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Toxicological information

Eye irritation

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Administrative data

Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
no details given
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Principles of method if other than guideline:
no details given
GLP compliance:
not specified
Remarks:
no information on GLP compliance available in this publication

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: nanomaterial
Details on test material:
MWNT-7, with a mean diameter of 60 nm and BET surface area of 23 m2/g, was purchased from Mitsui & Co. Ltd. (Tokyo, Japan).

Test animals / tissue source

Species:
rabbit
Strain:
other: Kbl:NZW
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: Kitayama Labes Co. Ltd. (Ina, Japan)
- Age at study initiation: 11 weeks
- Weight at study initiation: 2.2 - 2.5 kg
- Housing: individually in standard aluminum cages
- Diet: LRC4; Oriental Yeast Co. Ltd., Tokyo, Japan, ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: 6 days prior to the start of the experiment

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.0-25.0 °C
- Humidity (%): 40-70%
- Air changes (per hr): ventilation of 15-21 air changes/h
- Photoperiod (hrs dark / hrs light): 12-h light (7:00-19:00)/dark (19:00-7:00) cycle

Test system

Vehicle:
other: see remarks
Remarks:
The test substance was mixed with a minimum amount of olive oil to prepare a test material available in liquid form for ocular instillation.
Controls:
yes, concurrent no treatment
Amount / concentration applied:
1% MWNT-7; this amount was the maximum resulting in good contact and uniform distribution to the eye, but no overlow, when instilled into the conjunctival sac. The concentration of the MWCNT-7 was the maximum allowable for administration.
Duration of treatment / exposure:
no details given
Observation period (in vivo):
The responses, including corneal opacity, conjunctival redness, abnormality of the iris, and chemosis, were evaluated at 1, 24, 48 and 72 h
Duration of post- treatment incubation (in vitro):
not applicable
Number of animals or in vitro replicates:
3
Details on study design:
The eye irritation experiment was conducted according to the OECD Guideline 405 ''Acute Eye Irritation/Corrosion''. Only rabbits with no abnormalities in the anterior eye parts were used. After gently pulling the lower lid away from the eyeball, 0.1 mL of CNT in liquid form was instilled into the conjunctival sac of the left eye of each rabbit. The lids were gently held together for about 1 s in order to prevent loss of the material. The right eye, which remained untreated, served as a control. The initial test was carried using one rabbit. No corrosive effects were observed at 1 h after the ocular instillation of any CNT. The test was then repeated with two additional rabbits to confirm the initial indings. This strategy was used for the test CNTs. The responses, including corneal opacity, conjunctival redness, abnormality of the iris, and chemosis, were evaluated at 1, 24, 48 and 72 h according to OECD Guideline 405 (2002b). At 72 h after the ocular instillation, the corneal epithelium was stained using sodium luorescein. Damage to the corneal epithelium was determined according to McDonald and Shadduck (1977) method.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
cornea opacity score
Basis:
animal #1
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
4
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
cornea opacity score
Basis:
animal #2
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
4
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
cornea opacity score
Basis:
animal #3
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
4
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
animal #1
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
3
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
3
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
animal #3
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
3
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
iris score
Basis:
animal #1
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
2
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
iris score
Basis:
animal #2
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
2
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
iris score
Basis:
animal #3
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
2
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
chemosis score
Basis:
animal #1
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
4
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
4
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritation parameter:
chemosis score
Basis:
animal #3
Time point:
other: 1h, 24h, 48h, 72h
Score:
0
Max. score:
4
Reversibility:
other: not applicable
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
not applicable
Other effects:
The corneal epithelium damage was scored according to McDonald and Shadduck (1977): score = 0

Applicant's summary and conclusion

Conclusions:
The test item MWCNT-7 was not irritant to eyes.
Executive summary:

The eye irritation potential of MWCNT-7 test material was conducted in accordance to the OECD Guideline 405 ''Acute Eye Irritation/Corrosion'' with Kbl:NZW rabbits. The concentration of the MWCNT-7 was the maximum allowable for administration. No clinical signs or changes in body weight gain were observed in any groups after the instillation of MWCNT-7. Ocular responses, such as corneal opacity, conjunctival redness, abnormality of the iris, and chemosis, were not detected in rabbits instilled with MWCNT-7. The score of the corneal epithelium damage was calculated to be 0. The test item MWCNT-7 was not irritant to eyes.