Zinc dibenzoate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014-02-21 to 2014-03-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

adopted 2012-10-02

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Zinc dibenzoate

EC Number:

209-047-3

EC Name:

Zinc dibenzoate

Cas Number:

553-72-0

Molecular formula:

C7H6O2.1/2Zn

IUPAC Name:

zinc dibenzoate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Zinc benzoate- Physical state: white powder- Storage condition of test material: in a tightly closed original container, in a dry and well-ventilated place at room temperature, not stored together with oxidizing agent.

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS- Source: Manfred Bauer Kaninchen, Lohe 7/1, 74632 Neuenstein, Germany- Age at study initiation: approximately 4.5 - 5.5 months- Weight at study initiation: 3.6 - 3.9 kg- Housing: for 8 hours following test item application, the animals were kept singly in restrainers which allowed free movement of the head but prevented a complete body turn, wiping of the eyes with the paws and excluded irritation of the eye by excrements and urine. During the acclimatisation period and after the 8-hour period in restrainers, the animals were kept singly in cages with dimensions of 380 mm x 425 mm x 600 mm (manufacturer: Dipl.Ing. W. EHRET GmbH, 16352 Schönwalde, Germany).- Diet (ad libitum before and after the exposure period): commercial diet, ssniff® K-H V2333 (ssniff Spezialdiäten GmbH, 59494 Soest, Germany)- Water (ad libitum before and after the exposure period): tap water- Acclimation period: at least 20 adaptation daysENVIRONMENTAL CONDITIONS- Temperature: 20°C ± 3°C (maximum range) - Humidity: 30% - 70% (maximum range, the aim was 50% - 60%)- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL- Amount(s) applied (volume or weight with unit): 100 mg of the test item were administered into one eye each of three animals.The test item was placed into the conjunctival sac of the right eye of each animal after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second in order to prevent loss of the material. The left eye, which remained untreated, served as a control.

Duration of treatment / exposure:

1 hour

Observation period (in vivo):

prior to the administration and 1, 24, 48, 72 hours and 4 to 6 days after the administration

Number of animals or in vitro replicates:

3 female rabbits

Details on study design:

USE OF TOPICAL ANAESTHETICS AND SYSTEMIC ANALGESICSSixty minutes prior to test item administration, 0.01 mg Buprenovet®/kg b.w. were administered by subcutaneous injection (s.c.) to all animals to provide a therapeutic level of systemic analgesia to avoid or minimize pain and distress.Five minutes prior to the test item administration, two drops of Ophtocain®, a topical anaesthetic, was applied to each eye of all animals, to the right eye, in which the test item was to be applied, and to the left eye, which served as control.Eight hours after administration, 0.01 mg Buprenovet/kg, s.c. and 0.5 mg Metacam/kg, s.c. were administered to provide a continued therapeutic level of systemic analgesia. In addition, 0.5 mg Metacam/kg s.c. were applied to one animal on test day 4 and 5, and to two animals on test days 3 to 5.INITIAL AND CONFIRMATORY TESTThe test was performed initially using one animal. As no corrosive or severe irritant effects were observed in this animal 24 hours after administration, 2 further animals were employed 24 hours after start of the initial test.REMOVAL OF TEST SUBSTANCE- Washing (if done) :the eyes were rinsed with portions of 20 mL 0.9% aqueous NaCl solution, each.- Time after start of exposure: 1 hour after administration SCORING SYSTEM: according to the Draize scaleTOOL USED TO ASSESS SCORE: The eyes were examined ophthalmoscopically with a slit lamp.The eye reactions were observed and registered.One day before and 24 hours after administration, fluorescein was applied to the eyes before being examined to aid evaluation of the cornea for possible lesions. The fluorescein-test was repeated on each day of observation. OBSERVATIONSBody weight of all animals was measured at the beginning and at the end of the study. Behaviour and food consumption were monitored.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not fully reversible within: 6 days

Remarks on result:

other: On day 6 the animal was euthanised. Animal showed continuing severe pain or distress.

Results 2

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 3

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.67

Max. score:

3

Reversibility:

not fully reversible within: 6 days

Results 4

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

not fully reversible within: 6 days

Results 5

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 5 days

Remarks on result:

other: On day 5 the animal was euthanised. Animal showed continuing severe pain or distress.

Results 6

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 7

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.67

Max. score:

3

Reversibility:

not fully reversible within: 5 days

Results 8

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 5 days

Results 9

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

not fully reversible within: 5 days

Remarks on result:

other: On day 5 the animal was euthanised. Animal showed continuing severe pain or distress.

Results 10

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 11

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.67

Max. score:

3

Reversibility:

not fully reversible within: 5 days

Results 12

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2.67

Max. score:

4

Reversibility:

not fully reversible within: 5 days

Irritant / corrosive response data:

Under the present test conditions, a single administration of 100 mg zinc zinc benzoate per animal into the conjunctival sac of the right eye of three rabbits caused the following changes:Corneal opacity was observed in all animals:- animal no. 1: 48 hours (grade 1) and 72 hours to 6 days (grade 2) after administration;- animal no. 2: 24 hours (grade 1), 48 hours (grade 2) and 72 hours to 5 days (grade 3) after administration;- animal no. 3: 48 to 72 hours (grade 2) and 4 to 5 days (grade 3) after administration.The fluorescein-test performed 24 hours after administration revealed corneal staining in all animals (1/4 to 1/2 of the surface). The fluorescein-tests performed 48 hours to 6 days after administration revealed corneal staining in animal no. 1 (whole surface). Due to chemosis no fluorescein-test could be performed in animal nos. 2 and 3 since 48 hours after administration.Conjunctival redness was observed in all animals:- animal no. 1: 24 hours to 4 days (grade 1) and 5 to 6 days (grade 2) after administration;- animal nos. 2 and 3: 24 hours (grade 1) and 48 hours to 5 days (grade 2) after administration.Chemosis was observed in all animals:- animal no. 1: 48 to 72 hours (grade 1), 4 days (grade 2) and 5 to 6 days (grade 3) after administration;- animal no. 2: 24 hours (grade 1) and 48 to 5 days (grade 4) after administration,- animal no. 3: 48 hours to 5 days (grade 4) after administration.The irises were not affected by instillation of the test item.As the animals showed continuing severe pain or distress in form of:• abnormal posture of the head indicating severe pain to the eyes;• chemosis grade 4;• signs of necrosis of the mucous membranes of the eye,the animals were killed humanely 6 days (animal no. 1) or 5 days (animal nos. 2 and 3) after administration.

Other effects:

Please refer to the field "Irritant/corrosive response data" above

Applicant's summary and conclusion

Interpretation of results:

Category I

Remarks:

Migrated informationCriteria used for interpretation of results: EU

Conclusions:

The zinc benzoate causes irreversible effects on the eye.According to 67/548/EC and subsequent regulations, the substance is classified as risk of serious damage to eyes.According to the EC Regulation No. 1272/2008 and subsequent regulations, the substance is classified as Category 1.