Indium trihydroxide

Endpoint summary

Description of key information

Assessment of the acute oral toxicity of indium in Asakura et al 2008:

A limit study with Crj:CD (SD) IGS rats (SPF) was carried out according to OECD guideline no 401 to assess the oral LD50. No deaths and no abnormalities in clinical signs, body weights, and necropsy findings were observed for any of the animals. An LD50 value >2000mg/kg bw was reported.

No acute inhalation toxicity data were identified, or are required at this tonnage (1-10 tpa).

No acute dermal toxicity data were identified, or are required at this tonnage (1-10 tpa).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

not applicable

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Please refer to read-across justification report in section 13

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Crj: CD(SD) IGS rats (SPF)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan, Inc
- Age at study initiation: 5 wk
- Weight at study initiation: 125-145 g (male) and 116-130g (female)
- Fasting period before study: 18h
- Diet (ad libitum): pellet diet (MF, Oriental Yeast co, Ltd)
- Water (ad libitum): tap water irradiated by UV rays after passing through a 5µm filter
- Acclimation period: 6days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.2 ± 2
- Humidity (%): 55 ± 15
- Air changes (per hr): 12 changes per hour
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12 hrs light

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: the dosing volume was set at 10mg/kg and the dose volume for individual animals was calculated based on the body weight measured just before dosing

DOSAGE PREPARATION (if unusual): done on the administration day

Doses:

2000mg/kg

No. of animals per sex per dose:

12

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: body weights of all animals were measured before dosing and on days 4, 8, and 15 (day of administration was designated as day 1)
- Necropsy of survivors performed: no
- Other examinations performed:
clinical signs: observed 5 times (shortly before dosing, and 0.5, 1, 3 and 5h after dosing) on the those day and thereafter once a day for 14 days
body weight: measured before dosing and on days 4, 8, and 15

Statistics:

Barlett's test: to test the homogeneity of the variances of the data
one way analysis of variance: used when to variances of the treatment group and the control group were homogenous; to analyze statistical significances in the numerical data (body weight, food consumption, hematology, blood chemistry, and organ weights)
Kruskal-Wallis test: used when to variances of the treatment group and the control group were heterogenous; to analyze statistical significances in the numerical data (body weight, food consumption, hematology, blood chemistry, and organ weights)
Dunnett's test or Dunnett-type ranksum test: to examine statistical significances in the data between groups
chi square test: to examine statistical significances in graded categorical data (urinalysis)

Preliminary study:

a preliminary study was done in which no death were observed

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality observed

Clinical signs:

other: No abnormalities in clinical signs observed

Gross pathology:

Necroscopy:
no abnormalities observed

Other findings:

spontaneous changes: in one male of the 2000 mg/kg group pelvic dilatation of the kidneys was observed

none

Interpretation of results:

GHS criteria not met

Conclusions:

Tests done according to standard protocol. Good quality and considered useful for setting the reference value for acute oral toxicity (LD50>2000mg/kg)

Executive summary:

A limit study with Crj:CD (SD) IGS rats (SPF) was carried out according to OECD guideline no 401 to assess the oral LD50. No deaths and no abnormalities in clinical signs, body weights, and necropsy findings were observed for any of the animals. An LD50 value >2000mg/kg bw was reported.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the results of the available acute oral rat study with indium metal and upon read across, indium trihydroxide does not require classification for acute oral toxicity according to EU CLP criteria (EC 1272/2008).

No clear evidence of specific target organ toxicity was noted. As such, classification for STOT-SE is not considered appropriate.

There are no available data on which to evaluate acute dermal toxicity and also not required at this tonnage band. However, acute dermal toxicity can be considered to be low in view of the poor absorption by this route and the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route. Therefore, indium trihydroxide does not require classfication for acute dermal toxicity according to EU CLP criteria (EC 1272/2008)