ETHYLHYDROXYETHYL CELLULOSE

    EXPLANATION

         This substance was considered at the twenty-seventh meeting of
    the Committee (Annex 1, reference 62). At that time, the Committee,
    after reviewing general data available on modified celluloses and some
    specific studies on ethylhydroxyethyl cellulose, decided to include it
    on a temporary basis, in the group ADI of 0-25 mg/kg b.w. for modified
    celluloses, pending the results of a 90-day feeding study by 1985.
    Because the study was known to be in progress, the Committee extended
    the temporary ADI for ethylhydroxyethyl cellulose to 1986 (Annex 1,
    reference 70).

    BIOLOGICAL DATA

    Biochemical aspects

         No information available.

    Toxicological studies

    Acute toxicity

         No information available.

    Short-term studies

    Rats

         Ethylhydroxyethyl cellulose was administered to Charles River CD
    rats (20 males and 20 females/group) by continuous dietary
    incorporation at dose levels of 0, 250, 1375, or 2500 mg/kg b.w./day
    for 90 consecutive days. All the animals were observed daily and all
    signs of toxicity or behavioural changes were recorded. Body weights
    and food consumption were recorded weekly. Ophthalmoscopy and
    haematology analyses were carried out prior to termination. After 90
    days of treatment the animals were killed and macroscopic examination
    was carried out on all tissues from animals in the control and
    high-dose groups. A statistically-significant (P < 0.01) increase in
    cumulative food consumption was recorded in male rats of the high-dose
    group throughout the study (weeks 1, 4, 8, and 12) and in female rats
    of the high-dose group (P < 0.05) at weeks 4, 8, and 12. The
    increased food consumption was considered to represent a compensation
    for the dietary inclusion of the test substance. A corresponding
    marginal decrease in the efficiency of food utilization was noted in
    rats of this treatment group throughout the study. After adjustment
    for final body weight, a small decrease in liver weight (P < 0.05)
    was apparent in male rats of the high-dose group in comparison with
    control values. No morphological changes in the livers of these rats
    were apparent on histological examination. In all other respects,
    including general health, body weight, ophthalmoscopy, haematology,
    biochemistry, and macroscopic and microscopic pathology, rats
    receiving ethylhydroxyethyl cellulose were similar to the controls
    (Elliot et al., 1985).

    Long-term studies

         No information available.

    Observations in man

         No information available.

    Comments

         The 90-day study provided sufficient information on the apparent
    lack of toxicity of ethylhydroxyethyl cellulose when fed at high
    dietary levels to permit the Committee to include it in the group ADI
    with modified celluloses.

    EVALUATION

    Estimate of acceptable daily intake for man

         0-25 mg/kg b.w. (group ADI for modified celluloses)

    REFERENCE

    Elliot, P.H., Smith, P.A., Street, A.E., Gibson, W.A., Begg, S.E.,
         Otter, J.M., & Shillam, K.W.G. (1985). The effects of continuous
         dietary administration of ethylhydroxyethyl cellulose to rats for
         ninety days. Unpublished report from Huntingdon Research Centre,
         Huntingdon, England. Submitted to WHO by Huntingdon Research
         Centre.
    

    See Also:
       Toxicological Abbreviations