Magnesium diethyl dicarbonate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

other: in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-03-02 to 2010-03-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted according to Guidelines in a GLP certified laboratory

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 431 (In vitro skin corrosion:Human skin model test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EC Guideline 440 (Part B: Methods for determination of toxicity and other health effects, Guideline B.40 BIS "In vitro corrosion: Human skin model test"

Deviations:

no

GLP compliance:

yes

Remarks:

Self-Certified

Test material

Test material information

Constituent 1

Reference substance name:

Magnesium hydroxide

EC Number:

215-170-3

EC Name:

Magnesium hydroxide

Cas Number:

1309-42-8

Molecular formula:

H2MgO2

IUPAC Name:

magnesium dihydroxide

Details on test material:

Identification: Magnesium hydroxide
Molecular formula: Mg(OH)2
Molecular weight: 58.32
CAS Number: 1309-42-8
Stable under storage conditions: Stable

Test animals

Species:

human

Strain:

other: In vitro test with human skin model

Details on test animals or test system and environmental conditions:

Not applicable. In vitro test.

Test system

Type of coverage:

open

Preparation of test site:

other: Skin tissue was moistened with 25ul of Milli-Q water to ensure close contact to the tissue

Vehicle:

water

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 mg of magnesium hydroxide was applied directly on top of skin tissue which was moistened with 25 ul of Milli-Q water.

Duration of treatment / exposure:

3 minutes and 1 hour

Observation period:

3 minutes and 1 hour

Number of animals:

Not applicable

Details on study design:

Magnesium hydroxide was topically applied on a human three dimensional epidermal model. 25mg of Magnesium hydroxide was applied directly on top of the skin tissue which was moistened with 25µl of Milli-Q water.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Time point 3 minutes, max score 100

Value:

88

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Time point 1 hour, max score 100

Value:

95

Any other information on results incl. tables

Magnesium hydroxide was checked for possible direct MTT reduction by adding the test substance to MTT medium. Because no colour change was observed it was concluded that magnedium hydroxide did not interact with MTT.

The mean absorption at 540 nm measured after treatment with magnesium hydroxide and controls are presented in Table 1. Table 2 shows the mean tissue viability obtained after 3 minute and 1 hour treatments with magnesium hydroxide compared to the negative control tissues. Skin corrosion is expressed as the remaining cell viability after exposure to the test substance.

A test substance is considered corrosive in the skin corrosion test if:

1. The relative mean tissue viability obtained after 3 minutes of treatment compared to the negative control tissues is decreased below 50 %.

2. The relative tissue viability after 1 hour of treatment is decreased below 15 %.

 

A test substance is considered to be non-corrosive if: 

1. The relative mean tissue viability obtained after 3 minutes of treatment compared to the negative control tissues is above 50 %.

2. The relative tissue viability after 1 hour of treatment is not decreased below 15 % The relative mean tissue viability obtained after the 3 minute and 1 hour treatments with magnesium hydroxide compared to the negative control tissues were 88 % and 95 %, respectively. The absolute mean OD540 of the negative control tissues was within the historical control range. The mean relative tissue viability following 3 minutes and 1 hour of exposure to the positive control were 9 %. Therefore, it was concluded that the test system was suitable for this analysis. Table 1: Mean absorption in the in vitro skin corrosion test with magnesium hydroxide (OD₅₄₀)

 

	3 minute application			1 hour application
	A	B	Mean ± SD	A	B	Mean ± SD
Negative control	1.683	1.699	1.691 ± 0.011	1.707	1.710	1.708 ± 0.002
Magnesium hydroxide	1.586	1.393	1.490 ± 0.137	1.664	1.578	1.621 ± 0.061
Positive control	0.150	0.143	0.147 ± 0.005	0.148	0.145	0.147 ± 0.002

 

 

Table 2: Mean tissue viability

 

	3 minute application viability (% of control)	1 hour application viability (% of control)
Negative control	100	100
Magnesium hydroxide	88	95
Positive control	9	9

Applicant's summary and conclusion

Interpretation of results:

other: Not corrosive

Remarks:

Criteria used for interpretation of results: OECD GHS

Conclusions:

Based on the results of this study, it is concluded that magnesium hydroxide is not corrosive in the in vitro skin corrosion test.

Executive summary:

The potential of magnesium hydroxide to induce skin corrision was tested using a human three-dimensional epidermal model. The possible corrosive potential of magnesium hydroxide was tested using topical application for either 3 minutes or 1 hour. Twenty five mg of magnesium hydroxide was added directly on top of the skin tissue which was moistened with water. Water and potassium hydroxide were used as the negative and positive control substances, respectively.

The positive control had a mean relative tissue viability of 9 % after 3 minutes exposure, and the absolute mean optical density of the negative control tissues was within the historical control range, indicating the acceptability of the assay.

The mean relative tissue viabilities for magnesium hydroxide after 3 minute and 1 hour treatments were 88 % and 95 %, respectively. Because the mean relative tissue viability for magnesium hydroxide was not below 50 % after the 3 minute treatment or 15 % after the 1 hour treatment, it was concluded that magnesium hydroxide is not corrosive under the conditions of this test.