magnesium sodium fluoride silicate

Endpoint summary

Description of key information

The substance magnesium sodium fluoride silicate is not irritating or corrosive to the skin nor does it exhibit eye damaging properties.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-07-27 to 2011-08-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2010-07-22

Qualifier:

according to guideline

Guideline:

other: EpiSkinTM SOP, Version 1.8, ECVAM Skin Irritation Validation Study: Validation of the EpiSkinTM test method 15 min-42 hours for the predication of acute skin irritation of chemicals

Version / remarks:

February 2009

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Topy Indsutries Ltd. / 91108
- Expiration date of the lot/batch: 2014-11-20

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/vehicle: soluble and stable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: none

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: no
- Final preparation of a solid: No preparartion before administered

Test system:

human skin model

Source species:

human

Cell type:

other: reconstructed epidermis units

Vehicle:

other: Direct administration but 2 ml MTT soluation (0.3 mg/mL) added. MTT: [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Thiazolyl blue

Details on test system:

Test system preparation:
After receipt of the EpiSkinTM kit, all of the epidermis units used in the study were pre-incubated in maintenance medium (provided by kit supplier) at 37 °C, 5% CO2 for at least 24 hours before dosing.

Dose of test and control substances
Before topical application, the three epidermis units for test substance were moistened with 5 µl distilled water. Each of the three epidermis units for test chemical was dosed with test substance at 10 mg and incubated at room temperature for 15 minutes
Each of the three epidermis units for positive control was dosed with positive control substance (5% SDS) at 10 µl and incubated at room temperature for 15 minutes.
Each of the three epidermis units for negative control was dosed with negative control substance (PBS) at 10 µl and incubated at room temperature for 15 minutes.

Post-treatment incubation
After treatment, all the treated epidermis units were rinsed with PBS (approximately 25 ml per unit) at room temperature, following the user manual of the EpiSkinTM –SM reconstructed epidermis kit. After rinsing with PBS solution, the treated epidermis units will be incubated at 37 oC, 5% CO2 for approximately 42 hours.

MTT assay
After 42-hour incubation, the epidermis units were transferred into assay medium with 0.3 mg/ml MTT (protected from light) and incubated at 37 oC, 5% CO2 for 3 hours as described in the user manual of the EpiSkinTM –SM reconstructed epidermis kit.
The epidermis units were dried on absorbent paper at the end of incubation. Each epidermis unit were then gently separated using biopsy punch from the collagen matrix with the aid of forceps. The separated tissues were placed into a micro tube with 500 µl of acidic isopropanol and mixed thoroughly. The micro tubes were stored at 4 °C for approximately 70 hours (over the weekend).
The solution of in the micro tubes were vortexed to homogenize the solution colour. Two 200 µl of solution from each tube was transferred into a 96-well plate. The absorbance (OD) at 570 nm was read using microplate reader.

Control samples:

yes, concurrent negative control

yes, concurrent vehicle

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 10 mg

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 10 µl

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 10 µl 5 % SDS

Duration of treatment / exposure:

15 min

Duration of post-treatment incubation (if applicable):

42 h

Number of replicates:

3 replicates of magnesium sodium fluoride silicate, positive control and negative control; 1 preplicate for test substance without MTT

Irritation / corrosion parameter:

other: mean viability

Remarks:

value is 91 % after subtracting the interference of tissue staining without MTT

Value:

91

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the above results and Global Harmonised Classification System (GHS) as wll as CLP-Regulation, magnesium sodium fluoride silicate, is considered as non-irritant to skin; the skin irritation category of the test item is Unclassified (no category).

Executive summary:

Based on the above results and Global Harmonised Classification System (GHS) as wll as CLP-Regulation, magnesium sodium fluoride silicate, is considered as non-irritant to skin; the skin irritation category of the test item is Unclassified (no category).  

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-03-24 to 2011-03-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 438 (Isolated Chicken Eye Test Method for Identifying Ocular Corrosives and Severe Irritants)

Version / remarks:

2009-09-07

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Topy Indsutries Ltd. / 91108
- Expiration date of the lot/batch: 2014-11-20

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/vehicle: soluble and stable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: none

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: no
- Final preparation of a solid: No preparartion before administered

Species:

chicken

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Source: Gold Chic Poultry Supply Pte Ltd.
- Number of animals: 7 eyes
- Storage, temperature and transport conditions of ocular tissue (e.g. transport time, transport media and temperature, and other conditions): chilled
- indication of any existing defects or lesions in ocular tissue samples: no

Vehicle:

unchanged (no vehicle)

Controls:

yes

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.03 g per eye

Duration of treatment / exposure:

10 secinds. Max. 240 min observation period

Number of animals or in vitro replicates:

3 replicates of test item (magnesium sodium fluoride silicate) and positive control, 1 replicate negtaive control

Details on study design:

SELECTION AND PREPARATION OF CORNEAS
The eyelids were excised without damage of the cornea.
The undamaged eyes were then be dissected from the skull. The dissected eyes were placed on an abosrbant pad, the nictiating membrane and other connective tissue were removed.
The selected eyes were mounted in the stainless steel clamps with the cornea positioned vertically. The clamps were transferred into the chamber of the superfusion apparatus. The clamps were positioned such that the entire cornea was supplied with saline drip. The temperature of the chambers of the superfusion apparatus were controlled at 32 ± 1.5 °C.

QUALITY CHECK OF THE ISOLATED CORNEAS
Corneal integrity was assessed with a drop of 2% (w/v) sodium fluorescein applied to the corneal surface for a few seconds, and then rinsed with saline. Fluorescein-treated eyes were then examined with slit lamp to ensure that the cornea was undamaged.

NUMBER OF REPLICATES
3 replicates of test item (magnesium sodium fluoride silicate) and positive control, 1 replicate negtaive control

NEGATIVE CONTROL USED
0.9 % NaCL solution

POSITIVE CONTROL USED
NaOH

APPLICATION DOSE AND EXPOSURE TIME
0.03.g, 10 seconds

SCORING SYSTEM:
Mean corneal opacity value, mean flurescin retention score

DECISION CRITERIA: please specify if the decision criteria as indicated in the TG was used. Yes

Irritation parameter:

cornea opacity score

Value:

1.3

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Irritation parameter:

fluorescein retention score

Value:

1

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: No adverse morphological effect was observed

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes

Interpretation of results:

GHS criteria not met

Conclusions:

Under the condition of this study, magnesium sodium fluoride silicate is not considered as ocular corrosive or severe irritant using Isolated Chicken Eye Test Method.

Executive summary:

Under the condition of this study, magnesium sodium fluoride silicate is not considered as ocular corrosive or severe irritant using Isolated Chicken Eye Test Method.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Justification for classification or non-classification

The substance magnesium sodium fluoride silicate is not irritating or corrosive to the skin nor does it exhibit eye damaging properties.