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Description of key information

Repeated dose toxicity - oral route:
Rossiello (2013) performed a combined repeated dose toxicity study (scored Klimisch 1) with reproduction/developmental toxicity screening test via oral route in rats according to OECD guideline 422. This study was performed in compliance with GLP guidelines. A NOAEL of >=1000 mg/kg bw/day was derived (expressed as zirconium acetate anhydrous). No adverse effects were reported in this study. Zirconium acetate is a water-soluble zirconium compound with similar behaviour as zirconium dinitrate oxide. Therefore the results of this study are considered relevant for zirconium dinitrate oxide too.

Repeated dose toxicity: inhalation:
Inhalation of 11.3 mg/m3 zirconium dichloride oxide for 60 days produced no significant changes in mortality rate, growth, biochemistry, hematology values and histopathology in various animal species. The NOAEC is therefore considered to be >= 11.3 mg/m3.

Repeated dose toxicity: dermal:
No reliable data are available for repeated dose toxicity via the dermal route of exposure. Since key studies are available for two routes of exposure (oral and inhalation exposure), no testing is required via the dermal route.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Read across based on a study performed with zirconium acetate. The read across justification document is attached to IUCLID Section 13.
Reason / purpose for cross-reference:
read-across source
Key result
Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Based on:
act. ingr.
Remarks:
anhydrous zirconium dichloride oxide
Sex:
male/female
Basis for effect level:
other: Based on a lack of toxicologically relevant systemic effects in male or female parental animals in any dose group in an OECD 422 study performed with zirconium acetate.
Remarks on result:
other: Zirconium dichloride oxide is concluded not to present any hazard after repeated oral exposure.
Remarks:
Conclusion based on the results of an OECD 422 study (Rossiello, 2013) performed with zirconium acetate, a water-soluble zirconium compound with similar behaviour as zirconium dichloride oxide. It can be concluded that the NOAEL for zirconium dichloride oxide would also be >= 1000 mg/L in a similar study.
Key result
Critical effects observed:
no
Conclusions:
No repeated dose toxicity study with zirconium dichloride oxide is available. Data generated with the source substance zirconium acetate was used for endpoint coverage. Justification of the read-across approach is included in section 13. Based on the study results, the NOAEL for systemic toxicity was considered to be >=1000 mg/kg bw/day (expressed as zirconium acetate anhydrous) for males and females. The substance is considered not classified as STOT RE according to the criteria in the CLP Regulation. The same is assumed for zirconium dichloride oxide.
Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
2012-12-06 to 2013-02-07
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
according to guideline
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River Italia S.p.A., Calco (Lecco), Italy
- Age at study initiation: 6 to 7 weeks
- Weight at study initiation: 204.5 to 212.8 g (males); 164.8 to 180.2 g (females)
- Fasting period before study: none
- Housing: From arrival to pairing, animals were housed up to 5 of one sex to a cage, in polisulphone solid bottomed cages measuring 59.5 x 38 x 20 cm. Nesting material was provided inside suitable bedding bags and changed at least twice a week. During mating, animals were housed one male to one female in clear polycarbonate cages measuring approximately 43 x 27 x 18 cm with a stainless steel mesh lid and floor. Each cage tray held absorbent material which was inspected and changed daily. After mating, the males were re-caged as they were before mating while females were transferred to individual solid bottomed cages for the gestation period, birth and lactation.
- Diet: ad libitum, except prior to drawing of blood for clinical chemistry examinations
- Water: ad libitum
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 55 +/- 15%
- Air changes (per hour): 15 to 20
- Photoperiod (hours dark / hours light): 12/12

Route of administration:
oral: gavage
Vehicle:
other: purified water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS
The required amount of zirconium acetate solution (containing 40.7% of zirconium acetate anhydrous) was dissolved in the vehicle (purified water) to obtain final concentrations of 10, 30 and 100 mg/mL. The formulations were prepared daily or up to 7 days before dosing according to stability data. The concentrations were calculated and expressed in terms of zirconium acetate content (40.7%).

VEHICLE
- Concentration in vehicle: 10, 30, 100 mg/L (expressed as active compound content)
- Amount of vehicle (if gavage): 10 mL/kg body weight (for males, dose volumes were adjusted once per week for each animal according to the last recorded body weight; for females, dose volumes were calculated according to individual body weight on days 0, 7, 14 and 20 post coitum and on day 1 post partum, thereafter individual dose volumes remained constant)
- Purity: not requiered
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Prior to commencement of treatment, analysis was performed to confirm that the proposed formulation procedure was acceptable (check of concentration). Samples of dosing formulations prepared on Weeks 1 and 5 [when 10 females per group were present] were also analysed to verify the concentrations. Samples of the formulations were collected and sent at ambient temperature to the analytical laboratory. Chemical analyses were carried out according to an Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) method.
Duration of treatment / exposure:
- Males were treated two weeks prior to pairing, throughout pairing and thereafter through the day before scheduled sacrifice (32 days of dosing).
- Females were treated two weeks prior to pairing, throughout pairing until day 3 post partum or the day before scheduled sacrifice (up to 50 days of dosing).
Frequency of treatment:
Once daily
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
Dose / conc.:
53 other: mg/kg bw/day (actual dose received, based on Zr)
Dose / conc.:
159 other: mg/kg bw/day (actual dose received, based on Zr)
Dose / conc.:
530 other: mg/kg bw/day (actual dose received, based on Zr)
No. of animals per sex per dose:
10
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Dose levels were selected in consultation with the Sponsor based on information from a non-GLP 2 week preliminary toxicity study (RTC Study no. 94150EXT).
- Rationale for animal assignment: Rats were allocated to groups by computerised stratified randomisation to give approximately equal initial group mean body weights.
- Rationale for selecting satellite groups: not applicable (satellite group not included)
- Post-exposure recovery period in satellite groups: not applicable (satellite group not included)
Positive control:
None
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Animals were checked each morning and afternoon for mortality.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Once before commencement of treatment and at least once daily during the study, each animal was observed and any clinical sign was recorded. Observations were performed at the same time interval each day, the interval was selected taking into consideration the presence of post-dose reactions.

BODY WEIGHT: Yes
- Time schedule for examinations: Males were weighed weekly from allocation to termination. Females were weighed weekly from allocation to positive identification of mating and on Days 0, 7, 14 and 20 post coitum. Dams were also weighed on Days 1 and 4 post partum.

FOOD CONSUMPTION: Yes
- Time schedule for examinations: weekly during the pre-mating period starting from allocation. Individual food consumption for the females was measured on Days 7, 14 and 20 post coitum starting from Day 0 post coitum and on Day 4 post partum starting from Day 1 post partum.
- Parameters checked: the weight of food consumed by each cage of males and females

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: as part of the sarificial procedure
- Anaesthetic used for blood collection: Yes (isofluorane)
- Animals fasted: Yes
- How many animals: 5 per sex (females with viable litters i possible)
- Parameters checked: haematocrit; haemoglobin; red blood cell count; reticulocyte count; mean red blood cell volume; mean corpuscular haemoglobin; mean corpuscular haemoglobin concentration; white blood cell count; differential leucocyte count (neutrophils, lymphocytes, eosinophils, basophils, monocytes, large unstained cells); platelets

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: as part of the sarificial procedure
- Anaesthetic used for blood collection: Yes (isofluorane)
- Animals fasted: Yes
- How many animals: 5 per sex (females with viable litters i possible)
- Parameters checked: alkaline phosphatase; alanine aminotransferase; aspartate aminotransferase; gamma-glutamyltransferase; urea; creatinine; glucose; triglycerides; bile acids; phosphorus; total bilirubin; total cholesterol; total protein; albumin; globulin; A/G Ratio; sodium; potassium; calcium; chloride

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: for males 5 days before necropsy and for females on Day 3 post partum.
- Dose groups that were examined: from each group, 5 males and 5 females were randomly selected.
- Battery of functions tested: grip strength; sensory reactivity to stimuli; motor activity assessment

FUNCTIONAL OBSERVATION BATTERY TESTS
- Time schedule for examinations: once before commencement of treatment and at least once a week thereafter, each animal was given a detailed clinical examination.
- Battery of functions tested: removal (from cage); handling reactivity; lachrymation; palpebral closure; salivation; piloerection; rearing; spasms; myoclonia; mobility impairment; arousal (animal activity); vocalisation; stereotypies; unusual respiratory pattern; bizarre behaviour; urination; defecation; tremors; gait.
Sacrifice and pathology:
SACRIFICE: Yes
- Males were killed after the mating of all females (after 32 days of treatment period).
- Females with live pups were killed on Day 4 post partum while females which did not give birth 25 days after positive identification of mating were killed shortly (Day 27 post coitum).
- All parental animals were killed by exsanguination under isofluorane anaesthesia.
- Pups were euthanised by intraperitoneal injection of thiopenthal.

TISSUE PRESERVATION: Yes
- Procedure: Samples of tissues were fixed and preserved in 10% neutral buffered formalin (except eyes, testes and epididymides which were fixed in modified Davidson's fluid and preserved in 70% ethyl alcohol).
- Organs / tissues preserved: all abnormalities; adrenal glands; bone marrow (from sternum); brain; caecum; colon; duodenum; heart; ileum; jejunum (including Peyer’s patches); kidneys; liver; lungs (including mainstem bronchi); lymph nodes - cervical ; lymph nodes - mesenteric; nasal cavity; oesophagus; pituitary gland; prostate gland; rectum; sciatic nerve; spinal column; spinal cord (cervical, thoracic, lumbar); spleen; stomach; thymus (where present); thyroid ; trachea; urinary bladder
- Reproductive organs / tissues preserved: epididymides; ovaries with oviducts; seminal vesicles with coagulating glands; testes; uterus - cervix; vagina.

GROSS PATHOLOGY: Yes
- Time schedule for examinations: Terminal sacrifice. All animals.
- Organs / tissues examined: All parent animals and pups wee examined macroscopically for any structural changes.
- Reproductive organs / tissues examined: Sexual organs were specifically examined. The number of implantation sites and corpora lutea was recorded for all dams with litters. The uteri of non-pregnant females were placed in a solution of ammonium sulfide to visualize possible hemorrhagic areas of implantation sites.

HISTOPATHOLOGY: Yes
- Time schedule for examinations: Tissues were collected from 5 males and 5 females (randomly selected) in the control and high dose group killed at terminal sacrifice and from all animals with abnormalities in all dose groups.
- Procedure: Tissues were dehydrated and embedded in paraffin wax, sections of the tissues were cut at 5 micrometer thickness and stained with haematoxylin and eosin. Testes and epididymides were cut at 2-3 micrometer thickness and stained with Periodic Acid Schiff (PAS) and morphological evaluation of the seminiferous epithelium (staging of spermatogenic cycle) was performed.
- Organs / tissues examined: all abnormalities; adrenal glands; bone marrow (from sternum); brain; caecum; colon; duodenum; heart; ileum; jejunum (including Peyer’s patches); kidneys; liver; lungs (including mainstem bronchi); lymph nodes - cervical ; lymph nodes - mesenteric; pituitary gland; prostate gland; rectum; sciatic nerve; spinal cord (cervical, thoracic, lumbar); spleen; stomach; thymus (where present); thyroid ; trachea; urinary bladder
- Reproductive organs / tissues examined: epididymides; ovaries with oviducts; seminal vesicles with coagulating glands; testes; uterus - cervix; vagina

ORGAN WEIGHT: Yes
- Time schedule for examinations: Organs were collected from all animals surviving the scheduled test period.
- Procedure: Organs were dissected free of fat and weighed. The ratios of organ weight to body weight were calculated for each animal.
- Organs / tissues examined: adrenal glands; brain; heart; kidneys; liver; prostate gland; spleen; thymus
- Reproductive organs / tissues examined: epididymides; ovaries with oviducts; testes
Other examinations:
VAGINAL SMEARS: Yes
Vaginal smears were taken daily in the morning starting two weeks before pairing until a positive identification of copulation was made. The vaginal smear data were examined to determine anomalies of the oestrous cycle and pre-coital interval (i.e., the number of nights paired prior to the detection of mating).

REPRODUCTIVE INDICES: Yes
- The following reproductive indices were calculated: copulatory index; fertility index; pre-coital interval (mean number of days between pairing and mating); pre-implantation loss; pre-birth loss; pup loss at birth; cumulative pup loss on Day 4 post partum; sex ratios on Day 4 post partum.

SPERMATOGENIC CYCLE: Yes
- A detailed qualitative examination of the testes was performed in control and high dose groups. The evaluation, taking into account the tubular stages of the spermatogenic cycle, was conducted in order to identify treatment-related effects, such as missing germ cell layers or types, retained spermatids, multinucleated or apoptotic germ cells and sloughing of spermatogenic cells into the lumen.
- Seminiferous tubules were evaluated with respect to their stage in the spermatogenic cycle and to the integrity of the various cell types within the different stages.
Statistics:
- Standard deviations were calculated as appropriate. For continuous variables the significance of the differences amongst group means was assessed by Dunnett’s test or a modified t test, depending on the homogeneity of data.
- Statistical analysis of histopathological findings was carried out by means of the non-parametric Kolmogorov-Smirnov test if n was more than 5.
- The non-parametric Kruskal-Wallis analysis of variance was used for the other parameters. Intergroup differences between the control and treated groups were assessed by the non-parametric version of the Williams test.
- The criterion for statistical significance was p<0.05
Clinical signs:
no effects observed
Description (incidence and severity):
- No clinical findings of toxicological significance were observed. Hair loss was occasionally recorded throughout the study including control animals. One female of the mid-dose group had salivation on Day 20 post coitum. One high dose female, that did not give birth, showed prolapse of the uterus on Day 27 post coitum. Another high dose female had rales during pairing.
Mortality:
no mortality observed
Description (incidence):
- No mortality occurred in the study.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
- Body weight and body weight gain did not show relevant differences between groups. In particular, body weight gain was in some occasions higher in treated groups compared to the control group.
Body weight at term and organ weights did not show differences of toxicological relevance.
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
no effects observed
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Description (incidence and severity):
- No changes of toxicological relevance were recorded.
- A statistically significant decrease of lymphocytes recorded in some females dosed with 300 mg/kg bw/day (up to 42% below controls) was not dose-related and, therefore, considered incidental.
- No changes were observed in the coagulation test.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
- A number of males dosed with 1000 mg/kg bw/day showed a slight decrease of protein and globulin (approximately 10%). Due to the low severity, these changes were considered of no toxicological importance.
- In addition, one animal showed high triglycerides (6.2 fold compared with controls). Due to the low incidence, this finding cannot be conclusively attributed to treatment; however, it also cannot be ruled out that it was related to treatment.
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
- Motor activity recorded at the end of treatment did not show significant differences between control and treated groups.
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
- A slight significant reduction of epididymides weight occurred in the high-dose group; however, this reduction was found to be related to the higher terminal body weight in the high-dose group compared to controls. In addition, this change was minimal and no histological associated-findings were found. Therefore, it was considered of no toxicological relevance.
Body weight at term and organ weights did not show differences of toxicological relevance.
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
- Minimal, focal vacuolation of squamous epithelium (limiting ridge) of the non-glandular region of the stomach was observed in the high and mid-dose males with an increased incidence in the high dose males and similar severity levels across treatment groups. However, such gastric change was noted only in males, in a specific zone of the forestomach (limiting ridge) with focal and minimal severity and since humans do not have forestomach (squamous epithelium), such change could be considered toxicologically as a minor change.
- The remaining lesions reported in control and treated animals were considered to be an expression of spontaneous and/or incidental pathology, commonly seen in this species and age under the experimental conditions.
Histopathological findings: neoplastic:
not examined
Other effects:
effects observed, non-treatment-related
Description (incidence and severity):
Spermatogenic cycle:
- A detailed qualitative examination of the testes was performed in control and high dose groups. The evaluation, taking into account the tubular stages of the spermatogenic cycle, was conducted in order to identify treatment-related effects, such as missing germ cell layers or types, retained spermatids, multinucleated or apoptotic germ cells and sloughing of spermatogenic cells into the lumen.
Seminiferous tubules were evaluated with respect to their stage in the spermatogenic cycle and to the integrity of the various cell types within the different stages; regular layering in the germinal epithelium was noted.
Key result
Dose descriptor:
NOAEL
Remarks:
(systemic effects)
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Based on:
act. ingr.
Remarks:
anhydrous zirconium acetate
Sex:
male/female
Basis for effect level:
other: Based on a lack of toxicologically relevant systemic effects in male or female parental animals in any dose group.
Key result
Critical effects observed:
no

The overall results of the test formulation analyses were within the limits of acceptance for concentration (15% of the theoretical concentration).

Conclusions:
On the basis of the results obtained in this study, the No Observed Adverse Effect Level (NOAEL) for systemic toxicity was considered to be >=1000 mg/kg bw/day (expressed as zirconium acetate anhydrous) for males and females.
Endpoint:
sub-chronic toxicity: oral
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Critical effects observed:
not specified
Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
no data
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
significant methodological deficiencies
Remarks:
A Klimisch score 3 (not reliable) is assigned because 1) the study only lasted 16 days, 2) the laboratory testing conditions are not reported, 3) no information is given on feeding during the test, 4) there is no guideline reported, 5) no data is available on substance origin and purity, and 6) no data is available on the origin of the animals and the acclimation period.
Reason / purpose for cross-reference:
reference to same study
Qualifier:
no guideline followed
Principles of method if other than guideline:
Administration (oral gavage) to rats during 16 days.
GLP compliance:
not specified
Limit test:
no
Species:
rat
Strain:
Wistar
Sex:
female
Route of administration:
oral: gavage
Vehicle:
water
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
16 days
Frequency of treatment:
one time per day
Dose / conc.:
800 mg/kg bw/day (nominal)
No. of animals per sex per dose:
12 female rats
Control animals:
yes
Critical effects observed:
not specified

No impact on animal weight. No impact on water consumption. No significant impact on diuresis.

No histopathologic impact observed for all investigated tissues except for the ovaries.

The vessels of the ovarian medulla are dilated inconsistently at the end of the short-term toxicity period. After the rest period, the diameter of the vessels of the cortex and medulla is constantly increased giving a congestive aspect to the ovarian parenchyma.

Conclusions:
Iterative administration of zirconium oxychlorure at a dose of 800 mg/kg bw/day to rats during 16 days had no significant impact on growth, water consumption, diuresis. Only a fraction of zirconium administered is absorbed, it binds electively to the ovaries, more slightly to the lungs and bones. Zirconium oxychlorure causes hypervascularisation of the ovaries, still visible one month after the treatment.
No deaths were observed after administration of 800 mg/kg bw/day of oxychlorure de zirconium during 16 days to rats.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subacute
Species:
rat

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Remarks:
Well documented, scientifically sound study that is similar to OECD 413 "Subchronic Inhalation Toxicity: 90-day study" guideline with the following deviations: (1) only 1 dose tested rather than 3; (2) exposure was for 60 days rather than 90 days; (3) complete list of tissues examined for histopathology was not provided; (4) limited clinical chemistry and urinalysis; (5) 4 cats, 4 dogs, 20 Guinea pigs, 19 rabbits and 72 rats (sex not provided) were exposed rather than 10 rodents per sex per dose.
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
Deviations:
yes
Remarks:
see rationale for reliability
GLP compliance:
no
Limit test:
no
Species:
other: cat, dog, guinea pig, rabbit, rat
Strain:
not specified
Sex:
not specified
Route of administration:
inhalation: aerosol
Type of inhalation exposure:
whole body
Vehicle:
other: no data
Remarks on MMAD:
MMAD / GSD: Mass median particle diameter: 0.56 microns
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: copper-lined chamber constructed of wood with observation windows on three sides, 6 x 8 x 6 ft high and volume of 288 cubic feet.
- Method of conditioning air: A centrally located duct in the ceiling of the chamber served as the inlet for the test substance. Baffles below the inlet and two fans near the ceiling dispersed the test substance and distributed the test substance uniformly throughout the chamber. In the four bottom corners were outlets connected to an exhaust system. Air turnover during exposure was approximately 140 cfm or one change every two minutes with no recycling.
- System of generating particulates/aerosols: Wright dust feed.
- Temperature, humidity, pressure in air chamber: 74 +/- 3 degrees F; 47% +/- 6%; few hundredths of an inch of water less than atmospheric pressure.
- Air flow rate: 140 cfm or one change every two minutes.
- Method of particle size determination: test substance was twice ground in a Mikropulverizer to a mean bulk particle size.
- Treatment of exhaust air: not recycled

TEST ATMOSPHERE
- Brief description of analytical method used: Hourly samples were taken with a filter paper sampler and weighed on an analytical balance, spectrographic analysis of each day's accumulation of filter paper samples was used to verify the weight-samples and to make such slight adjustments in concentration results as might occasionally arise from varying amounts of nuisance dust.
- Samples taken from breathing zone: yes, hourly
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Hourly samples were taken with a filter paper sampler and weighed on an analytical balance, spectrographic analysis of each day's accumulation of filter paper samples was used to verify the weight-samples and to make such slight adjustments in concentration results as might occasionally arise from varying amounts of nuisance dust.
Duration of treatment / exposure:
60 days
Frequency of treatment:
6 hours/day, 5 days/week
Dose / conc.:
11.3 mg/m³ air (analytical)
No. of animals per sex per dose:
Cat- 4
Dog - 4
Guinea Pig - 20
Rabbit - 20
Rat - 72
Control animals:
other: yes, only control rabbits and rats were used
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: No data

BODY WEIGHT: Yes
- Time schedule for examinations: No data

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: weekly
- Animals fasted: No data
- How many animals: 4 dogs
- Parameters: Red blood cell and differential white cell counts, as well as determinations of hemoglobin, mean corpuscular cell volume and clotting time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: semi-monthly
- Animals fasted: No data
- How many animals: 4 dogs and 4 rabbits
- Parameters: Blood nonprotein nitrogen

URINALYSIS: Yes
- Time schedule for collection of blood: semi-monthly
- Animals fasted: No data
- How many animals: 4 dogs and 4 rabbits
- Parameters: Urinary protein

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
HISTOPATHOLOGY: Yes, lung, kidney, liver. Other tissues were evaluated, but a complete list of other tissues was not provided.
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Description (incidence):
3 guinea pig & 8 rats died during exposure to the test substances.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Throughout the exposure periods the weekly weight responses were identical with those of normal animals.
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
Decrease on hemoglobin in the blood for the 3 dogs. Minimum reached after 4 weeks. Depression in the red blood cells count was also observed but in a lower proportion. The lower depression occurred between week 5 & 7.
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
No significant blood changes were found among the criteria studied. Blood fibrinogen levels also remained constant during exposure of animals to the test substance.
Urinalysis findings:
no effects observed
Description (incidence and severity):
No significant urine changes were found among the criteria studied.
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
There are no reported histological changes that could be attributed to the test substance. The abnormalities that were reported were similar for all species regardless of dose, duration of exposure or test substance inhaled.
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Dose descriptor:
NOAEC
Effect level:
>= 11.3 mg/m³ air
Based on:
test mat.
Sex:
not specified
Basis for effect level:
body weight and weight gain
clinical biochemistry
clinical signs
haematology
histopathology: non-neoplastic
mortality
urinalysis
Critical effects observed:
no
Conclusions:
Inhalation of 11.3 mg/m3 zirconium dichloride oxide for 60 days produced no significant changes in animals in mortality rate, growth, biochemistry, hematology values or histopathology. In two animals (cats) among 124 testicular athrophy was observed.
Endpoint:
sub-chronic toxicity: inhalation
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Critical effects observed:
not specified
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
11.3 mg/m³
Study duration:
subchronic
Species:
other: various species

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Remarks:
Well documented, scientifically sound study that is similar to OECD 413 "Subchronic Inhalation Toxicity: 90-day study" guideline with the following deviations: (1) only 1 dose tested rather than 3; (2) exposure was for 60 days rather than 90 days; (3) complete list of tissues examined for histopathology was not provided; (4) limited clinical chemistry and urinalysis; (5) 4 cats, 4 dogs, 20 Guinea pigs, 19 rabbits and 72 rats (sex not provided) were exposed rather than 10 rodents per sex per dose.
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
Deviations:
yes
Remarks:
see rationale for reliability
GLP compliance:
no
Limit test:
no
Species:
other: cat, dog, guinea pig, rabbit, rat
Strain:
not specified
Sex:
not specified
Route of administration:
inhalation: aerosol
Type of inhalation exposure:
whole body
Vehicle:
other: no data
Remarks on MMAD:
MMAD / GSD: Mass median particle diameter: 0.56 microns
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: copper-lined chamber constructed of wood with observation windows on three sides, 6 x 8 x 6 ft high and volume of 288 cubic feet.
- Method of conditioning air: A centrally located duct in the ceiling of the chamber served as the inlet for the test substance. Baffles below the inlet and two fans near the ceiling dispersed the test substance and distributed the test substance uniformly throughout the chamber. In the four bottom corners were outlets connected to an exhaust system. Air turnover during exposure was approximately 140 cfm or one change every two minutes with no recycling.
- System of generating particulates/aerosols: Wright dust feed.
- Temperature, humidity, pressure in air chamber: 74 +/- 3 degrees F; 47% +/- 6%; few hundredths of an inch of water less than atmospheric pressure.
- Air flow rate: 140 cfm or one change every two minutes.
- Method of particle size determination: test substance was twice ground in a Mikropulverizer to a mean bulk particle size.
- Treatment of exhaust air: not recycled

TEST ATMOSPHERE
- Brief description of analytical method used: Hourly samples were taken with a filter paper sampler and weighed on an analytical balance, spectrographic analysis of each day's accumulation of filter paper samples was used to verify the weight-samples and to make such slight adjustments in concentration results as might occasionally arise from varying amounts of nuisance dust.
- Samples taken from breathing zone: yes, hourly
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Hourly samples were taken with a filter paper sampler and weighed on an analytical balance, spectrographic analysis of each day's accumulation of filter paper samples was used to verify the weight-samples and to make such slight adjustments in concentration results as might occasionally arise from varying amounts of nuisance dust.
Duration of treatment / exposure:
60 days
Frequency of treatment:
6 hours/day, 5 days/week
Dose / conc.:
11.3 mg/m³ air (analytical)
No. of animals per sex per dose:
Cat- 4
Dog - 4
Guinea Pig - 20
Rabbit - 20
Rat - 72
Control animals:
other: yes, only control rabbits and rats were used
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: No data

BODY WEIGHT: Yes
- Time schedule for examinations: No data

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: weekly
- Animals fasted: No data
- How many animals: 4 dogs
- Parameters: Red blood cell and differential white cell counts, as well as determinations of hemoglobin, mean corpuscular cell volume and clotting time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: semi-monthly
- Animals fasted: No data
- How many animals: 4 dogs and 4 rabbits
- Parameters: Blood nonprotein nitrogen

URINALYSIS: Yes
- Time schedule for collection of blood: semi-monthly
- Animals fasted: No data
- How many animals: 4 dogs and 4 rabbits
- Parameters: Urinary protein

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
HISTOPATHOLOGY: Yes, lung, kidney, liver. Other tissues were evaluated, but a complete list of other tissues was not provided.
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Description (incidence):
3 guinea pig & 8 rats died during exposure to the test substances.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Throughout the exposure periods the weekly weight responses were identical with those of normal animals.
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
Decrease on hemoglobin in the blood for the 3 dogs. Minimum reached after 4 weeks. Depression in the red blood cells count was also observed but in a lower proportion. The lower depression occurred between week 5 & 7.
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
No significant blood changes were found among the criteria studied. Blood fibrinogen levels also remained constant during exposure of animals to the test substance.
Urinalysis findings:
no effects observed
Description (incidence and severity):
No significant urine changes were found among the criteria studied.
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
There are no reported histological changes that could be attributed to the test substance. The abnormalities that were reported were similar for all species regardless of dose, duration of exposure or test substance inhaled.
Histopathological findings: neoplastic:
not examined
Other effects:
not specified
Dose descriptor:
NOAEC
Effect level:
>= 11.3 mg/m³ air
Based on:
test mat.
Sex:
not specified
Basis for effect level:
body weight and weight gain
clinical biochemistry
clinical signs
haematology
histopathology: non-neoplastic
mortality
urinalysis
Critical effects observed:
no
Conclusions:
Inhalation of 11.3 mg/m3 zirconium dichloride oxide for 60 days produced no significant changes in animals in mortality rate, growth, biochemistry, hematology values or histopathology. In two animals (cats) among 124 testicular athrophy was observed.
Endpoint:
sub-chronic toxicity: inhalation
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Critical effects observed:
not specified
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
11.3 mg/m³
Study duration:
subchronic
Species:
other: various species

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: dermal
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: dermal
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Repeated dose toxicity - oral route

On the repeated dose toxicity of zirconium dichloride oxide via the oral route of exposure, only a study of low reliability (Klimisch 3) was identified (Delongeas et al., 1983). This study demonstrated that iterative administration of the substance at a dose of 800 mg/kg bw/day to rats during 16 days has no significant impact on growth, water consumption, and diuresis. Only a fraction of the administered zirconium is absorbed, it binds electively to the ovaries, and more slightly to the lungs and bones. Zirconium dichloride oxide causes hypervascularisation of the ovaries, still visible one month after the treatment. No deaths were observed after administration of 800 mg/kg bw/day during 16 days to rats.

Because the available information on zirconium dichloride oxide is not sufficient to cover the endpoint, read across is performed from a combined repeated dose toxicity study with reproduction/developmental toxicity screening test via oral route in rats with zirconium acetate, a 'water soluble' zirconium substance with similar toxicokinetic behaviour as zirconium dichloride oxide. The read across justification is included in Section 13 of IUCLID.

In this study the systemic toxic effects of zirconium acetate solution (containing 40.7% of the active ingredient anhydrous zirconium acetate) after administration of repeated doses, as well as any toxic effects on reproduction and development, were investigated in Sprague Dawley rats up to early lactation (day 4 post partum). The study (Rossiello, 2013) was performed according to OECD guideline 422 (GLP)

 

Three groups of 10 males and 10 females each received the test item, by oral gavage, at 100, 300 and 1000 mg/kg bw/day, expressed as zirconium acetate (anhydrous). A similar constituted control group received the vehicle alone during the treatment period. The test item was diluted in purified water (vehicle) at concentrations of 10, 30 and 100 mg of zirconium acetate/mL. Chemical analyses of the formulated test item were performed during the study and the overall results were within the limits of acceptance. The overall dosing period was 32 days for males, which included 2 weeks before pairing and continuously thereafter up to the day before necropsy and up to 50 days for females including 2 weeks before pairing and thereafter during pairing, gestation and lactation periods until day 3 post partum.

 

The animals were followed for daily clinical signs, weekly body weight, food consumption, neurotoxicity assessment, oestrous cycle, mating performance, clinical pathology evaluation including haematology and clinical chemistry and offspring delivery. A detailed macroscopic examination, organ weights and histopathology including the spermatogenic cycle were performed.

 

No treatment-related findings were observed either during the in vivo phase or at post mortem examination. Microscopically, treatment-related finding was seen in males receiving 300 and 1000 mg/kg bw/day consisting of minimal focal vacuolation of squamous epithelium (limiting ridge) of non-glandular region of the stomach. This change may be attributed to a local irritant effect of the compound administered by oral gavage and since humans do not have forestomach or structure analogous to forestomach, it is not considered of toxicological relevance.

 

No systemic adverse effects were therefore reported. On the basis of these results, the NOAEL (No Observed Adverse Effect Level) for systemic toxicity after repeated oral exposure was considered to be >= 1000 mg of zirconium acetate/kg bw/day for both males and females.

Due to the indications for similar toxicokinetic behaviour of zirconium zubstances such as zirconium dichloride oxide and zirconium acetate, the results of the repeated dose toxicity study with zirconium acetate are considered relevant for zirconium dichloride oxide.

Repeated dose toxicity - inhalation route

A reliable study (Klimisch 2, reliable with restrictions) was identified for this endpoint: a repeated inhalation test in cats, dogs, guinea pigs, rabbits and rarts, which demonstrated that inhalation of 11.3 mg/m3 zirconium dichloride oxide for 60 days did not cause any significant changes in mortality rate, growth, biochemistry, hematology values or histopathology. Therefore the subacute endpoint is covered by this 60-day study.

Repeated dose toxicity - dermal route

A key study is available for the oral and inhalation route of exposure. According to the REACH Regulation, only one route of exposure should be tested for repeated dose toxicity (column 2, annex VIII, section 8.6.1). Therefore, it is not necessary to perform a repeated dose toxicity study via the dermal route of exposure

Annex IX further testing:

There is sufficient evidence available indicating that zirconium is barely absorbed after exposure via inhalation (see section 7.1) and is therefore of low bioavailability. In addition, no adverse effects have been reported after repeated inhalation exposure of test animals during 60 days to zirconium dichloride oxide (see above). Based on this information it is unlikely to expect any toxicity after a period of 90 days of repeated exposure via inhalation. As no adverse effect needs to be addressed, a test proposal for a 90-day inhalation study is not scientifically justified. Therefore, and for animal welfare reasons, a testing proposal is not included.

On the basis of the results observed in the OECD 422 test (Rossiello, 2013) performed with the read across substance zirconium acetate (NOAEL >= 1000 mg/kg bw/day; no systemic toxicity observed at the highest dose), no adverse effects need to be addressed by a subchronic oral repeated dose toxicity test. In addition, based on the toxicokinetics assessment, low absorption of zirconium is expected after oral exposure to 'water soluble' zirconium substances such as zirconium dichloride oxide and zirconium acetate. Therefore, and in accordance with the REACH Regulation (Annex IX, section 8.6.2, column 2), a test proposal for a 90-day oral study is not included for zirconium dichloride oxide as it is not scientifically justified.

Justification for classification or non-classification

Based on the available data for repeated dose toxicity via the oral route of exposure and according to the CLP criteria, zirconium dichloride oxide should not be classified for STOT - repeated exposure.