Registration Dossier

Administrative data

Description of key information

Acute oral study has been conducted with boric oxide and acute oral, dermal and inhalation studies have been performed with boric acid. Experimental data showed low acute toxicity to boric oxide and boric acid. The LD50 for boric oxide is greater than 2600 mg/kg. The mean of the male and female values were obtained from the key study (oral route; Keller 1962). The LD50 for boric acid is equivalent to 658.9 mg B/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:
No data
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP guideline study. This study is conducted on an analogue substance. Read-across is justified on the following basis: In aqueous solutions at physiological and acidic pH, low concentrations of simple inorganic borates such as boric acid, disodium tetraborate decahydrate, disodium tetraborate pentahydrate, boric oxide and disodium octaborate tetrahydrate will predominantly exist as undissociated boric acid. At about pH 10 the metaborate anion (B(OH)4-) becomes the main species in solution (WHO, 1998). This leads to the conclusion that the main species in the plasma of mammals and in the environment is un-dissociated boric acid. Since other borates dissociate to form boric acid in aqueous solutions, they too can be considered to exist as un-dissociated boric acid under the same conditions. For comparative purposes, exposures to borates are often expressed in terms of boron (B) equivalents based on the fraction of boron in the source substance on a molecular weight basis. Some studies express dose in terms of B, whereas other studies express the dose in units of boric acid. Since the systemic effects and some of the local effects can be traced back to boric acid, results from one substance can be transferred to also evaluate the another substance on the basis of boron equivalents. Therefore data obtained from studies with these borates can be read across in the human health assessment for each individual substance. Conversion factors are given in the table below. Conversion factor for equivalent dose of B Boric acid H3BO3 0.175 Boric Oxide B2O3 0.311 Disodium tetraborate anhydrous Na2B4O7 0.215 Disodium tetraborate pentahydrate Na2B4O7•5H2O 0.148 Disodium tetraborate decahydrate Na2B4O7•10H2O 0.113 Disodium octaborate tetrahydrate Na2B8O13•4H2O 0.210 Sodium metaborate (anhydrous) NaBO2 0.1643 Sodium metaborate (dihydrate) NaBO2•2H2O 0.1062 Sodium metaborate (tetrahydrate) NaBO2•4H2O 0.0784 Sodium pentaborate (anhydrous) NaB5O8 0.2636 Sodium pentaborate (pentahydrate) NaB5O8∙5H2O 0.1832 References: WHO. Guidelines for drinking-water quality, Addendum to Volume 1, 1998.
Qualifier:
according to
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
not specified
Qualifier:
according to
Guideline:
EU Method B.1 (Acute Toxicity (Oral))
Deviations:
not specified
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no
Species:
rat
Strain:
other: Crl:CD.BR
Sex:
male
Details on test animals 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.
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
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:
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 one of these rats displayed an increased breathing rate at the same time. Recovery, as judged by external appearance and behaviour was complete by Day 2.
Body weight:
All rats acheived satisfactory gains on Day 8 and 15.
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

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

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.
Read-across is justified on the basis detailed in the rationale for reliability above. This study is therefore considered to be of sufficient adequacy and reliability to be used as a supporting study and no further testing is justified.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
2 600 mg/kg bw
Quality of whole database:
High quality (there are a lot of reliable studies for different boron species available).

Acute toxicity: via inhalation route

Link to relevant study records
Reference
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:
other: see 'Remark'
Remarks:
GLP guideline study. This study is conducted on an analogue substance. Read-across is justified on the following basis: In aqueous solutions at physiological and acidic pH, low concentrations of simple inorganic borates such as boric acid, disodium tetraborate decahydrate, disodium tetraborate pentahydrate, boric oxide and disodium octaborate tetrahydrate will predominantly exist as undissociated boric acid. At about pH 10 the metaborate anion (B(OH)4-) becomes the main species in solution (WHO, 1998). This leads to the conclusion that the main species in the plasma of mammals and in the environment is un-dissociated boric acid. Since other borates dissociate to form boric acid in aqueous solutions, they too can be considered to exist as un-dissociated boric acid under the same conditions. For comparative purposes, exposures to borates are often expressed in terms of boron (B) equivalents based on the fraction of boron in the source substance on a molecular weight basis. Some studies express dose in terms of B, whereas other studies express the dose in units of boric acid. Since the systemic effects and some of the local effects can be traced back to boric acid, results from one substance can be transferred to also evaluate the another substance on the basis of boron equivalents. Therefore data obtained from studies with these borates c Conversion factor for equivalent dose of B Boric acid H3BO3 0.175 Boric Oxide B2O3 0.311 Disodium tetraborate anhydrous Na2B4O7 0.215 Disodium tetraborate pentahydrate Na2B4O7•5H2O 0.148 Disodium tetraborate decahydrate Na2B4O7•10H2O 0.113 Disodium octaborate tetrahydrate Na2B8O13•4H2O 0.210 Sodium metaborate (anhydrous) NaBO2 0.1643 Sodium metaborate (dihydrate) NaBO2•2H2O 0.1062 Sodium metaborate (tetrahydrate) NaBO2•4H2O 0.0784 Sodium pentaborate (anhydrous) NaB5O8 0.2636 Sodium pentaborate (pentahydrate) NaB5O8∙5H2O 0.1832 References: WHO. Guidelines for drinking-water quality, Addendum to Volume 1, 1998.
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes
Species:
rat
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hilltop Lab Animals, Scottdale, PA
- Age at study initiation: Young adult
- Weight at study initiation: Males 245 - 296 g; females 232 - 251 g
- Housing: singly in suspended stainless steel cages with mesh floors which conform to the size recommendations in the Guide for the Care and use of Laboratory Animals DHEW (NIH) No. 86.23. Litter paper was placed beneath the cage and was changed at least 3 times per week.
- Water: Ad libitum by rack-top carboy except during exposure.
- Acclimation period: 22 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 69 - 71 ºF
- Photoperiod (hrs dark / hrs light): 12 h light/dark
Route of administration:
inhalation: aerosol
Type of inhalation exposure:
whole body
Vehicle:
other: no data
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Rectangular whole body perspex chamber operated under slight negative pressure
- Exposure chamber volume: 100 L

TEST ATMOSPHERE
- Particle size distribution: An eight-stage Andersen cascade impactor was used to assess the particle size distribution of the test atmosphere. Samples were withdrawn from the breathing zone of the animals on 2 occassions. The filter paper collection stages were weighed before and after sampling to determine the mass collected at each stage. The aerodynamic mass median diamaeter and geometric standard deviation were determined graphically using two-cycle logarithmic probit axes.
Analytical verification of test atmosphere concentrations:
not specified
Duration of exposure:
4 h
Remarks on duration:
The exposure period was extended to 4 h and 9 min to provide for the chamber to reach equilibrium (T99). The times for 90 and 99 % equilibrium of the chamber atmosphere were 4.6 and 9.1 min respectively.
Concentrations:
Top dose ~ 2 mg/L, to prevent undue discomfort to the animals.
No. of animals per sex per dose:
5/sex/dose
Control animals:
not specified
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for signs of gross toxicity, behavioural changes and mortality to exposure and every 15 min during the first 30 min of exposure. Additional in chamber animal observations were limited due to the accumulation of the test substance on the walls of the exposure chamber. Upon chamber removal, the animals were examined at least once daily for 14 days. Observations included gross evaluation of of skin and fur, eyes and mucous membranes, respiratory, circulatory, autonomic and central nervous systems, somatomotor activity and behaviour pattern. Particular attention was directed to observations of tremors, convulsions, salivation, diarrhoea, sleep and coma.
- Necropsy of survivors performed: yes on all animals. Tissues and organs of the thoracic and abdominal cavities were examined.
- Other examinations performed: Clinical signs, body weight, organ weights and histopathology.
Statistics:
No data
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 2.03 mg/L air
Based on:
test mat.
Exp. duration:
5 h
Mortality:
No deaths occured.
Clinical signs:
Animal observations were limited due to the accumulation of test material on the walls of the exposure chamber. During the first 30 minutes of exposure, ocular discharge, hypoactivity and haunched posture were noted. Ocular discharge and or nasal discharge persisted in most animals
after removal from the chamber. All animals recovered by day seven.
Other findings:
The gravimetric and nominal chamber concentrations were 2.03 and 110.40 mg/L respectively. The mass median aerodynamic diameter was estimated to be 3.7 microns based on graphic analysis of the particle size distribution as measured with an Andersen Cascade Impactor.
Pre-test trial

Trial

No.

Compressed

Air

Pressure

(psi)

Compressed

Air

Volume

(Lpm)

Room

Air

Volume

(Lpm)

Total

Air

Volume

(Lpm)

Motor

Setting

Chamber

Conc.

(mg/L)

Particle

Size

Sampled

11

27

30

20.4

50.4

6.00

1.94

Yes

22

27

30

20.6

50.6

6.00

1.64

No

32

27

30

20.5

50.5

6.25

2.00

Yes

43

27

30

20.4

50.4

6.00

2.40

No

53

27

30

20.3

50.3

5.75

1.98

Yes

64

27

30

20.2

50.2

4.50

5

-

74

27

30

20.1

50.1

4.00

5

-

84

27

30

20.2

50.2

4.00

5

-

1Test substance used as received, unground

2Test substance used after grinding for 1 h in a ball mill

3Test substance used after grinding for 3 h in a ball mill

4Test substance used after grinding for 24 h in a ball mill

5Trial terminated due to the malfunction of the dust generator caused by the test substance

Summary of pre-test exposure trials1

Trial No.

Chamber Concentration (mg/L)

Mass Median Aerodynamic Diameter (microns)2

13

1.94

5.8

34

2.00

5.0

55

1.98

3.7

1 See table above for details of generation sysem

2 Figure is an estimation based on graphic analysis of the particle size distribution as measured with an Andersen Cascade Impactor

3 Test substance used as received, unground

4 Test substance used after grinding for 1 h in a ball mill

5 test substance used after grinding for 3 h in a ball mill

Gravimetric chamber concentrations

Sample

No.

Mass Collected

(mg)

Airflow

Sampled

(Lpm)

Collection Time

(min)

Chamber concentration (mg/L)

1

11.9

4

2

1.49

2

12.1

4

2

1.52

3

11.8

4

2

1.48

4

8.6

4

2

10.8

51

24.8

4

2

3.10

6

17.7

4

2

2.21

7

12.8

4

2

1.60

8

17.5

4

2

2.19

9

19.4

4

2

2.40

10

20.4

4

2

2.55

11

20.3

4

2

2.54

12

16.5

4

2

2.06

13

16.1

4

2

2.01

14

17.2

4

2

2.15

Average ± Standard Deviation

2.03 ± 0.54

1 due to the extremely low chamber concentrations recorded during samples 1 - 4, diluent air being supplied to the chamber was reduced from 30 to 15 Lpm prior ot sample #5.

Particle size distribution

Stage

Effective

cutoff

diameter

(microns)

% of total

particles

captured

(by weight)

Cumulative

(%)1

Sample 1

0

9.0

5.3

94.7

1

5.8

12.9

81.8

2

4.7

10.1

71.7

3

3.3

31.1

40.7

4

2.1

22.7

17.9

5

1.1

13.6

4.3

6

0.7

3.3

1.0

7

0.4

0.8

0.3

F

0.0

0.3

0.0

Sample 2

0

9.0

9.3

90.7

1

5.8

15.9

74.8

2

4.7

11.0

63.8

3

3.3

24.4

39.4

4

2.1

22.2

17.2

5

1.1

13.8

3.4

6

0.7

2.2

1.1

7

0.4

0.7

0.4

F

0.0

0.4

0.0

1 percent of particles smaller than corresponding effective cutoff

Summary of particle size distribution

Sample

No

Sampling

time

(min)

MMAD

(microns)1

Geometric

Standard

Deviation

1

4

3.6

1.82

2

4

6.7

1.87

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

Individual bodyweights

Animal No.

Sex

Bodyweight (g)

Initial

Day7

Day 14

5399

M

296

361

398

5400

M

257

310

343

5401

M

245

307

349

5402

M

260

316

340

5403

M

262

298

322

5404

F

232

250

261

5405

F

237

258

273

5406

F

236

263

289

5407

F

251

275

260

5408

F

234

267

275

Individual cage-side observations

Animal

no.

Finding

Day of

occurrence

Males

5399

Ocular discharge

CR1

Test substance on fur

CR-0 (20.5 h)

Nasal discharge

CR-6

Active and healthy

7-14

5400

Nasal discharge,

test substance on fur

CR-0 (20.5 h)

Active and healthy

2 – 14

5401

Test substance on fur

CR

Nasal discharge

CR-0 (20.5 h)

Active and healthy

2-14

5402

Ocular discharge,

test substance on fur

CR

Nasal discharge

CR-0 (20.5 h), 4 - 6

Piloerection

2 – 3

Active and healthy

7 - 14

5403

Ocular discharge,

test substance on fur

CR

Nasal discharge

CR-0 (20.5 h)

Active and healthy

2 – 3, 6 – 14

Ano-genital staining

4 - 5

Females

5404

Nasal discharge,

test substance on fur

CR1-0 (20.5 h)

Active and healthy

2 - 14

5405

Test substance on fur

CR-0 (20.5 h)

Nasal discharge

CR-5

Active and healthy

6 - 14

5406

Ocular discharge,

nasal discharge,

 test substance on fur

CR

Active and healthy

0 (20.5 h)-14

5407

Ocular discharge,

test substance on fur

CR

Nasal discharge

CR-0 (20.5)

Active and healthy

2 – 14

5408

 

Test substance on fur

CR

Active and healthy

0 (20.5 h)-14

Individual necropsy observations

Animal No.

Tissue

Findings

Males

53999 - 5403

Lungs

Moderately red1

Females

5404 - 5408

Lungs

Moderately red1

1customarily seen with CO2 inhlation euthanasia procedure

Interpretation of results:
other: No data
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
LC50 > 2.03 mg/L
No deaths occurred. Animal observations were limited due to the accumulation of test material on the walls of the exposure chamber. During the first 30 minutes of exposure, ocular discharge, hypoactivity and haunched posture were noted. Ocular discharge and or nasal discharge persisted in most animals after removal from the chamber. All animals recovered by day seven.
Read-across is justified on the basis detailed in the rationale for reliability above. This study is therefore considered to be of sufficient adequacy and reliability to be used as a supporting study and no further testing is justified.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LC50
2 030 mg/m³
Quality of whole database:
High quality (3 reliable studies available).

Acute toxicity: via dermal route

Link to relevant study records
Reference
Endpoint:
acute toxicity: dermal
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: see 'Remark'
Remarks:
Guideline study. This study is conducted on an analogue substance. Read-across is justified on the following basis: In aqueous solutions at physiological and acidic pH, low concentrations of simple inorganic borates such as boric acid, disodium tetraborate decahydrate, disodium tetraborate pentahydrate, boric oxide and disodium octaborate tetrahydrate will predominantly exist as undissociated boric acid. At about pH 10 the metaborate anion (B(OH)4-) becomes the main species in solution (WHO, 1998). This leads to the conclusion that the main species in the plasma of mammals and in the environment is un-dissociated boric acid. Since other borates dissociate to form boric acid in aqueous solutions, they too can be considered to exist as un-dissociated boric acid under the same conditions. For comparative purposes, exposures to borates are often expressed in terms of boron (B) equivalents based on the fraction of boron in the source substance on a molecular weight basis. Some studies express dose in terms of B, whereas other studies express the dose in units of boric acid. Since the systemic effects and some of the local effects can be traced back to boric acid, results from one substance can be transferred to also evaluate the another substance on the basis of boron equivalents. Therefore data obtained from studies with these borates can be read across in the human health assessment for each individual substance. Conversion factors are given in the table below. This study is conducted on an analogue substance. Read-across is justified on the following basis: In aqueous solutions at physiological and acidic pH, low concentrations of simple inorganic borates such as boric acid, disodium tetraborate decahydrate, disodium tetraborate pentahydrate, boric oxide and disodium octaborate tetrahydrate will predominantly exist as undissociated boric acid. At about pH 10 the metaborate anion (B(OH)4-) becomes the main species in solution (WHO, 1998). This leads to the conclusion that the main species in the plasma of mammals and in the environment is un-dissociated boric acid. Since other borates dissociate to form boric acid in aqueous solutions, they too can be considered to exist as un-dissociated boric acid under the same conditions. For comparative purposes, exposures to borates are often expressed in terms of boron (B) equivalents based on the fraction of boron in the source substance on a molecular weight basis. Some studies express dose in terms of B, whereas other studies express the dose in units of boric acid. Since the systemic effects and some of the local effects can be traced back to boric acid, results from one substance can be transferred to also evaluate the another substance on the basis of boron equivalents. Therefore data obtained from studies with these borates can be read across in the human health assessment for each individual substance. Conversion factors are given in the table below. Conversion factor for equivalent dose of B Boric acid H3BO3 0.175 Boric Oxide B2O3 0.311 Disodium tetraborate anhydrous Na2B4O7 0.215 Disodium tetraborate pentahydrate Na2B4O7•5H2O 0.148 Disodium tetraborate decahydrate Na2B4O7•10H2O 0.113 Disodium octaborate tetrahydrate Na2B8O13•4H2O 0.210 Sodium metaborate (anhydrous) NaBO2 0.1643 Sodium metaborate (dihydrate) NaBO2•2H2O 0.1062 Sodium metaborate (tetrahydrate) NaBO2•4H2O 0.0784 Sodium pentaborate (anhydrous) NaB5O8 0.2636 Sodium pentaborate (pentahydrate) NaB5O8∙5H2O 0.1832 References: WHO. Guidelines for drinking-water quality, Addendum to Volume 1, 1998.
Qualifier:
according to
Guideline:
other: FIFRA (40 CFR 163)
Deviations:
no
GLP compliance:
no
Remarks:
Study pre-dates GLP
Test type:
fixed dose procedure
Limit test:
yes
Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan F. Plummer
- Weight at study initiation: 1623 - 2922 g
Type of coverage:
semiocclusive
Vehicle:
physiological saline
Details on dermal exposure:
TEST SITE
- Area of exposure: The skin of all animals was abraded longitudinally every 2 - 3 cm, deep enough to penetrate the stratum corneum, but not cause bleeding.
- % coverage: > 10 % of body surface implied
- Type of wrap if used: Semi occlusive


REMOVAL OF TEST SUBSTANCE
- Washing (if done): Moist towel
- Time after start of exposure: 24 h


TEST MATERIAL
- For solids, paste formed: Yes


VEHICLE
- Amount applied: Substance moistened with 1.5 mL saline
Duration of exposure:
24 h
Doses:
Dosage to 2 g/kg
No. of animals per sex per dose:
5/sex/group
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: Yes
- Other examinations performed: Clinical signs, histopathology
Statistics:
Not applicable - limit test.
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
No deaths occurred
Clinical signs:
Clinical changes were limited to transient diarrhoea in 2 rabbits and some incidences of erythema (9), and oedema (30), atonia (2), desquamation (4), necrosis, and other evidence of irritation at 23 and ~70.5 h after treatment.
Body weight:
No data
Gross pathology:
No gross necrospy findings were observed. Observations included one animal with gas filled intestine, one animal with pale yellow-coloured kidneys and 5 animals with enlarged or swollen fallopian tubes.
Other findings:
No data

Gross necropsy findings in male and female rabbits at the end of the observation period:

Gross Necropsy Findings

Dosage at 2 g/kg

Number of animals necropsied

10

No gross necropsy findings

5

Intestine

Gas-filled

1

Kidneys

Pale yellow coloured

1

Fallopian tubes

Enlarged or swollen

4

Pale

1

External

Diarrhoea stains

1

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The study was performed according to FIFRA (40 CFR 163). The LD50 > 2000 mg/kg bw indicating no acute dermal toxicity. No deaths occurred. Clinical changes were limited to erythema, oedema, atonia, desquamation, necrosis and some incidences of skin irritation at more than 24 h of treatment.
Read-across is justified on the basis detailed in the rationale for reliability above. This study is therefore considered to be of sufficient adequacy and reliability to be used as a supporting study and no further testing is justified.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
2 000 mg/kg bw
Quality of whole database:
Guideline study.

Additional information

LD50values of >2000 mg/kg for boric acid were recorded for both oral and dermal routes and > 2 mg /L for the acute inhalation study. The highest attainable inhalation concentration was 2.12 mg/L. The LD50value for boric oxide is >2600 mg/kg.

Boric oxide is of low acute toxicity. Although some of the acute oral studies for boric acid were not of modern standards and were performed prior to the introduction of GLP, they are reproducible across a number of studies and species and of acceptable quality. For acute dermal and acute inhalation some studies do meet the modern GLP standard.


Justification for selection of acute toxicity – oral endpoint
GLP guideline study conducted with boric oxide.

Justification for selection of acute toxicity – inhalation endpoint
The study is GLP compliant and has Klimisch score of 1.

Justification for selection of acute toxicity – dermal endpoint
Best study available.

Justification for classification or non-classification

Boric oxide is not classified for the oral, dermal or inhalation routes, as the LD50 values exceed the limit for classification according to EU CLP Regulation (EC) No. 1272/2008.No acute inhalation or dermal toxicity studies with boric oxide were available however, theLD50 values for the dermal and inhalation routes for boric acid exceed the limit for classification.