Pentan-2-one

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was done in a GLP facility to OECD guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4500 (Acute Eye Irritation)

Deviations:

not applicable

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Pentan-2-one

EC Number:

203-528-1

EC Name:

Pentan-2-one

Cas Number:

107-87-9

Molecular formula:

C5H10O

IUPAC Name:

pentan-2-one

Constituent 2

Reference substance name:

MPK

IUPAC Name:

MPK

Constituent 3

Reference substance name:

2-Pentanone

IUPAC Name:

2-Pentanone

Test material form:

other:

Details on test material:

TEST MATERIAL IDENTIFICATION
Formulation name or number Eastman MPK
Batch (lot) number 81354
Physical description Cleat, Colorless Liquid

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

SPECIES: Rabbit
STRAIN/SOURCE: New Zealand White, HRP, Inc. (Denver, PA)
AGE ON RECEIPT: At least 16 weeks
NUMBER AND SEX: 6 females (nulliparous and non-pregnant)
WEIGHT: 2.47- 2.93 kg at receipt
IDENTIFICATION: Unique number written in one ear with an indelible marker and corresponding cage card
JUSTIFICATION OF USE: The rabbit is the recommended species for this test


The rabbits were held in quarantine for approximately 7 days after receipt. They were housed individually in stainless steel cages with screen-bottom floors. Environmental controls maintained temperatures of 60.8- 69.8°F, and humidity at 50± 10%. A 12-hour light:dark cycle was maintained. Air flow was regulated at 1 0 or more air changes per hour.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

Each animal received 0.1 ml of the test substance, which was instilled into the conjunctival sac of the left eye. The lids were held closed for 1 second to prevent loss of the material. The other eye was untreated and served as a control.

Duration of treatment / exposure:

All treated eyes were examined for ocular irritation at 1, 24, 48, 72 and 96 hours and 7 days after
instillation.

Observation period (in vivo):

All treated eyes were examined for ocular irritation at 1, 24, 48, 72 and 96 hours and 7 days after
instillation.

Number of animals or in vitro replicates:

6 Female rabbits

Details on study design:

Six naive female rabbits, free of ocular irritation, were assigned to the study. Each animal received 0.1 ml of the test substance, which was instilled into the conjunctival sac of the left eye. The lids were held closed for 1 second to prevent loss of the material. The other eye was untreated
and served as a control. All treated eyes were examined for ocular irritation at 1, 24, 48, 72 and 96 hours and 7 days after instillation. Sodium fluorescein stain was used at all examinations except at one hour. Irritation was graded and scored by the Draize technique. A rating was assessed using the method of Draize, Woodard and Calvery and assigned a category as used by the EPA. Clinical observations recorded once daily included, but were not limited to:
A. Any response with respect to body position, activity, coordination, or gait.
B. Any unusual behavior such as head flicking, compulsive biting or licking, circling, etc.
C. The presence of: Convulsions or tremors, increased salivation, increased lacrimation, increased or decreased urination or defecation (including diarrhea), piloerection, mydriasis or miosis (enlarged or constricted pupils), unusual respiration (fast, slow, gasping, or retching), unusual vocalization.
On SO 9, all the animals on study were killed with an overdose of sodium pentobarbital and discarded.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24 h

Score:

0

Max. score:

80

Reversibility:

fully reversible

Results 2

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

48 h

Score:

0

Max. score:

80

Reversibility:

fully reversible

Results 3

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

72 h

Score:

1.7

Max. score:

80

Reversibility:

fully reversible

Results 4

Irritation parameter:

iris score

Basis:

mean

Time point:

24 h

Score:

0

Max. score:

10

Reversibility:

fully reversible

Results 5

Irritation parameter:

iris score

Basis:

mean

Time point:

48 h

Score:

1.7

Max. score:

10

Reversibility:

fully reversible

Results 6

Irritation parameter:

iris score

Basis:

mean

Time point:

72 h

Score:

0

Max. score:

10

Reversibility:

fully reversible

Results 7

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24 h

Score:

2.6

Max. score:

20

Reversibility:

fully reversible

Results 8

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

48 h

Score:

2

Max. score:

20

Reversibility:

fully reversible

Results 9

Irritation parameter:

chemosis score

Basis:

mean

Time point:

72 h

Score:

0

Max. score:

20

Reversibility:

fully reversible

Any other information on results incl. tables

All of the eyes exposed to Eastman MPK developed a mild corneal opacity within 1-96 hours after instillation. The opacities were never more severe than Grade 1, and generally covered 1/2- 3/4 of the corneal surface. Positive uptake of the sodium fluorescein did indicate sloughing of the corneal epithelium. Three of the six treated eyes also exhibited a positive iris score. Conjunctival irritation was most prominent at the 1, 24 and 48 hour examinations, and consisted of mild redness, chemosis and discharge. Recovery from the ocular effects was observed in all rabbits at 7 days. A maximum mean irritation index of 12.83/110, calculated at one hour, classifies Eastman MPK as mildly irritating. The presence of positive corneal and iris responses also classifies the material as a positive irritant. Since all effects had cleared in 7 days, the material is a Category Ill substance

SUMMARY OF OCULAR SCORING
Animal Number	Group-Sex	1Hr	SD 1	SD 2	SD 3	SD 4	SD 7
H931	Group 1 - Female	6	12	0	0	0	0
H932	Group 1 - Female	6	7	2	0	0	0
H933	Group 1 - Female	10	22	2	0	0	0
H934	Group 1 - Female	18	4	2	5	0	0
H935	Group 1 - Female	25	2	7	0	0	0
H936	Group 1 - Female	12	2	2	0	10	0
Group 1	Mean Score	12.83	8.17	2.5	0.83	1.67	0

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: US CPSC / US OSHA

Conclusions:

A maximum mean irritation index of 12.83/110, calculated at one hour, classifies Eastman MPK as
mildly irritating. The presence of positive corneal and iris responses also classifies the material as a
positive irritant. Since all effects had cleared in 7 days, the material is a Category Ill substance.

Executive summary:

Six female rabbits were exposed to 0.1 ml of Eastman MPK which was instilled into the conjunctival sac of one eye. Observations to detect ocular irritation were made at 1 , 24, 48, 72 and 96 hours and 7 days after exposure. The study ended on SD 9. The rabbits were killed with an overdose of sodium pentobarbital and discarded. Eastman MPK is a mildly irritating substance, based on a maximum mean irritation index of 12.83/11.0 , calculated at one hour after exposure. Positive corneal and iris responses were observed in 6/6 and 3/6 treated eyes, respectively. Conjunctivitis was also noted in 6/6 rabbit eyes. Recovery from the ocular effects was noted in all animals at 7 days. Eastman MPK is a positive irritant, and is a Category Ill substance