N-vinylformamide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 7-21, 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (GLP)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-vinylformamide

EC Number:

236-102-9

EC Name:

N-vinylformamide

Cas Number:

13162-05-5

Molecular formula:

C3H5NO

IUPAC Name:

N-vinylformamide

Details on test material:

- Physical state: Clear pale yellow liquid
- Lot No.: RP-690-11890-1603
- Expiration date of the lot: October 27, 1991
- Analytical purity: 90 - 99%
- Impurities (identity and concentrations): Formamide 1 - 9%
- Storage condition of test material: At -20°C (freezer) in the dark unless stated otherwise
- Stability under storage conditions: stable for 30 days

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Broekman Institute, Someren, The Netherlands
- Age at study initiation: Approx. 12 weeks
- Weight at study initiation: 2561 - 2923 grams
- Housing: Individually in labelled cages with perforated floors and equipped with an automatic drinking system (ITL, Bergen, The Netherlands)
- Diet: Standard laboratory rabbit diet (LKK-20, pellet diameter 4 mm, Hope Farms, Woerden, The Netherlands) approx. 100 g per day
- Water: Tap-water diluted with decalcified water ad libitum
- Acclimation period: At least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21°C (Fluctuations were noted, but were considered not to have affected study integrity)
- Humidity (%): 55% (Fluctuations were noted, but were considered not to have affected study integrity)
- Air changes (per hr): 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 / 12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount applied (volume or weight with unit): 0.1 ml
- Concentration: undiluted

Duration of treatment / exposure:

unspecified

Observation period (in vivo):

21 days

Number of animals or in vitro replicates:

3 females

Details on study design:

NO REMOVAL OF TEST SUBSTANCE

SCORING SYSTEM:
Cornea
Opacity: degree of density (most dense area taken for reading)
0: No ulceration or opacity
1: Scattered or diffuse areas of opacity (other than slight dulling of normal lustre); details of iris clearly visible
2: Easily discernible translucent area; details of iris slightly obscured
3: Nacrous area; no details of iris visible; size of pupil barely discernible
4: Opaque cornea; iris not discernible through the opacity

Iris
0: Normal
1: Markedly deepened rugae, congestion, swelling, moderate circumcorneal hyperaemia; or injection; iris reactive to light (a sluggish reaction is considered to be an effect)
2: Hemorrhage, gross destruction, or no reaction to light

Conjunctivae
Redness (refers to palpebral and bulbar conjunctivae; excluding cornea and iris)
0: Normal
1: Some blood vessels hyperaemic (injected)
2: Diffuse, crimson colour; individual vessels not easily discernible
3: Diffuse beefy red

Chemosis
Swelling (refers to lids and/or nictating membranes)
0: Normal
1: Some swelling above normal
2: Obvious swelling, with partial eversion of lids
3: Swelling, with lids about half closed
4: Swelling, with lids more than half closed

Discharge
0: No discharge
1: Any amount different from normal (does not include small amounts observed in inner canthus of normal animals)
2: Discharge with moistening of the lids and hairs, just adjacent to lids
3: Discharge with moistening of the lids and hairs, in a considerable area around the eye

A Draize score was calculated for each day of observation, using the following formula (Draize et al., J. Pharmacol. Exp. Ther. 82, 1944):
(5x corneal opacity grade x area of opacity grade) + (5x iridial injury grade) + 2x (conjunctival redness grade + chemosis grade + discharge grade)

From the calculated maximum Draize score, a Kay and Calandra interpretation (J. Society of Cosmetic Chemists, Vol. 13 no. 6, 1962) was obtained, using the tables below. As can be seen in the second table, the Kay and Calandra interpretation takes into account the time required for the healing process.
0 - 0.5: Non-irritating (N)
0.5 - 2.5: Practically non-irritating (PN)
2.5 - 15: Minimally irritating (M1)
15 - 25: Mildly irritating (M2)
25 - 50: Moderately irritating (M3)
50 - 80: Severely irritating (S)
80 - 100: Extremely irritating (E)
100 - 110: Maximally irritating (Mx)
For borderline scores choose the higher rating.

Tentative Rating & Requirement for Maintenance:
N: MTS24 = 0; for MTS24 > 0, raise one level.
PN: As for N.
M1: MTS48 = 0; for MTS48 > 0, raise one level.
M2: MTS96 = 0; for MTS96 > 0, raise one level.
M3: (1) MTSf < 20 ; for MTSf > 20, raise one level, (2) ITSf < 10 (60%); if not true then no rabbit may show ITSf > 30; otherwise raise one level.
S: (1) As for M3 except use MTSf < 40, (2) As for M3 except use ITSf < 30 (60%) and 60 for high.
E: (1) As for M3 except use MTSf < 80, (2) As for M3 except use ITSf < 60 (60%) and 100 for high.
Mx: (1) MTSf > 80 (60%); for MTSf < 80, lower one level, (2) ITSf > 60 (60%); otherwise lower one level.
Symbols: MTS = Mean total score, ITS = Individual rabbit score. Subscripts denote scoring interval : 24, 48 or 96 hrs., f=final score (7 days).

TOOL USED TO ASSESS SCORE: hand-slit lamp & fluorescein

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 24, 48 and 72 h

Score:

1

Max. score:

4

Reversibility:

not reversible

Remarks:

within 21 days

Results 2

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

other: 24, 48 and 72 h

Score:

1

Max. score:

4

Reversibility:

not reversible

Remarks:

within 21 days

Results 3

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

other: 24, 48 and 72 h

Score:

1

Max. score:

4

Reversibility:

not reversible

Remarks:

within 21 days

Results 4

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

other: 24, 48 and 72 h

Score:

1

Max. score:

4

Reversibility:

not reversible

Remarks:

within 21 days

Results 5

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 24, 48 and 72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 7 days

Results 6

Irritation parameter:

iris score

Basis:

animal #1

Time point:

other: 24, 48 and 72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 7 days

Results 7

Irritation parameter:

iris score

Basis:

animal #2

Time point:

other: 24, 48 and 72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 7 days

Results 8

Irritation parameter:

iris score

Basis:

animal #3

Time point:

other: 24, 48 and 72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 7 days

Results 9

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 24, 48 and 72 h

Score:

3

Max. score:

3

Reversibility:

not fully reversible within: 21 days

Results 10

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

other: 24, 48 and 72 h

Score:

3

Max. score:

3

Reversibility:

not fully reversible within: 21 days

Results 11

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

other: 24, 48 and 72 h

Score:

3

Max. score:

3

Reversibility:

not reversible

Remarks:

within 21 days

Results 12

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

other: 24, 48 and 72 h

Score:

3

Max. score:

3

Reversibility:

not reversible

Remarks:

within 21 days

Results 13

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24, 48 and 72 h

Score:

2.7

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Results 14

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: 24, 48 and 72 h

Score:

2.3

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Results 15

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

other: 24, 48 and 72 h

Score:

2.7

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Results 16

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

other: 24, 48 and 72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Irritant / corrosive response data:

Cornea, iris and conjunctivae affected. The injection of the iris had resolved within 7 days in all three animals. The opacity of the cornea and the irritation of the conjunctivae however, had not resolved within the study period (22 days). Grey/white discolouration of the conjunctivae as signs of necrosis was observed in all three animals during the study. Signs of necrosis were still noted on the nictating membrane in animals 3541 and 3542 on day 22. Pannus (neovascularisation of the cornea), corneal opacity (grade 2; animal 3540, grade 1; animals 3541 and 3542) and conjunctival redness and swelling were noted in all three animals on day 22. Corneal opacity was observed throughout the study and no significant decrease was noted on day 22, compared to the observations made earlier in the study. Treatment of the eyes with 2% fluorescein, 24 and 72 hours and 7, 14 and 22 days after test substance instillation revealed corneal epithelial damage in all of the animals. A slow rate of corneal epithelial healing was noted.

Other effects:

No staining of peri-ocular tissues by the test substance was observed. No toxic symptoms were observed in the animals during the test period and no mortality occurred.

Any other information on results incl. tables

 Calculations for EEC classification:

Animal No.	Reading time (h)	Corneal opacity	Iris lesion	Conjunctivae
				Redness	Chemosis
3540 (1)	24	1	1	3	3
	48	1	1	3	2
	72	1	1	3	2
	mean	1	1	3	2.3
3541 (2)	24	1	1	3	3
	48	1	1	3	3
	72	1	1	3	2
	mean	1	1	3	2.7
3542 (3)	24	1	1	3	3
	48	1	1	3	3
	72	1	1	3	3
	mean	1	1	3	3

Draize scores: 

Time after administration	1 h	24 h	48 h	72 h	7 d	14 d	21 d
Mean total score	22.3	34	42.3	41	38	25.3	27

 

Applicant's summary and conclusion

Interpretation of results:

highly irritating

Remarks:

Migrated information Classification: risk of serious damage to eyes

Conclusions:

The test substance is severely irritating to the rabbit eye.

Executive summary:

The study was carried out in accordance with OECD Guideline 405 under GLP conditions.

The undiluted test substance (0.1 ml) was instilled into one eye of each of three female New Zealand White rabbits, followed by seven observations at approximately 1, 24, 48 and 72 hours and 7, 14 and 21 days after test substance administration. Under the conditions of this study, the test substance resulted in adverse effects on the cornea, iris and the conjunctivae. The injection of the iris had resolved within 7 days after instillation, but neither the opacity of the cornea nor the irritation of the conjunctivae had resolved within the study period in the three animals. Signs of necrosis on the conjunctivae were observed in all three animals and were still noted in two animals on day 22. The corneal opacity had been persistent throughout the study and had not decreased significantly on day 22. Neovascularisation of the cornea was noted in all three animal from day 8 onwards. No signs of systemic intoxication were observed during the study period.

Based on the Kay and Calandra interpretation of the calculated maximum Draize score (42.3), the test substance should be considered severely irritating (S) to the rabbit eye. The corneal opacity grades and persistency of the opacities to day 22 were considered to be corrosive effects caused by the test substance.

Conclusions: The test substance is severely irritating to the rabbit eye.