Potassium niobate

Endpoint summary

Description of key information

In an acute oral toxicity study in rats conducted according to OECD 423 no mortality occurred at the limit dose of 2000 mg/kg bw.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-08-24 to 2018-01-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, 97633 Sulzfeld, Germany
- Number of animals per group: 6 female
- Age at start of treatment: 9 - 11 weeks
- Body weight at start of treatment: Step 1: animals no. 1 - 3: 175 - 201 g; Step 2: animals no. 4 - 6: 185 - 194 g
- Identification: tail painting
- Acclimatization: at least 5 days
- Housing: in groups in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding
- Diet: ad libitum, pAltromin 1324 maintenance diet for rats and mice; removal of food 16 - 19 hrs before administration of test material until 4 hrs after administration
- Water: ad libitum, tap water, sulphur acidified to a pH value of approximately 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals)

ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/-3 °C
- Humidity (%): 55 +/-10 % R.H.
- Photoperiod (hrs dark / hrs light): 12/12
- Air changes per hour: 10

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg body weight

Doses:

once 2000 mg/kg bw

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

- Duration of observation period following administration: 15 days

OBSERVATION
- Weighing: day before dosing and Day 1, 8 and 15
- Mortality/Viability: there was no death
- Clinical signs: Day 1: at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose; daily thereafter
- Necropsy of survivors performed: yes, all animals were sacrificed

Statistics:

LD50 values and associated 95 % confidence interval

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

femals 0/6

Clinical signs:

other: slight to moderate piloerection, slightly reduced spontaneous activity during first 2 days; the animals were overtly normal by the 3rd day

Gross pathology:

Necropsy, on Day 15, revealed no significant macroscopic lesion.

Table 1: Results per Step

Step	Sex / No.	Starting dose (mg/kg bw)	Number of animals	Number of intercurrent deaths
Step 1	Female / 1 - 3	2000	3	0
Step 2	Female / 4 - 6	2000	3	0

bw = body weight

Table 2: Clinical Signs - Individual Data

Step	Animals No./Sex	Starting Dose (mg/kg bw)	Timepoint	Observations
1	1, 2, 3 / female	2000	0 – 30 min	Nsf
			30 – 60 min	Slight piloerection
			60 – 120 min	Slightly reduced spontaneous activity, moderate piloerection
			120 – 180 min	Slight piloerection
			180 – 240 min	Moderate piloerection
			240 min – d 2	Slight piloerection
			d 2 – d 15	nsf
2	4, 5, 6 / female	2000	0 – 120 min	nsf
			120 – 180 min	Slight piloerection
			180 min – d 15	nsf

d = day, min = minute, nsf = no specific findings

Table 3: Absolute body weights in g and body weight gain in %

Step	Animal No. / Sex	Starting dose (mg/kg bw)	bw (g)			Body weight gain in comparison to day 1 (%)
			Day 1	Day 8	Day 15
1	1 / female	2000	192	200	212	10
	2 / female		175	199	205	17
	3 / female		201	227	227	13
2	4 / female	2000	194	219	226	16
	5 / female		186	209	218	17
	6 / female		185	200	210	14

Table 4: Findings of the necropsy - individual data

Step	Animal No. / Sex	Starting dose (mg/kg bw)	Organ	Macroscopic findings
1	1 / female	2000	-	nsf
	2 / female		-	nsf
	3 / female		-	nsf
2	4 / female	2000	-	nsf
	5 / female		-	nsf
	6 / female		-	nsf

Table 5: LD50 cut-off

Starting dose (mg/kg bw)	Number of animals	Number of intercurrent death	LD50 Cut-off
2000	6	0	unclassified

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute oral toxicity study in rats conducted according to OECD 423 no mortality occurred at the limit dose of 2000 mg/kg bw. Hence, the LD50 value was determined to be greater than 2000 mg/kg bw.

Executive summary:

In an acute oral toxicity study (acute toxic class method, OECD 423), 6 fasted, 9 - 11 weeks old, female Wistar rats were given a single oral dose of Potassium niobate (≥ 99.8 % purity) in water at the limit dose of 2000 mg/kg bw and were observed for 15 days. All animals survived until the end of the study showing only mild signs of toxicity. The clinical findings in the animals treated with the test item at a dose of 2000 mg/kg bw were reduced spontaneous activity and piloerection. All symptoms were no longer detectable by day 2 after dosing.

Throughout the 14-day observation period, the body weight gain of the test animals was within the normal range of variation for this strain. At necropsy, no macroscopic findings were observed in any animal of any step. Based on the results from this study, the oral LD50 in rats is considered to exceed 2000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

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

In an acute oral toxicity study in rats conducted according to OECD 423 no mortality occurred at the limit dose of 2000 mg/kg bw. Hence, the LD50 value was determined to be greater than 2000 mg/kg bw.