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    FENITROTHION           JMPR 1976

    Explanation

         In 1969 the Joint Meeting evaluated fenitrothion in the light
    of the information then available;(FAO/WHO 1970). In 1974 extensive
    new information was evaluated and recommendations were made for
    maximum residue limits on a number of raw agricultural commodities
    including raw grains and milled cereal products as a result of
    post-harvest use of fenitrothion as a grain protectant insecticide
    (FAO/WHO 1975),

         The 1974 meeting listed several items of further work or
    information as desirable. These included results from studies on
    the effect of cooking on fenitrothion residues in rice, further
    studies to determine the fate of residues from cooking other cereal
    products from wheat and rye and information on the level and fate
    of residues following post-harvest use on oats, barley and rye. A
    considerable amount of additional research has been carried out to
    provide information on these points. The results of these studies
    have been made available for evaluation by the Meeting and the
    following monograph addendum has been prepared.

    USE PATTERN

    Post-harvest treatments

         No new use patterns have been developed for the postharvest
    application of fenitrothion as a grain protectant but several of
    the reports which were available only in manuscript form in 1974
    have now been published or submitted for publication.

         Ardley and Sticka (1974) compared fenitrothion applied at 2.5,
    5, 6 and 10 mg/kg with malathion applied at 12 and 18 mg/kg for the
    protection of bulk wheat in vertical bin silos and horizontal bulk
    depots of conventional construction. The results suggest that in
    both types of storage the persistence of the insecticides can be
    correlated with the temperature and moisture content of the grain.
    Under the conditions of silo storage both protectants remained
    effective for as long as 19 months; under the more severe
    conditions of horizontal bulk storage the higher applications were
    effective for only 6-7 months. Fenitrothion at one-half the
    application rate of malathion appears to give equivalent protection
    against attack from stored product insect pests.

         Bengston et al. (1976a) compared fenitrothion with three other
    new grain protectant insecticides and with malathion in extensive
    studies in Australia. The effects of concentration of insecticide
    and storage conditions on the biological performance of each
    compound were evaluated by bio-assay using both susceptible and
    organophosphorous-resistant strains of many different stored
    product pests. Fenitrothion was shown to give superior performance

    to malathion and comparable protection to chlorpyrifos-methyl,
    pirimiphos-methyl and methacriphos (CGA-20168).

         Further extensive trials carried out in 20 regional locations
    throughout Australia evaluated a mixture of fenitrothion and
    bioresmethrin against a combination of pirimiphos-methyl and
    bioresmethrin under a wide variety of storage conditions,
    temperatures, and moisture (Bengston et al., 1976b). These studies
    showed fenitrothion to be effective against all stored product
    species including numerous organophosphorus-resistant strains. The
    lesser grain borer Rhyzopertha dominica, which is not
    adequately controlled by fenitrothion, was completely inhibited by
    the addition of 1-2 mg/kg bioresmethrin. Extensive data were
    obtained on the effect of temperature, moisture and aeration on the
    durability of such grain protectants.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

         Table 1 from the work of Desmarchelier et al. (1976) shows the
    effects of storage time and temperature on the levels of residues
    of fenitrothion applied to grain stored in 20 different localities
    in Australia. It was known from previous studies that a
    concentration of approximately 5 mg/kg of fenitrothion in grain is
    required to control effectively the invasion of stored product
    pests. It was found by challenging sample insects under laboratory
    conditions that the application of Fenitrothion at a level within
    the range 10-12 mg/kg ensured complete protection of stored grain
    for approximately 20 weeks. However, under field conditions
    effective protection would be considerably longer. In extensive
    field trials from which these data were derived, wheat did not
    become infested even after 30 weeks. During this time, wheat in
    adjoining silos became invaded by pests, although it had been
    treated with malathion.

    FATE OF RESIDUES

    General

         Desmarchelier et al (1977) reported a collaborative study of
    residues on wheat of methacriphos, chlorpyrifoamethyl,
    fenitrothion, malathion and pirimiphos-methyl during 6 months'
    storage. These workers developed formulae by which it is possible
    to calculate the level of residues at any particular time following
    storage at known temperatures and humidity. The half-life at 30C
    of fenitrothion was calculated to be 16.2 weeks. This compared with
    12.6 weeks for malathion and 69 weeks for pirimiphos-methyl.

         Desmarchelier (1976a) in a study of the kinetic constants for
    breakdown of fenitrothion on grains in storage, found that the
    breakdown on wheat, rice paddy, oats and sorghum in storage at four
    temperatures, was first order with respect to fenitrothion and to
    grain moisture. At a given moisture content, water activities were


    
    TABLE 1. Fenitrothion residues in stored wheat: Effects of time and temperature on residue levels

                                                                                                                                  

                Grain             Fenitrothion residues after various intervals at indicated temperatures
    Location    Moisture, %
                        Interval  0              4 weeks       7 weeks       10 weeks      13 weeks      16 weeks       21 weeks
                                  mg/kg   C     mg/kg  C     mg/kg  C     mg/kg  C     mg/kg  C     mg/kg  C      mg/kg  C
                                                                                                                                  

    1           9.4               10.7    36     6.4                         4.4                         4.7    35
    2           9.4               11.8    33     8.3                         8.3                         6.6    30
    3           9.4               12.8    35                   6.9                         5.5    34     5.2    34
    4           9.0               12.0    29     8.3                         8.8    27
    5           11.2              9.8     31     9.8    29     8.8    29                   7.0    29     7.2    30      5.7    29
    6           -                 11.9    28     11.2   28     4.7    28                   8.2    28     7.4    27      7.5    28
    7           11.0              10.8    30     9.5    28     5.6    27                   6.2    27     3.4    27      3.8    27
    8           11.9              12.8    31     10.2   22     10.6   24                   9.0    24     7.0    24      7.6    23
    9           10.4              12.4    35                   8.0    28                   8.2    28     7.4    24      8.0    24
    10          10.8              12.3    34     9.6    28                   7.1    28     8.8    29     8.0    24
    11          9.6               10.4    -                                  3.3    25     2.8    23     2.1    23      2.5    22
    12          9.4               10.4    -                                  2.7    30     2.1    30     1.6    30      1.5    27
    13          10.4                                           10.0   34
    14          9.9               11.2                         7.8    34
    15          10.1              11.5           7.1                         4.3
    16          10.1              13.0           12.2                        6.8
    17          11.4              12.2           7.0                         3.8
    18          9.3               10.7           9.4                         6.6
    19          10.4              11.6                                       7.9
    20          10.2              11.3                                       7.2
                                                                                                                                  

    
    dependent upon, but rate constants ware independent of grain type. The
    effect of temperature on breakdown was of the form of the Arrhenius
    equation. A simple expression was derived from these basic concepts of
    kinetics which accurately predicted residues under 24 different
    conditions set by altering grain type, moisture content and
    temperature.

    In processing and cooking

         Barley

         A number of studies have been made into the fate of fenitrothion
    residues when treated grain is subjected to normal processing,
    preparation and cooking. These studies are discussed separately
    according to the grains involved.

         Desmarchelier (1976b) studying the decay of five insecticides
    during the storage and melting of barley, carried out experiments in
    triplicate on samples of barley with a moisture content of 13% held at
    25C. After three months storage the barley was malted by a primitive
    process and after 6 months by a commercial process. In neither case
    was germination affected by any of the pesticides, including
    fenitrothion. An initial application of 15 mg/kg fenitrothion had
    declined to 6.8 and 3.1 mg/kg after 3 and 6 months respectively. When
    subjected to the primitive malting process, barley containing 6.8
    mg/kg fenitrothion produced malt containing 2.9 mg/kg. The barley
    containing 3.1 mg/kg fenitrothion, when submitted to the commercial
    malting process, produced malt containing only 0.55 mg/kg of
    fenitrothion. Under similar conditions, barley containing 6.4 mg/kg of
    malathion produced malt which still contained 0.8 mg/kg of malathion.

         More extensive studies are currently under way in conjunction
    with the Australian Barley Board and co-operating maltsters but the
    data are not expected to be available until mid-1977.

         Oats

         Desmarchelier (1976c) studied the decay of five insecticides
    following the storage and cooking of oats. Duplicate samples of oats
    with a moisture content of 12% were stored at 25C and were analysed
    after 3 and 6 months. Oats treated with fenitrothion at the rate of 15
    mg/kg were found to contain 6.9 and 4.2 mg/kg fenitrothion at the end
    of 3 and 6 months respectively. Some of the oats which had been stored
    for 3 months were cooked in a minimum amount of boiling water for 5
    and 15 minutes without prior de-husking. The original residue level of
    6.9 mg/kg was found to have fallen to 4.6 mg/kg after 5 minutes
    cooking and to 4.0 mg/kg after 15 minutes cooking.

         A more extensive study in which the oats are to be de-husked,
    milled and rolled before cooking, is planned to be completed during
    1977.

         Rice

         Desmarchelier (1976d) studying the decay of five pesticides on
    rice during storage and processing, treated duplicate samples of rice
    in husk with fenitrothion at a concentration of 15 mg/kg. The rice had
    a moisture content of 13% and was stored at 25C for 3 and 6 months by
    which time the residue level had declined to 6.2 and 3.5 mg/kg
    respectively. After 6 months storage, the rice was milled and the
    resulting husked and polished rice analysed. It was found that the
    residue had been reduced to 0.62 mg/kg on the husked rice and 0.27
    mg/kg on the polished rice. Samples of husked and polished rice were
    cooked by boiling in a minimum amount of water for 15 minutes. Such
    cooking further reduced the residue level on the husked rice to 0.39
    mg/kg and on the polished rice to 0.13 mg/kg.

         In a series of parallel studies Desmarchelier (1976d) applied
    fenitrothion to husked (brown) rice which was stored at 25C for 6
    months. The rice, which had a moisture content of 12.5%, was treated
    at a concentration of 18.0 mg/kg. Samples were examined after 3 and 6
    months, by which time the fenitrothion concentration had declined to
    11.5 and 8.0 mg/kg respectively. Some of the rice which had been in
    storage for 3 months was cooked in a minimum amount of boiling water
    for 5 and 15 minutes after which it was found that the residue level
    had declined from 11.5 mg/kg to 5.3 and 3.8 mg/kg respectively. When
    rice which had been in storage for 6 months was similarly cooked for
    25 minutes, the fenitrothion concentration declined from 8.0 to
    4.2 mg/kg.

         The effect of storing and cooking polished (white) rice treated
    with fenitrothion was studied by Desmarchelier (1976d). Polished rice
    treated at 15 mg/kg still retained 10 mg/kg after 3 months and 7.5
    mg/kg after 6 months. When rice which had been in storage for 3 months
    was cooked in a minimum amount of boiling water for 5 and 15 minutes,
    the fenitrothion content declined to 5.0 and 3.0 mg/kg respectively.

         These studies on rice indicate that the fate of fenitrothion is
    not particularly different from that of pirimiphos-methyl,
    methacriphos or malathion which were examined concurrently, but its
    stability is somewhat greater than that of carbaryl or bioresmethrin. 

         Ito et al (1976) carried out an extensive and detailed study on
    the fate of Fenitrothion residues in rice. Following the application
    of Fenitrothion to husked rice the grain was stored for 12 months,
    then milled under standard conditions which yielded 87% polished rice
    and 13% bran. During the milling process the major portion of the
    residue in the husked rice was removed in the bran and this feature
    was independent of the storage period or the amount of fenitrothion
    applied. Only a minor proportion of the fenitrothion remained in the
    polished rice and even this was reduced by washing the grains before
    cooking. The residue in the washed grain was reduced to about half by
    cooking. The higher the temperature and pressure applied during
    cooking, the greater was the reduction in the fenitrothion residue.

         Table 2, summarising this work, shows that the ratio of the
    fenitrothion concentrations in polished rice and bran remains
    constant, irrespective of the amount of fenitrothion applied to the
    husked rice or found after prolonged storage. Only about 10% of the
    quantity occurring in the husked rice remains in the polished rice
    after milling. The polished rice was then washed and cooked, with the
    results shown in Table 3. Three types of cooking were employed in
    these studies. Cooking condition 1 represents the typical method of
    cooking rice in the home and consists of boiling the rice in an
    approximately equal weight of water at atmospheric pressure for 15
    minutes, followed by a further 15 minutes at a temperature of 80C.
    Cooking condition 2 consists of boiling the rice in an equal quantity
    of water for 10 minutes at 110C under a pressure of 1.5 atmospheres
    in an autoclave. Condition 3 consists of cooking for 10 minutes at a
    temperature of 120C under a pressure of 2.1 atmospheres. The
    increased temperature and pressure had a slight but significant effect
    upon the destruction of the remaining small quantity of fenitrothion
    in the cooked rice.

    TABLE 2. Fate of fenitrothion applied to husked (brown)
             rice during milling and cooking (Ito et al, 1976

                                                                        

    Amount       Storage                Residues (mg/kg) in
    Applied      Period
    mg/kg        Months      Husked Rice    Polished Rice*    Rice Bran*
                                                                        

    15           0           9.38           1.02              65.0

    2            12          0.61           0.09              4.03

    6            12          1.66           0.25              11.7

    15           12          4.39           0.55              31.6
                                                                        

    *Ratio polished rice to bran = 87:13

        TABLE 3. Effect of cooking on fenitrothion residues in rice
             (Ito et al, 1976)
                                                                                

    Amount    Storage                                  Cooking**    Residue
    applied   period       Residues (mg/kg) in         Condition    in cooked
    mg/kg     months    Polished   Washed    Wash*                  rice (mg/kg)
                        Rice       grains    water
                                                                                

    15        0         1.02       -         0.60          1        0.26

    2         12        0.09       0.03      0.05          1        0.02

                                                           2        0.01

                                                           3        0.01

    6         12        0.25       0.08      0.16          1        0.05

                                                           2        0.03

                                                           3        0.01

    15        12        0.55       0.18      0.37          1        0.12

                                                           2        0.07

                                                           3        0.04
                                                                                

    * Concentration expressed as mg/kg in grains before washing.
    ** For explanation see text.
      
         Wheat

         In a series of three trials, Desmarchelier (1976e) determined the
    fate of fenitrothion residues on wheat during milling and cooking.
    Table 4 shows the results, indicating that when wheat is milled for
    the production of white flour, only about 10% or less of the
    fenitrothion present in the raw grain is carried into the flour, the
    bulk being concentrated in the bran with a lesser amount in the shorts
    (pollard). When white bread is prepared from the flour, there is a
    further significant loss of fenitrothion so that the residue remaining
    in the bread is of the order of 1-2% of that present in the raw wheat.
    In the case of wholemeal bread, however, there is a significant
    carry-over of the residue from the grain, equivalent to 20-25% of the
    original fenitrothion concentration. In these trials, only a small
    proportion of the original residue remained as residual phenol
    (3-methyl-4-nitrophenol).

    TABLE 4. Fate of fenitrothion residues on wheat during milling and
    cooking

                                                                        

                                                       Trial 3          

                          Trial 1  Trial 2   Fenitrothion  3-methyl-
                                                           4-nitrophenol
                                                                        

    Time after
    application           19       13         10              -
    (weeks)

    Residue, mg/kg, in
      wheat               6.5      9.6        7.6             -

      wholemeal flour     3.5      4.8        6.1             -

      wholemeal bread     1.5      1.8        1.72            0.05

      bran               19.5     22.6       20.8             0.25

      shorts              5.8     11.0        3.3             0.12

      white flour         0.53     0.74       0.25            0.06

      white bread         0.09     0.21       0.08            0.06
                                                                        


         Ardley (1976) studied the level and fate of fenitrothion residues
    in wholemeal and wholemeal bread. For comparison, similar grain
    treated with malathion was also processed. Separate lots of clean
    wheat were treated with fenitrothion and malathion at the rate of 10
    mg/kg, using pilot scale facilities. The grain was stored at room
    temperature (approximately 20C) and was analysed 7 days later for
    fenitrothion and malathion by GLC using both flame ionization and
    thermionic phosphorus detectors. The results were comparable by both
    methods.

         Part of the grain was milled into wholemeal on a disc mill and
    part was converted into white flour on a roller mill. The wholemeal
    flour was combined with white flour prepared from untreated grain in
    the ratio of 90% wholemeal : 10% white flour and the products of the
    roller milling were recombined to give a similar blend containing the
    bran, shorts (pollard) and white flour in the same 90:10 proportion.
    The loaves were baked by standardised procedures and the bread and
    flour were subjected to residue analysis in the same way as the raw
    grain. Table 5 indicates the level of residues found in the wheat,
    wholemeal and bread. It will be observed that only about 50% of the

    residue was lost in the baking of wholemeal bread but fenitrothion was
    no different in this respect from malathion. It is now known that much
    of the residue data published on the level and fate of malathion in
    cooked cereal products is inaccurate because the extraction procedures
    used to recover the residue were incapable of removing the residue
    occluded in or combined with components of the prepared or cooked
    cereal.

    METHODS OF RESIDUE ANALYSIS

         Although no new basic concepts in residue analysis affecting the
    determination of fenitrothion residues in grain and milled cereal
    products have been noted since the previous monograph was prepared,
    two reports pointing to the problems involved in the sampling and
    extraction of grain and milled cereal products are worthy of
    attention.

         Snelson and Desmarchelier (1975) in a paper presented at the
    First International Working Congress of Stored Product Entomology,
    discussed the significance of pesticide residue analysis, and pointed
    to the wide variations in results between analysts and the unresolved
    variation between methods, making the meaning of analytical figures
    somewhat uncertain. The paper surveys the results of a collaborative
    programme of analysis of wheat for malathion and discusses sources of
    variance between analysts and between methods, the errors due to lack
    of primary analytical standards, and the variance caused by sampling,
    and points to the need for eliminating as many of these variations as
    possible.

         In an extensive report of a collaborative study of the analysis
    of residues in wheat of five grain protectant insecticides including
    fenitrothion, Desmarchelier et al (1977a), point particularly to the
    lack of consideration of the difference between the ease of extraction
    of freshly applied and "aged" or "weathered" deposits not withstanding
    the fact that techniques for accurately analysing aged deposits have
    been well documented.

         This work was undertaken to develop methods suitable for the
    determination of the insecticides in wheat and to assess the broader
    problem of variations among results, by means of a panel of analysts
    who studied, over a 6 month period, the breakdown of residues in grain
    from field trials. The error of basing recoveries on the analysis of
    fortified samples is particularly important in the case of stored
    grain.

         Because of the international movement of grain and the acceptance
    of maximum residue limits for a number of grain protectant
    insecticides, the methods of analysis should ideally be rapid and as
    independent as possible of special equipment. Extraction by standing
    whole grain in methanol is simpler than most procedures. From the
    extensive results of the study by Desmarchelier et al (1977a) there
    would seem to be no major errors associated with different conditions


    
    TABLE 5. Fate of fenitrothion and malathion on wheat used for the production of wholemeal bread

                                                                                                  

    Insecticide         Amount       Residue in      Residue         Residue in bread made from
    treatment           applied      grain 7 days    in flour
                        mg/kg        later                        Disc milled       Roller milled
                                                                                                  

    None                -            ND              ND           ND                ND

    Malathion           10           5.0             2.0          2.7               2.4

    Fenitrothion        10           5.5             2.6          3.2               3.1
                                                                                                  

    ND - Residue below limit of determination (0.05 mg/kg)

    

    for GLC or different types of specific phosphorus detectors. The
    method used works well with fenitrothion residues in grain even over a
    range of operating conditions.

    APPRAISAL

         Following the evaluation in 1974 (FAO/WHO 1975) the Joint Meeting
    considered that further work or information on the occurrence and fate
    of fenitrothion residues in stored products and milling products of
    stored grain was desirable. This information has been generated and
    evaluated. The data indicate that fenitrothion residues from
    treatments applied to the various raw grains in storage, are largely
    removed during processing, preparation and cooking except in the case
    of wheat converted into whole meal bread. In this case, 20-50% of the
    original deposit appears to remain in the bread after baking. Parallel
    studies have indicated that fenitrothion is little different in this
    respect from malathion, the detection of undecomposed residues in the
    prepared bread reflecting improved methods of extraction and analysis
    rather than greater stability on the part of fenitrothion.

         A number of studies point to the importance of the correct choice
    of extraction techniques, solvents and analytical methods for
    determining grain protectant insecticide residues on stored grain and
    particularly in milled and cooked cereal products.

         The new data confirm the recommendations for maximum residue
    limits made in 1974 and justify recommendations which would permit the
    use of fenitrothion for the postharvest protection of rice.

    RECOMMENDATIONS

         The following maximum residue limits are recommended. The limit
    for rice bran is new: the others replace recommendations made in 1974.
    In keeping with previous practice the limits are for the sum of
    fenitrothion and its oxygen analogue expressed as fenitrothion.

    Commodity                        Limit, mg/kg

    Rice bran                          20

    Rice (in husk and hulled)          10

    Rice (polished)                    1

    REFERENCES

    Ardley, J.H. The fate of fenitrothion and malathion residues
    1976                     in wholemeal bread. Report of Research and
                             Development Division, the Wellcome Foundation
                             Ltd. ANZ 29:12-76.

    Ardley, J.H. & Sticka, R. The effectiveness of fenitrothion
    1974                     and malathion as grain protectants under bulk
                             storage conditions in Australia. J. stored
                             Prod. Res., 10.


    Bengston, M., Connell, M., Crook, I.D., Desmarchelier, J.M.,
    1976a                    Hart, R.J., Phillips, M., Snelson, J.T., &
                             Sticka, R. Field trials to compare CGA-20168,
                             chlorpyrifos-methyl, fenitrothion,
                             pirimiphos-methyl and malathion for control
                             of malathion-resistant insects infesting
                             wheat. J. stored Prod. Res. 12 (in press).

    Bengston, M., Connell, M.., Crook, I.D., Desmarchelier, J.M.,
    1976b                    Hart, R.J., Phillips, M., Snelson, J.T., &
                             Sticka, R. Interim report of pilot studies
                             with fenitrothion and pirimiphos-methyl in
                             combination with bioresmethrin. Report to
                             Australian Wheat Board, May 1976. (Full
                             studies to be published).

    Desmarchelier, J.M. Kinetic Constants for breakdown of fenitrothion
    1976a                    on grains in storage. CSIRO, Division of
                             Entomology, Canberra, Australia. (in press).

    Desmarchelier, J.M. Decay of five pesticides on storage and
    1976b                    malting of barley, CSIRO Division of
                             Entomology, Canberra, Australia. (To be
                             published).

    Desmarchelier, J.M. Decay of five pesticides on storage and
    1976c                    cooking of oats. CSIRO Division of
                             Entomology, Canberra, Australia. (To be
                             published).

    Desmarchelier, J.M. Decay of five pesticides on storage and
    1976d                    processing of paddy rice, husked (brown) rice
                             and polished (white) rice. CSIRO Division of
                             Entomology, Canberra, Australia. (To be
                             published).

    Desmarchelier, J.M. Residues of insecticides on milled and baked
    1976e                    products from wheat treated and held in
                             storage 1975/76. CSIRO Division of
                             Entomology, Canberra, Australia. (To be
                             published).

    Desmarchelier, J.M. Baking and milling tests on wheat treated with
    1976f                    fenitrothion and chlorpyrifosmethyl. CSIRO
                             Division of Entomology, Canberra, Australia.
                             (To be published).

    Desmarchelier, J.M., Bengston, M., Connell, M., Minett, W.,
    1976                     Moore, B., Phillips, M., Snelson, J.T., &
                             Sticka, R. Preliminary report of pilot trials
                             in 5 states with combinations of
                             pirimiphos-methyl/ bioresmethrin and
                             fenitrothion/bioresmethrin. Report of
                             Australian Wheat Board Working Party on Grain
                             Protectants. (To be published).

    Desmarchelier, J.M., Bengston, M., Connell, M., Minett, W.,
    1977a                    Moore, B., Phillips, M., Snelson, J.T.,
                             Sticka, R., & Tucker, K. A collaborative
                             study of residues on wheat of methacrifos,
                             chlorpyrifosmethyl, fenitrothion, malathion
                             and pirimiphosmethyl. I. Method development.
                             J. stored Prod. Res. (Submitted for
                             publication).

    Desmarchelier, J.M., Bengston, M., Connell, M., Minett, W.,
    1977b                    Moore, B., Phillips, M., Snelson, J.T.,
                             Sticka, R., & Tucker, K. A collaborative
                             study of residues on wheat of methacrifos,
                             chlorpyrifos methyl, fenitrothion, malathion
                             and pirimiphos methyl. II. Rates of decay. J.
                             stored Prod. Res. (Submitted for
                             publication).

    Ito, T., Kageyama, Y., & Hirose, G. Fate of fenitrothion residues
    1976                     in rice grains. Report of Research
                             Department, Sumitomo Chemical Co. Ltd.,
                             Takarazuka City, Japan. (To be published).

    Snelson, J.T., & Desmarchelier, J.M. The significance of pesticide
    1975                     residues in stored grain. Proc. 1st Int.
                             Working Congress of Stored Product
                             Entomology, Savannah, Georgia 1975, p. 465.

    FAO/WHO                  1969 Evaluation of some pesticide residues in
    1970                     food. FAO/PL:1969/M/17/1, WHO/Food Add./70.38

    FAO/WHO                  1974 Evaluation of some pesticide residues in
    1975                     food.  FAO/AGP:1974/M/11, WHO Pesticide
                             Residues Series, No. 4.
    


    See Also:
       Toxicological Abbreviations
       Fenitrothion (EHC 133, 1992)
       Fenitrothion (HSG 65, 1991)
       Fenitrothion (ICSC)
       Fenitrothion (FAO/PL:1969/M/17/1)
       Fenitrothion (WHO Pesticide Residues Series 4)
       Fenitrothion (Pesticide residues in food: 1977 evaluations)
       Fenitrothion (Pesticide residues in food: 1979 evaluations)
       Fenitrothion (Pesticide residues in food: 1982 evaluations)
       Fenitrothion (Pesticide residues in food: 1983 evaluations)
       Fenitrothion (Pesticide residues in food: 1984 evaluations)
       Fenitrothion (Pesticide residues in food: 1986 evaluations Part II Toxicology)
       Fenitrothion (Pesticide residues in food: 1988 evaluations Part II Toxicology)
       Fenitrothion (JMPR Evaluations 2000 Part II Toxicological)