Bentonite, acid-leached

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study performed between 2 May 2005 to 12 May 2005.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed to GLP and internationally accepted guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Bentonite, acid-leached

EC Number:

274-324-8

EC Name:

Bentonite, acid-leached

Cas Number:

70131-50-9

Molecular formula:

unspecified for this UVCB substance

IUPAC Name:

Bentonite, acid-leached

Details on test material:

Name of test material (as cited in study report): Acid-activated bentonite
Physical state: pale beige powder
Batch No.: Tonsil EX 0096.
Chemical composition: SiO2 (66.8%), Al2O3 (14.2%), Fe2O3 (3.7%), MgO (2.3%), CaO (1.1%), Na2O (0.8%), K2O (2.2%), LOI (8.0%).
Storage condition of test material: room temperature in the dark
Moisture content: approx. 10%.
Particle size: 5 % > 150 µm; 17% > 100 µm; 29% > 63 µm; 40% > 45 µm; 60% > 25 µm.
pH (10% suspension): approximately 3.8.

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Test animals
Source: David Percival Ltd, Moston, Sandbach, Cheshire, UK
Age at study initiation: 12-20 weeks old.
Weight at study initiation: 2.0-3.5 Kgs.
Housing: housed in suspended cages.
Diet: ad libitum
Water: ad libitum
Acclimation period: five days

Environmental conditions
Temperature (°C): 17-23 °C
Humidity (%): 30-70%
Air changes (per hr): fifteen changes per hour
Photoperiod (hrs dark / hrs light): twelve hours continuous light / twelve hours dark

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: The left eye remained untreated and was used for control purposes.

Amount / concentration applied:

Test material:
Amount applied: 0.1 mL of test material which was found to weigh approximately 52 mg.

Duration of treatment / exposure:

one second

Observation period (in vivo):

1, 24, 48 and 72 hours.

Number of animals or in vitro replicates:

3

Details on study design:

Scoring system: Kay and Calandra classification system.

Tool used to assess score: use of light source from a standard ophthalmoscope.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

other: mean score for all animals

Time point:

other: 24, 48 72 h

Score:

0

Remarks on result:

other: according to criteria set out in CLP Regulation (EC) no. 1272/2008

Results 2

Irritation parameter:

iris score

Basis:

other: mean score for all animals

Time point:

other: 24, 48, 72 h

Score:

0

Remarks on result:

other: according to criteria set out in CLP Regulation (EC) no. 1272/2008

Results 3

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

mean score for all animals

Time point:

other: 24, 48, 72 h

Score:

0.67

Reversibility:

fully reversible within: 72 h

Remarks on result:

other: according to criteria set out in CLP Regulation (EC) no. 1272/2008

Results 4

Irritation parameter:

chemosis score

Basis:

other: mean score for animal #16

Time point:

other: 24, 48, 72h

Score:

0.33

Reversibility:

fully reversible within: 72 h

Remarks on result:

other: according to criteria set out in CLP Regulation (EC) no. 1272/2008

Results 5

Irritation parameter:

chemosis score

Basis:

other: mean score for animal #22 and #23

Time point:

other: 24, 48, 72 h

Score:

0

Irritant / corrosive response data:

Beige-coloured residual test material was noted in all treated eyes one hour after treatment. No corneal effects were noted during the study. Iridial inflammation was noted in all treated eyes one hour after treatment.
Minimal conjunctival irritation was noted in all treated eyes one hour after treatment and at the 24 and 48-hour observations. All treated eyes appeared normal at the 72-hour observation.
Individual scores are provided in table 1.

Any other information on results incl. tables

Table 1: Individual scores and individual total scores for ocular irriation

Rabbit number and sex	16 male				22 male				23 male
	IPR = 2				IPR = 2				IPR = 3
Time after treatment	1 h	24 h	48 h	72 h	1 h	24 h	48 h	72 h	1 h	24 h	48 h	72 h
CORNEA
E = degree of opacity	0	0	0	0	0	0	0	0	0	0	0	0
F = area of cornea involved	0	0	0	0	0	0	0	0	0	0	0	0
Score (E x F) x 5	0	0	0	0	0	0	0	0	0	0	0	0
IRIS
D	1	0	0	0	1	0	0	0	1	0	0	0
Score (D x 5)	5	0	0	0	5	0	0	0	5	0	0	0
CONJUNCTIVAE
A = redness	1	1	1	0	1	1	1	0	1	1	1	0
B = chemosis	1	1	0	0	1	0	0	0	1	0	0	0
C = discharge	1 Re	1	0	0	1 Re	1	0	0	1Re	1	0	0
Score (A + B + C) x 2	6	6	2	0	6	4	2	0	6	4	2	0
Total score	11	6	2	0	11	4	2	0	11	4	2	0

IPR = Initial pain reaction

Re - Beige-coloured residual test material noted in the treated eye.

Table 2. Individual Total Scores and group Mean Scores for Ocular Irritation.

Rabbit Number and Sex	Individual Total Scores at:
	1 hour	24 hours	48 hours	72 hours
Male 16	11	6	2	0
Male 22	11	4	2	0
Male 23	11	4	2	0
Group Total	33	14	6	0
Group Mean Score	11.0	4.7	2.0	0.0

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Acid-activated bentonite is not irritating to eyes according to the criteria set out in CLP Regulation (EC) no. 1272/2008