MOF, Alm.del - 2015-16 - Bilag 108: EFSAs konklusion vedr. glyphosat m.v., fra miljø- og fødevareministeren

Miljø- og Fødevareudvalget 2015-16
MOF Alm.del Bilag 108
Offentligt

PESTICIDES UNIT

EFSA explains the carcinogenicity assessment of

glyphosate

12 November 2015

Background

During the EFSA peer-review process for the renewal of the approval of the pesticide

active substance glyphosate, EFSA received a complementary mandate from the

European Commission to consider the findings by the International Agency for Research

on Cancer (IARC) regarding the potential carcinogenicity of glyphosate or glyphosate

containing plant protection products. Following the request, EFSA has incorporated its

scientific assessment in the on-going peer review of the active substance (EFSA, 2015a).

The EFSA Conclusions on Pesticides have a complex structure, designed for supporting

the European Commission and Member States in the approval process, the subsequent

assessments of the Plant Protection Products (PPPs) by the Member States (MSs), and

the revision of the Maximum Residue Levels (MRLs) of pesticides.

The EFSA Conclusions summarise the main outputs of the scientific assessments

(Sections 1 to 6), and then focus on the identification of data gaps and studies to be

generated (Section 7), recommendations to manage the identified risks (Section 8) and

concerns to be considered by risk managers (Section 9). An appendix presents the List

of Endpoints recommended by EFSA for the hazard and the risk assessment of the active

substance.EFSA also publish supporting background documents providing the scientific

justifications.

EFSA’s assessment on pesticide active substances is based on original studies

(mandatory regulatory Good Laboratory Practice (GLP) studies, other relevant studies

and the outcome of the search of peer-reviewed scientific studies published within the

last 10 years before the submission of the dossier), that are summarised by the

rapporteur Member State (RMS) in the draft renewal assessment report (RAR). The

peer-review includes a public consultation of the draft RAR and several commenting

phases by EFSA scientists and MSs experts, the possibility for requiring additional

information from the applicants, and a set of experts’ meetings covering different

scientific areas; this is reflected in a further development of the RMS RAR during the

EFSA peer review.

Due to the length and complexity of the peer review report supporting the EFSA

Conclusion (EFSA, 2015b) and the RAR (Germany, 2015) EFSA has considered

important to clarify some key elements of its scientific evaluation in this complementary

document, in particular, regarding the assessment of the carcinogenicity of the active

substance glyphosate.

Assessment of the carcinogenic potential of the active substance

glyphosate

EFSA has assessed the carcinogenicity and genotoxicity potential of the active substance

glyphosate according to the principles and criteria applicable for the classification and

labelling of chemical substances in the EU under Regulation (EC) No 1272/2008 (CLP

European Food Safety Authority • Via Carlo Magno 1A • 43126 Parma • ITALY

Tel. +39 0521 036 111 • Fax +39 0521 036 110 • www.efsa.europa.eu

MOF, Alm.del - 2015-16 - Bilag 108: EFSAs konklusion vedr. glyphosat m.v., fra miljø- og fødevareministeren

Regulation)

. This regulation implements in the EU the Globally Harmonized System

developed by the United Nations for the classification and labelling of hazardous

chemical substances. The European Chemicals Agency (ECHA) has developed guidance

on the application of these criteria (available in the ECHA web page) and submitted

specific comments regarding the Rapporteur Member State (RMS) assessment (EFSA,

2015b) that were considered by EFSA and the MSs during the peer review. Glyphosate

carcinogenicity was discussed in two experts’ meetings, first during the overall

assessment of the mammalian toxicity and second during a dedicated experts’

teleconference, involving a large number of experts.

Genotoxicity

The genotoxicity data package available for the peer review is comprehensive. A large

number of studies provided in the draft RAR (over 100 studies all together; Germany,

2013) was complemented by additional studies identified during the commenting period

and public consultation that took place in 2014, and which were included in the revised

RAR (Germany, 2015).

a) glyphosate

EFSA assessed the genotoxic potential of the active substance, glyphosate, and focused

on the studies performed on well characterized test substances as manufactured.

Glyphosate is produced by many different companies, each manufacturing a technical

material presenting different impurity profiles than the others. Where considered

necessary, data gaps have been set for each individual company to complete the

toxicological information on the impurities, which are present in their own technical

material (EFSA, 2015a).

All required genotoxicity endpoints that consist of gene mutation in bacterial and

mammalian cells, structural and numerical chromosome aberrations

in vitro

and

in vivo

have been investigated in validated OECD guideline-compliant studies following the

principles of GLP, as well as published studies often following non-GLP protocols

In vitro

tests

Bacterial and mammalian cells mutagenicity studies gave consistently negative results;

even studies that were considered less reliable and of lower quality did not reveal any

indication of genotoxicity. With regards to

in vitro

mammalian chromosome aberration

(CA), all tests that were performed under GLP conditions, as well as a number of

published studies gave negative results at concentrations up to 1250 µg/L. In contrast

positive results were obtained in some published studies on CA at lower dose levels, and

on other endpoints considered as indicator tests, such as sister chromatid exchange

(SCE) and induction of DNA strand breaks

in vitro.

The positive indications observed in

some

in vitro

tests were not confirmed by

in vivo

studies covering the appropriate end-

points, such as

in vivo

micronucleus tests.

In vivo

tests

Sixteen

in vivo

studies in somatic cells were reported on rodents treated orally with dose

levels up to 5000 mg/kg bw or via intraperitoneal injections. All studies conducted

according to internationally validated guidelines and some non-GLP published studies

gave negative results, while two non-GLP studies resulted positive in mice treated

intraperitoneally with dose levels in the range of the intraperitoneal LD

for mice, one

study presenting major flaws. Conflicting results were obtained regarding DNA adduct

Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on

classification, labelling and packaging of substances and mixtures, amending and repealing Directives

67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006. OJ L 353, 31.12.2008 p.1-1355

MOF, Alm.del - 2015-16 - Bilag 108: EFSAs konklusion vedr. glyphosat m.v., fra miljø- og fødevareministeren

formation; induction of DNA strand breaks was observed in mice treated

intraperitoneally with doses close to or in excess of the LD

, this induction may be

caused by secondary effects of cytotoxicity. No genotoxic effects on germ cells have

been detected in rats or mice treated orally at dose levels up to 2000 mg/kg bw.

Considering a weight of evidence approach, taking into account the quality and reliability

of all available data, it is concluded that glyphosate is unlikely to be genotoxic

in vivo

and does not require hazard classification regarding mutagenicity according to the CLP

Regulation. It is noted that unpublished studies that were the core basis of the peer

review evaluation were not available to the IARC experts as reported in the IARC

monograph 112 on glyphosate (IARC, 2015).

b) glyphosate-based formulations

A number of published studies performed with glyphosate based formulations of

unknown composition gave positive results when tested

in vitro

and

in vivo.

Some of the

test systems are not validated and/or of difficult interpretation due to possible

confounding, such as cytotoxicity, specific organ toxicity or unclear relevance to human

health when tested in fish, amphibians or invertebrates according to the current

knowledge. POE-tallowamine is one of the co-formulants that is known to be used in

some glyphosate-based formulations. This co-formulant has been shown to be more

toxic than the active substance glyphosate on several toxicological endpoints, namely

acute, short term, reproductive and developmental toxicity, further to equivocal

evidence of DNA damage

in vitro

at high doses (EFSA, 2015c). Although POE

tallowamine is not present in the representative formulation, for which data have been

submitted under the European re-approval procedure and which were assessed by EFSA,

the peer review concluded that the toxicity of formulations and in particular their

genotoxic potential should be further considered and addressed.

It is noted that a number of human studies were not evaluated, since the exposure was

linked to glyphosate-based formulations of unknown composition. Therefore their

assessment would not have changed the overall conclusion.

Carcinogenicity

a) Studies in animals

Long term toxicity and carcinogenicity potential of glyphosate was assessed in five

mouse studies and nine rat studies; one further study in mice and one in rats were

considered inadequate for the evaluation of glyphosate carcinogenicity.

In the nine long term rat studies, the EU peer review concluded that no significant

increase in tumour incidence was observed in any of the treated groups of animals.

Three of these studies were not evaluated by the IARC experts. In one study, the IARC

reported a statistically significant increased incidence of pancreatic islet cell adenomas in

males treated with the low dose, which was not reproduced at higher dose levels. In

another study, the IARC reported significant increases in pancreatic islet adenomas in

males at two dose levels (not dose-related), a significant positive trend for hepatocellular

adenomas in males without progression to malignancy and a significant trend for C-cell

adenomas in females. The two evaluations differ primarily regarding the statistical

evaluation: according to a pair-wise comparison [Fisher´s exact test (one-tailed) as well

as in combination with Bonferroni inequality procedure for incidences of non-neoplastic

(at p ≤ 0.01) and neoplastic lesions (at p ≤ 0.01 and ≤0.05) and Peto Analysis for

evaluation of histopathological data as planned in the study protocol] no significant

change is observed, while a trend analysis (Cochran-Armitage trend test) performed by

the IARC experts identified significant changes. EFSA is of the opinion that the planning

of a study before the initiation of the experimentation itself as established in the

respective protocol –that includes the statistical analysis - is a key element in assessing

MOF, Alm.del - 2015-16 - Bilag 108: EFSAs konklusion vedr. glyphosat m.v., fra miljø- og fødevareministeren

the quality of a study, therefore deviations from the statistical analysis used by the study

authors should be limited and properly justified. Furthermore, clear dose-response was

not always observed and when observed, it affected only the highest dose level of 940 to

1183 mg/kg bw per day in males and females respectively, a dose eliciting other adverse

effects on body weight, liver, stomach mucosa and eyes (cataracts).

In mice, the EU peer review evaluated five studies; another study was considered

inadequate for the evaluation of glyphosate carcinogenicity. From these studies, only one

study in Swiss albino mice presented a carcinogenic effect characterised by a statistically

significant increased incidence of malignant lymphomas at the top dose level of 1460

mg/kg bw per day. However, the validity of the study was questioned due to the

occurrence of viral infection that could influence survival as well as tumour incidence –

especially lymphomas. No other carcinogenic effects were observed up to the highest

dose levels of each of the other studies as tumour incidences remained within valid

historical control data from the respective performing laboratory and/or did not attain

the level of statistical significance. The IARC evaluated two of these studies and

identified positive trend in males for renal tubule adenomas and carcinomas in one study

and positive trend for haemangiosarcoma in the other study according to Cochran-

Armitage trend test. EFSA adopted a weight of evidence approach which was agreed by

the peer review taking into account all available data: the statistical significance found in

trend analysis (but not in pair-wise comparison) was balanced against the lack of

consistency in multiple animal studies, slightly increased incidences only at dose levels at

or above the limit dose of 1000 mg/kg bw per day recommended for the oral route of

exposure in chronic toxicity and carcinogenicity studies (OECD, 2012a), doses at which

confounding of concomitant toxicity is expected, incidences within valid historical control

range from the performing laboratory and lack of pre-neoplastic lesions.

Furthermore no genotoxic potential is attributed to the active substance glyphosate.

Other mechanisms of action were reported by IARC, such as inflammation,

immunosuppression, endocrine disrupting (ED) activity and oxidative stress. Although no

robust information is available to conclude on the immunomodulatory potential of

glyphosate, indications of such effects were limited to inflammatory responses of the

respiratory tract. No interaction of glyphosate with the oestrogen, androgen or thyroid

endocrine pathways were identified by the US EPA Endocrine Disruptor Screening

Program (EDSP) according to a full battery of Tier I screening assays (data gaps were

however identified in the EFSA conclusion for the submission of the respective studies for

confirmation); and no significant ED effects were identified in published studies reported

by IARC, except for a higher activity of formulations in comparison to the active

substance. Some indications of increased oxidative stress were observed in combination

with cytotoxic or degenerative effects of the target organs; however, even if these

indications are confirmed, the observation of a plausible mechanism of action

per se

insufficient to assume a carcinogenic potential in humans according to the current

knowledge. On this basis, EFSA concluded that glyphosate is unlikely to pose a

carcinogenic hazard to humans and no classification regarding carcinogenicity is

proposed according to CLP Regulation.

b) Epidemiological studies

Overall thirty epidemiological studies are reported in the IARC monograph, including

cohort, case-control studies and meta-analyses. A few of these studies were not

reported in the RAR (Germany, 2013), but were considered by the RMS in an addendum

on the assessment of the IARC monograph (Germany, 2015). In ten cohort studies, that

include the Agricultural Health Study (AHS) (Alavanja

et al.,

1996), the largest

prospective cohort study undertaken until today and used in many other publications,

glyphosate did not cause different types of cancer and did not increase the risk of all

cancers. Nine case-control studies did not indicate an increased risk of carcinogenicity by

glyphosate, or presented limited power. Further five case-control and one prospective

cohort studies were considered to assess the strength of evidence linking glyphosate to

MOF, Alm.del - 2015-16 - Bilag 108: EFSAs konklusion vedr. glyphosat m.v., fra miljø- og fødevareministeren

non-Hodgkin lymphoma (NHL), a statistical significant association was observed in a

small number of cases that was considered insufficient to conclude on the causality, due

to the poor consistency of the results. Epidemiological studies face several problems

linked to the small number of cancer cases and difficult identification/separation of

confounders: glyphosate is generally analysed together with several other pesticides,

exposure cannot be easily measured as it is generally based on interviews and

questionnaires that have several intrinsic recall bias, furthermore, the classification of

the type of cancer is not consistent, the adverse outcomes are not always obtained from

medical records, and finally, the contribution of co-formulants’ toxicity cannot be

assessed. Taking into consideration the weight of evidence, EFSA concluded that there is

a very limited evidence of association between glyphosate exposure and the occurrence

of NHL, which would not alter the classification proposal derived from animal studies that

glyphosate is unlikely to pose a carcinogenic hazard to humans.

Recognising the value that epidemiological studies can potentially provide to pesticide

risk assessments, EFSA has conducted a number of initiatives in this field. First, EFSA

granted an external review on epidemiological studies on pesticides which identified

some limitations (Ntzani

et al.,

2013). As a follow up, EFSA launched a project including

the preparation of two Scientific Opinions, one to facilitate the use of epidemiological

studies in the risk assessment of pesticides, and another investigating the potential link

of pesticides toxicity with Parkinson’s disease and childhood leukaemia by using criteria

within the Adverse Outcome Pathway framework. The two scientific Opinions are

expected to be launched for public consultation in November 2016 and June 2016

respectively.

Assessment of Plant Protection Products and co-Formulants

In line with Article 12 of Regulation (EC) No 1107/2009

the EFSA Conclusion presents

the assessment and properties of the active substance glyphosate, considering the

technical specifications provided by the applicants. The dossier includes a representative

formulated product. The information on this representative product has been considered

by EFSA during the evaluation of the active substance according to the relevant guidance

documents for the different scientific sections. Studies on the representative product or

other formulated products, either included in the dossier or made available during the

peer-review process, have been considered by EFSA when relevant for the assessment of

the active substance. The EFSA assessment would be relevant for the assessment of the

hazard properties, including classification and labelling, and risk assessment of PPPs by

the MSs, however, EFSA has not evaluated the hazard and risk of the PPPs as this is out

of the EFSA remits and would require a specific mandate and submission of additional

information, including the PPP dossiers.

EFSA has been mandated by the European Commission to assess a co-formulant, POE-

tallowamine, that although not present in the representative formulation, is reported as

co-formulant for other glyphosate containing PPPs. EFSA does not support the health-

based reference values proposed by the RMS, and considers that the genotoxicity, long

term toxicity/carcinogenicity, reproductive/developmental toxicity and endocrine

disrupting potential of this co-formulant should be clarified before setting health-based

reference values and conducting the risk assessment (EFSA, 2015c).

Consumer Risk Assessment

Regulation (EC) No 1107/2009 of the European Parliament and of the Council of 21 October 2009 concerning

the placing of plant protection products on the market and repealing Council Directives 79/117/EEC and

91/414/EEC. OJ No L 309, 24.11.2009, p. 1-50

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Following previous EU and JMPR assessments, the RMS in its initial assessment

(Germany, 2013) did not propose setting an Acute Reference Dose (ARfD). However,

following the re-evaluation during the EFSA peer-review, EFSA has concluded that the

toxicity of glyphosate requires setting an ARfD of 0.5 mg/kg bw. It should be noted that

this proposal has been agreed by the RMS.

This recommendation triggers the evaluation of acute exposure during the consumer risk

assessment. EFSA will consider this conclusion during the review of the MRLs for

glyphosate under Art. 12 of Regulation (EC) No 396/2005, to be conducted by EFSA in

cooperation with the MSs during 2016.

References

Alavanja et al., 1996. Alavanja, M.C.R.; Sandler, D.P.; McMaster, S.B.; Zahm,

S.H.; McDonnell, C.J.; Lynch, C.F.; Pennybacker, M.; Rothman, N.; Dosemeci,

M.; Bond, A.E.; Blair, A., The Agricultural Health Study. Environmental Health

Perspectives, Volume 104, Number 4, April 1996, 362-369

EFSA (European Food Safety Authority), 2015a. Conclusion on the peer review of

the pesticide risk assessment of the active substance glyphosate. EFSA

Journal 2015;13(issue):NNNN, 35 pp. doi:10.2903/j.efsa.2015.NNNN

EFSA (European Food Safety Authority), 2015b. Peer Review Report to the

conclusion regarding the peer review of the pesticide risk assessment of the

active substance glyphosate. Available at

www.efsa.europa.eu

EFSA (European Food Safety Authority), 2015c. Statement of EFSA on the

request for the evaluation of the toxicological assessment of the co-formulant

POE-tallowamine. Available at

www.efsa.europa.eu

Germany, 2013.

Renewal assessment report (RAR) on the active substance

glyphosate prepared by the rapporteur Member State Germany in the

framework of Regulation (EU) No 1141/2010, December 2013. Available at

www.efsa.europa.eu

Germany, 2015. Final Addendum to the renewal assessment report on

glyphosate,

compiled

EFSA,

October

2015.

Available

www.efsa.europa.eu

IARC (International Agency for Research on Cancer), 2015. Monographs, Volume

112: Some organophosphate insecticides and herbicides: tetrachlorvinphos,

parathion, malathion, diazinon and glyphosate. IARC Working Group. Lyon; 3–

10 March 2015. IARC Monogr Eval Carcinog Risk Chem Hum.

Ntzani

et al.,

2013. Ntzani EE, Chondrogiorgi M, Ntritsos G, Evangelou E,

Tzoulaki I, 2013. Literature review on epidemiological studies linking exposure

to pesticides and health effects. EFSA supporting publication 2013:EN-497,

159 pp. Available online:

www.efsa.europa.eu/publications

OECD (Organisation for Economic Co-operation and Development), 2012a.

Series on Testing and Assessment: No 116: Guidance document 116 on the

conduct and design of chronic toxicity and carcinogenicity studies, supporting

test guidelines 451, 452 and 453 2nd edition. ENV/JM/MONO(2011)47, 156

pp.

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Last date modified

Final draft version 7

DCM and JT

JT / JK / DCM / MT / BV / JS / JT

09/11/2015