Concentrates of lead and zinc compounds with sulfur resulting from hydrometallurgy (hot acid leaching, super-hot acid leaching and flotation)

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:

weight of evidence

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Used in risk assessment report for ZnSO4, acceptable for assessment.Read-across justificaton:Read-across from the most critical and bioavailable constituents (zinc and its compounds):The target substance is a solid inorganic UVCB substance and insoluble in water. Therefore, the transformation/dissolution study (OECD guidance 29) was conducted for the target substance to focus on the most critical bioavailable constituents of the substance. Based on the mineralogical composition, two major constituents of this target substance in addition to lead are zinc and sulphur. Zinc appears in sulphide form in the target substance. According to the 7-day and 28-day transformation/dissolution study at 100, 10 and 1 mg loadings (OECD guidance 29) zinc and sulphur are also soluble from the target substance. Since sulphur can appear either in sulphide or sulphate form in water, the read-across data focuses on the properties of zinc sulphate and other bioavailable forms of zinc. The read-across on zinc and its compounds are used in the chemical safety assessment for those endpoints where the adverse effects of the target substance can be affected by zinc content of the substance. The read-across data was justified in order to avoid unnecessary animal testing.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

not specified

Principles of method if other than guideline:

Not applicable

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Zinc sulphate

EC Number:

231-793-3

EC Name:

Zinc sulphate

Cas Number:

7733-02-0

Molecular formula:

H2O4S.Zn

IUPAC Name:

zinc sulfate

Details on test material:

- Name of test material (as cited in study report): zinc sulphate (ZnSO4.7H2O)

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

No information

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

Approximately 98.1 mg of the test material

Duration of treatment / exposure:

Single instillation, no eye wash

Observation period (in vivo):

At 1, 24, 48 and 72 hours, 7, 14 and 21 days after exposure.

Number of animals or in vitro replicates:

Three male animals

Details on study design:

No further details

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Time point:

other: 24 h

Score:

ca. 2

Max. score:

3

Reversibility:

not specified

Results 2

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Time point:

other: 48 h

Score:

2.7

Max. score:

3

Reversibility:

not specified

Results 3

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Time point:

other: 72 h

Score:

ca. 2.7

Max. score:

3

Reversibility:

not specified

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24 h

Score:

ca. 2

Max. score:

4

Reversibility:

not specified

Results 5

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 48 h

Score:

ca. 2.7

Max. score:

4

Reversibility:

not specified

Results 6

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 72 h

Score:

ca. 3.7

Max. score:

4

Reversibility:

not specified

Irritant / corrosive response data:

Corneal injury was seen as slight dulling of the normal lustre (opacity grade 0) and/or epithelial damage (10% of the corneal area) in two animals. This injury had resolved within 24 hours in one animal and within 72 hours in the other animal. Irritation of the conjuctivae was seen as redness (mean scores over 24-72 hours 2, 2.7 and 2.7), chemosis (mean scores 2, 2.7 and 3.7) and discharge.Yellow/white spots were observed in the tissue of the lower eyelid, nictitating membrane and/or sclera in all animals from day 7 until termination. These spots were described as signs of necrosis and consisted of encapsulated material of unknown origin which caused protrusions at termination of the study.

Other effects:

Reduced elasticity of the eyelids was noted in one animal, 72 hours and 7 days after instillation.

Any other information on results incl. tables

None       

Applicant's summary and conclusion

Interpretation of results:

highly irritating

Remarks:

Migrated informationCriteria used for interpretation of results: EU

Conclusions:

Based on the degree and persistence of the corneal injury, zinc sulphate is considered to cause severe ocular irritation

Executive summary:

In a well-performed eye irritation/corrosion study, conducted according to Directive 92/69/EEC B.5 and OECD guideline 405, three male New Zealand White rabbits were treated by instillation of approximately 98.1 mg of zinc sulphate (ZnSO_4.7H₂O) into the conjuctival sac of one eye. The other eye remained untreated and served as control. The eyes (unrinsed) were examined at 1, 24, 48 and 72 hours and 7, 14 and 21 days after instillation.

No symptoms of systemic toxicity were observed and no mortality occurred.

Corneal injury was seen as slight dulling of the normal lustre (opacity grade 0) and/or epithelial damage (10% of the corneal area) in two animals. This injury had resolved within 24 hours in one animal and within 72 hours in the other animal.

Irritation of the conjuctivae was seen as redness (mean scores over 24-72 hours 2, 2.7 and 2.7), chemosis (mean scores 2, 2.7 and 3.7) and discharge.

Yellow/white spots were observed in the tissue of the lower eyelid, nictitating membrane and/or sclera in all animals from day 7 until termination. These spots were described as signs of necrosis and consisted of encapsulated material of unknown origin which caused protrusions at termination of the study. Reduced elasticity of the eyelids was noted in one animal, 72 hours and 7 days after instillation.

Based on the degree and persistence of the corneal injury, zinc sulphate is considered to cause severe ocular irritation.