Zirconium sulphate

Endpoint summary

Description of key information

Skin corrosion / irritation:
In a K1 in vitro study (Corvaro, 2013) investigating the potential of the test item to be irritant or corrosive to skin, zirconium sulfate was concluded to be corrosive or severely irritant to the skin.
No in vivo study is available. The substance is classified based on the in vitro study and therefore no in vivo testing is required.
Eye corrosion / irritation:
No study available. The substance is classified based on the results of the in vitro skin corrosion study and therefore no testing is required.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 21 June 2012 to 22 June 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well-documented GLP study performed according to OECD guideline 435.

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Version / remarks:

Corrositex

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: Corrositex

Strain:

other: not applicable

Details on test animals or test system and environmental conditions:

The test system is composed of two components, a synthetic macromolecular biobarrier and a Chemical Detection System (CDS).
The test system is part of a commercially available kit (CORROSITEX) supplied by InVitro INTERNATIONAL.
Test system batch number: CT042011

The membrane barrier (biobarrier) consists of two components: a proteinaceous macromolecular aqueous gel and a permeable supporting membrane. The proteinaceous gel is supplied in the form of a powder to be reconstituted, prepared over the supporting membrane and stored. To prepare the gel, and after mixing the components, slow dissolution was allowed at a maximum temperature of 68-70°C by a magneting stirring hot plate for 20 minutes. After 5 minutes of rest, the solution was pipetted over the supporting membrane ensuring the entire membrane was covered and no bubbles were formed. The solidification was by immediate incubation at 2-8°C. The gel was used the day after preparation (stable up to 7 days).

Type of coverage:

other: not applicable

Preparation of test site:

other: not applicable

Vehicle:

unchanged (no vehicle)

Controls:

other: Details are mentioned in the field 'Any other information on materials and methods incl. tables’

Amount / concentration applied:

Comparability test (Qualification): 100 mg of the test item as supplied.
Timesclae category test (Categorisation): 100 mg of the test item as supplied.
Main Assay (Classification assay): 500 mg of test item as supplied.

Observation period:

Main study:
According to the time category 1 (determined in the preliminary test), test item samples were observed continuously at least during the following intervals: 0-5, 55-65 and 235-245 minutes.

Positive control vial was observed in the interval 0-15 minutes.
Negative control vial was observed at 60 minutes.

Number of animals:

The test item was tested in 4 replicates.

Details on study design:

- Preliminary Study:
A preliminary test was divided in two steps. A qualification of the test item was carried out to verify if the CDS undergoes a physical change (Step 1). A categorising test was then carried out to verify what time scale should have been used in the main experiment (Step 2). Finally the main experiment (classification assay) was performed out including all controls.

- Main Assay (Classification assay):
A main assay was carried out including the test item, positive and negative controls.
The pre-filled CDS vials were kept at room temperature (17-25°C) before use. A cold biobarrier disc, eventually kept on crushed ice on the bench, was added to the top of each vial. A fixed amount of samples was added to the top within 2 minutes from putting the biobarrier at room temperature.

Irritation parameter:

other: Penetration time

Remarks on result:

other: The mean penetration time (CORROSITEX Time) for the test item was estimated to be 32.42 ± 2.23 minutes.

Irritant / corrosive response data:

During an unscheduled control of the test system performed after the 5-minute observation sessions, the test item was found to have penetrated the barrier in all the 4 replicates. The time was recorded. The mean penetration time (CORROSITEX Time) for the test item was estimated to be 32.42 ± 2.23 minutes.

Positive and negative control results indicated a good functioning of the test system.
Negative control was not corrosive at 60 minutes.
Positive control was corrosive at 9.47 minutes (9’28’’), slightly below laboratory's historical control range (the minimum value observed in the range distribution is 11.58 minutes). However, since the number of experiments is limited (n = 10) and the distribution has a very low standard deviation (CV% is equal to 6.6%), the result obtained is considered acceptable.

Interpretation of results:

other: Corrosive

Remarks:

Criteria used for interpretation of results: other: OECD guideline 435 cut-off values

Conclusions:

According to the OECD guideline for testing of chemicals no. 435 "In vitro membrane barrier test Method for Skin Corrosion" (adopted on 19 July 2006) the test item is defined as corrosive to the skin. The corrosivity sub-category assigned is GHS 1B (Packing Group II).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In vitro skin irritation

The skin corrosion potential of zirconium sulfate was assessed with an in vitro membrane barrier assay, using the validated commercial kit Corrositex. The mean penetration time (CORROSITEX Time) for the test item was observed to be 32.42 ± 2.23 minutes. Positive and negative control results indicated good functioning of the test system. According to the OECD guideline for testing of chemicals no. 435 "In vitro Membrane Barrier Test Method for Skin Corrosion" (adopted on 19 July 2006), the test item is concluded to be corrosive to skin.

In vivo skin irritation

No study was performed as the substance should be classified as corrosive to skin based on the in vitro skin corrosion test results.

Eye irritation

No study was performed as the substance should be classified as corrosive to eyes based on the in vitro skin corrosion test results.

Justification for selection of skin irritation / corrosion endpoint:
There is only one reliable study available. Further studies are not scientifically required as the substance is corrosive to skin based on the results of the in vitro test.

Justification for selection of eye irritation endpoint:
No study available. Further studies are not scientifically required as the substance should be assumed to be corrosive to eyes based on the in vitro skin results.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Justification for classification or non-classification

Based on the available in vitro data and according to the criteria of the DSD and CLP Regulation, zirconium sulfate should be classified as skin corrosive category 1B - H314- GHS05 (CLP) and C, R34 (DSD).

As the substance is classified as corrosive to the skin, it should be classified as Xi, R41 (DSD) and Eye damage category 1 (CLP) according to the criteria of the DSD and CLP Regulation.