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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
August 1998 to December 2000
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Meets generally accepted scientific standards with acceptable restrictions. The highest dose level in this study, 10 mg/kg/day, did not result in toxicity of the parental animals.
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
other: OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Principles of method if other than guideline:
Similar to OECD 416
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Nickel(II) sulphate Hexahydrate; 10101-97-0
- Molecular formula (if other than submission substance): not different than submission substance
- Molecular weight (if other than submission substance): not different than submission substance
- Smiles notation (if other than submission substance): not different than submission substance
- InChl (if other than submission substance): not different than submission substance
- Structural formula attached as image file (if other than submission substance): not different than submission substance
- Physical state: blue green crystalline powder
- Purity: 99%
- Lot No.: 08516TQ
- Other details: not reported or not applicable

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, NY, USA
- Age at study initiation: 7 weeks
- Weight at study initiation: 205-257 g (males) and 147-213 (females)
- Fasting period before study: not reported
- Housing: individually
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 10 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-26 deg. C
- Humidity (%): 30-70%
- Air changes (per hr): 10-15 per hour
- Photoperiod (hrs dark / hrs light): 12-h light/dark photoperiod


IN-LIFE DATES: From: February 1, 1999 To: October 15, 1999

Administration / exposure

Route of administration:
oral: gavage
Type of inhalation exposure (if applicable):
other: not applicable
Vehicle:
other: reverse osmosis deionized water
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
The test substance was dissolved in reverse osmosis deionized water.  Control animals received appropriate volumes of water only.  The  
homogeneity and stability of the test substance in dosing solutions were determined.  The concentration of the test substance in dosing solutions  
was analytically confirmed at different time intervals during the study period. Groups of 56 test animals of each parental group (28 males/28  
females) received the test substance daily by gavage at the following dosage concentrations:  0, 0.1, 0.25, 0.50, and 1.00 mg/ml (equivalent to  
dose levels of 0, 1.0, 2.5, 5.0, and 10.0 mg/kg/day).  Dose volume was 10 ml/kg, adjusted for body weight.  F0 parents and F1 pups selected as the  
parental group for the F2 generation received the test substance daily by gavage.  F0 parental animals received the test substance (or vehicle for  
control group) daily for 10 weeks, starting 70 days prior to mating.  F1 offspring selected to produce the F2 generation received the test  
substance starting on postpartum day 22 and dosing continued until one day prior to sacrifice.

DIET PREPARATION
- not applicable

VEHICLE
- deionized water
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analyzed by AAS
Details on mating procedure:
- M/F ratio per cage: Animals were caged as mating pairs (1:1) until copulation was confirmed, then transferred to individual cages.
- Proof of pregnancy: The presence of a vaginal plug or sperm was designated as day 0 of gestation.
-Estrous cycle determinations (length and normality) were made daily prior to mating and during cohabitation.
-Dams and pups were caged together during lactation.
Duration of treatment / exposure:
Exposure period: F0: before and during mating, pregnancy, and through weaning of F1 offspring. F1: after weaning,
during growth, mating, production and weaning of F2 offspring
Premating exposure period (males): 70 days
Premating exposure period (females): 70 days
Duration of test: 2 generations
Frequency of treatment:
daily
Duration of test:
two generations
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 1.0, 2.5, 5.0, and 10.0 mg/kg/day
Basis:
nominal conc.
No. of animals per sex per dose:
28 males/28 females per dose
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Based on the results of 1 generation study, the doses of 0, 1, 2.5, 5.0, and 10.0 mg/kg/day were selected
- Rationale for animal assignment (if not random): random

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly
- During gestation and lactation, F0 and F1 females were examined daily for clinical signs of toxicity.

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule for examinations: weekly

Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
- Gravid uterus weight: Yes
- Number of corpora lutea: No data
- Number of implantation scar counts: Yes
- Number of live pups on lactation day 0
- Number of post-implantation losses: Yes
- Number of early resorptions: No data
- Number of late resorptions: No data
Fetal examinations:
- External examinations: Yes:
- Soft tissue examinations: Yes:
- Skeletal examinations: No data
- Head examinations: No data
Statistics:
One-way analysis of variance (ANOVA) was used to analyze parental and pup body weight, body weight gain, food consumption, organ weights, 
length of gestation and estrous cycle, and litter size.  If significance was detected, Dunnett's test was performed to compare control and treatment  
groups.  Copulation and fertility indices, pup sex ratios, numbers of live and dead pups, and pup survival were evaluated by Chi-Square test.   
Post-implantation loss was evaluated using the Mann-Whitney U test.  The level of significance was 5% (p<0.05).
Indices:
F0 and F1 Reproduction Indices: There were no statistically significant or toxicologically meaningful differences in F0 copulation and fertility indices, estrous cyclicity, precoital intervals, or gestation lengths.
Historical control data:
not reported

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:no effects

Details on maternal toxic effects:
CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS):
F0 generation: No test substance related mortality of clinical signs of toxicity.  

ALL PARAMETERS:
There were no toxicologically meaningful differences in body weight gain or food consumption, copulation and fertility indices, gestation length, implantation and post-implantation loss, or sperm parameters.  The numbers of live pups of treated female on lactation day 0 were not significantly different from that control group.  Post-implantation loss  was higher at 10 mg/kg/day (2.1), but was not statistically different from the control group (0.9). No treatment related changes found at gross necropsy.  Statistically significant differences in organ weights included decreased absolute and relative livers weights in males at 10 mg/kg/day, decreased absolute brain weight in females at 2.5 mg/kg/day, and increased relative liver weight in females at 1.0, 2.5, and 10.0 mg/kg/day.

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
10 mg/kg bw/day (nominal)
Basis for effect level:
other: other:

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
F1 generation: There were no toxicologically meaningful differences in pup viability data or pup body weights during lactation. Mean litter size on 
lactation day 0 ranged from 13.6 pups/litter (1.0 mg/kg/day group) to 11.4 pups per litter (10 mg/kg/day group).  Post-implantation loss was 
slightly higher at 10 mg/kg/day (1.2), but was not statistically different from the control group (0.9). Clinical signs were noted during lactation, 
but were not considered to be test-substance related.  Clinical signs were of low incidence and sporadically distributed among treatment groups. 
Vaginal opening and completion of preputial separation differences were not considered to be treatment related. Vaginal opening of control and 10 mg/kg/day pups occurred by postpartum day 35.  Preputial separation of control and male pups in the 10 mg/kg/day group was completed by 
postpartum day 46.  Gross necropsy observations included atelectasis and absence of milk in the stomach.  Other necropsy findings were of low 
incidence and sporadically  distributed among treatment groups.

Of F1 animals selected to produce the F2 generation, no test substance related mortality of clinical signs of toxicity were noted.  Clinical  
signs were of low incidence and sporadically distributed among treatment  groups and were, therefore, not considered test substance related.  
There were no toxicologically meaningful differences in body weight or body weight gains during the growth phase, however, mean body weight 
gain was significantly lower in the 1.0 and 5.0 mg/kg/day treatment groups during lactation days 14-21.  There were no toxicologically meaningful  
differences in food consumption.  No statistically significant differences were found in copulation or fertility indices, estrous cycle  
determinations, precoital intervals, or gestation lengths.  There were no  statistically significant differences in mean implantation scar counts,  
mean number of live pups on lactation day 0, or mean post-implantation loss. Statistically significant differences in organ weights included  
decreased absolute pituitary weight in 1.0 mg/kg/day males, increased relative adrenal weight and decreased relative liver weight in 5.0 and  
10.0 mg/kg/day males, and decreased relative liver weight in 2.5 and 10.0 mg/kg/day females.  There were no toxicologically meaningful 
differences in sperm parameters of 10 mg/kg/day males.  No test substance related microscopic histopathological changes were noted.

F2 generation: No test substance related clinical signs of toxicity were noted.  There were no statistically significant differences in body weights 
during  lactation. Gross necropsy observations included atelectasis and absence of milk in the stomach.  Other necropsy findings were of low 
incidence  and sporadically distributed among treatment groups.

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Any other information on results incl. tables

The study was conducted to evaluate the potential effects of nickel sulfate hexahydrate administered to Sprague-Dawley rats in a  

two-generation study.  Oral (gavage) administration of nickel sulfate hexahydrate at dose levels up to 10 mg/kg/day (2.2 mg Ni/kg) had no  

effect on F0 or F1 survival, growth, mating behavior, fertility, gestation, parturition, or lactation.  There was no test substance  

related mortality or clinical signs of toxicity in F0 and F1 rats or their offspring.  Pup viability and growth was not affected.  There were  

no toxicologically meaningful differences in estrous cycling, sperm parameters, copulation, and fertility indices, precoital intervals,  

gestation lengths, gross necropsy findings, or the onset of sexual maturation in F1 rats.  Histopathological examinations did not reveal any  

test article-related changes in the liver, reproductive organs, or other tissues examined.  Statistically significant reductions in absolute  

and/or relative liver weights in F0 males at 10 mg/kg/day and in F1 males at 5.0 and 10.0 mg/kg/day were not regarded as toxicologically  significant.  

Relative liver weight values were less than 10% different  from the respective control values.  

Applicant's summary and conclusion

Conclusions:
Based on these results, 10.0 mg/kg/day is considered a No-Observed-Adverse-Effect Level (NOAEL) for oral administration of nickel sulfate hexahydrate over two generations in rats.
Executive summary:

ROBUST SUMMARY DEVELOPED BY AN INDEPENDENT REVIEWER.

Robust Summary for Siglin (2000)

Male and female Sprague-Dawley rats were obtained from Charles River Laboratories, NY, USA, and acclimated to laboratory conditions. Food and  

water were provided ad libitum during the study period.  Environmental conditions during the study were maintained at a temperature of 18-26  

deg. C, a relative humidity of 30-70%, and a 12-h light/dark photoperiod.

Animals were caged as mating pairs (1:1) until copulation was confirmed, then transferred to individual cages.  Estrous cycle determinations  

(length and normality) were made daily prior to mating and during cohabitation.  The presence of a vaginal plug or sperm was designated as  day 0 of gestation.  

Dams and pups were caged together during lactation.


The test substance was dissolved in reverse osmosis deionized water.  Control animals received appropriate volumes of water only.  The  

homogeneity and stability of the test substance in dosing solutions were determined.  The concentration of the test substance in dosing solutions  

was analytically confirmed at different time intervals during the study period. Groups of 56 test animals of each parental group (28 males/28  females) 

received the test substance daily by gavage at the following dosage concentrations:  0, 0.1, 0.25, 0.50, and 1.00 mg/ml (equivalent to  

dose levels of 0, 1.0, 2.5, 5.0, and 10.0 mg/kg/day).  Dose volume was 10 ml/kg, adjusted for body weight.  F0 parents and F1 pups selected as the  

parental group for the F2 generation received the test substance daily by gavage.  F0 parental animals received the test substance (or vehicle for  

control group) daily for 10 weeks, starting 70 days prior to mating.  F1 offspring selected to produce the F2 generation received the test  

substance starting on postpartum day 22 and dosing continued until one  day prior to sacrifice.

General health checks of F0 and F1 parental animals were made twice daily, and more detailed clinical observations were made weekly. During  

gestation and lactation, F0 and F1 females were examined daily for clinical signs of toxicity.

Individual body weights were measured weekly in F0 and F1 parental animals. Mated females and females that delivered were weighed on days 0,  

7, 14, and 20 during gestation, and on days 1, 4, 7, 14, and 21 during lactation.  Food consumption was recorded weekly, except during  

cohabitation and lactation.   The following parameters were recorded for each pup during lactation: viability, external examinations, sex  

determinations, and body weights.  F1 and F2 litters were randomly adjusted to 4 males and 4 males on lactation day 4.

F1 pups used as the parental animals for the F2 generation were selected between postpartum days 4 and 21. A total of 28 male and 28 female F1  

pups were selected.  The remaining F1 pups and F2 pups were sacrificed and gross necropsy examinations were performed.  Surviving F0 and F1  

parental animals were sacrificed and an assessment was made of reproductive performance.  The following organs from surviving F0 and F1  

parental animals were preserved for histopathological examination:  adrenal glands, brain, gross lesions, kidneys, liver, ovaries, pituitary,  

prostate, right epididymis, testes, seminal vesicles, spleen, uterus, and  vagina.  The following organs from surviving F0 and F1 parental animals  

were weighed and recorded:  adrenal glands, brain, epididymides, kidneys,  testes, ovaries, pituitary, prostate, seminal vesicles, spleen, and  

uterus. Sperm was collected from F0 and F1 parental males and examined for sperm count, concentration, motility, and morphology.

One-way analysis of variance (ANOVA) was used to analyze parental and pup body weight, body weight gain, food consumption, organ weights, length of  

gestation and estrous cycle, and litter size.  If significance was detected, Dunnett's test was performed to compare control and treatment  

groups.  Copulation and fertility indices, pup sex ratios, numbers of live and dead pups, and pup survival were evaluated by Chi-Square test.   

Post-implantation loss was evaluated using the Mann-Whitney U test.  The level of significance was 5% (p0.05).

Homogeneity and stability of the test substance in gavage dosing solutions was found to be stable for 24 hours at room temperature and up  

to 21 days under refrigeration.

F0 generation:
No test substance related mortality of clinical signs of toxicity.  There were no toxicologically meaningful differences in body weight gain or  

food consumption, copulation and fertility indices, gestation length, implantation and post-implantation loss, or sperm parameters.  The  

numbers of live pups of treated female on lactation day 0 were not significantly different from that control group.  Post-implantation loss  

was higher at 10 mg/kg/day (2.1), but was not statistically different from the control group (0.9).

No treatment related changes found at gross necropsy.  Statistically significant differences in organ weights included decreased absolute and  

relative livers weights in males at 10 mg/kg/day, decreased absolute brain weight in females at 2.5 mg/kg/day, and increased relative liver  

weight in females at 1.0, 2.5, and 10.0 mg/kg/day.

F1 generation:
There were no toxicologically meaningful differences in pup viability data or pup body weights during lactation. Mean litter size on lactation  

day 0 ranged from 13.6 pups/litter (1.0 mg/kg/day group) to 11.4 pups per litter (10 mg/kg/day group).  Post-implantation loss was slightly higher  

at 10 mg/kg/day (1.2), but was not statistically different from the control group (0.9).

Clinical signs were noted during lactation, but were not considered to be test-substance related.  Clinical signs were of low incidence and  

sporadically distributed among treatment groups. Vaginal opening and completion of preputial separation differences were not considered to be  

treatment related. Vaginal opening of control and 10 mg/kg/day pups occurred by postpartum day 35.  Preputial separation of control and male  

pups in the 10 mg/kg/day group was completed by postpartum day 46.  Gross necropsy observations included atelectasis and absence of milk in the stomach.  

Other necropsy findings were of low incidence and sporadically  distributed among treatment groups.


Of F1 animals selected to produce the F2 generation, no test substance related mortality of clinical signs of toxicity were noted.  Clinical  

signs were of low incidence and sporadically distributed among treatment groups and were, therefore, not considered test substance related.  There  

were no toxicologically meaningful differences in body weight or body weight gains during the growth phase, however, mean body weight gain was  

significantly lower in the 1.0 and 5.0 mg/kg/day treatment groups during lactation days 14-21.  There were no toxicologically meaningful  

differences in food consumption.  No statistically significant differences were found in copulation or fertility indices, estrous cycle  

determinations, precoital intervals, or gestation lengths.  There were no statistically significant differences in mean implantation scar counts,  

mean number of live pups on lactation day 0, or mean post-implantation loss. Statistically significant differences in organ weights included  

decreased absolute pituitary weight in 1.0 mg/kg/day males, increased relative adrenal weight and decreased relative liver weight in 5.0 and  

10.0 mg/kg/day males, and decreased relative liver weight in 2.5 and 10.0 mg/kg/day females.  There were no toxicologically meaningful differences  

in sperm parameters of 10 mg/kg/day males.  No test substance related microscopic histopathological changes were noted.

F2 generation:
No test substance related clinical signs of toxicity were noted.  There were no statistically significant differences in body weights during  

lactation. Gross necropsy observations included atelectasis and absence of milk in the stomach.  Other necropsy findings were of low incidence  

and sporadically distributed among treatment groups.

The study was conducted to evaluate the potential effects of nickel sulfate hexahydrate administered to Sprague-Dawley rats in a  

two-generation study.  Oral (gavage) administration of nickel sulfate hexahydrate at dose levels up to 10 mg/kg/day (2.2 mg Ni/kg) had no  

effect on F0 or F1 survival, growth, mating behavior, fertility, gestation, parturition, or lactation.  There was no test substance  

related mortality or clinical signs of toxicity in F0 and F1 rats or their offspring.  Pup viability and growth was not affected.  There were  

no toxicologically meaningful differences in estrous cycling, sperm parameters, copulation, and fertility indices, precoital intervals,  

gestation lengths, gross necropsy findings, or the onset of sexual maturation in F1 rats.  Histopathological examinations did not reveal any  

test article-related changes in the liver, reproductive organs, or other tissues examined.  Statistically significant reductions in absolute  

and/or relative liver weights in F0 males at 10 mg/kg/day and in F1 males at 5.0 and 10.0 mg/kg/day were not regarded as toxicologically  significant.  

Relative liver weight values were less than 10% different from the respective control values.