Sodium 4-(methoxycarbonyl)phenolate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Remarks:

other: in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-02-13 to 2012-02-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: EU Method b.46 (Skin Irritation)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, München, Germany

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 4-(methoxycarbonyl)phenolate

EC Number:

225-714-1

EC Name:

Sodium 4-(methoxycarbonyl)phenolate

Cas Number:

5026-62-0

Molecular formula:

C8H8O3.Na

IUPAC Name:

methyl 4-hydroxybenzoate

Details on test material:

Name: Sodium methyl-4-hydroxybenzoate
CAS No.: 5026-62-0
Chemical Name: sodium 4-(methoxycarbonyl)phenolate
Physical State/Colour: solid/white
Storage Conditions: room temperature

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

other: EpiDerm( MatTek) rganotypic reconstructed three-dimensional model of the human epidermis

Cell source:

other: EpiDerm( MatTek)

Details on animal used as source of test system:

organotypic reconstructed three-dimensional model of the human epidermis

Justification for test system used:

Ths test method is able to detect chemicals that cause skin irritation, i.e. produce reversible daamage to the skin and allows for hazard identification in accordance with UN GHS category 2.

Vehicle:

other: Dulbecco's Phosphate Buffrered Saline (DPBS)

Details on test system:

This test used the EpiDerm TM reconstructed human epidermis model (MatTk) which consists of human keratinocytes (NHEK) and therefore represents in vitro the target organ of the species of ntrest and closely mimics the biochemical and physiological properties of the upper parts of the human, i.e. the epidermis.

Control samples:

yes, concurrent negative control

yes, concurrent vehicle

yes, concurrent positive control

Amount/concentration applied:

25 mg test substance in 25 µL DPBS

Duration of treatment / exposure:

60 ± 1 min

Duration of post-treatment incubation (if applicable):

Post-treatment incubation period: 42 ± 4 h

Number of replicates:

The test was performed in triplicates for each treatment and control group.

Test system

Details on study design:

3 replicate tissues are dosed with the test item, the negative control (DPBS) and the positive control (5% SDS), respectively. The tissues are incubated for 35 ± 1 minutes in a humidified incubator (37 ± 1 °C, 5 ± 1% CO2, 95% RH) and further 25 minutes at room temperature. Then the test item and the controls are rinsed off with DPBS and the tissues are post-incubated for 24 ± 2 h and, after medium renewal, for further 18 ± 2 h. Then the tissues are stained via MTT for 3 hours. Isopropanol extracts are measured photometrically at 550 nm.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Negative control / 60 min exposure / mean

Value:

>= 100

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Positive control / 60 min exposure / mean

Value:

ca. 2.2

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

5 % SDS

Remarks on result:

positive indication of irritation

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

test item/ 60 min exposure/ mean

Value:

ca. 6.2

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

The test item showed no direct MTT reducing capability and no colouring potential.

Any other information on results incl. tables

Name	Negative Control			Positive Control			Test Item
Tissue	1	2	3	1	2	3	1	2	3
corrected OD550	2.171	2.167	2.186	0.052	0.048	0.044	0.094	0.172	0.132
	2.111	2.203	2.114	0.050	0.046	0.048	0.099	0.176	0.134
mean corrected OD550 of the duplicates	2.141	2.185	2.150	0.051	0.047	0.046	0.097	0.174	0.133
mean corrected OD550 of 3 replicate tissues	2.159*			0.048			0.134
mean SD OD550		0.038			0.003			0.035
tissue viability [%]	99.2	101.2	99.6	2.4	2.2	2.1	4.5	8.1	6.2
SD tissue viability [%]***	1.1			0.1			1.8
CV [% viability]		1.1			5.5			28.7
mean tissue viability [%]	100.0			2.2**			6.2

^*       Corrected mean OD₅₅₀ of the negative control corresponds to 100% absolute tissue viability.

^**      mean relative tissue viability of the three positive control tissues is ≤ 20%

^***    standard deviation (SD) obtained from the three concurrently tested tissues is < 18%

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: Skin Irrit. 2, H315
DSD: Xi, R38

Executive summary:

In the present study the skin irritant potential of Sodium methyl-4-hydroxybenzoate was analysed. The EpiDerm TM-Standard Model (EPI-200 TM), a reconsituted three-dimensional human epidermis model, was used as a replacement of the Draize skin irritation test (OECD 404) to distinguish between UN GHS and EU CLP "Category 2" skin irritating test substances and not categorized test substances ("no category") which may be considered as non-irritant. Hereby, the test item was applied topically, cytotoxicity is expressed as the reduction of mitochondrila dehydrogenase activity measured by formazan production from MTTafter a 60 min exposure and 42 h post incubation period and compared to those of the concurrent negative controls. In this study under the given conditions the test item showed irritant effects. The relative mean tissue viability after 60 min of exposure and 42 h post incubation was < 50%. The test item is therefore classified as "irritant" in accordance with UN GHS and EU CLP "Category 2".