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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:
key study
Study period:
1996
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 guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
2-methylpentane-2,4-diol
EC Number:
203-489-0
EC Name:
2-methylpentane-2,4-diol
Cas Number:
107-41-5
Molecular formula:
C6H14O2
IUPAC Name:
2-methylpentane-2,4-diol
Details on test material:
- Name of test material (as cited in study report): Hexylene glycol
- Physical state: liquid
- Analytical purity: 99.72% Lot no: 0901/95-0121
- Storage condition of test material: room temperature in an unlit cabinet

Test animals / tissue source

Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: Charles River UK Ltd., Margate
- Age at study initiation: 13 to 16 weeks
- Weight at study initiation: 2.55 to 2.62 kg
- Housing: individually in floor-pens
- Diet (e.g. ad libitum): SQC TRB Rabbit Diet 9603 (pelleted) from Harlan Teklad, Bicester, available ad libitum
- Water (e.g. ad libitum): Mains water
- Acclimation period: approximately 3 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 16 to 22
- Humidity (%): 40 to 80
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 mL
Duration of treatment / exposure:
Single administration
Observation period (in vivo):
0.5, 1, 4, 24, 48, 72 hours and 7 days after treatment.
Number of animals or in vitro replicates:
3 animals
Details on study design:

SCORING SYSTEM: as in guideline (see attached scoring scale)


TOOL USED TO ASSESS SCORE: Either visually or with a pencil-beam torch or similar to illuminate and magnify the eye. Fluorescein staining was used as considered appropriate with a UV lamp.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
cornea opacity score
Basis:
animal #1
Time point:
24/48/72 h
Score:
1
Max. score:
4
Reversibility:
other: reversible in 4 days
Irritation parameter:
cornea opacity score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0.7
Max. score:
4
Reversibility:
other: reversible in 4 days
Irritation parameter:
cornea opacity score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0.7
Max. score:
4
Reversibility:
other: reversible in 4 days
Irritation parameter:
iris score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
2
Reversibility:
other: not applicable
Irritation parameter:
iris score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Max. score:
2
Reversibility:
other: not applicable
Irritation parameter:
iris score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Max. score:
2
Reversibility:
other: not applicable
Irritation parameter:
conjunctivae score
Basis:
animal #1
Time point:
24/48/72 h
Score:
1
Max. score:
3
Reversibility:
other: reversible in 4 days
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0.7
Max. score:
3
Reversibility:
other: reversible in 4 days
Irritation parameter:
conjunctivae score
Basis:
animal #3
Time point:
24/48/72 h
Score:
1
Max. score:
3
Reversibility:
other: reversible in 4 days
Irritation parameter:
chemosis score
Basis:
animal #1
Time point:
24/48/72 h
Score:
1.3
Max. score:
4
Reversibility:
other: reversible in 4 days
Irritation parameter:
chemosis score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0.3
Max. score:
4
Reversibility:
other: reversible in 4 days
Irritation parameter:
chemosis score
Basis:
animal #3
Time point:
24/48/72 h
Score:
1
Max. score:
4
Reversibility:
other: reversible in 4 days
Irritant / corrosive response data:
See attached Table 1 for results

Any other information on results incl. tables

No clinical signs of systemic toxicity or ill health were noted for any rabbits during the course of the study. The individual scores for ocular reactions elicited by hexylene glycol are given in Table 1. Instillation of hexylene glycol caused practically no initial sting responses. All rabbits developed corneal and conjunctival irritation within one hour of instillation of the test article. These changes did not exceed diffuse opacity and stippling of the cornea, a crimson appearance of the conjunctivae, chemosis sufficient to cause partial eversion of the eyelids and an ocular discharge. The conjunctival reactions for one rabbit intensified such that four hours after treatment the conjunctivae were crimson, chemosis was sufficient to obscure approximately one-half of the eye and there was a marked ocular discharge. Iridial inflammation was also apparent in this eye at the same examination. On the following day, all rabbits showed diffuse corneal opacity and conjunctival reactions not exceeding a crimson appearance, chemosis sufficient to cause partial eversion of the eyelids and an ocular discharge. Corneal absorption of fluorescein applied to the tear film confirmed disruption of the corneal epithelium. Progressive resolution of the effects of hexylene glycol was apparent from Day 2 and was complete by Day 4 (two rabbits) or Day 8.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Remarks:
Slightly irritating
Executive summary:

An eye irritation study on hexylene glycol has been performed in accordance with OECD Guidelines for the Testing of Chemicals No. 405 and in compliance with GLP. In this study, 0.1 mL of undiluted hexylene was instilled into one conjunctival sac of each of 3 New Zealand White rabbits. Ocular changes were assessed 0.5, 1, 4, 24, 48, 72 hours, and 7 days after treatment, and scoring was performed according to guideline methods. No clinical signs of systemic toxicity or ill health were observed in any rabbit during the course of the study. Instillation of hexylene glycol caused practically no initial sting responses.  All rabbits developed corneal and conjunctival irritation within 1 hour of instillation of the test substance. These changes did not exceed diffuse opacity and stippling of the cornea (a crimson appearance of the conjunctivae), chemosis sufficient to cause partial eversion of the eyelids, or an ocular discharge. The conjunctival reactions in one rabbit intensified such that, four hours after treatment, the conjunctivae were crimson, chemosis was sufficient to obscure approximately one-half of the eye, and a marked ocular discharge was observed. Iridial inflammation also was apparent in this eye at the same examination. On the following day, all rabbits showed diffuse corneal opacity and conjunctival reactions not exceeding a crimson appearance, chemosis sufficient to cause partial eversion of the eyelids, or an ocular discharge. Corneal absorption of fluorescein applied to the tear film confirmed disruption of the corneal epithelium. Progressive resolution of the observed effects was apparent from Day 2 and was complete by Day 4 (in 2 rabbits) or Day 8. Individual mean scores over 14, 48 and 72 hours were 1, 0.7 and 0.7 for cornea opacity, 0, 0 and 0 for iritis, 1, 0.7 and 1 for conjunctival irritation and 1.3, 0.3 and 1 for chemosis. Therefore, a single instillation of hexylene glycol into the conjunctival sac of 3 rabbits caused changes of the cornea, iris, and conjunctivae that resolved within seven days of treatment.