Barium zirconium trioxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

60±1 minute exposure on the surface of the EpiDermTM reconstructed human epidermis, and a 42 ±4 hours post-exposure incubation time

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Deviations:

yes

Remarks:

Optical Density (OD) values obtained with blanks were higher than 0.1 (0.160) causing a deviation from Acceptance Criteria 4. This deviation was not considered to have affected the integrity or interpretation of the results.

Principles of method if other than guideline:

In vitro assessment of the skin irritation potential of Barium Zirconate according to OECD guideline TG439: In vitro Skin Irritation: Reconstructed Human Epidermis (RHE) Test Method.
This in vitro risk assessment assay predicts the skin irritation potential of a chemical by measurement of its cytotoxic effect on the EpiDerm™ tissue model.
The detailed method followed in this study is described in XCellR8 SOP L0029: “EpiDermTM In vitro Reconstructed Human Epidermis Skin Irritation Test (OECD 439 28 Jul 2015 and is based on the MatTek protocol (MK-24-007-0023, 03 January 18) using the MatTek Corporation EpiDermTM reconstructed tissue model EPI-200.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Barium zirconium trioxide

EC Number:

234-546-8

EC Name:

Barium zirconium trioxide

Cas Number:

12009-21-1

Molecular formula:

BaO3Zr

IUPAC Name:

barium(2+);oxygen(2-);zirconium(4+)

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Supplier Thermograde Process Technology
Test Item name Barium Zirconate
Supplier batch/lot number 17/1791
CAS number 12009-21-1
Purity 99.17
Expiry Date 27 Sep 2020
Physical state Powder (white)
Storage Conditions Room Temp.
Administration method Topical application
Concentration tested Neat
XCellR8 test item code RCS001
Study test item code TA1

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

other: normal human-derived epidermal keratinocytes which have been cultured to form a multi-layered highly differentiated model of the human epidermis

Cell source:

other: . It consists of organised basal, spinous and granular layers and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo

Vehicle:

unchanged (no vehicle)

Details on test system:

After pre-wetting tissues with 25µl DPBS (Sterile Dulbecco’s Phosphate Buffered Saline) a single, topical application of nominal 25mg neat test item or 30µl of negative control (DPBS) or positive control (SDS 5%) to the surface of the EpiDermTM model for 60±1 minutes (25 minutes at room temperature and 35 minutes at 37°C, 5% CO2, ≥95% Relative Humidity (RH)), followed by 42±4 hours post-treatment incubation, prior to the MTT endpoint; three tissues per condition (n=3).

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

a single, topical application of nominal 25mg neat test item or 30µl of negative control (DPBS) or positive control (SDS 5%) to the surface of the EpiDermTM model

Duration of treatment / exposure:

60±1 minutes (25 minutes at room temperature and 35 minutes at 37°C, 5% CO2, ≥95% Relative Humidity (RH)

Duration of post-treatment incubation (if applicable):

42±4 hours post-treatment incubation

Number of replicates:

Three

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Mean result of three replicates

Value:

101.12

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

Acceptance criterion 1: The mean OD570 of the negative control (treated with DPBS) tissues must be ≥ 0.8 and ≤ 2.8 Result = 1.928 PASS
Acceptance criterion 2: The mean of the positive control relative percentage viability must be ≤ 20% of the mean of the negative controls. Result = 2.861 PASS
Acceptance criterion 3: The standard deviation of viability percentages for triplicate skin models in each experimental condition must be < 18%
NC: 5.209, PC: 0.853, TA1: 8.557 = PASS
Acceptance criterion 4: The mean OD of the 6 wells containing extraction solvent alone (blanks) must be ≤ 0.1. Result = 0.160 ACCEPT*
*All acceptance criteria were met except for criterion 4:
Optical Density (OD) values obtained with blanks were higher than 0.1 (0.160) causing a deviation from Acceptance Criteria 4. However, the spectrophotometer was fully validated and had passed all required tests. The OD values for blanks observed in this study are consistent with historical data using this spectrophotometer in the XCellR8 laboratory and meet our current internal acceptance criteria of blank OD values <0.244 (mean of XCellR8 historical data +2SD, based on blanks obtained during 88 historic runs), therefore this is not considered to be an issue in the interpretation of this study data.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this study, the skin irritation potential of Barium Zirconate was assessed in vitro according to OECD Test Guideline 439: In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method. After 60±1 minute exposure on the surface of the EpiDermTM reconstructed human epidermis, and a 42 ±4 hours post-exposure incubation time, viability of the tissues was assessed and compared to the negative control. The percentage of viability obtained was 101.124 % and therefore:
Barium Zirconate was classified as Non-Irritant to the skin.