Strontium fluoride

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-12-13 to 2017-12-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2015-07-28

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2015-09-14

Test material

Test material information

Constituent 1

Reference substance name:

Strontium fluoride

EC Number:

232-000-3

EC Name:

Strontium fluoride

Cas Number:

7783-48-4

Molecular formula:

F2Sr

IUPAC Name:

strontium fluoride

Test material form:

solid: particulate/powder

Details on test material:

Appearance: White powder
Storage conditions: Ambient temperature, dry, tightly closed in original container

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature

In vitro test system

Test system:

artificial membrane barrier model

Source species:

other: not specified

Cell type:

other: synthetic macromolecular bio-barrier

Cell source:

other: not specified

Source strain:

not specified

Details on animal used as source of test system:

not applicable

Justification for test system used:

Corrositex TM is a validated and accepted in vitro method to assess if a test item can produce skin corrosion and to distinguish between GHS corrosivity categories 1A, 1B, and 1C.

Vehicle:

unchanged (no vehicle)

Details on test system:

SOURCE AND COMPOSITION OF MEMBRANE BARRIER USED
- Was the Corrositex® test kit used: yes (lot no. CT120516; supplier: ROMER Labs Deutschland GmbH, 35510 Butzbach, Germany)
- Components: a synthetic macromolecular bio-barrier and a chemical detection system (CDS)
- Apparatus and preparation procedures: one day prior to testing the bio-barrier matrix was prepared. The bio-barrier powder was solved in the bio-barrier diluent and heated for 20 minutes at 68 – 70 °C in a water bath under continuous stirring. The temperature did not exceed 70 °C. The mixture was allowed to cool in the turned-off water bath for another 10 minutes. The mixture was then filled into the membrane holders (200 μL per membrane holder). Air bubbles were avoided. The filled membrane holders were sealed with parafilm and were stored at 2 – 8 °C until further use.

WAS THE COMPATIBILITY TEST PERFORMED: yes
In order to test whether the test system is suitable for the test item, approximately 100 mg of the test item were applied into the “Qualify Test Vial”. The vial was shaken until the solution appeared homogenous, and incubated for 1 minute. Afterwards, the colour change was noted.
The test item induced a change in colour in the qualify test after 1 minute incubation. Since a change in colour was visible in the “Qualify Test Vial”, the test item was considered to be suitable for the next step.

WAS THE TIMESCALE CATEGORY TEST PERFORMED: yes
In the categorisation test the observation period of the test item after application to the bio-barrier was determined:
- Category 1: observation period after application is 4 hours
- Category 2: observation period after application is 1 hour
Approximately 100 mg of the test item were applied into the “Category A Vial” as well as into the “Category B Vial”. The vials were shaken until the solution appeared homogenous. After 1 minute the colour change was monitored.
Based on the colour change obtained, a test item is assigned to a category. If an intense colour change (similar to the category 1 colour chart) is observed in “Category A Vial” or in “Category B Vial” the test item is assigned to category 1. If a less intense colour change (similar to the category 2 colour chart) is observed in “Category A Vial” or in “Category B Vial” the test item will be assigned to category 2. If no colour change is observed in either of the vials, a confirmation test is conducted. For the confirmation test two drops of the confirm reagent are added to the “Category B Vial”. The vial would be shaken for 5 seconds. The colour of the solution would match one of the colours shown in the accompanying colour chart, confirming that the test item is a category 2 substance.
The test item did not induce a change in colour neither in the Category A vial nor in the Category B vial after 1 minute incubation. The confirmation experiment was performed by adding the confirm reagent to the Category B vial. This induced a change in colour after 1 minute of incubation. Therefore, the test item was classified as category II.

TEMPERATURE USED DURING TREATMENT: room temperature

METHOD OF DETECTION
- Chemical or electrochemical detection system: chemical detection system

METHOD OF APPLICATION (CLASSIFICATION TEST):
8 vials containing the CDS were pre-warmed to room temperature (test item: 4 vials; negative control: 1 vial; positive control (sulfuric acid): 1 vial; positive control (sodium hydroxide): 1 vial; colour reference for CDS: 1 vial).
The prepared bio-barriers were placed on top of the CDS vials (not longer than 2 minutes prior to an application) and the test item or the respective controls were applied per bio-barrier for 1 hour, depending on the results of the categorisation test. The time interval of the possible colour change or precipitation in the CDS solution was recorded.

INTERPRETATION OF THE RESULTS:
For each vial the period until observable change in CDS solution was determined. The mean of the quadruplicate measurement was calculated. The test item was categorised according to the criteria in table 1 as presented in the field "Any other information on materials and methods incl. tables" below.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): approx. 500 mg of the neat test item

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 500 µL of citric acid (10 % (w/v) solution in deionised water)

POSITIVE CONTROL (two positive controls were used)
- Amount(s) applied (volume or weight):
1) 500 µL of sulfuric acid 95 - 97 %
2) 110 ± 15 mg of sodium hydroxide

Duration of treatment / exposure:

60 minutes

Duration of post-treatment incubation (if applicable):

not applicable

Number of replicates:

Test item: quadruplicates
Negative control: single measurement
Positive control: single measurement

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

penetration time (in minutes)

Value:

0

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Colour change was not observed up to 60 minutes (treatment period)

Other effects / acceptance of results:

QUALIFY TEST
The test item induced a change in colour in the qualify test after 1 minute incubation. Since a change in colour was visible in the “Qualify Test Vial”, the test item was considered to be suitable for the next step.

CATEGORISATION TEST:
The test item did not induce a change in colour neither in the Category A vial nor in the Category B vial after 1 minute incubation. A confirmation experiment was performed by adding the confirm reagent to the Category B vial. This induced a change in colour after 1 minute of incubation. Therefore, the test item was classified as category II.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: negative control did not induce a change in the colour of CDS reagent after 60 minutes (acceptability criteria: negative control does not induce a physical change (colour or precipitation) up to 60 minutes in the CDS solution in the classification test).

- Acceptance criteria met for positive control: the positive control sulfuric acid showed a distinct change in the colour of the CDS reagent in the time interval of 0 – 3 minutes. The positive control sodium hydroxide induced a change in the colour of the CDS reagent after 3 – 30 minutes.

Please also refer to the field "Any other information on results incl. tables" below.

Any other information on results incl. tables

HISTORICAL DATA:

Table: Historical range of breakthrough times for the positive control

Mean time till colour change of positive control Sulfuric acid [minutes]	1.24
Standard deviation [minutes]	0.37
Range of mean times	0.50 - 2.00

Data of 88 studies performed from September 2007 until March 2016.

CLASSIFICATION TEST:

Test Group		Time Interval of Colour Change	UN GHS
Negative Control		Colour change was not observed up to 60 minutes	Non-corrosive
Positive Control Sulfuric acid		1 minute 13 seconds	Corrosive subcategory 1A
Positive Control Sodium Hydroxide		6 minutes 30 seconds	Corrosive subcategory 1B
Test Item	Colour change was not observed up to 60 minutes		Non-corrosive

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item is not corrosive to the skin.
According to the Regulation (EC) No 1272/2008 and subsequent regulations, the test item is not corrosive to the skin.