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Effects on fertility

Link to relevant study records

Referenceopen allclose all

Endpoint:
one-generation reproductive toxicity
Remarks:
based on test guideline (migrated information)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
no data available
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Well reported study with respect to reproductive toxicity. Evidence of developmental findings is compromised or questionable, becaus in the treated groups only a low number of foetuses was available. In addition, findings were not assessed according to litters.
Reference:
Composition 0
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 415 (One-Generation Reproduction Toxicity Study)
Deviations:
yes
Remarks:
; only one dosage was tested.
GLP compliance:
no
Limit test:
no
Test material information:
Composition 1
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: (P) 180-200 g
- Housing: rats were kept in cages containing 4 to 5 animals.
- Diet: ad libitum
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Photoperiod: 12 hours dark/light cycle
No further details are given.
Route of administration:
oral: drinking water
Vehicle:
water
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
- The test substance was dissolved in drinking water at concentration of 200 ppm.

Details on mating procedure:
- M/F ratio per cage: 1:2; at the end of the exposure period, each male was placed in a separate cage with two virgin untreated females.
- Length of cohabitation: 5 days
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
No further details are given.
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
No details are given.
Duration of treatment / exposure:
Male rats were exposed for 70 days, and the females for 61 days (14 days premating, during mating, and throughout the whole length of gestation and lactation periods till weaning (21 days after births)).
Frequency of treatment:
daily
Details on study schedule:
No details are reported.
Remarks:
Doses / Concentrations:
about 20 mg NH4VO3/kg body weight/day
Basis:
nominal in water
No. of animals per sex per dose:
10 male and 20 female rats
Control animals:
yes
Details on study design:
Other:
- Fertility of males was investigated by mating of 10 exposed males and 10 control males with virgin untreated females (ratio 1M:2F).
- Female fertility was investigated by mating of 20 exposed females and 20 control females with untreated males (ratio 1M:2F).

Positive control:
No positive control substance was tested.
Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: after sacrifice

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No data; study was not performed as a fedding study

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
Estrous cyclicity (parental animals):
The control and ammonium metavanadate exposed females mated with untreated males were examined for estrous cycle regularity during the premating period.
Sperm parameters (parental animals):
After sacrifice of treated and control males, which were mated with untreated females, the following measurements were recorded: body weight and weight of testes, epididymis, prostate, and seminal vesicles.
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: no

PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
- Dead an live fetuses, fetal body weight (at brith and at days 4, 7, 14 and 21 after birth), fetal survival and viability indices during lactation period.
- Pups were examined for the presence of any behavioral defects (especially in the offspring obtained during lactation).

GROSS EXAMINATION OF DEAD PUPS:
- No further information available.
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: exposed males were removed after the mating period and killed by cervical dislocation under light ether anesthesia.
- Maternal animals: untreated females, which have been paired with treated males, were investigated to evaluate the effects of ammonium metavanadate exposure on fertility. Half of these untreated females were sacrificed with their fetuses on the 20th day of gestation, while the other half was sacrificed with their pups on day 21 of lactation to record the fertility endpoints.

GROSS NECROPSY
- Number of corpora lutea, implantation sites, resorptions, dead and live fetuses.
- Body weight at the end of gestation period and gravid uterine and placental weights.

HISTOPATHOLOGY / ORGAN WEIGHTS
- No further information available.
Postmortem examinations (offspring):
SACRIFICE
- F1 offspring were sacrificed on day 20 of gestation and on day 21 of lactation.

GROSS NECROPSY
- Offspring were subjected to macroscopic postmortem examinations for the presence of any gross malformations.

HISTOPATHOLOGY / ORGAN WEIGTHS
- 1/3 of the fetuses were preserved in Bouin's solution and examined for the presence of any visceral anormalies using the Wilson free hand technique.
- The remaining 2/3 of the fetuses were preserved in 95% ethanol and examined for the presence of any skeletal anormalies.
Statistics:
The data of treated male and female groups were compared to the control group. The data presented as percentage were analysed using Chi-square, however, other data were analysed using either one-way ANOVA or Student's t-test. The differences in the data were considered statistically significant at probability of P<0.05.
Reproductive indices:
The most indicative fertility endpoints were recorded:
- Mating and fertility indices, number of dams showing delayed birth date, pre- and postimplantation losses.
Offspring viability indices:
No details are reported about the viability indices that were calculated from lactation records of litters.
Clinical signs:
not specified
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Histopathological findings: non-neoplastic:
not specified
Other effects:
not specified
Reproductive function: estrous cycle:
effects observed, treatment-related
Reproductive function: sperm measures:
effects observed, treatment-related
Reproductive performance:
effects observed, treatment-related
BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
- Treatment with V(5+) had no influence on body weight development of the adult rats.

REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS)
- In the group of treated females mated with untreated males, the oestrous cycle was disturbed and the fertility reduced.
- The number of pregnant animals was 10 out of 20 (controls 19 out of 20).
- The mating index was 70 % (controls 100 %), the fertility index 71 % (controls 95 %).

REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS)
- In treated males, the weights of testes, epididymides, prostate and seminal vesicles were significantly lower than in control animals.
- Fertility was reduced in treated males mated with untreated females.
- The number of pregnant animals was 6 out of 20 (controls 19 out of 20).
- The mating index was 65 % (controls 100 %), the fertility index 46 % (controls 95 %).

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
- The number of implantation sites and the number of viable foetuses per animal were markedly reduced due to a significantly increased number of dead foetuses per animal and resorptions per litter.

Dose descriptor:
LOAEC
Remarks:
(only one dose tested)
Effect level:
ca. 20 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: effects on reproductive performance without parental toxicity; reduced mating and fertility indices in males and females; reduced number of implantation sites and viable foetuses
Clinical signs:
effects observed, treatment-related
Mortality / viability:
mortality observed, treatment-related
Body weight and weight changes:
not specified
Sexual maturation:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
effects observed, treatment-related
Histopathological findings:
not specified
VIABILITY (OFFSPRING)
- The number of implantation sites and the number of viable fetuses were significantly reduced in pregnant females of treated dams compared with the control group.

CLINICAL SIGNS (OFFSPRING)
- During lactation, the pups behavioral responses (such as learning and memory responses), fetal survival and viability indices were decreased in the treated groups.

GROSS PATHOLOGY (OFFSPRING)
- Gross anomalies such as stunted growth, subcutanusous hemorrhages and micrognathia were enhanced in fetuses from exposed males and females compared to the controls.
- Incidences of visceral anomalies of the head, thorax and pelvis were enhanced in fetuses from exposed males and females.
- Incidences of skeletal anomalies of the skull, sternebrae, ribs and limbs were enhanced in fetuses from exposed males and females.
- Incidences of the anomalies were partly higher in fetuses from exposed females than from exposed males.

OTHER FINDINGS (OFFSPRING)
- In the treated groups only a very low number of foetuses were available. In addition, findings were not assessed according to litter.
Reproductive effects observed:
not specified
Conclusions:
Reproductive toxicity was observed in absence of general maternal toxicity. Effects were observed on sexual organs and/or functions in treated males and females, mating and fertility indices were reduced, and implantation losses and dead fetuses were reported.
Executive summary:

The study was designed to investigate the effects of ammonium metavanadate on the fertility of male and female rats, as well as on the incidence of teratogenicity and behavioral effects on the offspring. Reproductive toxicity was observed in absence of general maternal toxicity. Effects were observed on sexual organs and/or functions in treated males and females, mating and fertility indices were reduced, and implantation losses and dead fetuses were reported.

Endpoint:
fertility, other
Remarks:
based on test type (migrated information)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Study period:
1990-09-18/19 (first exposure) to 1990-12-18/19 (necropsy date)
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well reported study. Test procedure in accordance with generally accepted scientific standards and described in sufficient detail.
Reason / purpose:
reference to same study
Reference:
Composition 0
Qualifier:
no guideline followed
Principles of method if other than guideline:
Groups of 10 male and 10 female mice were exposed to particulate aerosols of vanadium pentoxide at concentrations of 0, 1, 2, 4, 8, or 16 mg/m3 by inhalation, 6 hours per day, 5 days per week for 3 months. Effects on fertility and sexual function of male and female mice were evaluated after 90 days of inhalation exposure.
GLP compliance:
yes
Limit test:
no
Test material information:
Composition 1
Species:
mouse
Strain:
B6C3F1
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Taconic Farms, Inc. (Germantown, NY)
- Age at study initiation: average age: 6 or 7 weeks old on the first day of the study (4 weeks old on receipt)
- Weight at study initiation: range of mean body weights in the exposure groups: 25-26 g (males) and 20-21 g (females)
- Housing: housed individually; stainless steel wire mesh (Lab Products, Inc., Maywood, NJ), changed weekly
- Diet: ad libitum, except during exposure periods; NIH-07 open formula pelleted diet (Zeigler Brothers, Inc., Gardners, PA)
- Water: ad libitum; tap water (City of Chicago municipal supply) via automatic watering system
- Acclimation period: quarantined for 10 or 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): ca. 23.9± ca.2°C (75° ± 3° F)
- Humidity (%): 55% ± 15%
- Air changes (per hr): 15/hour
- Photoperiod (hrs dark / hrs light): 12 hours/day

IN-LIFE DATES: From: 1990-09-20 (first exposure) to 1990-12-21/22 (necropsy date)
- No further information on test material was stated.
Route of administration:
inhalation: aerosol
Type of inhalation exposure (if applicable):
whole body
Vehicle:
air
Details on exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- For the 16-day and 3-month studies, vanadium pentoxide aerosol generation was based on the principle of pneumatic dispersion and consisted of two major components: a screw feeder (Model 310, Accurate, White Water, WI) that metered vanadium pentoxide powder at a constant rate and a Jet-O-Mizer jetmill (Fluid Energy Corp., Harfield, PA) that used compressed air to disperse the metered powder and form the aerosol.
- Aerosol leaving the jetmill passed through a one-stage impactor and a vertical elutriator to eliminate or deagglomerate the large particles before entering a plenum and manifold distribution system. The aerosol delivery system consisted of three holding chambers that diluted the aerosol in three stages. A metered amount of diluted aerosol was removed and mixed with conditioned air at the inlet to each exposure chamber to achieve the appropriate exposure concentration. The electrical charge buildup on the aerosol particles was neutralized by mixing the aerosol with high concentrations of bipolar ions, which were generated using a Pulse Gun (Static Control Services, Palm Springs, CA) air nozzle. For the 3-month studies, a transvector air pump was installed at the aerosol inlet to each exposure chamber to provide additional control of the aerosol flow rate and improve stability of the chamber concentration.
- The stainless-steel inhalation exposure chambers (Lab Products, Inc., Maywood NJ), were designed so that uniform aerosol concentrations could be maintained throughout the chambers when catch pans were in place. The total active mixing volume of each chamber was 1.7 m³.

CHAMBER ATMOSPHERE CHARACTERIZATION
- The particle size distribution in each chamber was determined prior to the start of all studies, during the first week of the 16-day and 3-month studies, during the first 2 weeks of the 2-year studies, and monthly during the 3-month and 2-year studies.
- For the 16-day and 3-month studies, a 10-stage Quartz Crystal Microbalance-based cascade impactor was used to separate the aerosol particles into sequential size ranges; the mass median aerodynamic diameter was calculated from the corresponding mass fraction of particles at each stage.

OTHER
- The uniformity of aerosol concentration in the inhalation exposure chambers without animals was evaluated before each of the studies began; concentration uniformity with animals present in the chambers was also measured. During the 16-day and 3-month studies, minor excursions in chamber uniformity values were observed in one or more exposure chambers, but these excursions had no impact on the studies. Chamber concentration uniformity was acceptable throughout the 16-day special studies and 2-year studies.
- The stability of vanadium pentoxide in the exposure system was tested with XRD analysis. XRD analyses indicated no detectable build-up of degradation products at a detection limit of approximately 1%.
Details on mating procedure:
Animals were not mated.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
- During all studies, chamber aerosol concentrations were monitored with real-time aerosol monitors (RAMs) that used a pulsed-light-emitting diode in combination with a silicon detector to sense light scattered over a forward angular range of 45° to 95° by particles traversing the sensing volume. The instruments respond to particles 0.1 to 20 μm in diameter.
- During the 16-day and 3-month studies, an individual monitor was used for each exposure chamber. The voltage output of the online monitors was read and recorded, and the calibration curve was applied to the voltages measured by the RAM to convert the measured voltages to exposure chamber concentrations.
- Each RAM was calibrated daily during the 16-day and 3-month studies by correlating the measured voltage with vanadium pentoxide concentrations determined by gravimetric analysis of glass fiber filters and one to two times per week during the 2-year studies by ICP/AES or ICP/mass spectrometry analysis of Pallflex® TX40H120WW glass fiber filters.
Duration of treatment / exposure:
3 months (91-92 days)
Frequency of treatment:
6 hours per day, 5 days per week
Details on study schedule:
No further details are given.
Remarks:
Doses / Concentrations:
1 mg/m³ V2O5
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
2 mg/m³ V2O5
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
4 mg/m³ V2O5
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
8 mg/m³ V2O5
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
16 mg/m³ V2O5
Basis:
nominal conc.
No. of animals per sex per dose:
Core studies: 10 male and 10 female animals
Control animals:
yes
Details on study design:
- Dose selection rationale: based on decreased survival in the 32 mg/m3 males and body weight decreases in 32 mg/m3 males and females in a 16-day study, an exposure concentration of 32 mg/m3 was considered too high for use in a 3-month study. Therefore, the exposure concentrations selected for the 3-month inhalation study in rats were 0, 1, 2, 4, 8, and 16 mg/m3.
- Rationale for animal assignment (if not random): randomly into groups of approximately equal initial mean body weights.
- No further information on test material was stated.
Positive control:
not stated
Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Observed twice daily.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Clinical findings were recorded weekly.

BODY WEIGHT: Yes
- Time schedule for examinations: The animals were weighed initially, weekly, and at the end of the study.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No data (inhalation study)

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data (inhalation study)
Estrous cyclicity (parental animals):
- At the end of the 3-month studies, samples were collected for vaginal cytology evaluations from core study mice exposed to 4, 8, or 16 mg/m3.
- For 12 consecutive days prior to scheduled terminal sacrifice, the vaginal vaults of the females were moistened with saline, if necessary, and samples of vaginal fluid and cells were stained. Relative numbers of leukocytes, nucleated epithelial cells, and large squamous epithelial cells were determined and used to ascertain estrous cycle stage (i.e., diestrus, proestrus, estrus, and metestrus).
Sperm parameters (parental animals):
- At the end of the 3-month studies, samples were collected for sperm motility evaluations from core study mice exposed to 4, 8, or 16 mg/m3.
- Male animals were evaluated for sperm count and motility. The left testis and left epididymis were isolated and weighed. The tail of the epididymis (cauda epididymis) was then removed from the epididymal body (corpus epididymis) and weighed. Modified Tyrode’s buffer was applied to slides and a small incision was made at the distal border of the cauda epididymis. The sperm effluxing from the incision were dispersed in the buffer on the slides, and the numbers of motile and nonmotile spermatozoa were counted for five fields per slide by two observers.
- Following completion of sperm motility estimates, each left cauda epididymis was placed in buffered saline solution. Caudae were finely minced, and the tissue was incubated in the saline solution and then heat fixed at 65° C. Sperm density was then determined microscopically with the aid of a hemacytometer.
- To quantify spermatogenesis, the testicular spermatid head count was determined by removing the tunica albuginea and homogenising the left testis in phosphate-buffered saline containing 10% dimethyl sulfoxide. Homogenisation-resistant spermatid nuclei were counted with a hemacytometer.
Litter observations:
Not applicable; animals were not mated.
Postmortem examinations (parental animals):
Method of sacrifice: CO2

GROSS NECROPSY/ ORGAN WEIGHTS
- Necropsies were performed on all core study animals.
- The right testis were weighed.

HISTOPATHOLOGY
- Tissues for microscopic examination were fixed and preserved in 10% neutral buffered formalin, processed and trimmed, embedded in paraffin, sectioned to a thickness of 4 to 6 μm, and stained with hematoxylin and eosin.
- A complete histopathologic examination was performed on 0 and 16 mg/m3 mice.
Postmortem examinations (offspring):
Not applicable; animals were not mated.
Statistics:
Analysis of Continuous Variables:
Two approaches were employed to assess the significance of pairwise comparisons between exposed and control groups in the analysis of continuous variables. Organ and body weight data, which historically have approximately normal distributions, were analyzed with the parametric multiple comparison procedures of Dunnett (1955) and Williams (1971, 1972). Hematology, clinical chemistry, urinalysis, urine concentrating ability, cardiopulmonary, immunotoxicologic, cell proliferation, tissue concentrations, spermatid, and epididymal spermatozoal data, which have typically skewed distributions, were analyzed using the nonparametric multiple comparison methods of Shirley (1977) and Dunn (1964). Jonckheere’s test (Jonckheere, 1954) was used to assess the significance of the dose-related trends and to determine whether a trend-sensitive test (Williams’ or Shirley’s test) was more appropriate for pairwise comparisons than a test that does not assume a monotonic dose-related trend (Dunnett’s or Dunn’s test). Average severity values were analyzed for significance with the Mann-Whitney U test (Hollander and Wolfe, 1973). Treatment effects were investigated by applying a multivariate analysis of variance (Morrison, 1976) to the transformed data to test for simultaneous equality of measurements across exposure concentrations. (for more information see publication)
Reproductive indices:
no applicable
Offspring viability indices:
not applicable
Clinical signs:
effects observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Other effects:
not specified
Reproductive function: estrous cycle:
no effects observed
Reproductive function: sperm measures:
effects observed, treatment-related
Reproductive performance:
not specified
CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
- One male exposed to 16 mg/m3 died before the end of the study. The mouse that died early appeared thin.
- There were no other clinical findings related to vanadium pentoxide exposure.

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
- Mean body weights of 8 and 16 mg/m3 males and 4 mg/m3 or greater females were significantly less than those of the chamber controls.

REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS)
No significant differences were noted in estrous cycle parameters between exposed and chamber control females.

REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS)
The epididymal spermatozoal motility of males exposed to 8 or 16 mg/m3 was significantly decreased.

ORGAN WEIGHTS (PARENTAL ANIMALS)
- Organ weight changes were considered related to body weight decreases.

GROSS PATHOLOGY AND HISTOPATHOLOGY (PARENTAL ANIMALS)
- No effects on reproductive organs reported.
Dose descriptor:
NOAEC
Effect level:
> 16 mg/m³ air
Based on:
test mat.
Sex:
female
Basis for effect level:
other: no effects on oestrus cycle parameters determined
Dose descriptor:
NOAEC
Effect level:
4 mg/m³ air
Based on:
test mat.
Sex:
male
Basis for effect level:
other: decreased epididymal spermatozoal motility at an above 8 mg/m3
Clinical signs:
not examined
Mortality / viability:
not examined
Body weight and weight changes:
not examined
Sexual maturation:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
not examined
Histopathological findings:
not examined
Not applicable; parental animals were not mated.
Reproductive effects observed:
not specified
Conclusions:
In a 90-day inhalation study using divanadium pentaoxide, effects on the sexual organs and functions were observed in male mice at and above 8 mg/m3. No effects on reproductive organs and functions up to 4 mg/m3 could be detected in males. Female estrus cycle parameters were not affected up to the concentration tested.
Executive summary:

Groups of 10 male and 10 female B6C3F1 mice were exposed to V2O5 aerosols (whole body exposure) at concentrations of 0, 1, 2, 4, 8 or 16 mg/m3 by inhalation, 6 hours/d, 5 d/wk, for 3 months (91-92 days). At the end of the studies, sperm samples were collected from core study male mice in the 0, 4, 8, and 16 mg/m3 groups for sperm motility evaluations and the examination of the following parameters: spermatid heads per testis and per gram testis, spermatid counts, and epididymal spermatozoal motility and concentration. The left cauda, left epididymis, and left testis were weighed. Vaginal samples were collected for up to 12 consecutive days prior to the end of the studies from core study female mice exposed to 0, 4, 8, or 16 mg/m3 for vaginal cytology evaluations. The percentage of time spent in the various estrous cycle stages and estrous cycle length were evaluated.

The results showed that epididymal spermatozoal motility was significantly decreased in males exposed to 8 and 16 mg/m3. Female estrus cycle parameters wer not affected.

 

Effect on fertility: via oral route
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LOAEL
69.6 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
Several reliable studies are available. Results are not considered relevant for human exposure.
Effect on fertility: via inhalation route
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEC
17.9 mg/m³
Study duration:
subchronic
Species:
rat
Quality of whole database:
One reliable study is available. Results are considered equivocal, and are not considered relevant for human exposure. The route of exposure may not be relevant for divanadium tris(sulphate) solution.
Effect on fertility: via dermal route
Endpoint conclusion:
no study available
Additional information

An extensive literature/data search and evaluation programme on animal and human data relating to possible adverse effects of vanadium substances on reproductive toxicity has recently been conducted. As an outcome, some data are available for soluble pentavalent substances (V2O5and NaVO3) via the oral and inhalation route.

Oral exposure

The reproductive toxicity of sodium metavanadate was studied in male Swiss mice exposed doses of 0, 20, 40, 60 and 80 mg/kg bw per day given in the drinking water for 64 days. To evaluate the fertility of the vanadium-treated animals, males were mated with untreated females for 4 days. A significant decrease in the pregnancy rate was observed at 60 and 80 mg/kg per day. However, the test substance did not reduce fertility in male mice at 20 and 40 mg/kg per day. Decreased body and epididymis weight was only observed in the 80 mg/kg per day group, while testicular weights were not altered by the treatment. Sperm count was significantly decreased at 60 and 80 mg/kg per day, but the sperm motility was unaffected. Histopathological examination revealed that testes were normal and that epididymis of treated male mice contained normal appearing sperm. In this reproduction toxicity study in mice, a NOAEL of 40 mg/kg bw/d was determined for sodium metavanadate.

However, there is another reproduction toxicity study with ammonium metavanadate in rats available (Morgan et al 2003). Unfortunately, this study was designed to investigate the effects of ammonium metavanadate at only one dose level of 20 mg/kg bw/d. The effects on fertility of male and female rats, as well as on the incidence of teratogenicity and behavioural effects on the offspring were evaluated. Reproductive toxicity was observed in absence of general maternal toxicity. Effects were observed on sexual organs and/or functions in treated males and females, mating and fertility indices were reduced, and implantation losses and dead foetuses were reported. Thus, the dose level of 20 mg/kg bw/d represents an effect level for reproductive toxicity.

Inhalation exposure

Groups of 10 male and 10 female F344/N rats and B6C3F1 mice were exposed to V2O5aerosols (whole body exposure) at concentrations of 0, 1, 2, 4, 8 or 16 mg/m3by inhalation, 6 hours/d, 5 d/wk, for 3 months (91-92 days). At the end of the study period, sperm samples were collected from core study male rats and mice of the control and treatment groups for sperm motility evaluations and determination of spermatid heads per testis and per gram testis, spermatid counts, and epididymal spermatozoa motility and concentration. The left cauda, left epididymis and left testis were weighed. Vaginal samples were collected for up to 12 consecutive days prior to the end of the studies from core study female rats and mice exposed to 0, 4, 8, or 16 mg/m3for vaginal cytology evaluations. The percentage of time spent in the various oestrous cycle stages and oestrous cycle length were evaluated.

In rats, the results did not indicate effects on male sexual function, but in mice epididymal spermatozoal motility was significantly decreased in males exposed to 8 and 16 mg/m3V2O5. In contrast, female oestrus cycle parameters were not affected in mice, but oestrous cycles were significantly longer in rats exposed to 8 mg/m3 than in animals of the chamber control group, and the number of cycling females was lower in the 16 mg/m3group. Considering both, the results in male mice and female rats, an overall NOAEC for effect on fertility in rodents of 4 mg/m3can be established.

Read-across:

The read-across approach based on dissolved vanadium is based on the assumption that once inorganic vanadium compounds dissolve or become bioavailable, this will be in tetra- or pentavalent vanadium forms.In bioaccessibility tests of tri-, tetra- and pentavalent vanadium substances, tri-, tetra- and pentavalent forms dissolved within 2h in various media selected to simulate relevant human-chemical interactions (i.e. PBS mimicking the ionic strength of blood, artificial lung, lysosomal, and gastric fluid as well as artificial sweat). Tri-, tetra- and pentavalent vanadium substances are retained as pentavalent forms in physiological media, with the exception of artificial lysosomal fluid in which tetravalent V dominates after 2h and is the only form present after 24h.

Further, the registrant is of the opinion that the toxicity ofdivanadium tris(sulphate) is driven by the vanadium moiety and that the sulfate anion does not contribute to the overall toxicity ofdivanadium tris(sulphate)to any relevant extent, for the following reasons:

Sulfate anions are abundantly present in the human body in which they play an important role for the ionic balance in body fluids. Sulfate is required for the biosynthesis of 3′-phosphoadenosine-5′-phosphosulfate (PAPS) which in turn is needed for the biosynthesis of many important sulfur-containing compounds, such as chondroitin sulfate and cerebroside sulfate.TheJoint FAO/WHO Expert Committee on Food Additives (JECFA) concludes that the few available studies in experimental animals do not raise any concern about the toxicity of the sulphate ion in sodium sulphate. Sodium sulphate is also used clinically as a laxative. In clinical trials in humans using 2-4 single oral doses of up to 4500 mg sodium sulphate decahydrate per person (9000 – 18000 mg per person), only occasional loose stools were reported. These doses correspond to 2700 - 5400 mg sulphate ion per person. High bolus dose intake of sulphate ion may lead to gastrointestinal discomfort in some individuals. No further adverse effects were reported (JECFA 2000, 2002). This position was adopted by the European Food Safety Authority (EFSA2004) without alteration.

Based on the above information, one can therefore safely assume that the sulfate anion in divanadium tris(sulphate)does not contribute to the overall toxicity of divanadium tris(sulphate). It is concluded that only the effect of “vanadium” is further considered in the human health hazard assessment of divanadium tris(sulphate).

Thus, read-across of reproductive toxicity data from soluble pentavalent vanadium substances is justified.

Because the data base is regarded as insufficient for the derivation of an Occupational Exposure Limit with respect to the endpoints carcinogenicity and genotoxicity by various committees and for these above reasons including the fact that human data reporting a carcinogenic potential do not exist, classification for carcinogenicity should be examined once the needed data will be generated.

The registrant is aware that the National Toxicology Programme (NTP) in the US nominated tetra- and pentavalent vanadium forms(sodium metavanadate, NaVO3, CAS # 13718-26-8; and vanadium oxide sulphate, VOSO4, CAS # 27774-13-6), i.e. species present in drinking water and dietary supplements in 2007 (http://ntp.niehs.nih.gov/). A comprehensive characterisation via the oral route of exposure of

(i) chronic toxicity,

(ii) carcinogenicity, and 

(iii) multi-generation reproductive toxicity

is planned.

 

The NTP testing program began with sub-chronic drinking water studies on VOSO4& NaVO3as follows:

-Genetic toxicology studies, i.e. the Salmonella gene mutation assays, with NaVO3 and VOSO4 - negative

- 14 days with Harlan Sprague-Dawley rats and B6C3F1/N mice (Dose: R&M: 0, 125, 250, 500, 1000, 2000 mg/L) - already completed

-90-d oral toxicity studies (dosed feed: NaVO3; dosed water: VOSO4) with Harlan Sprague-Dawley rats and B6C3F1/N (dose: rats and mice: 0, 31.3, 62.5, 125, 250, or 500 ppm - ongoing

- Organ systems toxicity, i.e. 28-d immunotoxicity study of NaVO3 (dosed-water) with female B6C3F1/N mice (dose: 0, 31.3, 62.5, 125, 250, or 500 ppm) - ongoing

- Perinatal dose-range finding study: gestation day 6 (GD 6) until postnatal day 42 (PND 42) with Harlan Sprague-Dawley rats - ongoing

It can reasonably be anticipated that these studies will be of high quality and relevance, and thus will serve as a more robust basis than the current data base with all its shortcomings.In addition, repeated-dose inhalation toxicity studies (14, 28, and 90 days) with various vanadium substances are planned within the Vanadium Safety Readiness Safety Program. These studies will address issues for which to date equivocal or no data at all exist.Further information on these studies can be found in section 7.5.Only upon availability of the results from these studies, it will be possible to render a more meaningful decision on whether or not testing for carcinogenicity is required. Therefore for the time being this data requirement should be waived in consideration of animal welfare.


Short description of key information:
Studies via the oral and the inhalation route are available for soluble vanadium substances (NaVO3, NH4VO3, V2O5). Male and female fertility was evaluated in the k_NTP study (2002) in rats and mice at the end of the 90-day inhalation exposure period to V2O5 aerosols. One reproduction toxicity study (k_Loblet 1993) with different dose levels of ammonium metavanadate administered via drinking water to mice was identified and another study (k_Morgan 2003) with only one dose level of sodium metavanadate in drinking water in rats.

Justification for selection of Effect on fertility via oral route:
Data of the reproductive toxicity are available for very soluble pentavalent substances (NH4VO3 and NaVO3) via the oral route.

Justification for selection of Effect on fertility via inhalation route:
Data of the reproductive toxicity are available for very soluble pentavalent substances (V2O5) via the inhalation route. However, inhalation may not be a relevant route of exposure for divanadium tris(sulphate) solution.

Justification for selection of Effect on fertility via dermal route:
Data of the reproductive toxicity via the dermal route are not available for any vanadium substance. Following the HERAG guidance for metals and metal salts (see section 7.1.2 of the technical dossier: dermal absorption), negligible percutaneous uptake based on minimal penetration, i.e. a dermal absorption rate in the range of maximally 0.1 - 1.0 %, can be anticipated. Dermal absorption in this order of magnitude is not considered to be “significant”. Thus, regarding reproductive toxicity of vanadium substances, the dermal exposure route is not expected to be the most relevant.

References:
EBRC (2007) HERAG fact sheet - Assessment of occupational dermal exposure and dermal absorption for metals and inorganic metal compounds, EBRC Consulting GmbH, Hannover, Germany, August 2007, 49 pages.

Effects on developmental toxicity

Description of key information
Studies via the oral route are available for other soluble vanadium substances. One study (k_Sanchez 1991) with administration of different dose levels of sodium orthovanadate per gavage to pregnant mice was identified. One supportive developmental toxicity study (s_Paternain_1990) with administration of different dose levels of vanadium oxide sulphate to Swiss mice was identified. Evidence of maternal, embryo-/foetotoxicity and teratogenicity were observed at the lowest dose level investigated.
Effect on developmental toxicity: via oral route
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
33.2 mg/kg bw/day
Species:
mouse
Quality of whole database:
Data of the developmental toxicity are available for very soluble tetra- and pentavalent substances via the oral route.
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

An extensive literature/data search and evaluation programme on animal and human data relating to possible adverse effects of vanadium substances on developmental toxicity has recently been conducted. As an outcome, some data are available for very soluble tetra- and pentavalent substances (VOSO4 and Na3VO4) via the oral route.

Oral uptake

Vanadium oxide sulphate was evaluated for its embryotoxic, foetotoxic and teratogenic potential in Swiss mice. The compound was administered by gavage to pregnant mice at doses of 0, 37.5, 75 or 150 mg/kg body weight/day on days 6 -15 of pregnancy. On gestation day 18, all live foetuses were examined for external, visceral and skeletal malformations and variations. Maternal toxicity was observed in all vanadium-treated animals, evident by reduced weight gain, reduced body weight on gestation day 18 (corrected for gravid uterine weight) and decreased absolute liver and kidney weights at 75 and 150 mg/kg body weight/day. The number of total implants, live and dead foetuses, late resorptions, the sex ratio and the post-implantation losses were not significantly different between the vanadium-treated mice and the control. However, there was a significant increase in the number of early resorptions per litter at all dose levels. Foetotoxicity was evident by lower foetal weights and lengths and the presence of developmental variations. Malformation incidence also increased by administration of vanadium. Thus, the NOEL for maternal toxicity, embryo-/foetotoxicity and teratogenicity for vanadyl sulphate pentahydrate under these test conditions can be expected below 37.5 mg/kg body weight/day (11.72 mg V/kg bw/d) in Swiss mice (Paternain et al. 1990).

Sodium orthovanadate in deionised water was administered once daily by gavage on gestational days 6 -15 to mice at doses of 0, 7.5, 15, 30 and 60 mg/kg body weight/day. Dams were killed on day 18 of pregnancy, and foetuses were examined for external, visceral and skeletal defects. Maternal toxicity was observed at the highest doses levels, as evidenced by a significant number of deaths (60 and 30 mg/kg body weight/day) and reduced weight gain and food consumption (30 and 15 mg/kg body weight/day). Embryolethality and teratogenicity were not observed at maternally toxic doses and below, but foetal toxicity was evidenced by a significant delay in the ossification process of some skeletal districts at 30 mg/kg body weight/day. The NOAEL for maternal toxicity was 7.5 mg/kg body weight/day, and 15 mg/kg body weight/day represented a NOAEL for developmental toxicity in mice under the conditions of this study. However, it needs to be considered that foetal toxicity was observed at maternal toxic dose levels and can thus be regarded as secondary. Thus, the dose level of 30 mg/kg bw/d represents the LOEL for developmental effects and 15 mg/kg bw/d the NOEL for developmental effects at maternally toxic dose levels (reduced body weight gain and food consumption). These values correspond to 8.3 mg V/kg bw/d (LOEL) and 4.2 mg V/kg bw/d (NOEL). In the absence of other reliable information, the lowest NOEL for developmental effects of 15 mg/kg bw/d Na3VO4is used as starting point for this endpoint-specific DNEL derivation, although the effects observed can be considered as secondary due to maternal toxicity (Sanchez et al. 1991).

In the study with sodium metavanadate (Paternain et al. 1987), an oral NOAEL of 20 mg/kg bw/d was determined at the high dose level corresponding to 8.4 mg V/kg bw/d. There is no clear evidence of direct developmental effects in foetuses of dams exposed during gestational day 6-14 to different dose levels. However, information on maternal toxicity was not provided in the study.

Read-across:The read-across approach based on dissolved vanadium is based on the assumption that once inorganic vanadium compounds dissolve or become bioavailable, this will be in tetra- or pentavalent vanadium forms.In bioaccessibility tests of tri-, tetra- and pentavalent vanadium substances, tri-, tetra- and pentavalent forms dissolved within 2h in various media selected to simulate relevant human-chemical interactions (i.e. PBS mimicking the ionic strength of blood, artificial lung, lysosomal, and gastric fluid as well as artificial sweat). Tri-, tetra- and pentavalent vanadium substances are retained as pentavalent forms in physiological media, with the exception of artificial lysosomal fluid in which tetravalent V dominates after 2h and is the only form present after 24h.

Further, the registrant is of the opinion that the toxicity ofdivanadium tris(sulphate) is driven by the vanadium moiety and that the sulfate anion does not contribute to the overall toxicity ofdivanadium tris(sulphate)to any relevant extent, for the following reasons:

Sulfate anions are abundantly present in the human body in which they play an important role for the ionic balance in body fluids. Sulfate is required for the biosynthesis of 3′-phosphoadenosine-5′-phosphosulfate (PAPS) which in turn is needed for the biosynthesis of many important sulfur-containing compounds, such as chondroitin sulfate and cerebroside sulfate.TheJoint FAO/WHO Expert Committee on Food Additives (JECFA) concludes that the few available studies in experimental animals do not raise any concern about the toxicity of the sulphate ion in sodium sulphate. Sodium sulphate is also used clinically as a laxative. In clinical trials in humans using 2-4 single oral doses of up to 4500 mg sodium sulphate decahydrate per person (9000 – 18000 mg per person), only occasional loose stools were reported. These doses correspond to 2700 - 5400 mg sulphate ion per person. High bolus dose intake of sulphate ion may lead to gastrointestinal discomfort in some individuals. No further adverse effects were reported (JECFA 2000, 2002). This position was adopted by the European Food Safety Authority (EFSA2004) without alteration.

Based on the above information, one can therefore safely assume that the sulfate anion in divanadium tris(sulphate)does not contribute to the overall toxicity of divanadium tris(sulphate). It is concluded that only the effect of “vanadium” is further considered in the human health hazard assessment of divanadium tris(sulphate).

Thus, read-across of developmental toxicity data from soluble tetra- and pentavalent vanadium substances is justified.

Because the data base is regarded as insufficient for the derivation of an Occupational Exposure Limit with respect to the endpoints carcinogenicity and genotoxicity by various committees and for these above reasons including the fact that human data reporting a carcinogenic potential do not exist, classification for carcinogenicity should be examined once the needed data will be generated.

The registrant is aware that the National Toxicology Programme (NTP) in the US nominated tetra- and pentavalent vanadium forms(sodium metavanadate, NaVO3, CAS # 13718-26-8; and vanadium oxide sulphate, VOSO4, CAS # 27774-13-6), i.e. species present in drinking water and dietary supplements in 2007 (http://ntp.niehs.nih.gov/). A comprehensive characterisation via the oral route of exposure of

(i) chronic toxicity,

(ii) carcinogenicity, and 

(iii) multi-generation reproductive toxicity

is planned.

 

The NTP testing program began with sub-chronic drinking water studies on VOSO4& NaVO3as follows:

-Genetic toxicology studies, i.e. the Salmonella gene mutation assays, with NaVO3 and VOSO4 - negative

- 14 days with Harlan Sprague-Dawley rats and B6C3F1/N mice (Dose: R&M: 0, 125, 250, 500, 1000, 2000 mg/L) - already completed

-90-d oral toxicity studies (dosed feed: NaVO3; dosed water: VOSO4) with Harlan Sprague-Dawley rats and B6C3F1/N (dose: rats and mice: 0, 31.3, 62.5, 125, 250, or 500 ppm - ongoing

- Organ systems toxicity, i.e. 28-d immunotoxicity study of NaVO3 (dosed-water) with female B6C3F1/N mice (dose: 0, 31.3, 62.5, 125, 250, or 500 ppm) - ongoing

- Perinatal dose-range finding study: gestation day 6 (GD 6) until postnatal day 42 (PND 42) with Harlan Sprague-Dawley rats - ongoing

It can reasonably be anticipated that these studies will be of high quality and relevance, and thus will serve as a more robust basis than the current data base with all its shortcomings.In addition, repeated-dose inhalation toxicity studies (14, 28, and 90 days) with various vanadium substances are planned within the Vanadium Safety Readiness Safety Program. These studies will address issues for which to date equivocal or no data at all exist.Further information on these studies can be found in section 7.5.Only upon availability of the results from these studies, it will be possible to render a more meaningful decision on whether or not testing for carcinogenicity is required. Therefore for the time being this data requirement should be waived in consideration of animal welfare.


Justification for selection of Effect on developmental toxicity: via oral route:
In the absence of other reliable information, the lowest NOEL for developmental effects at a maternal toxic dose level was selected.

Justification for selection of Effect on developmental toxicity: via inhalation route:
Inhalation may not be a relevant route of exposure for divanadium tris(sulphate) solution.

Justification for selection of Effect on developmental toxicity: via dermal route:
Data of developmental toxicity via the dermal route are not available for any vanadium substance. Following the HERAG guidance for metals and metal salts (see section 7.1.2 of the technical dossier: dermal absorption), negligible percutaneous uptake based on minimal penetration, i.e. a dermal absorption rate in the range of maximally 0.1 - 1.0 %, can be anticipated. Dermal absorption in this order of magnitude is not considered to be “significant”. Thus, regarding developmental toxicity of vanadium substances, the dermal exposure route is not expected to be the most relevant.

References:
EBRC (2007) HERAG fact sheet - Assessment of occupational dermal exposure and dermal absorption for metals and inorganic metal compounds, EBRC Consulting GmbH, Hannover, Germany, August 2007, 49 pages.

Justification for classification or non-classification

An extensive literature/data search and evaluation programme on animal and human data relating to possible adverse effects of relevant vanadium substances on fertility and developmental toxicity has been conducted.

Based on read-across of data available for other very soluble vanadium substances, divanadium tris(sulphate) classifies as reproductive toxicant category 2 according to commission Regulation (EC) No 1272/2008. The placing in Category 2 is proposed on the basis of evidence in animal studies, which is not sufficiently convincing to place the substance in Category 1A or 1B.