Chrome antimony titanium buff rutile

Endpoint summary

Description of key information

ORAL

The NOAEL of >= 500 mg/kg bw/day (highest dose) was chosen from the oral 90-day key study (Bomhard et al., 1982).

INHALATION

The NOAEC of >= 60 mg/m3 (highest concentration) with a clearance half-life of 50 days in the lungs was taken from the 5-day inhalation key study (BASF AG, 33I0110/91008, 1994).

DERMAL

Assessment: dermal pathway not relevant due to lack of bioavailability.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (non-GLP

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

Levels of chromium and antimony in liver and kidneys, respectively, were measured after 1 and 2 months

Principles of method if other than guideline:

Method: T26-16 (comparable to OECD guideline 408)

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

other: SPF-derived Wistar TNO W74

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Winkelmann, Borchen, Germany
- Age at study initiation: 4-5 weeks
- Housing: macrolon cages
- Individual metabolism cages: no
- Diet (e.g. ad libitum): Altromin
- Water (e.g. ad libitum): tap water


ENVIRONMENTAL CONDITIONS
- reported as "standard conditions"

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

DIET PREPARATION
- Mixing appropriate amounts of powdered food with the test substance

Duration of treatment / exposure:

90 days

Frequency of treatment:

daily

Dose / conc.:

0 mg/kg diet

Remarks:

0 mg/kg bw/day

Dose / conc.:

10 mg/kg diet

Remarks:

0.5 mg/kg bw/day

Dose / conc.:

100 mg/kg diet

Remarks:

5 mg/kg bw/day

Dose / conc.:

1 000 mg/kg diet

Remarks:

50 mg/kg bw/day

Dose / conc.:

10 000 mg/kg diet

Remarks:

500 mg/kg bw/day

No. of animals per sex per dose:

15 (control: 30). 10 animals were used for analytical investigations (control: 20).

Control animals:

yes, concurrent vehicle

Details on study design:

- Post-exposure period: no

Observations and examinations performed and frequency:

The animals were observed daily, food consumption and body weight were determined once a week. Haematological, clinical and biochemical investigations (RBC, reticulocytes, platelets, haemoglobin, haematocrit, total and differential WBC, MCV, ALP, GOT, GPT, creatinine, urea, glucose, cholesterol, total plasma and urine proteins, urinalysis) were conducted using recommended methods after one month and at the end of the study on 5 male and 5 female rats of each group. In addition, thromboplastin time and glutamate dehydrogenase activity were measured after 3 months.

Sacrifice and pathology:

All animals, killed at the end of treatment by exsanguination under ether anaesthesia, were subjected to detailed macroscopic examination. Thyroid gland, thymus, heart, lung, liver, spleen, kidneys, adrenals, gonads were weighed and liver, aorta, eyes, intestines, femur, brain, urinary bladder, pituitary, cervical lymph nodes, stomach, oesophagus, epididymides, pancreas, prostate, seminal vesicle, sternum (bone marrow), trachea, uterus, skeletal muscle (M. quadriceps with N. ischiadicus) from 5 males and 5 females of the control and top dose groups were histopathologically examined. Paraffin slices were stained with haematoxylin and eosin. Additional kidney slices were stained by PAS and cryostat slices of liver with Oil Red O.

Other examinations:

After 1, 2 and 3 months liver and kidneys from 5 animals per gender and dose group analysed for their chromium and antimony contents by AAS. The detection limit for antimony was 5 ppb, chromium 2 ppb.

Statistics:

The results of the body and organ weight determination as well as the haematological and clinical chemical data were compared using the U-test according to WiIcoxon (1947). A difference was considered to be significant at P<=0.05.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Endocrine findings:

not examined

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Details on results:

No substance related effects on mortality, clinical signs, body weight/body weight gain, hematology, clinical chemistry, urinalysis, organ weights, gross pathology and histopathology were observed.

Food consumption was similar in all groups.

Key result

Dose descriptor:

NOAEL

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

clinical biochemistry

clinical signs

food consumption and compound intake

haematology

mortality

urinalysis

Key result

Critical effects observed:

no

CHEMICAL ANALYSIS

Antimony

In males and females the Sb concentrations in liver and kidney were below the detection limit at doses up to 1000 ppm. In the high dose groups the Sb levels slightly increased with exposure duration and reached max. 27 ppb in the liver (3 months) of males (range 15-40 ppb) and 17 ppb in females (kidney 14 ppb in males and 15 ppb in females).

Chromium

No measurable effect on chromium content of liver and kidney at any dose level and exposure duration. 

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

500 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

HYPOTHESIS FOR THE ANALOGUE APPROACH
The substance belongs to the group of inorganic pigments with a rutile lattice in which titanium ions are partially replaced by other metal ions (antimony, nickel, chrome). The solubility of the target and source substance in water is very low. Bioavailability is regarded as negligible for both, target and source substance.
For further information, please refer to the Read across justification attached in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Key result

Dose descriptor:

NOAEC

Effect level:

60 mg/m³ air

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

clinical signs

mortality

Key result

Critical effects observed:

no

CONTENT OF Ni AND Sb in:

LIVER: Mean Sb concentration (quantification limit 0.2 ng/g) in unexposed animals was 1.1 ng/g; directly post-exposure and on day 3-post-exposure the concentration was about 4-fold higher in exposed animals, and during later observation the concentration was similar to unexposed animals (1.3 ng/g on day 10). Mean Ni-concentration was in the same range in exposed and unexposed animals (however, below the quantification limit of 10 ng/g; outliers not considered). 

KIDNEYS: Mean Sb concentration in unexposed animals was below the detection limit (1 ng/g), in exposed animals it was above the detection limit but below the quantification limit (3 ng/g), only the day 3 post exposure group reached a value of 5.6 ng/g (2-3-fold increase compared with other observation days). Mean Ni concentration was below the detection limit (1 ng/g) in unexposed animals and above detection limit but below quantification limit (25 ng/g) in exposed animals, except on day 3 post-exposure 94 ng/g were determined (10-fold more than in other exposure groups. Authors comment: presumably due to contamination of the sample).  LUNG: Directly post-exposure the mean Ni and Sb concentration was 79 and 202 µg/lung , respectively (corresponding to 2 mg of pigment/lung). The concentration declined during the post-exposure period, following first order kinetics; the clearance half-life was 50 days.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

60 mg/m³

Study duration:

subacute

Species:

rat

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

ORAL

For the oral exposure pathway a valid subchronic study was performed in rats.

In a subchronic study performed similar to OECD guideline 408, male and female Wistar rats were treated with 0.5, 5, 50 and 500 mg/kg bw/d for 90 d (Bomhard et al., 1982). No substance related effects on mortality, clinical signs, body weight, hematology, clinical chemistry, organ weights, gross pathology and histopathology were observed. There were no indications for bioavailability.

INHALATION

For the inhalative exposure pathway a valid subacute study was performed in rats only with an analogous substance, the nickel rutile. In a GLP-compliant bioavailability study, male Wistar rats were exposed for 5 d to 60 mg/m3 of the test substance; the observation period was 0, 3, 10, 31 and 60 d (BASF AG, 33I0110/91008, 1994). No effects on mortality, clinical signs, body weights and body weight gains were found. Clearance half time was approximately 50 days in the lung. The study was not able to demonstrate bioavailability after inhalation of the test substance.

DERMAL

No leaching of metal ions in artificial sweat solution was detected in a leaching study (see chapter 7.9.3). Therefore, the dermal exposure pathway is considered as not relevant.

CONCLUSIONS

The study data on oral and inhalation exposure reveal no treatment related adverse effects in any study. The investigation of the dermal pathway was not considered relevant due to the lack of bioavailability.

Justification for classification or non-classification

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the substance does not need to be classified and labelled for repeated dose toxicity under Regulation (EC) No 1272/2008, as amended for the ninth time in Regulation (EC) No 2016/1179.