Registration Dossier

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

Constituent 1
Chemical structure
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 octaborate
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).