First draft prepared by
    Dr G.J.A. Speijers and Mrs M.E. van Apeldoorn
    National Institute of Public Health and Environmental Protection
    Laboratory for Toxicology
    Bilthoven, The Netherlands


         These substances were evaluated at the seventh and seventeenth
    meetings of the Committee (Annex 1, references 7 and 32). At the
    seventeenth meeting, an ADI of 0-50 mg/kg bw was established. Since
    these evaluations, additional data have become available and were
    reviewed by the Committee at its present meeting.

         Alginate solutions of different viscosities are used as texture
    modifiers in a wide variety of food and industrial applications.


    2.1  Biochemical aspects

    2.1.1  Absorption, distribution and excretion

         14C-Labelled alginates were fed as 10% of the diet to
    10-week-old rats that had been starved for 24 h; and the subsequent
    metabolism over a 17 h period was measured. Eighty-five to
    ninety-one % of the radioactivity was recovered in the faeces.
    Recoveries of administered 14C in urine (0.11-0.16%), respiratory
    CO2 (0.21-0.42%), and plasma (0.002-0.007%), show that alginate
    absorption under these conditions of feeding is extremely small
    (Humphreys & Triffitt, 1968).

         From the clinical experiments reported it appears that alginic
    acid does not bind sodium in man to any great extent (Feldman
     et al., 1952; Gill & Duncan, 1952).

         The absorption of orally administered riboflavin-5'-phosphate
    by healthy male subjects was increased significantly when the
    vitamin was administered in 50 ml of 2% alginate solution rather
    than water alone (Levy & Rao, 1972).

    2.2  Toxicological studies

    2.2.1  Acute toxicity

        Table 1. Acute toxicity of alginic acid and its salts

    Compound          Animal     Route       LD50                 References
                                            (mg/kg bw)

    Alginic acid      rat        i.p.       1600                  Thienes et al.,

    Sodium            mouse      i.v.       less than 200         Solandt, 1941

    Sodium            mouse      i.p.       LDLO 500              Arora et al.,
    alginate                                                      1968

    Sodium            rat        oral       >5000                 Woodward
    alginate                                                      Research Corp.

    Sodium            rat        i.v.       1000                  Sokov, 1970

    Sodium            rabbit     i.v.       approx. 100           Solandt, 1941

    Sodium            cat        i.p.       approx. 250           Chenoweth, 1948

    Calcium           rat        i.v.       64                    Sokov, 1970

    Calcium           rat        i.p.       1407                  Sokov, 1970
         Subcutaneous and intramuscular injections of 0.1 ml of a 1%
    dispersion of alginic acid were not followed by any injurious
    reactions in mice or rats (Chenoweth, 1948).

    2.2.2  Short-term studies  Rats

         Potassium alginate at a level of 5% in the feed acted as a
    laxative; calcium alginate 5% was without this effect (Thienes
     et al., 1957).

         Groups of 4 male and 4 female Charles river CD rats were fed a
    control diet or a diet with 10% sodium alginate at the expense of
    starch for 12 days. Faecal lipids were increased 5 times in the
    alginate group. Total blood cholesterol was decreased but not
    significantly. Total faecal sterols were somewhat increased (Mokady,

         When male Sprague-Dawley rats (5-7/group) received for 2 or 4
    weeks a non-fibre diet in which 5% sucrose was substituted by 5%
    sodium alginate, pancreatic-bile secretion was elevated. When
    alginic acid or calcium alginate was fed, no effect on pancreatic
    and biliary secretion was observed (Ikegami  et al., 1989).

         Groups of ten 21-day old male Wistar rats received a diet with
    10% casein or 10% soybean proteins with 0, 0.5, 1, 2 or 3% sodium
    alginate for 4 weeks. Sodium alginate had no effect on the protein
    efficiency ratio (Mouecoucou  et al., 1990).

         Groups of 5 rats were fed 5%, 10% or 20% of alginic acid in the
    diet for two months. Rats on the 20% diet showed a decreased food
    consumption and weight gain. Those on lower levels were unaffected
    (Thienes  et al., 1957).

         Groups of 6 rats were fed sodium alginate for 10 weeks at
    levels of 5%, 10%, 20% and 30% in the diet. The mortality rate was
    high in the 20% and 30% groups during the first two weeks,
    apparently due to inanition. Ten per cent or 5% in the diet had no
    effect on longevity. The weight gain of the 10% group was slightly
    decreased. Five per cent had no effect on weight gain (Nilson &
    Wagner, 1951).

         Groups of 10 male and 10 female Wistar rats (bw 46.0-47.3 g)
    received for 4 or 13 weeks 0, 0, 5, 15 or 45% low viscosity sodium
    alginate in their diet. Body weights were recorded weekly. Food
    consumption was determined at weeks 1-4 and weeks 12-13. During the
    first week faeces were collected. Appearance of faeces was judged at
    intervals during 90 days. After 4 weeks one control group and the 5
    and 45% groups were discarded. At week 13 haematology (Hb, Ht, Er,
    Leu, Diff) in all rats was carried out. In week 14 all rats were
    killed, relative organ weights were determined, macroscopy and
    microscopy (approximately 25 tissues) in all rats were carried out.

    In the first weeks rats on 45% sodium alginate showed abnormal hair
    loss resulting in practically complete baldness. Heavy diarrhoea was
    seen in the 45% group in the initial phase of the study. In the 15%
    group only slightly abnormal faeces were produced during the first
    weeks. In the 45% group considerable growth retardation was
    observed. At the 15% level growth was normal. In the final 2 weeks
    of the study the batch of sodium alginate had to be replaced by
    another sample. The feeding of the new material caused a sharp drop
    in body weight followed by a recovery which had not yet been
    completed at the end of week 12. Low food intake in the 15% group in
    the final week of the study is ascribed to the change of the test
    batch. The amount of faeces produced per 100 g of food consumed was
    considerably increased in rats fed sodium alginate. Haematology did
    not show abormalities. A significantly increased weight of the
    caecum, both filled and empty, was seen in the 15% sodium alginate
    group. Macroscopy showed enlarged, distended, heavy caeca.
    Histopathology revealed thickened urothelium with papillomatous
    appearance in the urinary bladder of 6/10 male and 3/10 female rats
    on 15% sodium alginate. Small calcium deposits under the sometimes
    thickened urothelium of the renal pelvis and/or under the surface of
    the renal papilla were seen in 6/10 male and 2/10 female rats on 15%
    sodium alginate. These changes were not seen in the control group
    (Feron  et al., 1967).  Guinea-pigs

         Two groups of five adult male albino guinea-pigs were given 1%
    sodium alginate in their drinking water for 10 weeks. A further four
    groups of six animals were used for a seven-month study. No ill
    effects were observed and no colon ulceration occurred (Watt &
    Marcus, 1972).  Dogs

         Groups of each six beagle dogs (equally divided by sex), were
    maintained on diets containing 0, 5 or 15% sodium alginate for one
    year. Weight gain, behaviour, appearance, periodic blood values,
    terminal urinalysis, blood urea nitrogen, blood glucose and serum
    alkaline phosphatase were within normal limits. Gross autopsy and
    histopathologic examination of tissues revealed no compound-related
    effects (Woodard Research Corp., 1959).

    2.2.3  Long-term/carcinogenicity studies  Mice

         Groups of 75 male and 75 female Swiss mice (age 6 weeks)
    received for 89 weeks a control diet or a diet containing sodium
    alginate at a dose level gradually increasing to 25% (week 39).
    Sodium alginate was incorporated into the control diet at the

    expense of equal amounts of the precooked control starch. The mice
    were observed daily for condition, behaviour and the appearance of
    faeces. Body weights were recorded at weeks 1, 2 and 4 and once
    every 4 weeks thereafter. Water intake was measured in at least 5
    animals/sex/group in week 87. Haematology was performed in 10
    animals/sex/group in weeks 40 and 78. Blood glucose and
    urea-nitrogen levels were determined in 10 animals/sex/group in
    weeks 78 and 86 after overnight fasting. Urinalysis was conducted in
    at least 5 males/group and 8 females/group in weeks 82 and 86,
    respectively. In week 87 half of the surviving male and female
    animals in the treated group were placed on control diet and 2-5
    weeks later urinalysis was performed in 6-8 males. The pH of faeces
    was measured in 4-5 males/group in weeks 82 and 85. In week 80, 10
    animals/sex/group and in weeks 89-92, all surviving animals were
    killed, organ weights were determined and macroscopy and microscopy
    were carried out.

         In the male control group between weeks 39 and 65, and in the
    male alginate group during the last six months, high mortality
    occurred due to haemorrhagic myocarditis. This phenomenon is not
    uncommon in this strain of mouse. Mean body weights in the alginate
    group were decreased from week 8 onwards in males and from week 20
    onwards in females. Alginate was nephrotoxic to mice as shown by
    extremely high water consumption (5-10 times control value), high
    urine production, urinary incontinence (8 males and 2 females), high
    pH and low specific gravity of the urine, increased level of blood
    urea nitrogen, increased kidney weights, distension of renal calyx
    and a high incidence of dilated distal tubules. Furthermore caecal
    and colonic enlargement and urinary changes were seen, but these
    changes appeared to be reversible and had completely or largely
    disappeared within 2-5 weeks after cessation of treatment in week
    87. The incidence of intratubular calcinosis or of concretions in
    the pelvic space was not reduced during the recovery period. In mice
    no renal pelvic calcification accompanied by hyperplasia of the
    papillary and pelvic epithelium, as seen in rats fed 15% sodium
    alginate in their diet, was observed. Probably the high water
    consumption together with the high production of urine with a low
    specific gravity prevented formation and deposition of calcareous
    concretions in the pelvic space of the kidneys of the mice on 25%
    sodium alginate. Furthermore, in mice no hyperplasia of the
    epithelium of the urinary bladder, as was seen in rats on 15% sodium
    alginate, was observed. No indication for a carcinogenic activity of
    sodium alginate in mice was seen (Til  et al., 1986).

         Infant albino mice (ICR/HA strain) were injected subcutaneously
    in the nape of the neck with suspensions of alginic acid (10 and
    100 mg/ml) or solvent alone in volumes of 0.1, 0.1, 0.2, and 0.2 ml
    on days 1, 7, 14, and 21 respectively after birth (so total dose in
    the two test groups was 6 and 60 mg alginic acid, respectively), and

    maintained on normal diets for 49 to 53 weeks. The initial number of
    mice was 170, 20 and 79, respectively, in the solvent control group,
    the 6 mg group and the 60 mg group. Tumour frequency fell within
    control ranges. At 21 days 16 out of 20 mice in the 6 mg group and
    16 out of 79 mice in the 60 mg group were alive, whereas in the
    solvent control group 147 out of 170 animals were alive. At week 49,
    10 out of 20 mice in the 6 mg group and only 11 out of 79 mice in
    the 60 mg group were alive, whereas in the solvent control group 118
    out of 170 animals were alive. Due to the limited number of animals
    in the lowest dosage group, the low number of survivors in the
    highest dosage group and the short duration of the experiment, the
    study is considered to be inappropriate for evaluation of a possible
    carcinogenic effect of alginic acid (Epstein  et al., 1970).  Rats

         Two groups of 10 male albino rats were fed two different
    commercial preparations of sodium alginate at the 5% level over
    their lifespan (maximum 128 weeks). Data on longevity, maximum
    weight and food and water consumption indicate no adverse effect.
    Gross necropsy studies revealed no abnormalities. Histopathological
    examination was not carried out (Nilson & Wagner, 1951).

    2.2.4  Reproduction studies  Rats

         Groups of 40 rats (equally divided by sex) were maintained on
    diets containing 0 or 5% sodium alginate for a period of two years.
    During this period approximately half the rats were bred once to
    produce an F1-generation, which was subsequently bred to produce
    an F2-generation. There were no significant differences in growth
    rate of test groups and controls, for either the parent group over
    the two-year period or the progeny (F1 and F2). Reproductive
    performance was normal. Haematological values of the parent group,
    as well as those of the F2 offspring, were normal. Gross and
    microscopic study of various tissues and organs of the parent groups
    at two years, and of the F1 and F2 groups at the conclusion of
    the rapid growth period, were normal (Morgan  et al., undated).

    2.2.5  Special studies on genotoxicity

        Table 2. Results of genotoxicity assays on sodium alginate

    Test system      Test object          Dose-levels       Results        References

    Ames test        Salmonella           up to 10          negative1      Isidate et
                     typhimurium          mg/plate                         al., 1984

    Chromosomal      Chinese hamster      up to 10          negative2      Isidate et
    aberrations      lung cells           mg/ml                            al., 1984
                     (CHL cells)

    Chromosomal      Chinese hamster      1, 50, 100        negative2      Larripa et
    aberrations      ovary cells          µg/per ml                        al., 1987

    Dominant         ICr/Ha Swiss         i.p. 82,          negative3      Epstein et
    lethal assay     mice                 200, 1000                        al., 1972
                                          mg/kg bw

    1    Assay with metabolic activation.
    2    Assay without metabolic activation.
    3    Test compound alginic acid.
    2.2.6  Special studies on immunotoxicity  Mice

         Four mice received an injection with 100 µg of sodium alginate
    (derived from  Mycrocystis pyriforma) 4 days before and at the day
    of inoculation with sheep red blood cells. Mice were bled 7 days
    after inoculation and serum was assayed for antibodies against sheep
    red blood cells by haemagglutination. Sodium alginate caused a
    significant increase in haemagglutination titer. However when the
    test was repeated the result was negative (Mayer  et al., 1987).

    2.2.7  Special studies on tumour inhibition  Rats

         Two groups of 10 male Spague-Dawley rats (age 5 weeks) received
    weekly for 12 weeks a s.c. injection with a solution of
    dimethylhydrazine (DMH) (dose 20 mg DMH/kg bw adjusted to pH 7 with
    sodium bicarbonate). One group received a basal diet while the
    second group received 1.5% sodium alginate (crude) in their diet

    during the 12 weeks of DMH treatment. The experiment was terminated
    8 weeks after the treatment period. Sodium alginate appeared to
    exert an inhibitory effect on the development of intestinal tumours
    resulting from DMH (Yamamoto & Maruyama, 1985).

    2.2.8  Special investigations on the interference of alginate
           with minerals

         Two groups of 12 male weanling Sprague-Dawley rats received a
    control diet or a diet with 10% Na-alginate, at the expense of corn
    starch, for 8 days. A marked increase in faecal dry matter was seen
    in the alginate group. Ca and Zn absorption were not affected by
    alginate. Absorption of Fe, Cr, and Co were significantly reduced in
    the alginate group (Harmut-Hoene & Schelenz, 1980).  Interference with Cd and Pb

         In vitro

         Equilibrium dialysis experiments were carried out in solutions
    containing varying concentrations of either Cd (as Cd(OH)2) in
    saline or Pb (as lead acetate) in water with or without the addition
    of 1 g alginic acid/100 ml. Equilibration lasted for a minimum of
    24 h at room temperature. The extent of the binding by alginate
    increased as metal concentration increased. At concentrations of 10
    and 50 µg Pb/L, 0.7 and 5 mg Pb, respectively, was bound per g
    alginic acid. At concentrations of 0.01, 0.1, 5 and 10 µg Cd/L 0.09,
    0.4, 2.1 and 7.5 mg Cd, respectively, were bound to 1 g alginic acid
    (Rose & Quarterman, 1987).


         A group of 6 male rats received for 4 weeks a diet supplemented
    with 200 mg Pb/kg (as lead acetate) together with 5 mg Cd/kg (as
    cadmium hydroxide). Furthermore, 40 g alginic acid/kg of diet was
    added. A control group of 10 male rats received the Pb/Cd
    supplemented diet without the addition of alginic acid. Deposition
    of Pb and Cd in liver, kidneys and femur was measured. A reduction
    of growth was seen in the alginic acid group. Alginic acid had no
    effect upon Cd deposition, but Pb content in femur and kidneys was

         Five groups of 6 male rats received 0, 1, 5, 10 or 40 g alginic
    acid in their diet for 4 days. On the third day all rats received by
    stomach tube 0.2 ml saline containing 2 µg radioactive Pb. On day 4
    the rats were killed and radioactivity in blood, duodenal mucosa,
    liver, kidney and gut-free carcass was measured. Pb retention was
    already increased at 1 g alginic acid/kg of diet (Rose & Quarterman,


         In a limited trial with 3 human volunteers, the absorption of
    203Pb was unchanged by alginate supplement (Harrison  et al.,
    1969).  Interference with radium


         Male mice (C57 Black, age 3 months) given a single i.p.
    injection with 226RaCl2 and fed from day 3 thereafter with bread
    containing 10% sodium alginate (intake Na-alginate was 13 g/kg bw)
    showed a reduction of the 226Ra content in the femur without
    decalcification. The amount of 226Ra decorporated was independent
    of the dose of 226Ra injected i.p. 226Ra content of blood was
    doubled and 226Ra content of faeces showed a 60% increase. Urinary
    level of 226Ra was not changed significantly (Kestens  et al.,

         Mice (BALB/c, age 3 months), given bread with 6% sodium
    alginate 2 h before oral administration (by gavage) of 226RaCl2,
    revealed a more than 100 times reduction of Ra uptake (measured in
    whole body). In the same experiment 47Ca uptake was only 1.2 times
    less than in controls (Vanderborght  et al., 1971).  Interference with strontium

         Humans and animals

         Several experiments in humans and animals which demonstrated a
    reduction of Sr uptake when Sr isotopes were administered very early
    before or together with alginate, in the majority of the cases via
    the oral route. In animals reductions of Sr intake of 1.2 to 10-fold
    were measured. The radioactive Sr isotopes were determined in
    carcass, skeleton, femur or whole body. In humans reductions in Sr
    uptake of 1.6 to 24--fold were reported. Radioactive Sr isotopes
    were measured in whole body or plasma (Vanderborght  et al. 1971).


         Male C57 Black mice (which had been contaminated with 85Sr
    3 weeks previously) were fed a dough containing 5% sodium alginate
    showed an increased 85Sr content of the blood (Vanderborght
     et al., 1971). It was hypothesized that the increased 85Sr
    content in blood was due to a shift in Sr-equilibria between
    intestinal lumen, blood and the skeleton (Van Barneveld  et al.,

         Simultaneous i.p. and oral (via a diet with starch containing
    dough) treatment of male Black mice with sodium alginate which had
    been contaminated with 85Sr 9 weeks previously, resulted in a
    5-fold increase of the blood content of 85Sr. 85Sr content of
    liver, kidney and spleen is increased 4-6 times by this combined
    treatment. Urinary and faecal excretion of 85Sr were increased 1.2
    and 1.8 times, respectively. Treatment with dietary alginate only
    caused a 2.5-fold rise in blood 85Sr content, 1.5-2 times
    increases of 85Sr contents in liver, spleen and kidney, a 2.1
    times rise in faecal excretion of 85Sr and urinary excretion was
    somewhat lowered. I.p. treatment with alginate only resulted in a
    2.3-fold increase in blood 85Sr content, 2.3-3.6-fold increases of
    85Sr contents of liver, spleen and kidney and a 1.7-fold increase
    in urinary 85Sr excretion, while faecal excretion was not changed.
    The biological half-life of Sr is about halved by the treatment with
    alginate via the diet together with i.p. alginate injection.
    Treatment with alginate via the diet only will speed decorporation
    of Sr from skeleton by about 40% (Vanderborght  et al., 1978).  Interference with calcium


         Rats received diets supplemented with calcium and phosphate
    with and without 10% sodium alginate. No effect on the absorption
    and skeletal retention of calcium was observed (Slat
     et al., 1971).


         Calcium balance experiments on six healthy adults taking 8 g of
    sodium alginate daily for seven days failed to show any interference
    with the absorption of calcium from a normal mixed diet (Millis &
    Reed, 1947).

         In 14 out of 15 men receiving 1.5 g sodium alginate the
    gastrointestinal content of strontium was reduced by a factor of two
    while calcium absorption was hardly affected (Harrison  et al.,

         The absorption and retention of 47Ca and 85Sr was compared
    for four human volunteers on a normal diet with and without sodium
    alginate supplement. Fifteen to twenty grams alginate/day was given
    for seven days. Alginate decreased the retention of 85Sr and
    47Ca by about 70 and 7%, respectively. No changes in excretion
    pattern of Na, K, Mg or P were observed (Carr  et al., 1968).  Interference with barium


         Rats were fed diets with 10% alginate (3 different types). At
    day 3 or 4 on diet the animals received an oral, i.p. or s.c. dose
    of 133Ba. The retention of barium in the carcass after oral
    administration was reduced 4 to 8 times with the different types of
    alginate. Four days after parenteral administration of radiolabelled
    barium, the barium content of the carcass was 5-12% lower than in
    controls accompanied by a small increase in faecal excretion of the
    marker (Sutton  et al., 1972).

    2.2.9  Observations in humans

         Six healthy adults were given 8 g of sodium alginate daily for
    seven days without untoward effects (Millis & Reed, 1947).

         Three patients whose clinical condition warranted sodium
    restriction were given oral doses of 15 g of alginic acid three
    times daily for seven days. A slightly increased faecal sodium and
    potassium excretion was noted, but no changes in plasma electrolyte
    concentration (Feldman  et al., 1952).

         Six patients with essential hypertension were given daily doses
    of 45 g of alginic acid containing 10% of potassium alginate for
    five to nine weeks and three patients in an oedematous state were
    given the same dosage for about a week. It was well tolerated and
    produced no gastrointestinal disturbance (Gill & Duncan, 1952).

         Five healthy male volunteers received 175 mg sodium alginate/kg
    bw/day for 7 days, followed by 200 mg/kg bw for a further 16 days.
    The daily doses were consumed in three measured portions at
    intervals each day. The portions were prepared by adding the weighed
    aliquots of sodium alginate by rapid stirring to 220 ml cold
    distilled water. The hydrocolloid was then allowed to hydrate for
    24 h to a thick, but fluid gel to which each volunteer added a
    predetermined amount of orange juice prior to consumption. The
    treatment period was preceded by a 7 day initial control period
    during which a daily amount of orange juice, equal to that to be
    taken later, was consumed. During the treatment period enquiries
    were made with respect to apparent allergic responses. At day 3 of
    the initial control period, on the last day of the 23 day treatment
    period and on the last day of the 7 day recovery period the
    following parameters were examined; fasting blood glucose, plasma
    insulin, breath hydrogen concentrations, haematological parameters
    (Hb, Ht, MCV, MCH, MCHC, Er, Leu, Diff, platelets) and biochemical
    parameters (Na, Cl, K, CO2, urea, LDH, AST, bilirubin, alk.

    phosphatase, phosphate, Ca, protein, albumin, creatinine, urate,
    lipids, cholesterol, HDL cholesterol and triglycerides). Routine
    urinalysis was carried out during the initial control week and
    during the third week of treatment. Five day faecal collections were
    made during days 2-6 of the initial control period and during days
    16-20 of the treatment period. Faecal transit time, wet weight, dry
    weight, water content, pH, occult blood, neutral sterols, fat,
    volatile fatty acids and bile acids in faeces were determined. No
    allergic reactions were reported nor observed. Sodium alginate acted
    as a bulking agent of moderate efficiency as indicated by a
    significant increase in faecal dry and wet weight and an increase in
    water content of faeces without a significant change in transit
    time. Faecal pH remained normal. Total faecal volatile acids
    increased in four volunteers but decreased in one. No changes in
    faecal total and individual neutral sterols or in total and
    individual bile acids were seen. Haematological, biochemical and
    urinalysis parameters did not show significant changes with the
    exception of some parameters of one volunteer who suffered from
    influenza (Anderson  et al., 1991).

         Two-hundred-and-eight workers who are exposed to dust from
    dried milled seaweed and pure alginate compounds in an alginate
    factory were examined for pulmonary hypersensitivity. Fifteen out of
    these 208 workers showed symptoms definitely related to dust
    exposure at work. Serological tests showed that 8 of the 15 workers
    with definite symptoms and one worker without definite symptoms had
    precipitating antibodies to prepared extracts in their serum.

         Chest X-rays of these 16 workers were normal. Twelve workers
    with either evidence of work related respiratory symptoms or
    precipitating antibodies in their serum or both (3 out of 12) were
    exposed to an atmosphere artificially contaminated with raw seaweed
    dust for a maximum of one hour. Measurements of pulmonary function
    were made before, immediately after, and 1, 3, 5 and 24 h after
    exposure. A significant reversible deterioration in pulmonary
    function was seen as shown by an acute and sometimes severe airway
    obstruction, followed by a delayed loss of lung volume with
    reduction in transfer factor (Henderson  et al., 1984).


         Three limited long-term dietary studies, one in mice and two in
    rats, provided no indication of a carcinogenic effect of alginates.
    Neiher an  in vitro nor an  in vivo genotoxicity study showed any
    genotoxic activity. No effects on the reproduction of rats were
    observed, but the experimental design of the study was limited. A
    long-term study in mice using only a single dose level of 25% sodium
    alginate in the diet showed a clear effect (soft stool, distended
    caecum, decreased growth and deposition of calcium in the pelvis of
    the kidney).

         In a 90-day study in rats, 15% sodium alginate in the diet
    resulted in an enlarged, distended, heavy caecum, a papillomatous
    appearance in the urinary bladder and calcium deposits in the renal
    pelvis and/or renal papilla. A slight decrease in growth was seen in
    only one short-term experiment with rats at the 10% level, but the
    effects were not specific and were also seen with other poorly
    absorbed compounds. Recent studies have shown slight interference
    with the absorption of a number of minerals.


         The Committee recalled the similar effects of poorly absorbed
    compounds (modified celluloses, polyalcohols, gums, modified
    starches) reviewed in Section 2.2.3 of the report of the
    thirty-fifth meeting (Annex 1, reference 88); for such compounds an
    ADI "not specified" usually had been allocated. The Committee
    therefore allocated a group ADI "not specified" to alginic acid and
    its ammonium, calcium, potassium and sodium salts, but pointed out
    (as it had for other compounds causing this effect) that laxative
    effects might occur at a high level of intake.

         Propyleneglycol alginate was evaluated at the Committee's
    seventeenth meeting (Annex 1, reference 32) when an ADI of
    0-25 mg/kg bw was allocated. It was not re-evaluaed at the present


    Dietary effects of sodium alginate in humans.  Food Add. Contam.,
    8: 237-248.

    ARORA, C.K., CHAUDHURRY, S.K. & CHAUHAN, P.S. (1968) Sodium-alginate
    toxicity in mice.  Indian J. Physiol. Pharmacol., 12: 129-130.

    Reduction in the absorption and retention of dietary strontium in
    man by alginate.  Int. J. Radiol. Biol., 14: 225.

    CHENOWETH, M.B. (1948) Toxicity of sodium alginate in rats.  Ann.
     Surg., 127: 1173.

    EPSTEIN, S.S., FUJII, K., ANDREA, J. & MANTEL, N. (1970)
    Carcinogenicity testing of selected food additives by parenteral.
     Tox. Appl. Pharmacol., 16: 321-334.

    EPSTEIN, S.S, ARNOLD, E., ANDREA, J., BASS, W. & BISHOP, Y. (1972)
    Detection of chemical mutagens by the dominant lethal assay in the
    mouse.  Tox. Appl. Pharmacol., 23: 288-325.

    A.A. (1952) Cation adsorption by alginic acid in humans.  Proc. Soc.
     Exp. Biol. Med., 79: 439-441.

    FERON, V.J., TIL, H.P. & GROOT, A.P. DE (1967) Unpublished Report of
    the Central Institute for Nutrition and Food Research TNO, Zeist,
    The Netherlands to Kon. Scholten-Honig N.V. (Foxhol) and
    AVEBE-D.W.M. (Veendam). Report R2456. Sub-chronic toxicity test with
    a modified potato starch (propylene oxide) and an alginate in albino
    rats. July 1967.

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    See Also:
       Toxicological Abbreviations
       Alginic acid and its ammonium, calcium, potassium and sodium salts (WHO Food Additives Series 5)