (mouse), 2-generation reproduction (rat), developmental toxicity (rat and rabbit), and genotoxicity.
From the results of toxicity studies, the effects of glyphosate treatment were observed mainly in body weight (reduced weight gain), the gastrointestinal tract (soft stool, increased cecum weight, etc.) and the blood (anemia). No carcinogenicity, reproductive effect, teratogenicity or genotoxicity was observed.
The definition of residue: substance for exposure evaluation in agricultural commodities was established as glyphosate (parent compound only).
The lowest no-observed-adverse-effect-level among the toxicity test results was 100 mg/kg body weight/day in the developmental toxicity test in rabbits, and this was used as the basis and was divided by the safety factor 100 to give 1 mg/kg body weight/day, which was established as the acceptable daily intake (ADI).
It was judged that there was no need to establish the acute reference dose (ARfD) because the lowest observed adverse effect level concerning the toxic effect that may be caused by single oral treatment, etc. with glyphosate was 5,000 mg/kg body weight obtained in the acute toxicity test in rats and mice, which was not less than the cutoff (500 mg/kg body weight).

6. Summary of assessment of glyphosate (5)

Assessment of the Effect of Food on Health regarding “Glyphosate” (CAS No. 1071-83-6) [glyphosate-isopropylammonium (CAS No. 38641-94-0)] was performed using various documents.

Study results used in assessment included animal metabolic fate (rat), plant metabolic fate (rice, apple, etc.), residues in crops, subacute toxicity (rat and dog), subacute neurotoxicity (rat), chronic toxicity (dog), combined chronic toxicity/carcinogenicity (rat), carcinogenicity (mouse), 2-generation reproduction (rat), developmental toxicity (rat and rabbit), and genotoxicity.
From the results of toxicity studies, the effects of glyphosate treatment were observed mainly in the gastrointestinal tract (soft stool, diarrhea, etc.). No neurotoxicity, carcinogenicity, reproductive effect, teratogenicity or genotoxicity was observed.
The definition of residue: substance for dietary exposure evaluation in agricultural commodities was established as glyphosate (parent compound only).
The lowest no-observed-adverse-effect-level among the toxicity test results was 200 mg/kg body weight/day in the developmental toxicity test in rabbits, and this was used as the basis and was divided by the safety factor 100 to give 2 mg/kg body weight/day, which was established as the acceptable daily intake (ADI).
It was judged that there was no need to establish the acute reference dose (ARfD) because no toxic effect that may be caused by single oral treatment, etc. with glyphosate was observed.

7. Summary of studies related to residues in livestock products

(1) Animal metabolic fate test in livestock

As a result of animal metabolic fate test in livestock (lactating goats and egg-laying hens) with ¹⁴C-labeled glyphosate, the major radioactive component in urine, feces, organs and tissues was unchanged glyphosate, and a small amount of B was observed among metabolites.

(2) Residues in livestock products test

As a result of the residues in livestock products test performed in Japan using glyphosate as analyte, glyphosate was detected at 0.01-0.03 μg/g in the liver of pigs in the 7.5- or 15-mg/kg treatment group, and at 0.01 μg/g in the chicken yolk of the 15-mg/kg treatment group, while it was all below the detection limit (0.01 μg/g) in the other samples (pig muscle and fat, and chicken muscle, fat and liver). It was less than 0.02 μg/g in cow milk.

As a result of the residues in livestock products test performed overseas using glyphosate and metabolite B as analytes, the maximum residues of glyphosate and B were 9.1 and 0.97 μg/g, respectively, in the porcine kidney.

(3) Definition of residue: Substance for dietary exposure evaluation in livestock products

As a result of animal metabolic fate test in livestock, metabolite B was observed, but metabolite B is also observed in rats, thus the substance for exposure evaluation in livestock products was established as glyphosate (parent compound only).

8. Assessment by international organizations, etc. (carcinogenicity)

(1) Assessment by IARC

IARC assessed the carcinogenicity of glyphosate as “Probably carcinogenic to humans” (Group 2A) because there was a limited evidence in humans based on that relationship with non-Hodgkin lymphoma was observed, and because there were sufficient evidences on carcinogenicity in laboratory animals based on test results in ICR mice and SD rats.

In addition, it was investigated upon the assessment if the carcinogenic mechanism in animal studies could also occur in humans. It was taken into account that: glyphosate products induced chromosomal damages in blood cells in a cytogenetic survey in human population; and that it was assessed that there was a strong evidence that glyphosate, glyphosate products and metabolite B induced oxidative stress in an in vitro test in human cells and in a test in laboratory animals. (Reference 1)

(2) Assessment by EFSA

It was concluded by EFSA that glyphosate is not carcinogenic in humans, and that there is no need for classification and labeling based on the CLP¹ regulation.

There was no statistically significant increase in the frequency of tumors in 9 studies in rats. Although an increase in malignant lymphoma was observed at the highest dose of the 1,460 mg/kg body weight/day treatment group in 1 of 5 studies performed in mice, it was not considered that glyphosate showed carcinogenicity according to the criteria based on the current guidelines. (Reference 2)
In addition, the evidence on the relationship between glyphosate products and non-Hodgkin lymphoma was very limited, and the causal relationship between glyphosate and cancer in surveys in humans was not conclusive. (Reference 2)

Moreover, the genotoxicity results were negative in in vitro studies performed according to GLP and many published literature. Chromosomal aberrations, sister chromatid exchanges and DNA strand breaks were seen in some of published literature, while positive results concerning these endpoints were not observed in in vivo studies. On the other hand, all results were negative in in vivo studies in somatic cells, excluding 2 studies with intraperitoneal administration. The dose in the studies with positive results was over the LD₅₀, and thus the results were considered to be the secondary effects of cytotoxicity. As a result of overall judgment including the quality and reliability of all available studies, it was judged that glyphosate has no genotoxicity in the living body. (Reference 3)

9. Overall assessment

Glyphosate is formulated and used as ammonium salt, isopropylamine salt or potassium salt, dissociates in aqueous solution, and presents as free acid in crops after herbicide application. Based on this, the ADI and the ARfD were established on the basis of toxicity studies mainly using glyphosate (acid) in glyphosate (1)-(5), and the overall assessment of glyphosate was performed by investigating these assessments cross-sectionally. A summary of the assessment is described below:

As a result of animal metabolic fate test with ¹⁴C-labeled glyphosate, the plasma radioactivity concentration after oral treatment in rats reached the C_max comparatively rapidly, and then rapidly attenuated. The absorption rate was considered to be at least 20%. Excretion was rapid, and the administered radioactivity was mainly excreted in feces. Unchanged glyphosate and metabolite B were observed as components in urine and feces.
As a result of animal metabolic fate test with ¹⁴C-labeled glyphosate in livestock (lactating goats and egg-laying hens), the major radioactive component in urine, feces, organs and tissues was unchanged glyphosate, and a small amount of B was observed among metabolites.
As a result of plant metabolic fate test with ¹⁴C-labeled glyphosate, isopropylamine salt, glyphosate-potassium, trimesium salt and sodium salt, B was observed as a metabolite over 10%TRR. In glyphosate-tolerant soybean and maize, N-acetylglyphosate and metabolite F were observed over 10%TRR.
Based on the results of toxicity studies with glyphosate, the effects of glyphosate treatment were observed mainly in body weight (gain suppression), the gastrointestinal tract (diarrhea, increased cecum weight, intestinal dilation, intestinal mucosal hypertrophy, etc.) and the liver (elevated ALP , liver cell hypertrophy, etc.). No neurotoxicity, carcinogenicity, reproductive effect, teratogenicity or genotoxicity was observed.
The lowest no-observed-adverse-effect-level among the toxicity test results performed with respective technical materials was 75 mg/kg body weight/day obtained in the developmental toxicity test in rabbits with glyphosate (1). Although the equivalence of the drug substances has not been shown, the Pesticides Expert Committee, Food Safety Commission of Japan judged that the no-observed-adverse-effect-level of glyphosate in the developmental toxicity test in rabbits was 100 mg/kg body weight/day considering comprehensively toxicity observations and dose settings in studies performed with the other technical materials.
Therefore, because the lowest no-observed-adverse-effect-level among the test results was 100 mg/kg body weight/day in the 90-day subacute toxicity test in rats, the 90-day subacute toxicity test and the 1-year chronic toxicity test in dogs, and the developmental toxicity test in rabbits, and this was used as the basis and was divided by the safety factor 100 to give 1 mg/kg body weight/day, which was established as the acceptable daily intake (ADI) by the Pesticides Expert Committee, Food Safety Commission of Japan.
It was judged that there was no need to establish the acute reference dose (ARfD) because the no-observed-adverse-effect-level concerning the toxic effect that may be caused by single oral treatment, etc. with glyphosate was not less than the cutoff (500 mg/kg body weight).
As a result of plant metabolic fate test and animal metabolic fate test in livestock, metabolites B and F and N-acetylglyphosate in plants, and metabolite B in livestock were observed as metabolites over 10%TRR. While metabolite F and N-acetylglyphosate were not observed in rats, the acute oral toxicity of metabolite F was mild (LD₅₀: > 5,000 mg/kg body weight) and the genotoxicity result was negative, and thus the definition of residue: substances for dietary exposure evaluation in agricultural commodities were established as glyphosate and N-acetylglyphosate, and the definition of residue: substance for dietary exposure evaluation in livestock products was established as glyphosate (parent compound only).
ADI 1 mg/kg body weight/day
(ADI justification document (1)) subacute toxicity test

(Animal species) rat

(Period) 90 days

(Treatment method) oral gavage

(ADI justification document (2)) subacute toxicity test

(Animal species) dog

(Period) 90 days

(Treatment method) oral capsule

(ADI justification document (3)) chronic toxicity test

(Animal species) dog

(Period) 1 year

(Treatment method) oral capsule

(ADI justification document (4)) developmental toxicity test

(Animal species) rabbit

(Period) Day 6-18 of gestation

(Treatment method) oral gavage

(No-observed-adverse-effect-level) 100 mg/kg body weight/day

(Safety factor) 100

ARfD Establishment not required
Exposure amount should be checked when the provisional standard is reviewed based on this assessment result.
Reference

ADI* 1.0 mg/kg body weight/day

(ADI justification document) combined chronic toxicity/carcinogenicity test

(Animal species) rat

(Period) 2 years

(Treatment method) dietary

(No-observed-adverse-effect-level) 100 mg/kg body weight/day

(Safety factor) 100

* Group ADI of glyphosate and metabolite B
ARfD Establishment not required

ADI 0.5 mg/kg body weight/day

(ADI justification document) developmental toxicity test

(Animal species) rabbit

(Period) Day 7-19 of gestation

(Treatment method) oral gavage

(No-observed-adverse-effect-level) 50 mg/kg body weight/day

(Safety factor) 100

ARfD 0.5 mg/kg body weight/day

(ARfD justification document) developmental toxicity test

(Animal species) rabbit

(Period) Day 7-19 of gestation

(Treatment method) oral gavage

(No-observed-adverse-effect-level) 50 mg/kg body weight/day

(Safety factor) 100

cRfD 1.75 mg/kg body weight/day

(cRfD justification document) developmental toxicity test

(Animal species) rabbit

(Period) Day 6-27 of gestation

(Treatment method) oral gavage

(No-observed-adverse-effect-level) 175 mg/kg body weight/day

(Uncertainty factor) 100

aRfD Establishment not required

(Reference 2, 4, 5)

1. IARC: Monographs on the Evaluation of Carcinogenic Risks to Humans Volume112 (2015)
2. EFSA: Conclusion on the peer review of the pesticide risk assessment of the active substance glyphosate (2015)
3. EFSA explains the carcinogenicity assessment of glyphosate (2015)
4. JMPR: “glyphosate,” Pesticide residues in food - 2004 Evaluations. Part II. Toxicological. p. 95-169(2004)
5. US EPA: Federal Register/Vol. 67, No.188, 60934-60950(2002)
References used in individual assessment are listed in the section of in individual assessment reports.

1^ Classification, Labelling and Packaging