Dibutyltin bis(2-ethylhexanoate)

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

26 July 2010 and 14 September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: A GLP compliant study conducted in accordance with OECD guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dibutyltin dilaurate

EC Number:

201-039-8

EC Name:

Dibutyltin dilaurate

Cas Number:

77-58-7

IUPAC Name:

dibutyltin dilaurate

Details on test material:

Sponsor's identification : CAS No 77-58-7
Description : clear colourless liquid
Batch number : LA6K05N001
Date received : 26 March 2010
Expiry date : 26 March 2011
Storage conditions : ~4°C in the dark under nitrogen
The integrity of supplied data relating to the identity, purity and stability of the test item is the responsibility of the Sponsor.

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories U.K. Ltd., Loughborough, UK
- Age at study initiation: Twelve to twenty weeks old
- Weight at study initiation: 2.30 or 2.79 kg
- Housing: The animals were individually housed in suspended cages
- Diet : Free access to food (2030 Teklad Global Rabbit diet supplied by Harlan Laboratories U.K. Ltd., Oxon, UK)
- Water : Free access to mains drinking water
- Acclimation period: At least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 23°C
- Humidity (%): 30 to 70%
- Air changes (per hr): The rate of air exchange was at least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): The lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness

Test system

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml of the test item was placed into the conjunctival sac of the right eye, formed by gently pulling the lower lid away from the eyeball. The upper and lower eyelids were held together for about one second immediately after treatment, to prevent loss of the test item, and then released. The left eye remained untreated and was used for control purposes.

Duration of treatment / exposure:

72 hours

Observation period (in vivo):

14 days

Number of animals or in vitro replicates:

2 male rabbits

Details on study design:

SCORING SYSTEM:
Immediately after administration of the test item, an assessment of the initial pain reaction was made according to the six point scale shown in table 1.
Assessment of ocular damage/irritation was made approximately 1 hour and 24, 48 and 72 hours following treatment, according to the numerical evaluation shown in table 2, (from Draize J H (1977) "Dermal and Eye Toxicity Tests" In: Principles and Procedures for Evaluating the Toxicity of Household Substances, National Academy of Sciences, Washington DC p.48 to 49).

The numerical values corresponding to each animal, tissue and observation time were recorded. The data relating to the conjunctivae were designated by the letters A (redness), B (chemosis) and C (discharge), those relating to the iris designated by the letter D and those relating to the cornea by the letters E (degree of opacity) and F (area of cornea involved). For each tissue the score was calculated as follows:

Score for conjunctivae = (A + B + C) x 2
Score for iris = D x 5
Score for cornea = (E x F) x 5

Using the numerical data obtained a modified version of the system described by Kay J H and Calandra J C (1962), J. Soc. Cosmet. Chem. 13, 281-289 (see table 3) was used to classify the ocular irritancy potential of the test item. This was achieved by adding together the scores for the cornea, iris and conjunctivae for each time point for each rabbit. The group means of the total scores for each observation were calculated. The highest of these group means (the maximum group mean score) together with the persistence of the reactions enabled classification of the eye irritancy potential of the test item.

If evidence of irreversible ocular damage is noted, the test item will be classified as corrosive to the eye. The results were evaluated according to EU labelling regulations Commission Directive 2001/59/EC for classification and labelling of dangerous substances.

TOOL USED TO ASSESS SCORE: xamination of the eye was facilitated by the use of the light source from a standard ophthalmoscope.

Any other ocular effects were also noted. Any clinical signs of toxicity, if present, were also recorded.
Additional observations were made on Days 7, 14 and 21 to assess the reversibility of the ocular effects.
Individual bodyweights were recorded on Day 0 (the day of dosing) and at the end of the observation period.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

overall irritation score

Basis:

animal #1

Time point:

other: 1 hour

Score:

12

Max. score:

110

Reversibility:

fully reversible within: 21 days

Results 2

Irritation parameter:

overall irritation score

Basis:

animal #1

Time point:

other: 24 hours

Score:

17

Max. score:

110

Reversibility:

fully reversible within: 21 days

Results 3

Irritation parameter:

overall irritation score

Basis:

animal #1

Time point:

other: 48 hours

Score:

39

Max. score:

110

Reversibility:

fully reversible within: 21 days

Results 4

Irritation parameter:

overall irritation score

Basis:

animal #1

Time point:

other: 72 hours

Score:

39

Max. score:

110

Reversibility:

fully reversible within: 21 days

Results 5

Irritation parameter:

overall irritation score

Basis:

animal #1

Time point:

other: 7 days

Score:

30

Max. score:

110

Reversibility:

fully reversible within: 21 days

Results 6

Irritation parameter:

overall irritation score

Basis:

animal #1

Time point:

other: 14 days

Score:

6

Max. score:

110

Reversibility:

fully reversible within: 21 days

Results 7

Irritation parameter:

overall irritation score

Basis:

animal #2

Time point:

other: 24 hours

Score:

19

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: (irritation score of 2 at 21 days)

Results 8

Irritation parameter:

overall irritation score

Basis:

animal #2

Time point:

other: 1 hour

Score:

12

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: (irritation score of 2 at 21 days)

Results 9

Irritation parameter:

overall irritation score

Basis:

animal #2

Time point:

other: 39

Score:

48

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: (irritation score of 2 at 21 days)

Results 10

Irritation parameter:

overall irritation score

Basis:

animal #2

Time point:

other: 72 hours

Score:

39

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: (irritation score of 2 at 21 days)

Results 11

Irritation parameter:

overall irritation score

Basis:

animal #2

Time point:

other: 7 days

Score:

32

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: (irritation score of 2 at 21 days)

Results 12

Irritation parameter:

overall irritation score

Basis:

animal #2

Time point:

other: 14 days

Score:

11

Max. score:

110

Reversibility:

other: Almost fully recoverd by day 21

Remarks on result:

other: (irritation score of 2 at 21 days)

Results 13

Irritation parameter:

overall irritation score

Basis:

animal #2

Time point:

other: 21 days

Score:

2

Max. score:

110

Results 14

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 1 hour

Score:

12

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: Group mean score of 1

Results 15

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24 hours

Score:

18

Max. score:

110

Reversibility:

other: Almost fully reversible by day 21

Remarks on result:

other: Group mean score of 1.0 at 21 days

Results 16

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 48 hours

Score:

39

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: Group mean score of 1.0 at day 21

Results 17

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 72 hours

Score:

39

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: Group mean score of 1.0 at day 21

Results 18

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 7 days

Score:

31

Max. score:

110

Reversibility:

other: Almost fully recovered by day 21

Remarks on result:

other: Group mean score of 1.0 at day 21

Results 19

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 14 days

Score:

8.5

Max. score:

110

Reversibility:

other: Almost fully recoved by day 21

Remarks on result:

other: Mean group score of 1.0 at day 21

Results 20

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 21 days

Score:

1

Max. score:

110

Reversibility:

other: One rabbit (1 out of 2) was fully recovered by day 21.

Irritant / corrosive response data:

Scattered or diffuse corneal opacity was noted in both treated eyes at the 48-Hour,
72- Hour and 7-Day observations and persisted in one treated eye at the 14-Day observation.
Iridial inflammation was noted in both treated eyes at the 24, 48, and 72-Hour and 7-Day observations.
Moderate conjunctival irritation was noted in both treated eyes one hour after treatment and at the 24, 48 and 72-Hour and 7-Day observations. Minimal conjunctival irritation was noted in both treated eyes at the 14-Day observation with minimal conjunctival redness in one treated eye at the 21-Day observation.
A hardened dark brown/black coloured scab (up to 15mm x 15mm) on the outer surface of the lower and/or upper eyelids was noted in both treated eyes at the 7, 14 and 21-Day observations with alopecia also noted in both treated eyes at the 14 and 21-Day observations.

Other effects:

Both animals showed expected gain in bodyweight during the study.

Any other information on results incl. tables

Table 4: IndividualScores and Individual Total Scores for Ocular Irritation

Rabbit Number and Sex	69446Male							69549Male
	IPR = 2							IPR = 2
Time After Treatment	1 Hour	24 Hours	48 Hours	72 Hours	7 Days	14 Days	21 Days	1 Hour	24 Hours	48 Hours	72 Hours	7 Days	14 Days	21 Days
CORNEA
E = Degree of Opacity	0	0	1	1	1	0	0	0	0	1	1	1	1	0
F = Area of Cornea Involved	0	0	4	4	3	0	0	0	0	4	4	3	1	0
Score (E x F) x 5	0	0	20	20	15	0	0	0	0	20	20	15	5	0
IRIS
D	0	1	1	1	1	0	0	0	1	1	1	1	0	0
Score (D x 5)	0	5	5	5	5	0	0	0	5	5	5	5	0	0
CONJUNCTIVAE
A = Redness	2	2	2	2	2	1	0	2	2	2	2	2	1	1
B = Chemosis	2	2	3	3	2	1	0	2	3	3	3	2	1	0
C = Discharge	2	2	2	2	1	1	0	2	2	2	2	2	1	0
Score (A + B + C) x 2	12	12	14	14	10	6	0	12	14	14	14	12	6	2
Other ocular reactions	-	-	-	-	St	StAl	StAl	-	-	-	-	St*	St*Al	St*Al
Total Score	12	17	39	39	30	6	0	12	19	39	39	32	11	2
IPR= Initial pain reaction St =    A hardened dark brown/black coloured scab (approximately 15mm x 10mm) on the outer surface of the upper eyelid St* =  A hardened dark brown/black coloured scab (approximately 15mm x 15mm) on the outer surface of the lower and upper eyelids Al =    Alopecia - =       Not applicable

Table 5: 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	7 Days	14 Days	21 Days
69446Male	12	17	39	39	30	6	0
69549Male	12	19	39	39	32	11	2
Group Total	24	36	78	78	62	17	2
Group Mean Score	12.0	18.0	39.0	39.0	31.0	8.5	1.0

 

Table 6: Individual Bodyweights and Bodyweight Changes

Rabbit Number and Sex	Individual Bodyweight (kg)		Bodyweight Change (kg)
	Day 0	Day 21
69446Male	2.79	3.14	0.35
69549Male	2.30	2.41	0.11

Applicant's summary and conclusion

Interpretation of results:

highly irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item produced a maximum group mean score of 39.0 and was classified as a severe irritant (Class 6 on a 1 to 8 scale) to the rabbit eye according to a modified Kay and Calandra classification system.
The test item was also classified as irritant according to EU labelling regulations Commission Directive 2001/59/EC. The symbol “Xi”, the indication of danger “Irritant” and the risk phrase R 36 “IRRITATING TO EYES” are therefore required.

Executive summary:

The test material was administed into the eyes of two New Zealand White rabbits to assess the irritation potential in a GLP compliant study conducted in accordance with the OECD guideline 405. The test item produced a maximum group mean score of 39.0 and was classified as a severe irritant (Class 6 on a 1 to 8 scale) to the rabbit eye according to a modified Kay and Calandra classification system.