Calcium metaborate (Ca(BO2)2) and calcium tetraborate (CaB4O7), amorphous reaction products of boric acid with lime

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Deviations:

not specified

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Diboron trioxide

EC Number:

215-125-8

EC Name:

Diboron trioxide

Cas Number:

1303-86-2

Molecular formula:

B2O3

IUPAC Name:

bicyclo[1.1.1]diboroxane

Details on test material:

- Name of test material: Diboron trioxide (anhydrous boric acid)
- Physical state: White powder
- Analytical purity: > 99 %
- Lot/batch No.: 5C183709
- Other: CHE dispensary No. 0604/95-1341

Test animals

Species:

rat

Strain:

other: Crl:CD.BR

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd., Margate
- Age at study initiation: 5 - 8 weeks of age
- Weight at study initiation: 142 - 217 g
- Housing: Up to 5 rats were accommodated in suspended stainless steel mesh cages (dimensions 55 x 34 x 20 cm). The cages were suspended over carboard lined trays for collection of excreta. The liners were replaced at least twice weekly.
- Diet: Ad libitum except during fasting period
- Water: Ad libitum
- Fasting period before study: 18 h prior to dosing until 3 h after dosing
- Acclimation period: 6 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25 C
- Humidity (%): 40 - 70 % relative humidity
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12 dark/light; typically 0600 to 1800 h.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Amount of vehicle: 10 mL/kg
- Lot/batch no.: 1132


MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg


DOSAGE PREPARATION: All formulations were used on the day of preparation.

Doses:

1540 and 2600 mg/kg

No. of animals per sex per dose:

5 males per dose

Control animals:

no

Details on study design:

No data

Statistics:

No data

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LD50

Effect level:

> 2 600 mg/kg bw

Based on:

test mat.

Remarks on result:

other: There were no deaths at this dose level.

Mortality:

No animal died following administration.

Clinical signs:

other: No clinical signs were observed for animals dosed at 1540 mg/kg. Piloerection was apparent from approximately 15 min after dosing and for the remainder of Day 1, for all 5 males dosed at 2600 mg/kg. Two rats were lethargic three hours after dosing and on

Gross pathology:

No macroscopic changes were observed during necropsy of Day 15 for animals at 2600 mg/kg.
Isolated changes seen in two rats dosed at 1540 mg/kg included a few red foci on the thymus (animals no 677) and pale lungs and distension of the jejunum (animal No. 678).

Other findings:

No data

Any other information on results incl. tables

Clinical signs following treatment at dose level 2600 mg/kg:

Clinical sign	Animal No.					Time of first observation	Time of recovery
	675 M	658 M	659 M	660 M	661 M
Pilo-erection	+	+	+	+	+	0.25 h	Day 2
Lethargy	-	+	-	+	-	3 h	Day 2
Tachypnoea	-	+	-	-	-	3 h	Day 2

+/- = sign present or absent

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: other: Classification and Labelling Requirements for Dangerous Substances and Preparations, as stated in Annex IV to Commission Directive 93/21/EC

Conclusions:

A single oral administration of anhydrous boric acid to groups of five fasted rats at dose levels of 1540 or 2600 mg/kg resulted in no deaths. The acute median lethal oral dose was therefore considered to be greater than 2000 mg/kg bw.
Based on the results of this study, the general Classification and Labelling Requirements for Dangerous Substances and Preparations, as stated in Annex IV to Commission Directive 93/21/EC, indicate that no risk phrase is required for anhydrous boric acid in respect of its acute oral toxicity.