Trilithium hexafluoroaluminate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

There is no indication for fertility risks caused by lithium cryolite based on the results of the two-generation study with the structural analogue cryolite. The justification of the read-across strategy is available in the attached document of the endpoint study record of the target substance.

Link to relevant study records

Reference

Reference 1

Endpoint:

two-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 83-4 (Reproduction and Fertility Effects)

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

Test animals: albino rat
Strain: CD (Sprague Dawldey derived)
Age at receipt: 30 days
Supplier: CharlesR iver Laboratories, Inc. Portage, Michigan 49081
Animals were acclimated for approximately two weeks.
Housing: Suspended, stainless steel, wire mesh bottom cages. Animals were housed individually throughout the study with the following exceptions: the first week of acclimation( two animals/sex/cage); mating (one male and one female/cage overnight); lactation( dam and litter/cage) and post-weaninogf the FI pups (one- two llttermates/sex/cage until formali nitiation of the pre-matingt reatmentp eriod which followed weaning of the last litters).
Feed and water: Ad libitum. Certified Rodent Diet No. 5002 (mash) was provided fresh at least weekly during the study. Analysis of each feed lot used during this study was performed by the supplier (Purina Mills, Inc. St. Lous, MO).

Environmental conditions: 12 hour light/dark cycle, actual temperature: 64-80°F (18-27°C), actual relative humidity: 24-79%.

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

Appropriate amounts of the test substance were mixed with the basal granulated diet to achieve the desired concentrations (prepared at a fixed concentration [ppm] in the diet and no correction for purity of the test substance was used). Fresh diets were prepared and presented to animals weekly during the study. Control animals received standard laboratory diet only. Unused portions of diet (control and treated) were stored at ambient temperature during intervals when not being presented to animals.

Prior to the initiation of the study, full-size (mock) batches of diets at the low- and high concentration levels( 200 and 1800 ppm, respectively) were evaluated to determine that diets prepared using the proposed mixing procedure were homogeneous. To determine homogeneity, three randomly drawn diet samples (approximately 100 grams each) were taken from each mix at each of three levels (top, middle, bottom - total of nine samples) in the mixer. If the data demonstrated that the mean of the values for the three levels were within ±15% of each other and ±20% of the nominal (desired) concentration, the batches were considered homogeneous.

In previous studies conducted in this Testing Facility with dietary administration of Kryocide, the stability of the Kryocide in the diet for 14 days post-preparation at ambient storage was established at dose levels that ranged from 50 to 5000 ppm. On the basis of these stability data, the only additional stability assessment performed for this study was a 21-day stability at ambient storage. These analyses were performed at the low- and high- concentrations (200 and 1800 ppm, respectively) for diets prepared to establish homogeneity. Following 21 days of storage at ambient temperature, two samples of approximately 100 grams each were collected at each concentration level and analyzed.

Details on mating procedure:

Initially, one male was co-housed with one female from the same treatment group nightly until evidence of mating was observed or for seven consecutive days. Each morning following cohabitation with the male, the female was evaluated for evidence of mating (microscopic observation of sperm in the vaginal smear and/or copulation plug in the vagina). The day on which evidence of mating was observed was defined as Day 0 of gestation. Once mated, females were removed from the mating unit and housed individually for the remainder of gestation. Females unmated after the initial seven-day mating interval were redistributed (randomly) to a different male within the same treatment group until evidence of mating was observed or for seven additional days. This same procedure was repeated for a third seven-day mating interval for unmated females. This same mating design was used for F1 generation. In the mating assignments of the F1 generation, care was taken in establishing the mating units to avoid brother-sister matings.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Two diet samples of approximately 100 grams each were collected for each test diet and control at the weekly preparation intervals through out the study. Analyses to confirm concentration levels of diets intended for use on study were performed for the first four mixes (Study Weeks 1-4) and subsequently for every fourth mix (Study Weeks 8, 12, 16, 20. 24. 28, 32, 36, 40, 44 and 48) for the remainder of the study. Samples collected from mixes not scheduled for analyses have been retained frozen at this testing facility until issuance of the final report.
Diet samples analyzed were evaluated in duplicate. The diets were considered acceptable for study if values for the duplicate assays were within ± 20% of each other and the mean of the two values were within ± 20% of the nominal (desired) concentration. All diet analyses (i.e., homogeneity, stability and confirmation of concentration levels) were performed by the Analytical Department of Pharmaco LSR, Toxicology Services North America.

Duration of treatment / exposure:

F0 generation animals received the appropriate treated diets for 14 weeks prior to initiation of mating (i.e., pre-mating period) and treatment continued until sacrifice. Following the formal initiation of the pre-mating period, F1 generation animals received the appropriate treated diets for 14 weeks prior to initiation of mating and treatment continued until sacrifice. F1 pups consumed diets at the treatment level of the dam late in lactation and selected F1 animals continued to consume diets at these concentration levels during the post-weaning period through to the formal initiation of the pre-mating period.

Frequency of treatment:

continuous

Details on study schedule:

Both parental generations received a 14-week pre-mating period and treatment continued during a 21-day mating period and post-mating interval (males and unmated females) until sacrificed. Mated females continued to be treated during the ensuing gestation, lactation and post-weaning periods until sacrifice.

Remarks:

Doses / Concentrations:
200, 600 and 1800 ppm
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
14, 42, and 128 mg/kg bw/day for males and 16, 49 and 149 mg/kg bw/day for females
Basis:
Actual received in diet

No. of animals per sex per dose:

30

Control animals:

yes, plain diet

Details on study design:

Parental animals (F0, F1) were observed twice daily for mortality and unusual findings and each animal received a detailed physical examination weekly. Body weights and food consumption for the parental animals were recorded weekly during the pre-mating treatment periods and these parameters continued to be recorded weekly for males during the mating and post-mating period through to sacrifice. Body weights and food consumption were recorded for mated females at regular intervals during the gestation period and females with litters continued to be weighed at regular intervals during the lactation period. Each parental generation produced a single litter and pups were weaned on lactation day 21. On lactation day 4, litters with greater than eight pups were culled to that number so as to equalizes sex distribution (four/sex), when possible; litters with less than eight pups at Day 4 were not adjusted. During lactation, litter size, pup weights and pup sex distribution data were recorded. Randomly selected pups from the F1 litters (at least one pup/sex/litter) were chosen to become the F1 parental generation. At sacrifice, parental animals were given a gross postmortem examination and reproductive tissues, pituitary glands and gross lesions were taken and preserved in 10% neutral buffered formalin. During the sacrifice of the F1 parental males, testes and epididymal weights were also recorded. Reproductive tissues and pituitary glands were evaluated histomorphologically for control and high-dose animals from both parental generations and gross lesions with the exclusion of incisor observations, were evaluated for all animals.

Positive control:

No

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes (observations of mortality and gross clinical findings)
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes (Detailed physical examination for signs of local or systemic toxicity, pharmacological effects and palpation for tissue masses).
- Time schedule: weekly

BODY WEIGHT: Yes

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes. Compound intake was calculated using food consumption and the nominal concentration in the diet.

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: [yes]
- Maximum of 8 pups/litter

PARAMETERS EXAMINED
The following parameters were examined in [F1 / F2 / F3] offspring:
-number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities

GROSS EXAMINATION OF DEAD PUPS:
-yes, for external and internal abnormalities; possible cause of death was determined for pups born or found dead

Postmortem examinations (parental animals):

At sacrifice, parental animals w ere given a gross postmortem examination and reproductive tissues, pituitary glands and gross lesions were taken and preserved in 10% neutral buffered formalin. During the sacrifice of the F1 parental males, testes and epididymal w eights w ere also recorded. Reproductive tissues and pituitary glands were evaluated histomorphologicallfy or control and high-dose animals from both parental generations and gross lesions w ith the exclusion of incisor observations, were evaluated for all animals.

Postmortem examinations (offspring):

The unselected F1 pups and all F2 pups were sacrificed at weaning or shortly thereafter, and evaluated for external and internal irregularities and only abnormal tissues were saved (10% neutral buffered formalin).

Statistics:

Several statistical methods were used, dependent on the parameter studied.

Reproductive indices:

Mating, pregnancy and fertility rates; mean number of days-to-mating

Offspring viability indices:

percentage of pups alive at day 4

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, non-treatment-related

Description (incidence):

In the control group, one P0 male died. No mortality occurred in the P0 parental animals from the low- or mid-dose groups. In the high-dose group, one female died (mortality rate = 3.3%). This female delivered a litter of 15 dead pups and died two days post-delivery. At necropsy, an enlarged pituitary gland was seen along with a discoloured uterus. The cause of death for this animal could not be determined from the macro- or microscopic evaluations. No mortality occurred among the P0 high-dose males. The mortality seen in the high-dose animal was not considered indicative of a treatment-related response.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Mean weekly body weights during the pre-mating treatment period and mean weight gain over the entire 14-week period for the treated groups (both sexes) were comparable to control data and no adverse effect of treatment was indicated from these data. Mean body weights for the treated group males during the mating and and post-mating periods were comparable to control.
Mean maternal body weights during gestation (Days 0, 7, 14 and 21) and lactation (Days 0, 4, 7, 14 and 21) and mean weight gains over these respective intervals (Days 0-20 of gestation and 0-21 of lactation) for the treated groups were comparable to control for both parental generations.

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

effects observed, treatment-related

Description (incidence and severity):

200 and 600 ppm:
No adverse effects of treatment at dietary levels of 200 or 600 ppm were evident from parental or neonatal parameters.
During the detailed physical evaluations of the parental animals, white discoloration of the incisors (upper and/or lower) was seen in both generations at both concentration levels and at the 600 ppm level, additional observations involving the incisors i.e., presence of a beveled edge along the anterior margin and/or a mottled appearance, were seen with increased frequency. These effects which were considered indicative of a treatment-related response were almost identical to toxic effects noted with excessive fluoride exposure i.e., dental fluorosis. This was not entirely unexpected considering the chemistry of the test material. No changes in the critical reproductive indices were seen at the low- and mid-dose levels during either generation and the effects seen were clearly non-reproductive organ effects involving the teeth.

1800 ppm:
At the 1800 ppm dietary level, no adverse effects of treatment were evident in the parental generation animals (F0, F1). The only treatment-related responses seen in these parental-animals involved observations to the incisors similar to those discussed above. All of these types of observations were seen with increased frequency at this treatment level. Bevelled anterior edge of the lower incisor was observed in 67% of animals from both generations at 1800 ppm.
No adverse effect of treatment at the 1800 ppm dietary level was evident from the macroscopic evaluations of the parental animals. Likewise, microscopic evaluation of the reproductive tissues and pituitary glands of the parental animals (F0, F1) revealed no adverse effects. Additionally, microscopic evaluation of the incisors of several F1 males with findings at necropsy i.e., white discoloration, beveled edges, and other gross lesions for both parental generations revealed no adverse effect of treatment.

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Mating indices for both males and females, pregnancy rates and male fertility indices for the treated groups were comparable to control for both parental generations. These indices for the treated groups did not differ statistically from control data during either litter interval and were within the range of values for recent historical control data for multigeneration studies.
Mean gestation lengths for the pregnancies producing the F2 litters for the treated groups were comparable to control and were within the range of recent historical control data for multigeneration studies.
Mean litter size data on Day 4 (pre- and post-cull) and throughout the remainder of lactatino (Days 7, 14 and 21) for the treated groups were considered comparable to control data. Litter survival indices for the treated groups were comparable to control.

Dose descriptor:

LOAEL

Remarks:

general toxicity

Effect level:

200 ppm (nominal)

Sex:

male/female

Basis for effect level:

other: dental fluorosis

Dose descriptor:

NOAEL

Remarks:

fertility

Effect level:

1 800 ppm (nominal)

Sex:

male/female

Basis for effect level:

reproductive performance

Mortality:

no mortality observed

Description (incidence):

No mortality occurred among the control or treated F1 parental animals.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

Mean body weights during the pre-mating treatment period and mean weight gain over the entire 14-week interval for the low- and mid-dose groups (both sexes) were comparable to control data. Mean weight data for the high-dose females during this period were also comparable to control while mean weight gain over the entire interval was 10% high than control and this difference was statistically significant (p<0.05). This type of response i.e., increase in weight gain, for the high-dose females over the pre-mating period was not considered idicative of an adverse effect of treatment.
In the high-dose males, mean body weight at initiation of the pre-mating period was slightly lower than control, a difference of -7%, and mean weights continued to be lower than control throughout the pre-mating period. Some of these differences were statistically significant; however, since mean weight gain for these animals over the entire pre-mating interval was comparable to control, no adverse effect of treatment was indicated.
Mean body weights for the treated group males during the mating and and post-mating periods were comparable to control.
Mean maternal body weights during gestation (Days 0, 7, 14 and 21) and lactation (Days 0, 4, 7, 14 and 21) and mean weight gains over these respective intervals (Days 0-20 of gestation and 0-21 of lactation) for the treated groups were comparable to control for both parental generations.

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

effects observed, treatment-related

Description (incidence and severity):

200 and 600 ppm:
No adverse effects of treatment at dietary levels of 200 or 600 ppm were evident from parental or neonatal parameters.
During the detailed physical evaluations of the parental animals, white discoloration of the incisors (upper and/or lower) was seen in both generations at both concentration levels and at the 600 ppm level, additional observations involving the incisors i.e., presence of a beveled edge along the anterior margin and/or a mottled appearance, were seen with increased frequency. These effects which were considered indicative of a treatment-related response were almost identical to toxic effects noted with excessive fluoride exposure i.e., dental fluorosis. This was not entirely unexpected considering the chemistry of the test material. No changes in the critical reproductive indices were seen at the low- and mid-dose levels during either generation and the effects seen were clearly non-reproductive organ effects involving the teeth.

1800 ppm:
At the 1800 ppm dietary level, no adverse effects of treatment were evident in the parental generation animals (F0, F1). The only treatment-related responses seen in these parental-animals involved observations to the incisors similar to those discussed above. All of these types of observations were seen with increased frequency at this treatment level. Bevelled anterior edge of the lower incisor was observed in 67% of animals from both generations at 1800 ppm.
No adverse effect of treatment at the 1800 ppm dietary level was evident from the macroscopic evaluations of the parental animals. Likewise, microscopic evaluation of the reproductive tissues and pituitary glands of the parental animals (F0, F1) revealed no adverse effects. Additionally, microscopic evaluation of the incisors of several F1 males with findings at necropsy i.e., white discoloration, beveled edges, and other gross lesions for both parental generations revealed no adverse effect of treatment.

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Mating indices for both males and females, pregnancy rates and male fertility indices for the treated groups were comparable to control for both parental generations. These indices for the treated groups did not differ statistically from control data during either litter interval and were within the range of values for recent historical control data for multigeneration studies.
Mean gestation lengths for the pregnancies producing the F2 litters for the treated groups were comparable to control and were within the range of recent historical control data for multigeneration studies.
Mean litter size data on Day 4 (pre- and post-cull) and throughout the remainder of lactatino (Days 7, 14 and 21) for the treated groups were considered comparable to control data. Litter survival indices for the treated groups were comparable to control.

Dose descriptor:

LOAEL

Remarks:

general toxicity

Effect level:

200 ppm (nominal)

Sex:

male/female

Basis for effect level:

other: dental fluorosis

Dose descriptor:

NOAEL

Effect level:

1 800 ppm (nominal)

Sex:

male/female

Basis for effect level:

reproductive performance

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Description (incidence and severity):

Mean pup viability and weaning indices, respresenting pup survival over the Day 0-4 and 4-21 lactation intervals, respectively, for the treated groups were comparable to control and no adverse effect of treatment was indicated from these data.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Mean pup weights at birth at each recording interval during lactation (Days 4, 7, 14 and 21) for the low- and mid-dose groups were comparable to control for the F1 litter intevals. In the high-dose group, mean pup weights at birth were comparable to control but for the remainder of the lactation period, mean pup weights were lower than control and in most instances these differences were statististically significant. These decreases in pup weight data for the high-dose group during the lactation period were considered indicative of a treatment-related response.

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

At the high-dose level, pale kidneys, pale/white livers and/or enlarged hearts were seen in some pups and these findings were considered to be treatment-related; these findings were not seen in any of the control pups. In the F1 litters, pale kidneys (incidence: 8/110) and livers (incidence 7/110) were seen in some pups from two high-dose females. In addition, enlarged hearts (incidence: 4/110) were seen in pups from one litter.

Histopathological findings:

no effects observed

At the 1800 ppm dietary level, a decrease in mean body weights during lactation for both the F1 and F2 litters (significantly decreased pup body weights during lactation days 7, 14, and 21 (82%-88% of control in F1 offspring) and days 4, 7, 14, and 21 (74%-89%) of control in F2 offspring) and an increased incidence of F1 and F2 animals with pale/white livers and/or kidneys and enlarged hearts at weaning.

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

600 ppm (nominal)

Sex:

male/female

Basis for effect level:

body weight and weight gain

gross pathology

Clinical signs:

no effects observed

Mortality / viability:

mortality observed, non-treatment-related

Description (incidence and severity):

Mean pup viability and weaning indices for the treated groups were considered comparable to control and no adversely affected by treatment.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Mean pup weights at birth at each recording interval during lactation (Days 4, 7, 14 and 21) for the low- and mid-dose groups were comparable to control for the F2 litter intevals. In the high-dose group, mean pup weights at birth were comparable to control but for the remainder of the lactation period, mean pup weights were lower than control and in most instances these differences were statististically significant. These decreases in pup weight data for the high-dose group during the lactation period were considered indicative of a treatment-related response.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

At the high-dose level, pale kidneys, pale/white livers and/or enlarged hearts were seen in some pups and these findings were considered to be treatment-related; these findings were not seen in any of the control pups. In the F2 litters, pale/white livers (incidence: 11/154) were seen in pups from three high-dose females. In addition, pale kidneys (incidence: 5/154) ) and enlarged hearts (incidence: 7/154) were seen in some pups from two of the same litters.

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

600 ppm (nominal)

Sex:

male/female

Basis for effect level:

body weight and weight gain

gross pathology

Reproductive effects observed:

not specified

Conclusions:

From this study a NOAEL for fertility of >1800 ppm corresponding to >128 mg cryolite/kg bw/day can be derived. Besides dental fluorosis and teeth whitening, no other compound-related systemic toxic effects could be revealed from this study with daily dosages of up to and including 128 mg cryolite/kg bw/day.

Executive summary:

In a two-generation reproduction study performed according to GLP and EPA Guideline 83 -4, Sprague-Dawley rats (30 per group) were administered trisodium hexafluoroaluminate (cryolite) in the diet at dose levels of 0, 200, 600, or 1800 ppm (representing 0, 14, 42, and 128 mg/kg/day for males and 0, 16, 49, and 149 mg/kg/day for females, respectively). Compound-related systemic toxicity was observed in a dose related manner among both sexes and generations at all dose levels as evidenced

by clinical signs of dental fluorosis. Whitening of the upper and/or lower incisors was observed in most treated animals of both generations. Bevelled anterior edge of the lower incisor was observed in 67% of animals from both generations at 1800 ppm. Mottled appearance of the lower incisor was noted at dose levels ≥ 600 ppm in 6%-40% of F1 animals; however, this effect was not dose related.

Reproductive toxicity was observed at 1800 ppm as evidenced by significantly decreased pup body weights during lactation days 7, 14, and 21 (82%-88% of control in F1 offspring) and days 4, 7, 14, and 21 (74%-89% of control in F2 offspring). Gross findings were also observed in pups of both generations at 1800 ppm by the time of weaning. They were manifested as pale kidneys, pale livers and enlarged hearts and were considered to be compound related. No effects were observed on parental reproductive performance.

From this study a NOAEL for fertility of >1800 ppm corresponding to >128 mg cryolite/kg bw/day can be derived. Besides dental fluorosis and teeth whitening, no other compound-related systemic toxic effects could be revealed from this study with daily dosages of up to and including 128 mg cryolite/kg bw/day.

Based on the observed decreased mean body weights during lactation for both the F1 and F2 litters and an increased incidence of F1 and F2 animals with pale/white livers and/or kidneys and enlarged hearts at weaning at 1800 ppm, a NOAEL for developmental toxicity of 600 ppm (42 mg cryolite/kg bw/day) is derived from this study.

Reference 2

Endpoint:

two-generation reproductive toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See attached justification.

Reason / purpose for cross-reference:

read-across source

Key result

Remarks on result:

other: There is no indication for fertility risks caused by lithium cryolite based on the results of the two-generation study with the structural analogue trisodium hexafluoroaluminate.

Critical effects observed:

no

Key result

Remarks on result:

other: See Remarks.

Remarks:

There is no indication for fertility risks caused by lithium cryolte based on the results of the two-generation study with the structural analogue trisodium hexafluoroaluminate.

Critical effects observed:

no

Key result

Reproductive effects observed:

no

Conclusions:

There is no indication for fertility risks caused by lithium cryolite based on the results of the two-generation study with the structural analogue trisodium hexafluoroaluminate.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

128 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

GLP compliant guideline study, klimisch 1

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

No two-generation reproduction toxicity study is available on lithium cryolite. However, Article 13 of the REACH legislation states that, in case no appropriate animal studies are available for assessment, information should be generated whenever possible by means other than vertebrate animal tests, i.e., applying alternative methods such as in vitro tests, QSARs, grouping and read-across.

For the structural analogue cryolite, a two-generation toxicity study is available. In this two-generation reproduction study, Sprague-Dawley rats (30 per group) were administered cryolite in the diet at dose levels of 0, 200, 600, or 1800 ppm (representing 0, 14, 42, and 128 mg/kg/day for males and 0, 16, 49, and 149 mg/kg/day for females, respectively, during premating) (Pharmaco LSR, Inc., 1994). Compound-related systemic toxicity was observed in a dose related manner among both sexes and generations at all dose levels as evidenced by clinical signs of dental fluorosis. Whitening of the upper and/or lower incisors was observed in most treated animals of both generations. Bevelled anterior edge of the lower incisor was observed in 67% of animals from both generations at 1800 ppm. Mottled appearance of the lower incisor was noted at dose levels ≥ 600 ppm in 6%-40% of F1 animals; however, this sign was not dose related.

Reproductive toxicity was observed at 1800 ppm as evidenced by significantly decreased pup body weights during lactation days 7, 14, and 21 (82%-88% of control in F1 offspring) and days 4, 7, 14, and 21 (74%-89%) of control in F2 offspring). Gross findings were also observed in pups of both generations at 1800 ppm by the time of weaning. They were manifested as pale kidneys, pale livers and enlarged hearts and were considered to be compound related. No effects were observed on parental reproductive performance.

From this study a NOAEL for fertility of >1800 ppm (>128 mg cryolite/kg bw/day) can be derived. As there is no indication for fertility risks, a quantitative assessment for effects on fertility is not necessary. Besides dental fluorosis and teeth whitening, no other compound-related systemically toxic effects could be revealed from this study with daily dosages of up to and including 128 mg cryolite/kg bw/day. Based on the observed decreased mean body weights during lactation for both the F1 and F2 litters and an increased incidence of F1 and F2 animals with pale/white livers and/or kidneys and enlarged hearts at weaning at 1800 ppm, a NOAEL for developmental toxicity of 600 ppm (42 mg cryolite/kg bw/day) is derived from this study (see also section on developmental toxicity).

Based on the available data (repeated dose toxicity studies with lithium cryolite in which only local effects were observed and the two-generation study with cryolite), there is no indication for fertility risks caused by lithium cryolite. Therefore, a quantitative assessment is not considered necessary for this endpoint.

Effects on developmental toxicity

Description of key information

No developmental toxicity was observed up to the highest dose level tested (90 mg/kg) in the OECD 414 study with the source substance lithium carbonate and the effects observed in the two-generation study with cryolite are not sufficient for C&L as developmental toxicant.

However, in the two-generation study with cryolite the observed reduced offspring body weight gain during the pre-weaning period in the highest dose group as well as compound related pathological organ findings in several pup organs at the time of weaning, were considered indicative for a specific toxic potential of cryolite adverse to development. Therefore it was proposed to classify cryolite as H362 (‘May cause harm to breast-fed children’). Based on the structural similarities, the target substance lithium cryolite should also be classified as H362 (‘May cause harm to breast-fed children’).

The justification of the read-across strategy is available in the attached document of the endpoint study record of the target substance.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 83-3 (Prenatal Developmental Toxicity Study)

GLP compliance:

yes

Limit test:

no

Species:

mouse

Strain:

other: Crl:CD-1 (ICR) BR

Details on test animals or test system and environmental conditions:

One hundred fifty four sexually mature, virgin female mice, CrI:CD-1. (ICR) BR, were received from Charles River Breeding Laboratories, Inc., Montreal, Quebec, on June 11, 1991. The animals were approximately 10 weeks old upon receipt. Upon arrival and until pairing, all animals were individually housed in clean, wire-mesh cages suspended above cage-board. Body weights ranged from 18.3 to 32.8 g. All animals were housed for 16 days for acclimation purposes.

The basal diet used in this study was Purina Certified Rodent Chow #5002. Drinking water delivered by an automatic watering system and the feed were provided ad libitum throughout the acclimation period and during the study.

All animals were housed throughout the acclimation period and during the study in an environmentally-controlled room. Controls were set to maintain temperature at 72° + 3°F and relative humidity at 40-80%. Room temperature and relative humidity were recorded daily. Temperature ranged from 68°F to 72°F and relative humidity ranged from 46% to 70% during the study period. The single variation from the set temperature level did not apparently affect the outcome of the study. Light timers were calibrated to provide a 12-hour light/12-hour dark photoperiod. Air handling units were set to provide approximately 10 fresh air changes per hour.

Route of administration:

oral: gavage

Vehicle:

other: 0.5% aqueous methylcellulose

Details on exposure:

The test mixtures were administered orally by gavage, via a stainless steel gavage cannula, once daily for 10 consecutive days initiating on gestation day 6 and continuing up to and including day 15 of gestation. A dosage volume of 5 ml/kg was used for all dosage levels. The control animals received 0.5% aqueous methylcellulose on a comparable regimen of 5 ml/kg. Individual dosages were based on the most recently recorded body weights to provide the correct mg/kg dose.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of dosing preparations from each group, including the control group, were analyzed using a dissolution/ion-selective electrode method to determine homogeneity, 8-day stability and concentration. The suspensions were homogeneous, contained the proper amount of test material and were stable for eight days under refrigeration.

Details on mating procedure:

At the conclusion of the acclimation period, all available females were weighed and examined in detail for physical abnormalities. At the discretion of the study director, animals judged to be in good health and meeting acceptable body weight requirements (24.0 to 32.0 g) were placed in suspended wire-mesh cages with a resident male. The resident males were untreated, sexually mature mice utilized exclusively for breeding. These CrI:CD 1(ICR)BR male mice were also received from Charles River Breeding Laboratories, Inc., Montreal, Quebec, on June 11, 1991, and were the same age as the females (approximately 10 weeks old). The animals were paired on a 1:1 basis. The male mice were maintained under similar laboratory conditions as the females. The selected females were approximately 12 weeks old when paired for breeding.

Positive evidence of mating was confirmed by the presence of a copulatory plug in the vagina. Each mating pair was examined daily. The day on which evidence of mating was identified was termed day 0 of gestation and the animals were separated.

Duration of treatment / exposure:

from gestation days 6 through 15

Frequency of treatment:

once daily

Duration of test:

up to gestation day 18

Dose / conc.:

30 mg/kg bw/day

Dose / conc.:

100 mg/kg bw/day

Dose / conc.:

300 mg/kg bw/day

No. of animals per sex per dose:

25

Control animals:

yes, concurrent vehicle

Details on study design:

The experimental design for WlL-160005 consisted of three Kryocide treated groups and one control group. The bred females were consecutively assigned in a block design to groups containing 25 mice each by the following randomization procedure. The first mated female and the appropriate gestation day 0 designation were entered on the form and the female was assigned to group 1, the second mated female was assigned to group 2, and the third to group 3, etc. This process was continued daily until 25 females had been placed into each group. Surplus females were returned to individual wire-mesh cages for scheduled euthanization.
All mice were observed twice daily for moribundity and mortality. Individual detailed clinical findings, as appropriate, were recorded from days 0 through 18 of gestation (prior to compound administration during the dosing period). Animals were also observed for signs of toxicity approximately one hour following treatment during the dosing period. In addition, significant clinical findings were also observed and recorded for single animals on two days at the time of dosing. Animals aborted and animals moribund were euthanized at the study directors request, necropsied and the findings recorded. Females that delivered on gestation day 18 were necropsied. Because gestation day 18 is the normal length of gestation for this species, fetuses from dams that delivered on gestation day 18 were processed as described for those examined after Cesarean section if all implantation sites were accounted for.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: From days 0 through 18 of gestation

BODY WEIGHT: Yes
- Time schedule for examinations: Gestation days 0, 6-16 and 18

FOOD CONSUMPTION: Yes
- Time schedule: From days 0 through 18 of gestation

WATER CONSUMPTION: No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 18

Ovaries and uterine content:

On day 18 of gestation, all surviving females were euthanized for a scheduled Cesarean section. The uteri and ovaries were examined and the numbers of fetuses, early and late resorptions, total implantations and corpora lutea were recorded. Mean gravid uterine weights and net body weight changes were calculated for each group.

Fetal examinations:

On day 18 of gestation, atl surviving females were euthanized for a scheduled Cesarean section. Fetuses were weighed, sexed and examined for external, skeletal and soft tissue malformations and developmental variations.

Statistics:

All analyses were conducted using two-tailed tests for a minimum significance level of 5% comparing each treated group to the vehicle control group. Each mean was presented with the standard deviation (S.D.) and the number animals (N) used to calculate the mean. All statistical tests were performed by a Digital Microvax 3400 computer with appropriate programming.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Maternal toxicity was expressed by two mortalities in the 300 mg/kg bw/day group. Another animal from this group was euthanized at the study directorts request. One mortality in the 100 mg/kg bw/day group was the only other potential maternal effect in the study. Clinical signs were observed in the animal euthanized in the 300 mg/kg bw/day group and in the animal found dead in the 100 mg/kg bw/day group. Necropsy findings in these animals were limited to reddened mucosa of the glandular portion of the stomach, dark red areas of the glandular portion of the stomach, pale liver and dark red contents in the stomach. Clinical findings in animals surviving to the scheduled necropsy could not be attributed to test article administration. No adverse effects were apparent on body weight gain and food consumption at any dose level.

Dose descriptor:

NOAEL

Effect level:

30 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Although there was no indication that embryonic survivability or fetal growth were affected at this dose level, anatomical development was apparently affected; s notably increased (although not statistically significant) incidence of the fetal variant bent ribs was expressed at this dose level. In conjunction, two fetuses in two separate litters had bent limb bones, a limited and non statistically significant incidence of a fetal malformation. Neither bent ribs nor bent limb bones have occurred in control mice in this laboratory. However, abnormal morphology of the limb bones was not reproduced in a previous developmental toxicity study with the substance. A single maternal mortality in the 100 mg/kg bw/day group was the only indication of potential maternal toxicity at this dose level. However, because fetal anatomical development, survival and fetal growth were not affected at this dose level, 100 mg/kg/day was considered to be the NOAEL (no observable adverse effect level) for developmental toxicity. The 30 mg/kg bw/day dose level was considered to be the NOAEL for maternal toxicity.

Dose descriptor:

NOAEL

Effect level:

100 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: developmental toxicity

Abnormalities:

not specified

Developmental effects observed:

not specified

Executive summary:

Trisodium hexafluoroaluminate (cryolite) was investigated for prenatal developmental toxicity in mice in a GLP compliant study according to EPA Guideline 83 -3. Cryolite was administered by oral gavage to female CD-1 mice (25/group) at dose levels of 0, 30, 100 or 300 mg/kg bw/day once daily from gestation days 6 to 15 (WIL Research Laboratories, 1991). There was increased mortality at 300 mg/kg bw/day. The glandular portion of the stomach was red beginning at 100 mg/kg bw/day. In addition, females in the 300 mg/kg bw/day group exhibited dark red contents of the stomach. Fetuses at 300 mg/kg bw/day exhibited bent ribs and bent limb bones. The study reveals severe maternal toxicity in terms of mortality and signs of toxicity in the gastrointestinal tract induced at dosages of >100 mg cryolite/kg bw/day leading to derivation of a NOAEL for maternal toxicity of 30 mg cryolite/kg bw/day.

Based on the observation of skeletal anomalies at the dose level of 300 mg cryolite/kg bw/day also a NOAEL for developmental toxicity of 100 mg cryolite/kg bw/day can be derived from the study. As these anomalies were only reported at dose levels showing severe maternal toxicity, the effects are not considered to be indicative for a substance specific teratogenic potential of cryolite.

Reference 2

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See attached justification.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Remarks on result:

other: See Remark

Remarks:

Information from the structural analogue trisodium hexafluoroaluminate (cryolite) has been used to assess the developmental toxicity of lithium cryolite. The lithium moiety of the molecule was assessed by using the results of a developmental toxicity study with lithium carbonate. Based on these results lithium cryolite is not to be considered as developmental toxicant.

Key result

Remarks on result:

other: See remark.

Remarks:

Information from the structural analogue trisodium hexafluoroaluminate (cryolite) has been used to assess the developmental toxicity of lithium cryolite. The lithium moiety of the molecule was assessed by using the results of a developmental toxicity study with lithium carbonate. Based on these results lithium cryolite is not to be considered as developmental toxicant.

Developmental effects observed:

no

Conclusions:

Information from the structural analogue trisodium hexafluoroaluminate (cryolite) has been used to assess the developmental toxicity of lithium cryolite. The potential effect of the lithium moiety has been assessed by analogy with lithium carbonate. Based on these results lithium cvryolite is not to be considered as developmental toxicant.

Reference 3

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-02-18 to 2010-07-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline compliant study.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.31 (Prenatal Developmental Toxicity Study)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

other: Crl: CD(SD)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Research, Models and Services Germany GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
- Age at study initiation: 8 - 9 weeks
- Weight at study initiation: 185 - 234 g
- Housing: MAKROLON cages (type III) with a basal surface of approx. 39 cm x 23 cm and a height of approx. 15 cm
- Diet: Commercial ssniff® R/Z V1324, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3 degree C
- Humidity (%): 55 +/- 15 %
- Photoperiod (hrs dark / hrs light): 12 hrs dark/ 12 hrs light

Route of administration:

oral: gavage

Vehicle:

other: 0.5% aqueous hydroxypropyl methyl cellulose gel (Methocel)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was suspended in the vehicle 0.5% aqueous hydroxypropyl methyl cellulose gel (Methocel)1 to the appropriate concentrations and was administered orally at a constant volume of 5 mL/kg b.w. once daily from the 6th to the 19th day of pregnancy. The dose of the test item was adjusted to the animal's body weight daily. The control animals received the vehicle at a constant volume of 5 mL/kg b.w. orally once daily in the same way. The test item mixtures were freshly prepared every day approx. 1h before use.

Applied volume: 5 mL/kg bw/day

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

For the analysis of the test item formulations, samples of approx. 10 mL were taken at the following times:
At the beginning of the administration period: Analysis of concentration/homogeneity.
At start of administration, during (middle) administration and before administration to the last animal of each group (3 samples/dose level group).
Total number of samples: 9

At termination of the administration period ata time point when the majority of animals was dosed: Analysis of concentration/homogeneity.
At start of administration, during (middle) administration and before administration to the last animal of each dose level group (3 sample/dose level group).
Total number of samples: 9

Thus, the sum of all samples is 18.

The samples were labelled with the study number, species, type of sample, test item, concentration, sampling time and date and were stored immediately after withdrawal at -20 degree C or colder until dispatch.

The formulation samples were analysed for Lithium levels according to GLP by the Test Site AllessaChemie GmbH. The Phase Plan “Bestimmung des Lithiumgehaltes in Trägergemisch mittels ICP-OES (Teil-Prüfplan VP-Nummer 005/2010)” and any amendments to this Phase Plan are part of the LPT Study Plan 24635.

The analysis of the test item-carrier mixtures for Lithium levels revealed that the formulations used for the administrations in groups 2 to 4 were correctly prepared. The measured actual concentrations ranged from 96.45% to 103.64% of the nominal values. The results were within the expected range of the theoretical concentrations.

Details on mating procedure:

Sexually mature ('proved') male rats of the same breed served as partners. The female breeding partners were randomly chosen. Mating was monogamous: 1 male and 1 female animal were placed together in one cage during the dark period. Each morning a vaginal smear was taken to check for the presence of sperm. If findings were negative, mating was repeated with the same partner. The day on which sperm was found was considered as the day of conception (day 0 of pregnancy). This procedure was repeated until enough pregnant dams were available for all groups. Rats which did not become pregnant were excluded from the analysis of the results and replaced by other animals. A post-mortem negative staining according to SALEWSKI was carried out in the replaced animals in order to confirm the non-pregnancy status.

Duration of treatment / exposure:

From the 6th to the 19th day of pregnancy.

Frequency of treatment:

Once daily from the 6th to the 19th day of pregnancy.

Duration of test:

20 days after mating

No. of animals per sex per dose:

25

Control animals:

yes

Details on study design:

Summary on animals examined: 21 dams per dose group

Evaluated litters: 20 per dose group

Non pregnant dams: 1 in dose groups 0, 30 and 90 mg/kg bw/ day, i.e. 3 in total

Dams without viable fetuses: 1 (dose group 30 mg/kg bw/day)

Maternal examinations:

CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Immediately after administration, any signs of illness or reaction to treatment were recorded. In case of changes, the animals were observed until the symptoms disappeared. In addition, animals were checked regularly throughout the working day from 7.00 a.m. to 3.45 p.m. On Saturdays and Sundays, the animals were checked regularly starting from 7.00 a.m. to 11.00 a.m. with a final check performed at approximately 3.30 p.m.

BODY WEIGHT: Yes
- Time schedule for examinations: The weight of each rat was recorded on day 0 of gestation (the day of detection of a positive mating sign), followed by daily weighings - always at the same time of the day. The body weight gain was also calculated in intervals (i.e. day 0-3, 3- 6, 6-9, 9-12, 12-15, 15-18 and 18-20).

FOOD CONSUMPTION: Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

Weights of fetuses and weights of the placentae were determined (fetuses were considered as runts if their weight was less than 70% of the mean litter
weight). Fetuses were inspected externally for damages, especially for malformations. The fetuses were sacrificed by an ether atmosphere.

Statistics:

For all numerical values, homogeneity of variances was tested using the BARTLETT chi-square test. When the variances were homogeneous, the DUNNETT test (p <= 0.01) was used to compare the experimental groups with the control group. In case of heterogeneity of variances, the STUDENT's t-test was carried out, limit of significance was p <= 0.01. For the comparison of classification measurements (for example malformation-, resorption-, retardation- and variation rate) the FISHER's exact test (n < 100) or chi2-test with YATES' correction for continuity (n >= 100) (p <= 0.05 and p <= 0.01) was employed.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Slight but significant reductions were noted for the net weight change and the food intake.

Dose descriptor:

NOEL

Effect level:

30 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Dose descriptor:

NOEL

Effect level:

90 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: embryotoxicity

Abnormalities:

not specified

Developmental effects observed:

not specified

Influence on the dam:

Mortality: None of the dams treated with 10, 30 or 90 mg Lithium Carbonate/kg b.w./day died prematurely during the course of the study.

Clinical signs: Pilo-erection was noted in four high-dosed dams treated with 90 mg Lithium Carbonate/kg b.w./day on two to four days, starting on gestation day 17 or 19 and lasting until laparotomy on gestation day 20. The drinking water intake of all high-dosed dams treated with 90 mg Lithium Carbonate/kg b.w./day was increased starting on gestation day 17, 18 or 19 and lasting until laparotomy on gestation day 20.

Body weight and body weight gain: Marginal reductions were noted for the mean body weights of the high-dosed dams (90 mg Lithium Carbonate/kg b.w./day) during the last gestation days. The increase in the mean body weight from the start value (day 0 of pregnancy) was 66.9% at the time point of laparotomy (control: 74.4%). Significant reductions (at p ≤ 0.01) were noted for the net weight change of the high-dosed dams from day 6 of gestation to laparotomy on gestation day 20 (carcass weight minus day 6 body weight).

Food consumption: Slight but statistically significant reductions (at p <= 0.01 or p <= 0.05) were determined for the relative food consumption of the high-dosed dams (90 mg Lithium Carbonate/kg b.w./day) on gestation days 7, 9, 11 to 13 and 19 (up to 18.3% below the control value).

Drinking water consumption: Increased intake of drinking water was noted in all high dosed females treated with 90 mg Lithium Carbonate/kg b.w./day on one to four days, starting on gestation day 17 (qualitative observation by visual appraisal).

Necropsy findings: No test item-related pathological findings were noted.

Uterus and carcass weights: The gravid uterus weight and the carcass weight were not influenced by the exposure to the test item. Influence on the fetus: No test item-related influence was noted on the prenatal fetal development at 10, 30 or 90 mg Lithium Carbonate/kg b.w./day with respect to the number of corpora lutea, implantation sites, resorptions, sex distribution, fetal and placental weights, number of live fetuses at birth and the values calculated for the pre- and postimplantation loss when compared to the control. No dead fetuses or runts were noted at laparotomy. Malformations No malformations were noted in the fetuses during external/ internal examination, skeletal examination (according to DAWSON) or soft tissue evaluation (according to WILSON). Variations No test item-related variations were noted in the fetuses during external / internal examination, skeletal examination (according to DAWSON) or soft tissue evaluation (according to WILSON). Retardations No test item-related influence was noted for the incidence of skeletal retardations.

Toxicokinetics: The toxicokinetic analysis based on Lithium plasma levels revealed a clear dose related systemic exposure to Lithium. Mean peak plasma levels of 1.66, 3.59 and 9.65 mg Li/L plasma, respectively, were observed at 10, 30 or 90 mg Lithium Carbonate/ kg b.w./day on gestation day 19. The plasma concentrations declined with a mean elimination half-life for Lithium between 8.4 to 12.0 hours. Toxicokinetics demonstrated dose proportional increases of Lithium plasma concentrations between 10 and 90 mg Lithium Carbonate/kg b.w./day. Peak time and half-life and increased with dose levels.

Analysis of test item formulation (performed by the Test Site AllessaChemie GmbH, Germany): The analysis of the test item-carrier mixtures for Lithium levels revealed that the formulations used for the administrations in groups 2 to 4 were correctly prepared. The measured actual concentrations ranged from 96.45% to 103.64% of the nominal values. The results were within the expected range of the theoretical concentrations.

Conclusions:

Under the present test conditions, the no-observed-effect level (NOEL) was 30 mg Lithium Carbonate/kg bw/day for the dams. The NOEL for the fetuses was >= 90 mg Lithium Carbonate/kg bw/day.

Executive summary:

An prenatal developmental toxicity study was performed in rats (strain: Crl CD (SD)) according to OECD guideline 414 and EU method B.31. In this rat embryotoxicity study, the test item Lithium Carbonate was administered to female rats at concentrations of 10, 30 or 90 mg/kg bw/day orally by gavage from the 6th to 19th day of pregnancy. Under the present test conditions, the no-observed-effect level (NOEL) was 30 mg Lithium carbonate/kg bw/day for the dams (maternal NOEL). At 90 mg Lithium carbonate/kg bw/day, pilo-erection was noted in a few dams. Furthermore, slight but significant reductions were noted for the net weight change and the food intake. The NOEL for the fetuses was >= 90 mg Lithium Carbonate/kg bw/day. There was no test item-related increase in the incidence of fetal malformations, external/ internal, skeletal or soft tissue variations or skeletal retardations. The toxicokinetic analysis revealed a clear dose-related systemic exposure to Lithium. In conclusion, no embryotoxic properties of the test item were noted during external/ internal, skeletal and soft tissue examinations. No test item-related increase was noted in the incidence of malformations, variations or retardations, not even at the materno-toxic dose level of 90 mg Lithium Carbonate/kg bw/day.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

42 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

GLP compliant guideline study, klimisch 1

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

No developmental toxicity study is available on lithium cryolite. However, Article 13 of the REACH legislation states that, in case no appropriate animal studies are available for assessment, information should be generated whenever possible by means other than vertebrate animal tests, i. e., applying alternative methods such as in vitro tests, QSARs, grouping and read-across. For the structural analogue cryolite, developmental toxicity studies are available.

Cryolite was investigated for prenatal developmental toxicity in rats, mice and rabbits with the oral route of administration. While in the studies with rats and with rabbits no evidence of prenatal developmental toxicity was observed, some indications of bent ribs and bent limb bones were reported in the mice study which is therefore considered for the read-across approach.

Cryolite was administered by gavage in the developmental toxicity study to female CD-1 mice (25/group) at dose levels of 0, 30, 100 or 300 mg/kg bw/day once daily from gestation days 6 through 15 (WIL Research Laboratories, 1991). There was increased mortality at 300 mg/kg bw/day. The glandular portion of the stomach was red beginning at 100 mg/kg bw/day. In addition, females in the 300 mg/kg bw/day group exhibited dark red contents of the stomach. Fetuses at 300 mg/kg bw/day exhibited bent ribs and bent limb bones. The study reveals severe maternal toxicity in terms of mortality and signs of toxicity in the gastrointestinal tract induced at dosages of 100 mg cryolite/kg bw/day leading to derivation of a NOAEL for maternal toxicity of 30 mg cryolite/kg bw/day.

Based on the observation of skeletal anomalies at the dose level of 300 mg cryolite/kg bw/day also a NOAEL for developmental toxicity of 100 mg cryolite/kg bw/day can be derived from the study. As these anomalies were only reported at dose levels showing severe maternal toxicity, the effects are not considered to be indicative for a substance specific teratogenic potential of cryolite.

 

During the two-generation study with cryolite in rats (Pharmaco LSR, Inc., 1994), effects on postnatal growth evidenced by significantly decreased pup body weights during lactation as well as pathologic gross findings in several organs (kidney, liver, heart) of the pups resulted from dose levels without any parental toxicity. Because these effects occurred without any significant sign for parental toxicity it is considered to be indicative for a specific toxic potential of cryolite adverse to postnatal development. The respective NOAEL for these effects in this study was 42 mg cryolite/kg bw/day.

 

As systemic toxicity of both cryolite and lithium cryolite is primarily governed by accumulation of the fluoride formed upon hydrolysis of fluoroaluminate moieties, the same type of effects on reproduction and development as observed for cryolite can also be expected for lithium cryolite.

To assess the potential effects of the lithium moiety on the developmental toxicity, a read-across is performed with a prenatal developmental toxicity study performed with Lithium Carbonate in rats (strain: Crl CD (SD)) according to OECD guideline 414 and EU method B.31. In this rat embryotoxicity study, the test item Lithium Carbonate was administered to female rats at concentrations of 10, 30 or 90 mg/kg bw/day orally by gavage from the 6th to 19th day of pregnancy. Under the present test conditions, the no-observed-effect level (NOEL) was 30 mg Lithium carbonate/kg bw/day for the dams (maternal NOEL). At 90 mg Lithium carbonate/kg bw/day, pilo-erection was noted in a few dams. Furthermore, slight but significant reductions were noted for the net weight change and the food intake. The NOEL for the fetuses was >= 90 mg Lithium Carbonate/kg bw/day. There was no test item-related increase in the incidence of fetal malformations, external/ internal, skeletal or soft tissue variations or skeletal retardations. The toxicokinetic analysis revealed a clear dose-related systemic exposure to Lithium. In conclusion, no embryotoxic properties of the test item were noted during external/ internal, skeletal and soft tissue examinations. No test item-related increase was noted in the incidence of malformations, variations or retardations, not even at the materno-toxic dose level of 90 mg Lithium Carbonate/kg bw/day.

Therefore, the lithium moiety does not generate additional developmental toxicity effects to lithium cryolite.

Justification for classification or non-classification

In the two-generation study with cryolite the observed reduced offspring body weight gain during the pre-weaning period in the highest dose group as well as compound related pathological organ findings in several pup organs at the time of weaning, were considered indicative for a specific toxic potential of cryolite adverse to development. Therefore it was proposed to classify cryolite as H362 (‘May cause harm to breast-fed children’). Based on the structural similarities, the target substance lithium cryolite should also be classified as H362 (‘May cause harm to breast-fed children’).