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EC number: 237-410-6
CAS number: 13775-53-6
Bioaccumulation for cryolite is not to
be expected as the substance dissociates into various ions. Data is
available on uptake and metabolism of fluoride and aluminium ions. The
availability of inorganic substances for uptake may vary depending on
factors such as pH, hardness, temperature and redox conditions, all of
which may affect speciation. BCF values will therefore be influenced by
water chemistry. In general, only dissolved ions are potentially
available for direct uptake.
Several authors have studied the
bioaccumulation factor of aluminium in fish. Cleveland et al.
(1986) exposed brook trout (Salvelinus fontinalis) eggs, larvae
and juveniles to 300 µg/L total aluminium at three pH levels. At 30 days
post-hatch for larvae and for an exposure period of 30 days for
juveniles (37 to 67 days), significantly more aluminium was accumulated
at pH 5.28 than at either pH 7.24 or 4.44. Aluminium levels at pH 5.28
were 398 and 112 mg/kg for the larvae and juveniles, respectively. At pH
7.24 residues were 12 and 33 mg/kg, and at pH 4.44, 71 and 17 mg/kg,
respectively. The corresponding BCF values s were 1,327 and 373 L/kg at
pH 5.28, 40 and 110 L/kg at pH 7.24 and 237 and 57 L/kg at pH 4.44.
In another study Cleveland et al.
(1991) maintained brook trout in water containing 200 µg/L total
aluminium at pH values of 5.0, 6.0 and 7.2 for 56 days. Estimated steady
state bioconcentration factors for aluminium, which were inversely
related to pH, were 215 L/kg at pH 5.3, 123 L/kg at pH 6.1 and 36 L/kg
at pH 7.2. Elimination during the 28-day depuration phase was more rapid
at pH 5.3 than at pH 6.1 or 7.2.
Karlsson-Norrgren et al. (1986)
found that brown trout (Salmo trutta) accumulated significantly
more aluminium in gill tissue at pH 5.5 than at pH 7.0 (60-160 µg/kg and
10-40 µg/kg dry weight, respectively) when exposed to 200-500 µg total
aluminium/L. Skogheim et al. (1984) found a gill aluminium
accumulation of 70 to 341 µg/g fresh weight in dying Atlantic salmon (Salmo
salar) during an episodic fish kill in the river Ogna, Norway, at pH
5.4-5.5 and total aluminium and labile aluminium concentrations of 160
and 130 µg/L, respectively.
Segner et al. (1988) exposed
young brown trout (Salmo trutta) to total aluminium (230 µg/L) at
pH 5.0 in high calcium water at a temperature of 12°C for 5 days. Whole
body aluminium concentrations were 230 mg/kg dry weight in
aluminium-exposed fish, as compared to 75 mg/kg (pH 5.0) and 44 mg/kg
(pH 7.2) for fish in aluminium-free water.
Also the bioaccumulation of fluoride in
fish is extensively studied. In fish uptake occurs both in soft tissue
and bone. As in other vertebrates, a higher level is found in osseous
tissue than in muscles. Fish (Catla catla) exposed for 4 days to
an effluent containing 4, 7 or 13 mg/L contained 3, 4 and 9 times more
fluoride than control fish, respectively, on the basis of dry weights.
BCF values were similar: 53 to 58 L/kg dw (Pillai and Mane, 1985). BCF
for brown trout (Salmo trutta) were ≤2 L/kg ww after exposure for
1 week to 5, 10 or 20 mg/L (Wright, 1977). It is not clear whether or
not equilibrium levels were reached in these accumulation studies.
In an experimental marine mesocosm study
with fish, crustaceans and plants, F was found to accumulate in all
species. The highest value, 149 L/kg, was found in fish. BCF values for
crustaceans ranged from 27 to 62 L/kg, plants did not accumulate
fluoride (Hemens and Warwick, 1972).
As extensive data is available for the dissolved
ions that are potentially available for direct uptake, and which
do not indicate that cryolite would be bioaccumulative a BCF test on
cryolite itself does not seem necessary.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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