sec-BUTYLAMINE      JMPR 1977


    sec-Butylamine was evaluated for acceptable daily intake by the 1975
    Joint Meeting (FAO/WHO, 1976). A temporary ADI for humans was
    established to be 0.2 mg/kg body weight. Maximum residue limits were
    recommended for citrus and citrus products. It was considered that the
    following information was required before the ADI and maximum residue
    limits could be confirmed.

    1. Fate of residues especially after processing of meat and milk.

    2. Quantitative metabolic studies in animals.

    3. Information on the fate of sec-butylamine residues in livestock
    when citrus pulp and citrus molasses containing sec-Butylamine are
    used as components in the ration of livestock.

    4. Information on the use of sec-butylamine for the control of
    post-harvest rot on fruits other than citrus and on residues resulting
    from such uses.

    It was considered that information from mutagenicity studies with
    techniques currently available and clinical observations in humans
    were desirable.

    It has been interpreted that the first requirement is a duplication of
    requirement number 3 which is expressed in clearer terms.

    Information in fulfillment of some of these requirements has been made
    available and the following monograph addendum summarises these



    In the 1975 monograph (FAO/WHO 1976), it was indicated that
    sec-butylamine had proved useful and was widely used for the
    post-harvest treatment of citrus. It was stated that in addition it
    had been shown to be useful for controlling post-harvest decay of
    apples, pears, peaches and bananas.

    In response to the request for information on the use of
    sec-butylamine for the control of post-harvest rot on fruits other
    than citrus, one of the principal manufacturers advised that in the
    United States sec-butylamine has been cleared only for use on
    citrus. The reason for this is that experimentation on other crops was
    not promising enough to warrant further investigation. In the case of
    apples, excellent decay control could be obtained with apples
    inoculated with Penicillium expansum as long as the experiments were
    conducted at room temperature. However, in refrigerated storage the

    sec-butylamine treatment was not effective in preventing spoilage;
    this observation discouraged further work. Also, there was some
    indication of phytotoxicity to apples from some important apple
    growing regions.

    Notwithstanding the interest in the use of sec-butylamine on
    potatoes in Europe, no interest has developed in this application in
    USA and certain other countries because sec-butylamine is rather
    ineffective against the two main spoilage organisms on stored potatoes
    in these countries -- Fusarium dry rot and bacterial soft rot.

    Much of the potato crop grown in the United Kingdom is from seed
    produced by growers in Scotland where, at present the most serious
    tuber diseases are gangrene, caused by the fungus Phoma exigua var.
    foveata, and skin spot, caused by the fungus Oospora pustulans.

    Both fungi are particularly difficult to control as they can be latent
    in association with the tubers. This means that the fungus may persist
    or develop extremely slowly in the seed tuber long before any visible
    lesions may be found. Even at the end of the storage period, tubers
    may look healthy but still be carrying the disease organisms.

    At present, some potato seed tubers are dipped in organo-mercury
    disinfectant solutions which control a range of pathogens and give
    reasonable control of gangrene. However, there are serious
    difficulties in using organo-mercury solutions.

    Extensive research has shown that sec-butylamine applied by
    fumigation at the rate of 200 mg/kg of potato tubers over a period of
    30/40 minutes with further recirculation for 2 hours is most effective
    against these diseases. The treatment has been adopted at a number of
    centres in Scotland.

    For general commercial use it is unlikely that more than a few farmers
    would find it economically worthwhile to construct suitable fumigation
    chambers, so the treatment is being carried out in official
    installations, though mobile fumigation chambers are being constructed

    Residues of sec-butylamine remain on and in treated potatoes, and
    cannot even be removed by boiling. Therefore the process may at
    present only be used for treating seed potatoes and such potatoes must
    not be subsequently sold for human consumption or fed to stock.* No
    significant residues have been found in crops grown from treated seed.

    * It must be expected that there will be a move to obtain clearance
    for use on potatoes destined for human consumption, since it is not
    practicable to sort seed potatoes from ware potatoes as they are
    delivered from the fields, which is the time when treatment must be


    No information other than the results of further studies on citrus has
    come to hand since this compound was evaluated in 1975.


    In Animals

    In response to the request for information on the fate of
    sec-butylamine residues in livestock when citrus pulp and citrus
    molasses containing sec-butylamine are used as components in the
    ration of livestock, the meeting was supplied with details of two

    The objective of the first experiment (Eli Lilley, 1967) was to
    determine sec-butylamine residues in faeces, blood, milk, urine,
    liver, kidney, fat and muscle of lactating dairy cows fed various
    amounts of sec-butylamine in their diets. Cows of varying milk
    production were divided into a control group and a treated group, each
    penned separately. During the base-line period of two weeks, all
    animals were on control feed: a maximum of 15 lbs twice daily of a
    dairy lactation ration, with concentrate hand-fed to each cow, 2 1/2
    lbs twice daily at milking time. Milking and feeding were on a 12 hour
    schedule. Samples from individual cows were analysed and reported
    separately. The treated cows were fed a ration to which was added
    sec-butylamine as the phosphate at levels of 100, 20, 10, 5, and 2
    ppm. Twenty-four hour composite milk samples, samples of edible tissue
    (immediately after withdrawal) from the 100 and 2 ppm cows and grab
    samples of urine, blood and faeces from the 100 and 10 ppm cows were
    assayed for sec-butylamine.

    The 100 ppm feeding level is 5-10 times the level that would be
    expected in a dairy ration containing citrus by-products.

    The sec-butylamine was determined as the dinitrophenyl derivitive by
    gas-chromatography using electron affinity detection, with a limit of
    determination of 0.003-0.01 mg/kg, depending upon the substrate.

    Endogenous sec-butylamine was found to be present in most samples
    from control cows: it was identified in milk by infra-red spectroscopy
    and gas chromatography.

    The volatile amines in the milk sample were isolated by steam
    distillation and subsequent formation of the dinitrophenyl
    derivatives, which were separated by thin-layer chromatography. The
    dinitrophenyl derivative of C4 amines were eluted from the absorbent
    and the sec-butylamine content determined by gas chromatography. The
    specificity and sensitivity of this procedure were described by Day et
    al. (1966). The large quantity of volatile amines in milk necessitated
    extensive isolation and purification procedures involving 10 separate
    operations. Table 1 indicates the level of sec-butylamine found in


    the milk of animals receiving 100 ppm in the total diet (equivalent to
    1.6 g of sec-butylamine per head per day) as compared with the milk
    of control animals.

    A dose-response relationship was observed between the amount of
    sec-butylamine fed and the amount found in milk, blood, urine,
    faeces, kidney and liver. The sec-butylamine appeared to be readily
    absorbed and excreted in the milk and urine. It is estimated that less
    than 1% of the amount fed was found in the milk.

    The composite range and range of individual results for each type of
    sample are shown in Table 2.

    Although the amount of sec-butylamine in lean meat was not
    significantly higher in the dosed than in the control animals, there
    were significant amounts of sec-butylamine in kidneys at all feeding
    levels with a maximum of 2-6 mg/kg at 100 ppm, and in liver at the 100
    and 10 ppm feeding levels. A dose-response relationship was observed
    in these tissues.

    The residue levels found in the blood, faeces and urine show that
    sec-butylamine is readily absorbed and mainly excreted in the urine.

    The second experiment (Peoples 1968) was designed to determine the
    levels of sec-butylamine in milk, muscle, liver, fat and kidney of
    lactating cows fed a dried citrus pulp ration made from oranges which
    had been treated with sec-butylamine. Seven Holstein cows were used
    in this study, three as controls and four receiving a ration
    containing 16 ppm sec-butylamine. The control ration was fed to all
    animals during a 7 day conditioning period.

    The average level of sec-butylamine found in the milk over the
    treatment period for all animals was 0.33 mg/kg, and the range of
    values was 0.071-0.67 mg/kg. There was no appreciable build-up of
    sec-butylamine as the feeding period progressed. The average residue
    at the first sampling after the feeding began was 0.35 mg/kg, 0.37
    mg/kg at the mid-point and 0.42 mg/kg on the last day. Results are
    shown in Table 3.

    The average and range of residue levels found in each tissue and blood
    are shown below.

                   sec-butylamine, mg/kg
    Tissue         Average        Range
    Muscle         0.050          036-0.064
    Fat            0.018          0.001-0.028
    Liver          0.179          0.148-0.198
    Kidney         1.56           0.96-2.68
    Blood          0.04           0.012-0.057

    TABLE 1. sec-Butylamine feeding study in lactating
    cows (Lilley, 1967)


    Days on                     sec-butylamine in milk (mg/kg)
    Treated Feed        Control Animals          Treated Animals*

                        303     305              302     650

    0                   0.003   0.002            0.002   0.002

    0                   >0.10   0.006            0.27    0.016

    0                   0.012   0.16             0.32    0.30

    3                   0.003   0.002            2.54    1.94

    7                   0.010   0.081            2.58    1.20

    10                  0.003   0.006            1.27    1.72

    14                  0.023   0.017            0.65    1.42

    17                  0.047   0.037            1.51    2.08

    21                  0.031   0.043            0.81    1.07

    25                  0.050   0.030            0.86    1.46

    28                  0.016   0.023            0.91    1.28

    Mean                                         1.39    1.52

    Range               0.002 - 0.16             0.7  -  2.6


    * Cows received 100 ppm sec-butylamine in total diet equivalent
      to 1.6 g sec-butylamine/head/day.

        TABLE 2. sec-Butylamine feeding study residues in milk, tissues and fluids
    of lactating cows (Lilley, 1967)

                             mg/kg sec-butylamine found at dietary level of
    SAMPLE              0 ppm     2 ppm     5 ppm     10 ppm    20 ppm    100 ppm

    Milk                0.02      0.02      0.04      0.04      0.09      1.46
                        0.00-     0.01-     0.01-     0.01-     0.05-     0.65-
                        0.32      0.04      0.07      0.15      0.11      2.58

    Kidneya   Mean      0.01      0.06      -         0.23      -
              Range     <0.01     0.05-               0.18-               0.43,
                        0.021b    0.10                0.30                2.61

    Livera    Mean      0.02      <0.01     -         0.10
              Range     <0.01     <0.01-    -         0.04-               0.15,
                        0.031     0.02                0.14                0.19

    Lean      Mean      0.02      <0.01     -         0.03
    meata     Range     <0.01-    <0.01               0.01-               0.05,
                        0.05      0.01                0.06                0.07

    Fata      Mean      <0.01     <0.01     -         <0.01     -
              Range     0.00-     -                   -                   0.01,
                        0.03                                              0.03

    Urine     Mean      0.28      -         -         3.6                 72
              Range     <0.01-                        0.03-               16-
                        1.96                          15.2                179

    Blood     Mean      0.06      -         -         0.02      -         0.58
              Range     <0.01-                        0.01-               0.07-
                        0.63                          0.04                3.0

    Feces     Mean      0.04      -         -         0.11      -         0.23
              Range     <0.01-    -         -         0.01-               0.04-
                        0.85                          0.84                0.81

    a 7 samples at 0 ppm; 4 samples at 2 ppm; 3 samples at 10 ppm; 2 samples at 100 ppm.

    b One value of 0.198 omitted.

        TABLE 3. Residues in milk of cows fed sec-butylamine (Peoples, 1968)
                            sec-butylamine, mg/kg (mean values from multiple analyses)
    Days On                 Cow No.     cow No.     Cow No.     Cow No.
    Treated Feed*           1338        1340        1341        1342

    0                       0.002       0.001       0.003       0.003

    3                       0.33        0.45        0.29        0.32

    7                       0.46        0.59        0.34        0.39

    10                      0.44        0.57        0.26        0.38

    14                      0.36        0.35        0.35        0.31

    17                      0.42        0.47        0.26        0.34

    21                      0.24        0.47        0.21        0.14

    24                      0.35        0.38        0.31        0.16

    28                      0.12        0.65        0.16        0.12

    31                      0.54        0.45        0.35        Sample Lost

    34                      0.42        0.60        0.34        0.34

    Average all analyses    0.32        0.49        0.28        0.24

    Range all analyses      0.097-0.54  0.22-0.67   0.16-0.44   0.071-0.53

    * Cows received 16 ppm sec-butylamine in the total diet.

    In this experiment it was again observed that the major route of
    excretion was through the urinary system. Levels up to 37.1 mg/kg were
    found in the urine of treated animals and an average of 16 mg/kg was
    observed during the treatment period. The mean urine level of control
    animals was only 0.3 mg/kg.


    Following evaluation of this compound in 1975, the Joint Meeting
    considered that additional information was required before the
    temporary ADI and maximum residue limits could be confirmed. Some of
    this information was available to the Meeting.

    In spite of early indication that sec-butylamine was effective
    against a range of fungal organisms which are detrimental to a number
    of fruits and vegetables, there is no indication that it is being
    utilized commercially on fruits other than citrus on which there was a
    complete monograph in 1975. There has been limited use on potatoes for
    the control of gangrene and skin spot. Although it is known that
    significant residues remain no detailed information was available.
    There is no indication that these residues transfer into the tubers
    that develop when the treated seed is planted, but it would be
    desirable to have information on the level and fate of residues in
    edible potatoes treated before being stored.

    Cows receiving dried citrus pulp containing normal commercial residues
    and excessive dosages of sec-butylamine excreted most of the residue
    unchanged in the urine, but milk contained from 0.071 to 0.67 mg/kg of
    sec-butylamine residues (mean 0.33 mg/kg). There was no tendency for
    residues to accumulate as a result of repeated administration. Traces
    of sec-butylamine could be detected in muscle, blood and fat of cows
    slaughtered immediately at the end of a period of continuous ingestion
    of sec-butylamine residues. Significant residues (1-2.7 mg/kg) were
    found in kidney and lesser amounts (0.15-0.2 mg/kg) in liver.

    sec-Butylamine occurs naturally at concentrations up to 0.3 mg/kg in
    fresh milk and much higher in sour milk, together with significant
    quantities of other endogenous amines. Extensive isolation and
    purification procedures are required to separate, recover and measure
    residues of sec-butylamine resulting from the ingestion of feeds
    containing residues of the fungicide.

    It is considered that the information received fulfils the
    requirements listed in 1975 with the exception of certain specified
    toxicological information.


    The following temporary maximum residue limits are proposed to cover
    the residues resulting from the feeding of citrus pulp and citrus
    molasses containing sec-butylamine.

    Commodity                     Limit, mg/kg

    Edible offal                  2 mg/kg
    Milk and milk products        0.5 mg/kg
    Meat                          0.1 mg/kg


    Required (before 30 June 1978)

    Quantitative metabolic studies in animals.


    1. Mutagenicity studies with techniques currently available.

    2. Clinical observations in humans.

    3. Information on the level and fate of sec-butylamine residues on


    Eli Lilly & Company (1967) -- 2-aminobutane feeding study on lactating
    cows. VPR-107-741

    Day, E.W., Golab, T., and Koons, J.R. (1966) Determination of
    micro-quantities of C1-C4 primary and secondary amines by electron
    affinity detection. Analyt. Chem., 38:1053.

    FAO/WHO (1976) 1975 evaluations of some pesticide residues in food.
    AGP:1975/M/13; WHO Pesticide Residue Series No. 5.

    Peoples, S.A. (1968) Feeding study in lactating dairy cows using dried
    citrus pulp from 2-aminobutane treated oranges. -- Report from School
    of Veterinary Medicine -- University of California -- Davis.

    See Also:
       Toxicological Abbreviations
       Butylamine, sec- (WHO Pesticide Residues Series 5)
       Butylamine, sec- (Pesticide residues in food: 1978 evaluations)
       Butylamine, sec- (Pesticide residues in food: 1979 evaluations)
       Butylamine, sec- (Pesticide residues in food: 1980 evaluations)
       Butylamine, sec- (Pesticide residues in food: 1981 evaluations)