FAO, PL:CP/15
WHO/Food Add./67.32
EVALUATION OF SOME PESTICIDE RESIDUES IN FOOD
The content of this document is the result of the deliberations of the
Joint Meeting of the FAO Working Party and the WHO Expert Committee on
Pesticide Residues, which met in Geneva, 14-21 November 1966.1
1 Report of a Joint Meeting of the FAO Working Party and the WHO
Expert Committee on Pesticide Residues, FAO Agricultural Studies, in
press; Wld Hlth Org. techn. Rep. Ser., 1967, in press
CONTENTS
Introduction
Note to the reader
The Monographs:
Aldrin
Dieldrin
Carbaryl
DDT
Dichlorvos
Diphenyl
Ethylene dibromide
Methyl bromide
gamma-BHC
Heptachlor
Hydrogen phosphide
Malathion
Phenylmercury acetate (and other organomercury compounds)
Piperonyl butoxide
Pyrethrins
Diazinon
Dimethoate
Phosphamidon
INTRODUCTION
A Joint Meeting of the FAO Working Party and the WHO Expert Committee
on Pesticide Residues was held in Geneva in November 1966.
The general considerations, including the principles adopted for the
evaluation, and a summary of the results of evaluations on a number of
pesticide residues appear in a publication entitled "Report of a Joint
Meeting of the FAO Working Party and the WHO Expert Committee on
Pesticide Residues".a Additional information, such as biological
data, toxicological evaluation and agricultural data and their
evaluation, considered at the joint meeting is to be found in this
document.
As much relevant information as possible has been included in the
monographs. Wherever possible this has been obtained from the
published literature, but other sources of information have also been
used. The members of the meeting thanked all those who had made
information available to them and offered their apologies to any
authors whose work may not have been taken into consideration. They
emphasized the need for the early and complete publication of the
results of research in this field, particularly of that part which
could form the basis of the determination of an acceptable daily
intake for man. This is necessary so that the work reported can be the
subject of scrutiny and informed criticism by a wider group of
scientists covering disciplines not necessarily represented at the
Committee meeting.
Unpublished data, because they may include more detail than
published work, may often be required for the determination of
acceptable daily Intakes. These data must be complete,
non-confidential and with an indication of the authorship of the
report. The information will not be considered unless it is received
at least three months before the announced date of the joint meeting
in sufficient copies (at least two) to be distributed to suitable
experts.
The acceptable daily intakes have been established according to the
principles set out in previous reports. Furthermore, in the
evaluation of those pesticides for which several long-term studies
have been reported and the lowest dosage showed an effect of
questionable significance, a greater margin of safety has been used.
In other cases a "temporary ADI" has been estimated with the condition
that additional necessary information be available within a specified
period of time. The figure will be reviewed within a specified period
of time as set out in the relevant monographs. If no action has been
taken to provide this further evidence required, it will be assumed
that neither the manufacturers nor the user countries are interested
in continuing the use of the pesticide.
a FAO Meeting Report, in press; Wld Hlth Org. techn. Rep. Ser.,
1967, in press
Certain problems were encountered in the toxicological evaluation of
the organochlorine pesticides, which have been used extensively and
have proved agriculturally efficacious. Many have been shown to be
persistent and cumulative in the animal and human body. In addition,
there is evidence that even in low doses they have an effect on the
liver. During the past few years, evidence has become available that
these compounds stimulate the activity of microsomal enzymes in the
liver cells. These may affect the metabolism of other compounds. lt
was therefore urged that methods of toxicological investigation aimed
at defining and clarifying the various biological changes seen in the
reported studies of these compounds be developed, with a view to
removing doubts which may remain as to their safety in use.
As used in the following monographs, "tolerance" is the permitted
concentration of a pesticide residue in or on a food. A "temporary
tolerance" is given in either of two circumstances: (a) when it is
derived from a temporary ADI; (b) when it is derived from an ADI which
could be exceeded when the pesticide is applied according to good
agricultural practice; such temporary tolerances are valid for a
specified period during which additional data on toxicity and on the
disappearance of the pesticide residues during storage and processing
of food should become available. "Practical Residue Limits" are
suggested for use by governments as administrative decisions based on
residues actually found in those cases where unintentional residues of
pesticides occur in foods from background and environmental
contamination.
The monographs only contain comments on the suitability of stated
methods of residue analysis for specific purposes, the reader being
referred to publications in the scientific literature for the details
of the techniques in individual cases. The methods have been
considered particularly with regard to their suitability for general
regulatory purposes rather than for use after planned experimental
application of the pesticides. Partly for this reason and as explained
in the report of the second session of the FAO Working Party,a
multidetection systems of analysis have been given some emphasis.
Whilst the methods referred to, and particularly the clean-up
procedures, are thought to be adequate, some of them may not have been
specifically tested for the various foods mentioned. In various
instances, therefore, the methods may need some modification.
Accordingly, each laboratory should make a preliminary examination of
any suggested procedure, in order to obtain satisfactory recoveries.
a FAO Report No. PL/1965/12.
Note to the reader
Any comments on agricultural data and their evaluation should be
addressed to:
Crop Protection Branch
Plant Production and Protection Division
Food and Agriculture Organization
Rome, Italy
Any comments on biological data and toxicological evaluation
should be addressed to:
Food Additives Unit
World Health Organization
Geneva, Switzerland