Disodium octaborate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Disodium octaborate

EC Number:

234-541-0

EC Name:

Disodium octaborate

Cas Number:

12008-41-2

Molecular formula:

Na2B8O13

IUPAC Name:

disodium bis[(oxoboranyl)oxy]bicyclo[5.5.1]hexaboroxane-3,5-bis(olate)

Details on test material:

- Name of test material: Disodium octoborate tetrahydrate
- Physical state: White powder
- Analytical purity: > 98 %
- Lot/batch No.: 4H22
- Stability under test conditions: Stable.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hilltop Lab Animals, Scottdale, PA
- Age at study initiation: Young adult
- Weight at study initiation: Males 224-260 g; females 207 -234 g

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

other: no data

Details on inhalation exposure:

TEST ATMOSPHERE
- Particle size distribution: Not an aerosol study
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): MMAD 2.8 µm + GSD 2.15 µm

- Rationale for the selection of the starting concentration: Top dose ~ 2 mg/L was the highest that was obtainable under the conditions of the test

Analytical verification of test atmosphere concentrations:

yes

Remarks:

No further details

Duration of exposure:

4 h

Concentrations:

Nominal concentration 2000 mg/m³
Analytical concentration 2010 ± 140 mg/m³

No. of animals per sex per dose:

5/sex/group

Control animals:

no

Details on study design:

- Necropsy of survivors performed: Yes
- Other examinations performed: Clinical signs

Statistics:

No data

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.01 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No data

Clinical signs:

other: Animal observations were limited due to the accumulation of test material on the walls of the exposure chamber. During exposure, ocular discharge, hypoactivity and haunched posture were noted. All animals recovered after removal from chamber.

Body weight:

See table

Gross pathology:

No specific findings observed except red lung discolouration consistent with CO2 inhalation (caused by euthanasia technique). All tissue sand organs were normal.

Other findings:

No data

Any other information on results incl. tables

Gravimetric chamber concentrations:

Sample No.	Mass collected (mg)	Airflow sampled (Lpm)	Collection time (min)	Chamber concentration (mg/L)
1	14.5	4	2	1.81
2	19.1	4	2	2.38
3	15.4	4	2	1.93
4	17.5	4	2	2.19
5	17.1	4	2	2.14
6	14.6	4	2	1.83
7	14.4	4	2	1.80
Average ± Standard deviation				2.01 ± 0.23

Summary of particle size distribution:

Sample No.	Sampling time (min)	Mass mean aerodynamics diameter (μm)^1	Geometric standard deviation
1	2	2.7	2.08
2	2	2.8	2.15

¹ This figure is an estimation based on graphic analysis of the particle size distribution as measured with an Andersen Cascade Impactor

Individual body weights:

Animal No.	Sex	Body weight (g)
		Initial	Day 7	Day 14
5409	M	224	338	376
5410	M	256	332	374
5411	M	224	303	351
5412	M	260	340	392
5413	M	225	296	329
5414	F	207	232	240
5415	F	215	223	231
5416	F	215	235	249
5417	F	234	250	253
5418	F	207	222	233

Applicant's summary and conclusion

Interpretation of results:

other: EU GHS Criteria not met

Conclusions:

The sample was ground in a ball mill for 24 hours to give a MMAD 2.8 µm + GSD 2.15 µm
Top dose ~ 2 mg/L was the highest that was obtainable under the conditions of the test. The acute inhalation LC50 was > 2.01 mg/L (2.01 g/m³).

Executive summary:

The test item disodium octaborate tetrahydrate was assessed for inhalation acute toxicity in rats in a GLP study according to OECD Guideline 403. Five animals per sex per dose were exposed per whole body to a maximum attainable test item concentration of 2.01 mg/L for 4 hours. The acute inhalation LC50 was > 2.01 mg/L (2.01 g/m³).