How the Big 3: EPA, FAO/WHO, European Union arrive at the ADI for glyphosate.

Untitled_00The ADI, Acceptable Daily Intake is traditionally based on the lowest dosage, in grams per kilogram, for bodyweight per day, that a person can tolerate, divided by 100 (for a safety margin) on a daily basis over a lifetime without an appreciable health risk.  It is established via laboratory studies where scientists administer doses of (e.g glyphosate). When they reach a NOAEL (No Observable Adverse Effect), and that becomes the NOAEL the amount in milligrams per kilogram (mg/kg) per bodyweight per day (bw/day), that then gets divided by 100 to form the ADI.

The ADI is an imperfect beast because at this point in time the regulatory authorities, WHO/FAO, USA EPA and the European Union’s EFSA, don’t necessarily pick the lowest NOAEL where toxicity occurs.  For example rats dosed with glyphosate may show damage to the mother and foetus (eg. the mothers dying or the rats being deformed) at a lower NOAEL (Ie. it shows toxicity at lower levels of the chemical).  This is called reproductive and developmental toxicity. This is not necessarily picked. Instead, like the USA EPA which picked a study at 175mg instead of the Street study which shows a lower level of NOAEL for developmental toxicity based on 10mg per kilogram per bodyweight per day.

Because we are not all pregnant mums with babies in our tummies, right?

The different organisations, the FAO/WHO, EPA and European Union (EFSA/DG SANCO) regard many studies and then select the study that they will choose to be the study with the lowest dose where there is NOAEL that will be divided by 100 to become the ADI.

Yet the needs of a pregnant mother and foetus are largely ignored. All three organisations have studies, outdated and unpublished, that are lower than the studies that define the ADI.  And modern independent science has plenty of studies that should bring these studies lower, for the pregnant mother and foetus.

How the three most influential organisations in the world arrive at the ADI – acceptable daily intake, of a pesticide:


Pesticide residues in food – 2004 Joint FAO/WHO Meeting on
Pesticide Residues Evaluations 2004. Part II—Toxicological

ADI  1.0mg/kg bw/day:  In 2004 WHO/FAO re-evaluated to this higher level.

When they first assessed glyphosate in 1986 FAO/WHO arrived at 0.3mg/kg a day, following a 26 month study in rats setting the NOEL at 31 mg/kg bw/day (even though rats had increased tumours at that same level) (Lankas, 1981) [1].

Increased to 1 mg/kg bw day based on research by: Atkinson et al., 1993b [2].  This unpublished study is said to be ‘in compliance with principles of GLP’.  It is possible that this study is not necessarily GLP, following EU comments on studies cited by the EU that studies are GLP like, whereas the FAO/WHO says they are ‘in compliance with the principles of GLP’. This casts doubt on the supposition that the FAO/WHO studies are actually GLP.

European Commission:

Last review dated 21 January 2002, document 6511/VI/99-final

ADI  0.3mg/kg bw/day: The European Commission’s established ADI is 0.3mg/kg bw/day (page 13), based on the 1981 Lankas study that gave a NOEL of 31 mg/kg (Page 12 – even though rats had increased tumours at that same level).

The Lankas study cannot be referenced on the European Commission pages – however it can be cross referenced with the WHO 2004 Part II Toxicological Evaluations of glyphosate – page 95 – ‘was last evaluated by the JMPR in 1986, when an acceptable daily intake (ADI) of 0– 0.3mg/kg bw was established based on a no-observed-adverse-effect level (NOAEL) of 31mg/kg bw per day, the highest dose tested in a 26-month study of toxicity in rats.’  Records are held on the IPSC INCHEM website – 1986 data gives Lankas 1981.

In another study put forward for considerations major visceral anomalies were found at the lower dose of 20 mg/kg bw/day in the rabbit teratogenicity study,  by Suresh, T.P. 1993.[3].  This is not used.

Note: Many chemical company submitters for the European assessment recommended lower ADI’s. See Page 135 of Annex B-5, used as part of the decision making process [4].

USA EPALast reviewed in 1990, the Reregistration Eligibility Decision (RED)

ADI  2.0mg/kg bw/day: For  glyphosate,  the  acceptable daily  dietary  exposure,  referred in the USA  as a  reference  dose  (RfD)  has  been  set  at  2  mg/kg/day  (175 mg/kg/day  NOAEL  divided  by  100  =  1.75  mg/kg/day  rounded  up  to  2 mg/kg/day).

The USA acknowledges in its Reregistration Eligibility Decision the earlier WHO recommendation of 0.3mg (Lankas 1981) but places no importance on the study.

The ADI (RfD) is based on the recommended NOAEL of 175 mg/kg bw/day from the study by Rodwell, D.E.; Tasker, E.J.; Blair, M.; et al. (1980) [5].


 References: Please note only chemical companies supply the studies.

[1] Lankas, G.R.; Hogan, G.K. (1981): A Lifetime Feeding Study of Glyphosate (Roundup Technical) in Rats: Project No. 772062.  Unpublished study received Jan 20, 1982 under 524-308; prepared by Bio/dynamics, Inc., submitted by Monsanto Co., Washington, D.C.; CDL:246617-A; 246618; 246619; 246620; 246621. MRID 00093879.

[2] Atkinson, C., Strutt, A.V., Henderson, W., Finch, J. & Hudson, P. (1993b) Glyphosate: 104 week combined
chronic feeding/oncogenicity study in rats with 52 week interim kill (results after 104 weeks.). Unpublished
report No. 7867, IRI project No. 438623, dated 7 April 1993, from Inveresk Research International,
Tranent, Scotland. Submitted to WHO by Cheminova A/S, Lemvig, Denmark.

[3] Suresh, T.P. (1993):  Two generation reproduction study in Wistar rats. Rallis India, Ltd., Rallis Agrochemical Research Station, Bangalore, India. Unpublished. Study no. TOXI:885-RP-G2. 30. Dates of experimental work: May 1991-April 1992.  Submitted by Feinchemie

[4]  Requested from the European Commission by Earth Open Source as part of their investigation  querying why the assessors for toxicity of Roundup/glyphosate dismissed research that found that glyphosate causes birth defects in frog and chicken embryos.

[5] Rodwell, D.E.; Tasker, E.J.; Blair, M.; et al. (1980): Teratology Study in Rabbits: IRDC No. 401-056. MRID 00046363  (Unpublished study received May 23, 1980 under 524-308; prepared by International Research and Development Corp., submitted by Monsanto Co., Washington, D.C.; CDL:242516-B)

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