Potassium metaborate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Remarks:

publication / peer-reviewed report

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

peer-reviewed

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Remarks:

publication / peer-reviewed report

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

peer-reviewed

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
see target record

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

read-across source

Remarks:

target record

Qualifier:

no guideline required

Principles of method if other than guideline:

Review of literature data

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

no data

Vehicle:

not specified

Controls:

not specified

Amount / concentration applied:

various, see free-text field below

Duration of treatment / exposure:

various, see free-text field below

Observation period (in vivo):

various, see free-text field below

Duration of post- treatment incubation (in vitro):

various, see free-text field below

Number of animals or in vitro replicates:

various, see free-text field below

Details on study design:

a) Six young rabbits had 100 mg of boric acid applied to one eye of each rabbit. The eyes were rinsed after 24 hours and irritation scores in individual animals ranged from 0 to 18.
b) Six young rabbits had 77 mg of borax, Na2B4O7.10H2O, applied to one eye of each rabbit. The eyes were rinsed after 24 hours and irritation scores in individual animals ranged from 0 to 39.
c) Six young rabbits had 100 mg of disodium tetraborate pentahydrate, Na2B4O7.5H2O, applied to one eye of each rabbit. The eyes were not rinsed, and the ocular reaction was recorded after 1, 24, and 72 hours and up to 10 days after treatment.
d) About 50 mg of boric oxide was placed in the left eye of four rabbits.
e) Sodium perborate tetrahydrate was tested for eye irritation on two female rabbits and the Draize scale was used for assessment of irritation. The test substance (approximately 100 mg) was applied to the conjunctival sac of the left eye of each rabbit, the other eye was untreated. The eyes were examined after 1 to 2 hours, and up to 3 or 21 days after application for each of the animals, respectively.
f) 50 mg of sodium perborate tetrahydrate was introduced into the rabbit eye.
g) The irritation of a small volume of sodium perborate tetrahydrate was assessed in three rabbits. The methods used were similar to those described above except that the amount of test material used was less, in this case a volume of 0.01 ml was used (approximating to 6 mg).
h) A 1% solution of sodium perborate tetrahydrate was instilled to the rabbit eye.
i) A test in rabbits investigated the effect of an eye washing procedure on the irritant effect of sodium perborate tetrahydrate. After instilling 100 mg of the test material into the left eye, groups of 3 rabbits received either no further treatment or the eye was washed 4 or 30 seconds later.

Reversibility:

fully reversible within: 7 days

Remarks:

or less

Remarks on result:

other: irritating

Remarks:

100 mg H3BO3 in one eye

Reversibility:

fully reversible within: 8-21 days

Remarks on result:

other: corneal irritation

Remarks:

77 mg Borax in one eye

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: severe irritation

Remarks:

100 mg Na2B4O7 * 5H2O in one eye

Remarks on result:

other: Severe irritant to the rabbit eye

Remarks:

Observed up to 21d; 100 mg NaBO3 * 4H2O in one eye.

Remarks on result:

other: Serious damage to unwashed left eye, but slight damage when rinsed after 4 or 30 seconds

Remarks:

100 mg NaBO3 * 4H2O in one eye

Reversibility:

fully reversible within: 10 days

Remarks on result:

other: Acute conjunctivitis, corneal irritation at 48 hours

Remarks:

50 mg NaBO3 * 4H2O in one eye

Remarks on result:

other: moderate irritant

Remarks:

observed up to 21 d; 6 mg (0.01ml) NaBO3 * 4H2O in one eye

Remarks on result:

other: non-irritant

Remarks:

1% NaBO3 * 4H2O solution in one eye

Remarks on result:

other: severe irritant

Remarks:

Observed up to 21 days; 50 mg NaBO3 * H2O in one eye

Remarks on result:

other: corrosive to unwashed eye

Remarks:

Observed up to 21 days; 0.1 mg NaBO3 * H2O in one eye

Remarks on result:

other: Immediate conjunctivitis, caused by exothermic hydrolysis to boric acid

Remarks:

50 mg B2O3 in one eye

Irritation parameter:

cornea opacity score

Time point:

24/48/72 h

Remarks on result:

other: not available

Irritation parameter:

iris score

Time point:

24/48/72 h

Remarks on result:

other: not available

Irritation parameter:

conjunctivae score

Time point:

24/48/72 h

Remarks on result:

other: not available

Irritation parameter:

chemosis score

Time point:

24/48/72 h

Remarks on result:

other: not available

Interpretation of results:

study cannot be used for classification

Conclusions:

The present information was based on a literature review (peer-reviewed) of various borates studies, which gave inconsistent results ranging from not irritating to irritating. The scores as indicated in Regulation 1272/2008, which are required for classification, are not given. Further, due to inconsistent results, no conclusion based on expert judgement can be drawn.

Executive summary:

A literature review of borates showed that these borates induced none to irritating responses, no conclusion on classification can be drawn.

Cross-reference 2

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Remarks:

publication / peer-reviewed report

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

peer-reviewed

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
see target record

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

read-across source

Remarks:

target record

Qualifier:

no guideline required

Principles of method if other than guideline:

Review of literature data

GLP compliance:

no

Species:

other: mostly rabbits, also guinea pigs, rats, dogs

Strain:

not specified

Type of coverage:

other: various

Preparation of test site:

other: various

Vehicle:

other: various

Details on study design:

a) The procedure for testing and evaluating the primary skin irritation of borax, Na2B4O7.10H2O, (10 ml, 5% in water (w/v)) or boric acid (5ml, 10% in water (w/v)) on rabbit skin was identical to that described in the U.S. Regulations (21 CFR 191.11), except that the rabbits were not immobilised, and the 1-inch square cellulose pads were used instead of surgical gauze. The substance was applied to 6 rabbits with intact and 6 with abraded skin. A similar test procedure in the guinea pig included application of the aqueous solutions of the materials on cellulose pads held in contact with the skin under an appropriate sleeve. Six guinea pigs with clipped, depilated, intact abdomens and 6 with clipped, depilated, abraded backs were used with each material.
b) The primary dermal irritation of disodium tetraborate pentahydrate, Na2O4O7 * 5H2O, was determined by applying 0.5 g moistened with saline on two clipped sites on the backs of 6 rabbits. The contact time was 4 hours under an occlusive dressing, with observation for up to 76 hours.
c) The detailed toxicological properties of boric oxide (B2O3) in rats, rabbits and dogs have been published. boric oxide dust (1g/25cm2) was topically applied to the clipped wetted backs of four rabbits.
d) Sodium perborate tetrahydrate was tested for skin irritation on six male rabbits. An area on the right flank of each animal was clipped and about 500 mg perborate, moistened to a paste with water, was applied to the test site (25x25 mm) under an occlusive dressing for 4 hours. The Draize scale was used to assess the degree of erythema and oedema at the site 1 hour and 1, 2 and 3 days after the removal of the dressing.
e) Sodium perborate tetrahydrate was applied as a paste in oil, for a 4 hour exposure.
f) A study investigating the irritant effects of repeated exposures of sodium perborate tetrahydrate to rat skin was performed over a course of 12 consecutive daily applications.

Time point:

other: 24&72h

Remarks on result:

other: Mild irritant after 24 and 72 h in primary irritation test

Remarks:

H3BO3, rabbit, 5ml, 10% in water (w/v), intact and abraded skin

Time point:

other: 24&72h

Remarks on result:

other: Moderate irritant after 24 and 72 h in primary irritation test

Remarks:

H3BO3, guinea pig, 5ml, 10% in water (w/v), intact and abraded skin

Time point:

other: 24&72h

Remarks on result:

other: Mild irritant after 24 and 72 h in primary irritation test

Remarks:

Na2B4O7.10H2O, rabbit, 10ml, 5% in water (w/v), intact and abraded skin

Time point:

other: 24&72h

Remarks on result:

other: Mild irritant after 24 and 72 h in primary irritation test

Remarks:

Na2B4O7.10H2O, guinea pig, 10ml, 5% in water (w/v), intact and abraded skin

Remarks on result:

no indication of irritation

Remarks:

Na2B4O7.5H2O, rabbit, 0.5 g, clipped back, 4h, Non-irritant

Remarks on result:

no indication of irritation

Remarks:

NaBO3.4H2O, rabbit, 500 mg, paste with 0.2 ml water, on intact skin, 4h, Classified as non-irritant

Remarks on result:

no indication of irritation

Remarks:

NaBO3.4H2O, guinea pig, in vegetable oil ointment, 4h, Non-irritant

Remarks on result:

other: Moderately to severely irritant, but 1% solution non-irritating after 12d

Remarks:

NaBO3.4H2O, rat, solid applied to skin, 12 daily

Remarks on result:

other: Slightly irritating

Remarks:

NaBO3.H2O, rabbit, 0.5 g on skin, 4h

Remarks on result:

no indication of irritation

Remarks:

NaBO3.H2O, rabbit, 500 mg, paste with 0.2 ml water, on intact skin, 4h, Non-irritant

Remarks on result:

other: Produced erythema, that persisted for 2-3 d

Remarks:

B2O3, rabbit, 1 g/25cm2 dust applied to clipped wetted back

Irritation parameter:

erythema score

Time point:

24/48/72 h

Remarks on result:

other: not available

Irritation parameter:

edema score

Time point:

24/48/72 h

Remarks on result:

other: not available

Interpretation of results:

study cannot be used for classification

Conclusions:

The present information was based on a literature review (peer-reviewed) of borate studies, which gave inconsistent results ranging from not irritating to irritating. Edema and erythema scores as indicated in Regulation 1272/2008, which are required for classification, are not given. Further, due to inconsistent results, no conclusion based on expert judgement can be drawn.

Executive summary:

A literature review of borate studies showed that these borates induced none to irritating responses, no conclusion on classification can be drawn.

Data source

Reference

Reference Type:

review article or handbook

Title:

Technical Report No 63, Reproductive and General Toxicology of some Inorganic Borates and Risk Assessment for Human Beings

Author:

ECETOC

Year:

1995

Bibliographic source:

ISSN-0773-8072-63

Materials and methods

Test guideline

Qualifier:

no guideline required

Principles of method if other than guideline:

Review of literature data

GLP compliance:

no

Type of study:

other: "skin sensitization test"

Justification for non-LLNA method:

The present review was published in 1995 and takes into account all information available at that time. The LLNA method was not adopted as guideline at that time yet.

Test material

Test material information

Constituent 1

Reference substance name:

Sodium peroxometaborate

EC Number:

231-556-4

EC Name:

Sodium peroxometaborate

Cas Number:

10332-33-9

Molecular formula:

NaBO3*H2O

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Study design: in vivo (non-LLNA)

Induction

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

0.5ml of the solid

Adequacy of induction:

not specified

Challenge

Vehicle:

water

Concentration / amount:

5% dilution in distilled water

Day(s)/duration:

after 14 days

Adequacy of challenge:

not specified

No. of animals per dose:

5

Details on study design:

A skin sensitization test on sodium perborate monohydrate was carried out on 5 male and 5 female Hartley albino guinea pigs. Another similar group served as controls. Twenty four hours prior to each induction, an area of 5 x 5 cm on the left flank of each animal was clipped free of hair, 0.5 ml of the solid was applied to the depilated area and covered with an occlusive dressing. The challenge (5% dilution in distilled water) was applied to the depilated right flank 14 days after the induction.

Positive control substance(s):

not specified

Results and discussion

In vivo (non-LLNA)

Results

Key result

Remarks on result:

no indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met