DEMETON JMPR 1975
Explanation
This pesticide was last evaluated by the 1967 FAO/WHO Joint
Meeting (FAO/WHO, 1968). Data on residues in the total diet and on
losses during processing and preparation of food required by the 1967
Meeting have not been supplied. New information an national tolerances
has become available however, and methods of analysis for disulfoton
reported to the 1973 Meeting (FAO/WHO, 1974) should be suitable for
regulatory determinations of demeton.
Additional or amended national tolerances are summarized in Table
1 and methods of residue analysis are discussed in the Appraisal
below.
TABLE 1. National tolerances for demeton reported to the Meeting
(Changes and additions since the 1967 Evaluation)
Pre-harvest
Tolerance interval
Country Commodity mg/kg (days)
Argentina
(provisional) Apples, barley, grapefruits, 0.4
lemons, pears, oranges,
table grapes
Peaches, plums, damask plums, 0.5
sugar beets (roots)
Broccoli, cabbage, cauliflower, 0.75
celery, cottonseed,
Jamaica-peppers, lettuce,
pecans, pineapples, potatoes,
strawberries, tomatoes,
vetches, walnuts
Hops 1.25
Alfalfa (fresh), barley, clover 5.0
(fresh), oats, rye (fodder),
sugar beets (leaves), wheat
Alfalfa (hay), clover (hay) 12.0
Broad beans 0.2
TABLE 1. (continued)
Pre-harvest
Tolerance interval
Country Commodity mg/kg (days)
Australia
("recommended") Cereals, fruit, vegetables 0.5
(demeton, including demeton-O,
demeton-S, demeton-O-methyl,
demeton-S-methyl and
oxy-demeton-S-methyl)
Canada Almonds, apples, apricots, 0.75
broccoli, Brussels sprouts,
cabbage, cauliflower, celery,
grapes, lettuce, peaches,
pears, peas, pecans, peppers,
plums (fresh prunes), walnuts
Grapefruit, lemons, oranges, 0.5
strawberries
Beans, muskmelons, tomatoes 0.3
Potatoes 0.2
Alfalfa (fresh), barley (grain) N. R.
cottonseed, eggplant, hops,
oats (grain), sugar beets,
wheat (grain)
Federal Cereals 0.1
Republic (disulfoton,
of Germany disulfoton-sulfoxide,
disulfoton-sulfone, demeton-O,
demeton-S, demeton-sulfoxide,
demeton-sulfane: calculated
altogether as disulfoton)
Potatoes 0.2
Italy General 30
Netherlands General 0
Norway General 21
Switzerland Fruit 0.4
TABLE 1. (continued)
Pre-harvest
Tolerance interval
Country Commodity mg/kg (days)
United States Alfalfa (hay), clover (hay) 12.0
of America
Alfalfa (fresh), almond (hulls), 5.0
barley (green fodder, straw),
clover (fresh), oats (green
fodder, straw), sugar beets
(tops, pulp), wheat (green
fodder, straw)
Grapes, hops 1.25
Almonds, apples, apricots, 0.75
barley (grain), broccoli,
Brussels sprouts, cabbage,
cauliflower, celery, cotton
seed, filberts, grapefruit,
lemons, lettuce, muskmelons,
nectarines, oats (grain),
oranges, peaches, pears,
peas, pecans, peppers, plums
(fresh prunes), potatoes,
strawberries, tomatoes,
walnuts, wheat (grain)
Sugar beets 0.5
Beans, eggplants 0.3
Sorghum (grain and forage) 0.2
USSR Cottonseed-oil 0.35
Yugoslavia General 0.4 21 proposed
APPRAISAL
Data concerning residues in processed food for direct consumption
and on residues in the total diet which were required by the 1967
Joint Meeting (FAO/WHO, 1968) have not become available. New
information on national tolerances has been provided.
The GLC methods for residue analysis of disulfoton reported by
the 1973 Joint Meeting (FAO/WHO, 1974) should be suitable for
regulatory purposes to determine demeton residues present as parent
compound, demeton sulfoxide or demeton sulphone.
The Meeting, recognizing the suitability of these procedures, the
similarity of demeton and disulfoton toxicologically, and the low
concentration of the residues involved, recommends that residues of
demeton and/or disulfoton and their several metabolites should be
expressed as disulfoton for the following reasons.
(1) Demeton may also be used in many situations where disulfoton
is used.
(2) Residues of disulfoton also include demeton sulfoxide and
sulfone.
(3) It is not always possible or convenient to determine, from
the residue found, whether demeton has been used as part of
a programme which also includes disulfoton.
(4) Analytical methods suitable for regulatory purposes are most
conveniently based on the one procedure for both compounds
and their metabolites.
Taking these factors into account, and since no new residue data
have been received, the maximum residue limits listed below are based
on the data received by the 1967 Meeting taking into account this
Meeting report and that of 1973 (FAO/WHO, 1974).
Where demeton and disulfoton have the same or similar use
patterns, further maximum residue limits are included with those
recommended for disulfoton (see monograph addendum on disulfoton).
RECOMMENDATIONS
The following maximum residue limits refer to the total residues
of demeton, demeton sulfoxide and demeton sulfone determined as
demeton sulfone and calculated as disulfoton.
Maximum Residue Limits
Commodity Limit, mg/kg
Apricots, grapes, peaches 1
Apples, citrus fruit, pears 0.5
Plums 0.2
Melons, strawberries 0.1
Further maximum residue limits are included in those recommended
for disulfoton (see this Meeting Report).
FURTHER WORK OR INFORMATION
DESIRABLE
(1) Validation of residue analytical method for regulatory
purposes.
(2) Residue data from supervised trials for commodities not
mentioned above or under disulfoton, but included in
national tolerance lists.
(3) Data on residues in commodities moving in commerce.