FAO/PL:1969/M/17/1
WHO/FOOD ADD./70.38
1969 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD
THE MONOGRAPHS
Issued jointly by FAO and WHO
The content of this document is the result of the deliberations of the
Joint Meeting of the FAO Working Party of Experts and the WHO Expert
Group on Pesticide Residues, which met in Rome, 8 - 15 December 1969.
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
WORLD HEALTH ORGANIZATION
Rome, 1970
BROMIDE ION
Explanation
Residues as bromide ion resulting from use of ethylene dibromide and
methyl bromide have been previously evaluated (FAO/WHO, 1967b, 1968b
and 1969b).* At the Fourth Session of the Codex Committee on Pesticide
Residues (FAO/WHO, 1969c)* some doubts were expressed regarding the
validity of some of the data on which certain of the recommendations
had been based. The Fourth Session of the Codex Committee on Pesticide
Residues had also asked for clarification of the kinds of treatments
that had been reviewed (e.g. whether including pick-up from treated
soil) and concerning the identity of certain of the residues. These
aspects were briefly reviewed as follows:
EVALUATION FOR ACCEPTABLE DAILY INTAKE
The Meeting noted that the presence of unreacted bromide in certain
foods had recently been reported when using modern methods of residue
analysis and that the analytical methods used in some of the earlier
work may have resulted in the erroneous inclusion of some organic
bromide in residues reported as inorganic bromide. The possibility of
establishing 'Acceptable Daily Intakes' for the principal fumigants
concerned was therefore reconsidered. As outlined in the parent report
of the meeting (FAO/ WHO 1970a, Section 2.7),* the possibilities of
doing this by considering data pertaining to the inhalation of the
fumigants was considered; but it was concluded that acceptable daily
intakes for these fumigants could not be established at this time.
Notwithstanding the possibility that some organic bromide may
previously have been reported as inorganic bromide, it was also
concluded that there would be a continuing need to consider residues
of bromine that do occur as inorganic bromide.
RESIDUES IN FOOD AND THEIR EVALUATION
(a) Tolerance of 20 ppm on fresh fruit
It was noted that the recommended tolerance of 20 ppm on fresh fruit,
other than citrus, strawberries and avocadoes, was not acceptable to
certain countries since it did not take into account residues
resulting from soil treatments. As no additional data on this aspect
had been assembled or received since the Fourth Session of the Codex
Committee in October 1969 it was decided not to amend the tolerance
recommendation but generally to review the contribution of soil
treatments at a subsequent meeting (see GENERAL CONCLUSION AND
RECOMMENDATION).
*See Appendix II
(b) Tolerances on a variety of fruit or vegetable products
It was noted that a requirement for tolerances for certain products
(including musk melon, banana pulp, egg plant, pineapple and lettuce)
had been proposed at the 1969 Fourth Session of the Coder Committee
(1969), and that such products might contain residues following
treatments for phytosanitary (i.e. quarantine) purposes. In the
absence of experimental or other data, however, detailed consideration
of the matter had to be deferred to a later meeting (see GENERAL
CONCLUSION AND RECOMMENDATION).
(c) 30 ppm tolerance for dried fruit
On reconsidering the 1968 recommendations for tolerances for dried
fruits, it was decided that the list of exceptions from the 30 ppm
figure should remain unaltered. Any such exceptions for other products
would need to be based on additional data (see GENERAL CONCLUSION AND
RECOMMENDATION).
(d) Tolerance of 400 ppm on dried eggs and certain other dried foods
In a general review of this subject it was noted that the initial
consideration by the Joint Meeting, of methyl bromide and ethylene
dibromide, had been only concerned with cereal grains (FAO/WHO,
1967b).* The fairly considerable amount of data on these products
indicated that the formation of inorganic bromide occurs moderately
readily, due to methylation of proteins, in the case of methyl bromide
but not with ethylene dibromide. Ethylene dibromide, on the other
hand, is far less readily dissipated from products during airing and
there is a higher risk of its retention as such in foodstuffs in
commerce. Some of the earlier analyses did not clearly differentiate
between organic and inorganic forms.
In the limited time available since the Fourth Session of the Codex
Committee on Pesticide Residues, the original data, from which the 400
ppm figure for dried eggs had been derived, had not become available
for review. As the work had been performed in 1964 or earlier when
satisfactory analytical methods specific for the free unchanged
fumigants and for inorganic bromide ware not available however, it was
considered likely that further experimental work on the fumigation of
dried eggs with ethylene dibromide and with methyl bromide would be
needed to clarify the position.
In the meantime it was decided that the tolerance recommendation for
dried eggs should remain in suspense.
*See Appendix II
GENERAL CONCLUSION AND RECOMMENDATION
In the course of a general discussion, the need to fumigate dried eggs
and certain other products with methyl bromide, ethylene dibromide and
similar fumigants was raised. It was decided that further information
on this aspect should be sought. It was also decided that such
information should be included in a general review of bromide
residues, which should take points a, b, and c of this monograph into
account. This review should be undertaken at the 1971 Meeting. By that
time further information should also be available on various
foodstuffs examined by methods of analysis able to identify the nature
of residues more clearly than hitherto.