All doses greater than 450 µg/mL with and without activation were
toxic, as is evident by the relative total growth of 38% or less. Sodium
fluoride was not mutagenic at the HGPRT locus of Chinese hamster ovary
cells.

870.5300

In Vitro mammalian cell gene mutation test

Purity = 99.99%

Tong et al. (1988). The Lack of Genotoxicity of Sodium Fluoride in a
Battery of Cellular Tests. Cell Biology and Toxicology 4.2:173-186.

Open Literature

ARL 1 (rat liver epithelial cell line) were exposed to sodium fluoride
for 72 hours.

2, 10, 20, 40, 80, or 160 µg/mL

NEGATIVE

The higher doses (80 and 160 µg/mL) were toxic and were not analyzed
for gene mutatins. Sodium fluoride at doses up to 40 µg/mL did not
result in any significant increase in TGR mutants above the control.
Sodium fluoride was not mutagenic at the HGPRT locus.

870.5300

In Vitro mammalian cell gene mutation test

Purity not reported

Toxicology and Carcinogenesis Studies of Sodium Fluoride (CAS No.
7681-49-4) in F344/N Rats and B6C3F1 Mice (Drinking Water Studies).
National Toxicology Program, Technical Report Series No. 393, NIH
Publication No. 91-2848, December 1990, Pgs. 1-477.

Acceptable

Guideline

Trifluorothymidine (TFT)-resistant cells at the thymidine kinase (TK)
locus exposed to sodium fluoride in lymphoma L5178Y cells cultured in
vitro in either distilled water or culture medium for 4 hours at
concentrations ranging from 50 to 600 µg/mL in the presence of
mammalian metabolic activation (S9 derived from Aroclor 1254-induced
Fischer 344 male rats) and from 50 to 1000 µg/mL in the absence of
metabolic activation.

POSITIVE

There was evidence of a concentration related positive response of
induced mutant colonies over background.

Sodium fluoride was tested up to cytotoxic concentrations (the maximum
dose tested was 1000 µg/mL in one laboratory and 800 µg/mL in
another).  Mutant frequencies increased in a dose-related manner.
Statistically significant (p<0.05) responses were observed in all
trials, ±S9, at the high doses.  Mutant fractions (vs. the solvent
control response) at the highest doses tested in each trial were
reported to be 83.0x10-6 vs. 29.5x10-6, 41.3x10-6 vs. 24.3x10-6,
134.0x10-6 vs. 58.0x10-6, and 195.5x10-6 vs. 51.0x10-6 in cultures
tested in the absence of metabolic activation, and 94.0x10-6 vs.
25.8x10-6 and 75.7x10-6 vs. 33.0x10-6 in cells tested in the presence of
metabolic activation.

870.5375

In Vitro mammalian chromosome aberration test

Purity not reported

Aardema MJ, et al.  (1989). Sodium Fluoride-Induced Chromosome
Aberrations in Different Stages of the Cell Cycle: A Proposed Mechanism.
 Mutation Research 223:191-203.

Open Literature

Cells were exposed to 465, 650, 911, 1276, or 1786 ug/mL NaF for 4
hours, +/- S9 for 8 or 20 hours of incubation.

In separate experiments, cells were exposed to 100 ug/mL of sodium
fluoride for 1 or 2 hours or concentrations of 0.1, 1.0, 10, 25, 50, 75,
and 100 ug/mL for 3 hours

POSITIVE

A high level of toxicity was observed at 1786 go/mL (high-dose) that
limited chromosome aberration analysis to the lower dose groups.  There
was an increase in average cell generation time (AGT) as the
concentration of sodium fluoride increased; indicating a
treatment-related cell-cycle delay.  At 20 hours after treatment,
greater than 50% of the cells were in their first mitosis at 911 and
1276 go/mL +/-S9 and at 465 and 650 go/mL +S9.

Overall, there was a significant increase in the percentage of aberrant
cells in sodium fluoride treated groups at the 8 and 20 hour
post-treatment harvesting of cells.  There were 4.5- and 3.5-fold
increases in the percentage of aberrant cells, at the 8 hour harvest
time, in the 465 and 911 go/mL dose group, respectively, in the absence
of metabolic activation.  In the presence of S9, the 465, 650, and 1276
go/mL dose groups exhibited 6.3-, 3.7-, and 5.0-fold increases,
respectively, in the number of aberrant cells.  In the 20 hour
harvesting assay there was only one significant increase in the number
aberrant cells; a 6.5-fold increase at the 1276 go/mL sodium fluoride in
the presence of metabolic activation.  In both harvest (8 or 20 hours)
the aberrations were almost exclusively chromatid-type deletions and
gaps.

There was evidence of endoreduplicated cells observed in the chromosome
aberration screening assay.  At the 465, 650, 911, and 1276 go/mL dose
levels, the percentages of endoreduplicated cells were 2, 3, 5, and 11%
for -S9 and 4, 12, 15, and 14% for +S9, respectively.  These cells all
had an M0/M1 staining pattern indicating they had gone through 0 or 1
round of DNA synthesis.  Endoreduplicated cells were also observed in
the CHO 8 and 20 hour harvest time assays.  At the

 8 hour timepoint in the absence of metabolic activation there was a 6%
increase in endoreduplicated cells with the 1276 go/mL dose of sodium
fluoride.  There were endoreduplicated cell increases of 6, 16, and 22%
in -S9 and 28, 26, and 34% in +S9 at the 20 hour harvest time point for
the sodium fluoride concentrations of 650, 911, and 1276  go/mL,
respectively.

In separate experiments cells were exposed to 100 go/mL of sodium
fluoride for 1 or 2 hours or concentrations of 0.1, 1.0, 10, 25, 50, 75,
and 100 go/mL for 3 hours.  There were no significant changes from
control in chromosome aberrations until the 3 hour incubation assay.
Sodium fluoride at doses greater than 10 go/mL induced increases in the
percentage of aberrant cells that were significant at concentrations
greater than or equal to 50 go/mL.  The types of aberrations were
chromatid deletions, isochromatid deletions, and a large number of gaps
but not chromatid exchanges.In this CHO assay, cell-cycle kinetic
studies indicated that aberrations were induced in cells exposed to
sodium fluoride at the 20 hour harvest time (G1/S phase) but the
increases in aberrant cells were greater at the 8 hour time point where
most of the metaphases were from cells exposed to sodium fluoride in the
G2 stage of the cell cycle.  This sensitivity of the G2 cells was
evident in the 3 hour exposure assay with increases in aberrant cells at
concentrations greaterthan 10 go/mL; concentrations that are relatively
much greater than levels present in water or dentifrices.  The
researchers suggest that the level of sodium fluoride-induced
mutagenicity is dependent on both the cell-cycle stage that cells are in
during exposure and the length of time until harvest.  Sodium fluoride
induced positive mutagenic results in CHO cells at concentrations
greater than or equal 50 go/mL when exposed for 3 hours in the presence
and absence of metabolic activation.  However, longer exposure times (8
or 20 hours) required greater concentrations of sodium fluoride (greater
than or equal to 465 go/mL) to achieve mutagenic results.

870.5375

In Vitro mammalian chromosome aberration test

Purity not reported

Albanese.  (1987). Sodium Fluoride and Chromosome Damage (In Vitro Human
Lymphocyte and In Vivo Micronucleus Assays).  Mutagenesis 2:497-499.

Open Literature

Cells were exposed to 20 or 40 ug/mL NaF for 28 or 2 hours, +/-S9

POSITIVE

Sodium fluoride was mutagenic in human peripheral blood lymphocytes in
both the presence and absence of metabolic activation.  However,
mutagenicity appeared to be dependent on exposure time and
concentration.  There were significant dose-dependent increases in
chromosome aberrations in the experiment without metabolic activation;
with 6- and 18-fold increases in total number of damaged cells at the 20
and 40 go/mL dose levels, respectively, after 28 hours of incubation.
In the presence of metabolic activation, there was a significant
2.5-fold increase in total number of damaged cells over control at the
40 go/mL dose level, after 2 hours of incubation.  The chromosome
aberrations observed following the administration of sodium fluoride
were predominantly gaps, breaks, and fragments.  No exchange-type
aberrations (the type thought to correlate better with the carcinogenic
potential of chemicals) were found at any dose level or exposure period.

870.5375

In Vitro mammalian chromosome aberration test

Purity not reported

Khalil.  (1995). Chromosome Aberrations in Cultured Rat Bone Marrow
Cells Treated with Inorganic Fluorides.  Mutation Research 343:67-74.

Open Literature

Bone marrow cells of Sprague-Dawley rats

0.1, 1.0, 10 or 100 uM for 12, 24, or 36 hours of incubation

experiments performed in quadruplicate/dose

POSITIVE

Chromosomal aberrations in bone marrow cells increased following the
administration of sodium fluoride in a dose- and time-dependent manner.
Sodium fluoride was mutagenic in Sprague-Dawley rat bone marrow cells
within the confines of this study.

Overall, there was a significant increase in the percentage of aberrant
cells in sodium fluoride treated groups for the 12-, 24-, and 36-hour
exposures.  Only the 0.1 uM treatment, 12-hour exposure cells did not
have a significant increase in breaks/cell or in the percent of aberrant
cells compared to controls.  The increased aberrations at the other
treatment levels mainly consisted of simple aberrations, such as breaks
and fragments.  Small number of complex aberrations, such as chromatid
exchanges and rings, occurred sporadically, at doses 1.0, 10.0, and
100.0 uM.

The number and percentage of aberrations increased with the increasing
concentrations of sodium fluoride and with the prolongation of
treatment.  The only significant exposure time-related effects observed
were between the 12- and 36-hour exposures at concentrations of 1.0,
10.0, and 100.0 uM.

870.5375

In Vitro mammalian chromosome aberration test

Purity not reported

Toxicology and Carcinogenesis Studies of Sodium Fluoride (CAS No.
7681-49-4) in F344/N Rats and B6C3F1 Mice (Drinking Water Studies).
National Toxicology Program, Technical Report Series No. 393, NIH
Publication No. 91-2848, December 1990, Pgs. 1-477.

Acceptable

Guideline

Chinese hamster ovary cells were exposed to sodium fluoride in culture
medium at concentrations between 50 and 1600 µg/mL with metabolic
activation (S9 from Aroclor 1254-induced male Sprague-Dawley rat livers)
for 2 hours, or between 16 and 800 µg/mL without metabolic activation
for 10 hours.

POSITIVE

There was evidence of a concentration related positive response of
chromosome aberrations induced over background in one laboratory testing
without metabolic activation; no other evidence of a positive response.

870.5375

In Vitro mammalian chromosome aberration test

Purity not reported

Tsutsui T, et al.  (1984). Sodium Fluoride-Induced Morphological and
Neoplastic Transformation, Chromosome Aberrations, Sister Chromatid
Exchanges, and Unscheduled DNA Synthesis in Cultured Syrian Hamster
Embryo Cells.  Cancer Research 44.3:938-941

Open Literature

Syrian hamster embryo (SHE) cells were exposed to sodium fluoride for 16
and 28 hours

50 or 100 ug/mL for 16 hours

100 or 200 ug/mL for 28 hours

POSITIVE

There was a dose- and time-dependent increase in chromosomal aberrations
following administration of sodium fluoride in Syrian hamster embryo
cells.  Sodium fluoride was mutagenic in SHE cells within the confines
of this study.

Treatment-related effects on mortality were observed in SHE cells
administered sodium fluoride.  At sodium fluoride concentrations of 75,
100, and 125 go/mL, there were decreases in cell survival that were 10,
47, and 61%, respectively, less than control.

There were significant dose-dependent increases in chromosome
aberrations in the sodium fluoride-treated SHE cells.  Sodium fluoride
incubation of 16 hours exhibited increases in aberrant metaphases that
were 9- and 24-fold greater than the control at the 50 and 100 go/mL/mL
dose levels, respectively.  After 28 hours of exposure, the 100 and 200
go/mL/mL dose levels of sodium fluoride induced aberrant metaphases that
were 19- and 29.5-fold greater than control, respectively.  The
chromosomal aberrations were predominantly gaps and some breaks.

870.5375

In Vitro mammalian chromosome  aberration test

Tsutsui, T., N. Suzuki, et al.  (1984). Cytotoxicity, Chromosome
Aberrations and Unscheduled DNA Synthesis in Cultured Human Diploid
Fibroblasts Induced by Sodium Fluoride.  Mutation Research 139:193-198.

Open Literature

A separate cytotoxicity test was preformed with sodium fluoride
administered to JHU-1 cells at concentrations of 50, 100, or 150
go/mL/mL for 1, 2, 6, 12, or 24 hours.  Sodium fluoride was administered
to JHU-1 cells in the mutagenicity assay at concentrations of 25, 50 or
75 go/mL/mL for 12 hours of exposure and 20 or 40 ug/mL for 24 hours
exposure. Analyses for chromosome aberrations were performed in 100-500
metaphases.

POSITIVE

There was a dose- and time-dependent increase in chromosomal aberrations
following administration of sodium fluoride in cultured human diploid
fibroblasts.  Sodium fluoride was mutagenic in JHU-1 cells within the
confines of this study.

Treatment-related cytotoxic effects were observed in JHU-1 cells
administered sodium fluoride.  Cell survival decreased as the sodium
fluoride concentration and duration of exposure increased.  At sodium
fluoride concentrations of 50, 100, and 150 go/mL, there were decreases
in cell survival that were 100, 98, and 90% after 1 hour; 100, 75, and
65% after 2hours; 70, 48, and 40% after 6 hours; 55, 22, and 15% after
12 hours; and 17, 7, and 1% after 24 hours of exposure, respectively.
Sodium fluoride was cytotoxic to JHU-1 cells and cell survival decreased
linearly with increasing dose or exposure time.

There were significant dose- and time-dependent increases in chromosome
aberrations in the sodium fluoride-treated JHU-1 cells.  The 12 hour
sodium fluoride incubation exhibited increases in aberrant metaphases
that were 3.5- and 22.4-fold greater than the control at the 25 and 50
go/mL dose levels, respectively.  Sodium fluoride at 75 go/mL provided
few metaphases to analyze for chromosomal aberrations.  After 24 hours
of exposure, the 20 and 40 go/mL dose levels of sodium fluoride induced
aberrant metaphases that were 7- and 47-fold greater than control,
respectively.  The chromosomal aberrations were predominantly gaps and
some breaks.

870.5380

Mammalian Spermatogonial

Chromosomal aberration test

Purity not reported

Li, Dunipace, and Stookey.  (1987). Effect of Fluoride on the Mouse
Sperm Morphology Test.  J. Dent. Res. 66:1509-1511.

Open Literature

B6C3F1 male mice were fed a low fluoride diet (<0.2 ppm) via stomach
intubation at concentrations of 0.1, 1.0, 10, 20, 35, or 70 mg/kg.
Treated daily for 5 days.

5 mice/group (except 70 mg/kg dose group with 9 mice)

NEGATIVE

The frequency of abnormal sperm in NaF-treated groups was not
significantly different from controls.  NaF did not cause spermatogenic
damage as determined by the frequency of sperm abnormalities and weights
of testes.

There was an increase in bone fluoride content with increasing dosage;
concentrations less than or equal to 10 mg/kg exhibited significantly
lower bone fluoride content than concentrations greater than or equal to
20 mg/kg.  The increase in bone fluoride demonstrated that fluoride was
adequately absorbed following intubation, and therefore, the route of
administration of NaF used was justified.  NaF was nonspermatogenic in
male mice and supports the view point that Fl has no adverse mutagenic
effects.

870.5380

Mammalian Spermatogonial

Chromosomal aberration test

Purity not reported

Mohamed and Chandler.  (1982). Cytological Effects of Sodium Fluoride on
Mice.  Dept. of Biology and School of Medicine, University of Kansas
City, Missouri.  Presented at the 12th I.S.F.R. Conference.

Open Literature

Male BALB/c mice were administered a low fluoride diet for 1 week and
sodium fluoride in drinking water for 3 or 6 weeks

0.263 ppm fluoride in diet

1, 5, 10, 50, 100, or 200 ppm NaF in drinking water

4 mice/time period/dose

POSITIVE

There were significant treatment-related increases from controls in
aberration rates among spermatocytes.  There was evidence of cytogenetic
damage found in animals administered sodium fluoride.  Sodium fluoride
within the parameters of this study was found to be mutagenic.

In the three week study, all of the treatments demonstrated a
significantly higher frequency of chromosomal aberrations compared to
controls.  A dose-related response occurred at doses 5 to 200 ppm, but
the frequency of aberrations in the low dose (1 ppm) compared to the 5
ppm group did not express the same increasing trend.

In the three week study, all of the treatments demonstrated a
significantly higher frequency of chromosomal aberrations compared to
controls.  A dose-related response occurred at doses 5 to 100 ppm, but
the frequency of aberrations in the low dose (1 ppm) compared to the 5
ppm group and the 100 ppm group compared to the 200 ppm group did not
express the same increasing trend.

870.5380

Mammalian Spermatogonial

Chromosomal aberration test

Purity not reported

Pati and Bhunya.  (1987). Genotoxic effect of an environmental
pollutant, sodium fluoride, in mammalian in vivo test system.  Carylogia
40:79-87.

Open Literature

Male Swiss mice were administered sodium fluoride as intraperitoneal
injections of 5 equal parts of each dose of sodium fluoride over 5 days
with 24 hours between each injection.

10, 20, or 40 mg/kg

Number of animals not reported

POSITIVE

 Sodium fluoride was mutagenic to spermatogonial cells in Swiss mice
within the confines of this study.

There was a dose-related increased in the number of abnormal sperm that
increased with increasing dose.  The mean percentages of sperm
abnormalities were 6.4, 6.8 and 7.6% for the 10, 20, and 40 mg/kg dose
levels, respectively, of sodium fluoride.  There were significant
dose-dependent increases in the frequency of spermatogonial aberrations
that were 3.1-, 3.3-, and 3.7-fold greater than the control at the
sodium fluoride doses of 10, 20, and 40 mg/kg, respectively.

The higher incidence of sperm abnormalities induced by sodium fluoride
may be a measure of the genetic damage caused in the germline cells.
There were significant increases over control in the number of
spermatogonial aberrations in animals receiving sodium fluoride.

870.5385

Mammalian bone marrow chromosomal aberration test

Purity not reported

Martin G, et al.  (1979). Lack of Cytogenetic Effects in mice or
mutations in salmonella receiving sodium fluoride.  Mutation Res
66:159-167.

Open Literature

Male BALB/c mice were administered sodium fluoride in the diet and in
drinking water for six weeks 0.5 ppm NaF in the diet

1,5, 10, 50, or 100 ppm NaF in drinking water

Number of animals not reported

NEGATIVE

There were no significant treatment-related differences observed in
aberration rates among bone marrow cells.  There was no evidence of
cytogenetic damage found in animals administered sodium fluoride.

870.5385

Mammalian bone marrow chromosomal aberration test

Purity not reported

Mohamed and Chandler.  (1982). Cytological Effects of Sodium Fluoride on
Mice.  Dept. of Biology and School of Medicine, University of Kansas
City, Missouri.  Presented at the 12th I.S.F.R. Conference.

Open Literature

Male BALB/c mice were administered a low fluoride diet for 1 week and
sodium fluoride in drinking water for 3 or 6 weeks

0.263 ppm fluoride in diet

1, 5, 10, 50, 100, or 200 ppm NaF in drinking water

4 mice/time period/dose

POSITIVE

There were significant treatment-related differences observed in
aberration rates among bone marrow cells.  There was evidence of
cytogenetic damage found in animals administered sodium fluoride.
Sodium fluoride within the parameters of this study was found to be
mutagenic.

In the three week study, all of the treatments demonstrated a
significantly higher frequency of chromosomal aberrations compared to
controls.  A dose-related response occurred at doses 1 to 50 ppm, but
the aberration frequencies in the higher doses were not significantly
different from each other.

In the six week study, all of the treatments demonstrated a
significantly higher frequency of chromosomal aberrations compared to
controls.  A dose-related response occurred at doses 1 to 10 ppm, but
the frequency of aberrations in the higher doses were not significantly
different from each other.

870.5385

Mammalian bone marrow chromosomal aberration test

Purity not reported

Pati and Bhunya.  (1987). Genotoxic Effect of an Environmental
Pollutant, Sodium Fluoride, in Mammalian In Vivo Test System.  Carylogia
40:79-87.

Open Literature

Swiss mice were administered sodium fluoride orally, ip, or
subcutaneously for 6, 24, or 48 hours

10 or 20 mg/kg intraperitoneally for 24 hours

40 mg/kg orally or subcutaneously for 24 hours

40 mg/kg intraperitoneally for 6, 24, or 48 hours

8 injections of  5 mg/kg intraperitoneally for 120 hours

Number of animals not reported

POSITIVE

Sodium fluoride was found to be mutagenic in Swiss mice bone marrow
cells within the confines of this study.

There were significant dose-related increases in chromosomal aberrations
in the 24 hour experiment.  Intraperitoneal injections of sodium
fluoride at concentrations of 10, 20, and 40 mg/kg were 3.3-, 4.3-, and
5.2-fold greater than control, respectively.  Similar and significant
results were observed in the oral and subcutaneous experiments with 5.5-
and 5.0-fold increases, respectively, over controls at the 40 mg/kg dose
level.  There were 1.9 and 3.3-fold increases over control at the 40
mg/kg dose levels of sodium fluoride administered intraperitoneally at 6
(not significant) and 48 hours (significant), respectively.  The
multiple, 5-time dosing of 8 mg/kg resulted in a significant 2.9-fold
increase over control in mouse chromosomal aberrations.

There were treatment-related aberrations, including chromatid gaps and
breaks, isochromatid gaps, fragments and exchanges in mouse bone marrow
cells.  Gaps were observed more frequently than breaks.  Sodium fluoride
induced dose- and time-dependent increases in the number of chromosomal
aberrations, but there was no evidence of route-sensitivity.  There was
no practical difference observed at the same dose level in the 3
administration routes employed.   Additionally, the chronic, repeated
exposure of fractionated doses induced less aberrations than that of an
equivalent dose treated once.  The increases in chromosome aberrations
were significantly greater than control in all experiments with one
exception.  Intraperitoneal injection of 40 mg/kg sodium fluoride over 6
hours failed to induce a significant number of chromosomal aberrations.

870.5385

Mammalian bone marrow chromosomal aberration test

Purity not reported

Zeiger et al.  (1994). Cytogenetic Studies of Sodium Fluoride in Mice.
Mutagenesis 9:467-471.

Open Literature

Male B6C3F1 mice were administered fluoride in the diet for 1 week and
sodium fluoride in drinking water for 7 days/week for 6 weeks

10-16 mice/dose

100, 200 or 400 ppm in drinking water

NEGATIVE

There were no significant treatment-related differences observed in
aberration rates among metaphase and anaphase bone marrow cells.  There
was no evidence of cytogenetic damage found in animals administered
sodium fluoride.

Three of sixteen mice from the 400 ppm group died during the
sixteen-week treatment period.  A decrease in body weight gain and water
consumption occurred at the 200 and 400 ppm group.  There were no other
treatment-related signs.

870.5395

Mammalian erythrocyte micronucleus test

Purity not reported

Albanese.  (1987). Sodium Fluoride and Chromosome Damage (In Vitro Human
Lymphocyte and In Vivo Micronucleus Assays).  Mutagenesis 2:497-499.

Open Literature

Oral gavage of 500 or 1000 mg/kg NaF to Male Alpk:APF Sprague-Dawley
rats, 5/group/sample time

NEGATIVE

There were no significant increases in the frequency of micronucleated
polychromatic erythrocytes in rat bone marrow cells at the
concentrations of sodium fluoride used in this study.  Sodium fluoride
was not mutagenic in Alpk:APFSD rat bone marrow cells.

There were no treatment-related effects on mortality in any of the
low-dose (500 mg/kg) group; however, 4 of the 5 rats in the 1000 mg/kg
group died prior to the 48 hour sampling period.  No other abnormal
signs were observed in the remaining animals in other dose/time groups.
The ratio of normochromatic erythrocytes (NCEs) to PCEs was 1:1; which
indicated that at the doses used sodium fluoride was not cytotoxic to
the bone marrow cells.

870.5395

Mammalian erythrocyte micronucleus test

Purity not reported

Gocke et al.  (1981). Mutagenicity of Cosmetics Ingredients Licensed by
the European Communities.  Mutation Research 90.2:91-109

Open  Literature

Male and female NMRI mice and Sprague-Dawley rats

NEGATIVE

There were no a significant increases in the frequency of micronucleated
polychromatic erythrocytes in mouse bone marrow cells at the
concentrations of sodium fluoride used in this study.  Sodium fluoride
was not mutagenic in NMRI mouse bone marrow cells.

There were no treatment-related effects on mortality (100% survival) or
MNPCEs in mice receiving administrations of phenol.

870.5395

Mammalian erythrocyte micronucleus test

Purity not reported

Pati and Bhunya.  (1987). Genotoxic effect of an environmental
pollutant, sodium fluoride, in mammalian in vivo test system.  Carylogia
40:79-87.

Open Literature

Swiss mice were administered intraperitoneal NaF 2 times over 24 hours

10, 20, or 40 mg/kg

Number of animals not reported

POSITIVE

There were treatment-related increases in MNPCEs in animals administered
sodium fluoride, with 3-, 3.5-, and 5.15-fold increases over control at
the 10, 20, and 40 mg/kg dose levels, respectively.  These increases
were significantly greater than the control with the exception of the
low-dose (10 mg/kg).  The induction of MN in bone marrow cells increased
with sodium fluoride dose.  MN frequency was at its highest in PCEs and
least in immature white cells.  There was evidence of mutagenicity in
mouse bone marrow cells administered sodium fluoride within the confines
of this study.

870.5395

Mammalian erythrocyte micronucleus test

Purity not reported

Zeiger et al.  (1994). Cytogenetic Studies of Sodium Fluoride in Mice.
Mutagenesis 9:467-471.

Open Literature

Male B6C3F1 mice were administered fluoride in the diet for 1 week and
sodium fluoride in drinking water for 7 days/week for 6 weeks.

10-16 mice/dose

100, 200, or 400 ppm

NEGATIVE

There were no significant increases in the frequency of micronucleated
polychromatic erythrocytes and normochromatic erythrocytes in B6C3F1
mice peripheral blood cells in the parameters of this study.  Sodium
fluoride was not mutagenic in B6C3F1 mice peripheral blood cells.

Three of sixteen mice from the 400 ppm group died during the
sixteen-week treatment period.  A decrease in body weight gain and water
consumption occurred at the 200 and 400 ppm group.  There were no other
treatment-related signs.

870.5500

Bacterial DNA damage or repair tests

Purity = 99.99%

Tong et al.  (1988). The Lack of Genotoxicity of Sodium Fluoride in a
Battery of Cellular Tests.  Cell Biology and Toxicology 4.2:173-186.

Open Literature

Male Fischer F-344 rat hepatocyte primary cultures (HPC) were
administered sodium fluoride for 18 hours

20 cells/slide were scored

2, 10, 20, 40, 80, or 160 ug/mL

Number of animals not reported

NEGATIVE

There was no significant increase in net nuclear grain counts at sodium
fluoride concentrations up to 160 go/mL.  Sodium fluoride did not elicit
DNA repair synthesis in the rat hepatocytes.

870.5550

Unscheduled DNA synthesis in mammalian cell culture

Purity not reported

Tsutsui T, et al.  (1984). Sodium Fluoride-Induced Morphological and
Neoplastic Transformation, Chromosome Aberrations, Sister Chromatid
Exchanges, and Unscheduled DNA Synthesis in Cultured Syrian Hamster
Embryo Cells.  Cancer Research 44.3:938-941

Open Literature

Syrian hamster embryo (SHE) cells were exposed to sodium fluoride for 4,
8, 12, 24, or 33 hours.

10, 20, or 40 ug/mL

POSITIVE

A dose- and time-dependent increase in unscheduled DNA synthesis was
observed following administration of sodium fluoride in Syrian hamster
embryo cells.  Sodium fluoride was mutagenic in SHE cells within the
confines of this study.  Treatment-related effects on mortality were
observed in SHE cells administered sodium fluoride.  At sodium fluoride
concentrations of 75, 100, and 125 go/mL, there were decreases in cell
survival that were 10, 47, and 61%, respectively, less than control.

There was no evidence of UDS at any dose of sodium fluoride in the 4 or
8 hour exposure time period.  However, significant dose- and
time-dependent increases in UDS were observed in the SHE cells treated
with all three doses of sodium fluoride for 12 hours or greater.  After
12 hours of exposure, the UDS (as measured by [3H]dThd cpm/culture well
(x 10-2)) was at a level of 0.55 and 1.30 [3H]dThd cpm/culture well (x
10-2) for the 20 and 40 go/mL, respectively, dose groups.  Sodium
fluoride induced UDS levels of 0.75, 1.45, and 2.30 after 24 hours of
exposure and 0.45, 2.25, and 5.55 after 33 hours of exposure at
concentrations of 10, 20, and 40 go/mL, respectively.

870.5550

Unscheduled DNA synthesis in mammalian cell culture

Tsutsui, T., N. Suzuki, et al.  (1984). Cytotoxicity, Chromosome
Aberrations and Unscheduled DNA Synthesis in Cultured Human Diploid
Fibroblasts Induced by Sodium Fluoride.  Mutation Research 139:193-198.

Open Literature

A separate cytotoxicity test was performed with sodium fluoride
administered to JHU-1 cells at concentrations of 50, 100, or 150 go/mL
for 1, 2, 6, 12, or 24 hours.  Sodium fluoride was administered to JHU-1
cells in the mutagenicity assay at concentrations of 50, 70, 100, 150,
200, 300, or 400 go/mL for 4, 8, 12, 16, or 24 hours of exposure.

POSITIVE

There was a significant dose-dependent increase in unscheduled DNA
synthesis following administration of sodium fluoride in cultured human
diploid fibroblasts.  Sodium fluoride was mutagenic in JHU-1 cells
within the confines of this study.

Treatment-related cytotoxic effects were observed in JHU-1 cells
administered sodium fluoride.  Cell survival decreased as the sodium
fluoride concentration and duration of exposure increased.  At sodium
fluoride concentrations of 50, 100, and 150 go/mL, there were decreases
in cell survival that were 100, 98, and 90% after 1 hour; 100, 75, and
65% after 2hours; 70, 48, and 40% after 6 hours; 55, 22, and 15% after
12 hours; and 17, 7, and 1% after 24 hours of exposure, respectively.
Sodium fluoride was cytotoxic to JHU-1 cells and cell survival decreased
linearly with increasing dose or exposure time.

UDS was not induced by sodium fluoride treatment over the dose range of
50-5000 go/mL for 1 hour.  There were increases in the level of UDS
after 4 hours of exposure; however, none exceeded 7 [3H]TdR cpm/culture
well (x 10-2) and were not significantly different from untreated cells.
 No significant UDS was detected until the cells were treated for longer
than 4 hours.  The UDS levels were 9, 22, 29, and 41 for 8 hours and 3,
22, 44, and 52 for 12 hours of exposure at the sodium fluoride
concentrations of 100, 150, 200, and 300 go/mL, respectively.  The UDS
levels increased with dose after 16 hours of exposure, with 15, 39, and
47 [3H]TdR cpm/culture well (x 10-2) at 150, 200, and 300 go/mL sodium
fluoride, respectively.  The inducibility was markedly decreased in
cells treated for 24 hours; most likely a result of cytotoxicity.

870.5900

In Vitro sister chromatid exchange assay

Purity not reported

Khalil A, Da'Dara A.  (1994). The Genotoxic and Cytotoxic Activities of
Inorganic Fluoride in Cultured Rat Bone Marrow Cells.  Arch Environ
Contam Toxicol 26:60-63.

Open Literature

Bone marrow cells of Sprague-Dawley rats from tibia and femurs

0.1, 1, 10, 100, 1,000 and 10,000 uM for 12, 24, and 36 hours

NEGATIVE

Cell survival and cell division was significantly reduced at the
high-doses (1,000 and 10,000 uM).  However, Sodium fluoride did not
induce a SCE increase in bone marrow cells; there was no evidence of
mutagenicity.

870.5900

In Vitro sister chromatid exchange assay

Purity not reported

Li Y, et al.  (1987). Genotoxic Effects of Fluoride Evaluated by
Sister-Chromatid Exchange.  Mutation Res 192:191-201.

Open Literature

Male CHO cells

0.05, 0.5, 1.0, 2.10, 4.20, 5.30, or 6.30 mM, performed in triplicate in
the presence and 1.2, 2.4, 6.0, or 12.0 mM for 24 hours of incubation

NEGATIVE

The 5.30 and 6.30 mM dose levels of sodium fluoride were toxic and were
not evaluated.  There were no significant increases from controls in
SCEs in CHO cells exposed to 0.05 to 4.20 mM sodium fluoride.  Sodium
fluoride did not induce a SCE increase in CHO cells; there was no
evidence of mutagenicity.

870.5900

In Vitro sister chromatid exchange assay

Purity = 99.99%

Tong et al.  (1988). The Lack of Genotoxicity of Sodium Fluoride in a
Battery of Cellular Tests.  Cell Biology and Toxicology 4.2:173-186.

Open Literature

Human peripheral blood lymphocytes (HPBL) were exposed to sodium
fluoride for 72 hours

2, 10, 20, 40, 80, or 160 ug/mL

NEGATIVE

The 160 go/mL dose of sodium fluoride was toxic as indicated by total
lack of cell entering the mitotic cycle.  SCEs of cells exposed to
sodium fluoride concentrations of 80 go/mL or lower did not differ
significantly from the control. Sodium fluoride did not induce an
increase in SCEs in HPBL cells; there was no evidence of mutagenicity.

870.5900

In Vitro sister chromatid exchange assay

Purity = 99.99%

Tong et al.  (1988). The Lack of Genotoxicity of Sodium Fluoride in a
Battery of Cellular Tests.  Cell Biology and Toxicology 4.2:173-186.

Open Literature

Chinese hamster cells (CHO) were exposed to sodium fluoride for 24-27
hours

2, 10, 20, 40, 80, or 160 ug/mL

NEGATIVE

The 80 and 160 go/mL dose levels of sodium fluoride were toxic.  There
were no significant increases from control in SCEs in CHO cells exposed
to 2-40 go/mL sodium fluoride.  Sodium fluoride did not induce a SCE
increase in CHO cells; there was no evidence of mutagenicity.

870.5900

In Vitro sister chromatid exchange assay

?????

Toxicology and Carcinogenesis Studies of Sodium Fluoride (CAS No.
7681-49-4) in F344/N Rats and B6C3F1 Mice (Drinking Water Studies).
National Toxicology Program, Technical Report Series No. 393, NIH
Publication No. 91-2848, December 1990, Pgs. 1-477.

Acceptable

Guideline

??????

POSITIVE

There was evidence of a concentration related positive response in SCEs
induced over background in one of two studies performed, while the
second did not find any evidence of a positive response.

870.5900

In Vitro sister chromatid exchange assay

Purity not reported

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Aberrations, Sister Chromatid Exchanges, and Unscheduled DNA Synthesis
in Cultured Syrian Hamster Embryo Cells.  Cancer Research 44.3:938-941

Open Literature

Syrian hamster embryo (SHE) cells were exposed to sodium fluoride for 24
hours

20, 40, or 80 ug/mL

POSITIVE

A dose-dependent increase in sister chromatid exchanges was observed
following administration of sodium fluoride in Syrian hamster embryo
cells.  Sodium fluoride was mutagenic in SHE cells within the confines
of this study.

Treatment-related effects on mortality were observed in SHE cells
administered sodium fluoride.  At sodium fluoride concentrations of 75,
100, and 125 go/mL, there were decreases in cell survival that were 10,
47, and 61%, respectively, less than control.

There were significant dose-dependent increases in SCE frequency in the
sodium fluoride-treated SHE cells. After 24 hours of exposure, the
frequency of SCEs increased 1.4-, 1.6-, and 2.1-fold over control at the
20, 40, and 80 go/mL dose levels of sodium fluoride, respectively.

870.5915

In Vivo sister chromatid exchange assay

Purity not reported

Li Y, et al.  (1987). Genotoxic Effects of Fluoride Evaluated by
Sister-Chromatid Exchange.  Mutation Res 192:191-201.

Open Literature

Male Chinese hamsters

0.1, 1, 10, 60 or 130 mg/kg

3 animals/dose (except for the 130 mg/kg dose group in which 8 animals
were used)

NEGATIVE

Sodium fluoride did not induce a SCE increase in CHBM cells; there was
no evidence of mutagenicity.   Death occurred in three out of the eight
hamsters in the 130 mg/kg/day group. Although toxic effects were seen in
the high dose group, there were no treatment-related increases in SCE.

Special Study Developmental Neurotoxicity

Purity not reported

Mullenix et al. (1995). Neurotoxicity of Sodium Fluoride in Rats.
Neurotoxicology and Teratology 17:169-177.

Open Literature

Sprague-Dawley rats administered NaF via subcutaneous injection during
the prenatal period on gestation periods 14-18 and 17-19.  Weanlings
received drinking water containing 0, 75, 100, or 125 ppm F for 6 to 20
weeks.  3-month old adults received 100 ppm for 6 weeks.

No maternal or offspring toxicity was indicated by reduced body weight
in dams during prenatal treatment or in their pups soon after birth.
However, prenatal exposure to sodium fluoride altered the behavioral
outcome in male offspring when exposure occurred on GD 17-19 and
consisted of time structure changes in eleven behaviors and behavioral
sequences.  The behavioral differences did not coincide with the plasma
fluoride levels.

Body-weight was significantly reduced from the control group in 3-week
old rats administered 125 ppm fluoride.  Concentrations below 125 ppm
did not affect body weight gain during 6-week exposures.  Plasma
fluoride levels were significantly increased in all test groups compared
to control groups.  The same direction of behavioral change (initiation
and total time) occurred in treated animals when compared to controls.
This change was independent and unrelated to sex of the animal, exposure
time (6 or 16 weeks), or dose level (100 or 125 ppm).  The act of
standing and the related attention cluster tended to increase in total
time, while the other acts consistently decreased in initiations and
total times. The adult exposure to 100 ppm sodium fluoride had a
significant effect on female behavior consistent with the behavioral
change in the 3-week old rats.  Similar behavioral time structure
effects occurred when adult and weanling exposed rats approached 5
months of age.

The effect on behavior varied with the timing of exposure during CNS
development.  There were differences between behavioral changes in
weanling and adult exposure when compared to prenatal exposures.
Prenatally induced behavioral effects were unaccompanied by changes in
body weight or elevated plasma fluoride levels.  The behavioral effects
induced by weanling and adult exposures were accompanied often by weigh
reduction and always by elevated plasma fluoride levels.

Rats were exposed to sodium fluoride at concentrations ranging from
75-125 ppm for 6 or 20 weeks.  Plasma fluoride levels reached
0.059-0.640 ppm and after 6 weeks of consuming 75 and 100 ppm of sodium
fluoride animals exhibited greater plasma fluoride levels than animals
treated with 125 ppm.  The researchers suggest that there was a taste
aversion that limited the water consumption at the 125 ppm level;
prolonging the period needed to attain plasma levels that were achieved
in 6 weeks by the two lower exposure levels.  The levels of fluoride in
plasma best predicted effects on behavior.

870.7485

General Metabolism

Hall et al.  (1977). Kinetic Model of Fluoride Metabolism in the Rabbit.
 Environmental Research 13:285-302.

Open Literature

Adult male New Zealand rabbits were administered sodium fluoride in the
diet, water, and  in a single oral dose injected directly into stomach
through nasal catheter

15 ppm in the diet

1 ppm in the water

0.5 mg/kg oral

6 rabbits

Urine excretion following oral administration of NaF was 5 and 13% for
60 and 600 minutes, respectively.  Under steady state conditions
approximately 15% of fluoride ingested in food and water was absorbed by
animal.  15% was excreted in urine and 85% of ingested fluoride was
involved in fecal excretion.

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