Reaction mass of 1,1'-oxybis(ethylbenzene) and Styrene, oligomers

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014-2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to OECD and GLP guidelines, and was considered to be relevant, adequate and reliable.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

yes

Remarks:

see textbox below

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU method B.40 bis (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

yes

Remarks:

see textbox below

Principles of method if other than guideline:

The inter-tissue variability in viability between two tissues and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues treated with the positive control were above the acceptability criteria (up to 32.1 and 19.2%, respectively at the 3-minute treatment period). The mean viability of two tissues and one of the two tissues treated with the positive control was above the acceptability criteria (up to 17.5%, at the 1-hour treatment period).
Evaluation: Since all individual tissues of the positive control were clearly positive and intertissue variability in viability between two tissues and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues were just above the acceptance criteria of 30 and 15% respectively this deviation has no influence on the study integrity.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of (1,1’ oxybis(ethylbenzene) and styrene, oligomers

IUPAC Name:

Reaction mass of (1,1’ oxybis(ethylbenzene) and styrene, oligomers

Constituent 2

Reference substance name:

SMPO Heavy Ends

IUPAC Name:

SMPO Heavy Ends

Test material form:

liquid: viscous

Details on test material:

- Name of test material (as cited in study report): SMPO Heavy Ends; Reaction mass of (1,1’ oxybis(ethylbenzene) and styrene, oligomers
- Substance type: UVCB
- Physical state: Brown liquid
- Analytical purity: 100%
- Purity test date: No data
- Lot/batch No.: BC604 17-10-2014
- Expiration date of the lot/batch: No data
- Stability under test conditions: Not indicated
- Storage condition of test material: At room temperature protected from light

Test animals

Species:

other: in vitro

Details on test animals or test system and environmental conditions:

EpiDerm Skin Model (EPI-200, Lot no.: 21262 kit C and 20578 kit H for dead skin).
The model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis. It consists of organized 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. The EpiDerm tissues (surface 0.6 cm²) were cultured on polycarbonate membranes of 10 mm cell culture inserts.
Source: MatTek Corporation, Ashland MA, U.S.A.

Test system

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): The liquid test substance was applied undiluted (50 µL) directly on top of the tissue.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: mean tissue viability

Basis:

mean

Time point:

other: 3 minutes

Score:

94

Remarks on result:

other: 94% = 50%

Results 2

Irritation parameter:

other: mean tissue viability

Basis:

mean

Time point:

other: 1 hour

Score:

29

Remarks on result:

other: 29 % = 15% in combination with = 50 % atfter 3 minutes: non-corrosive

Any other information on results incl. tables

SMPO Heavy Ends was checked for colour interference and for possible direct MTT reduction by adding the test substance to MTT medium. Because a colour change by adding MTT-medium was observed it was concluded that SMPO Heavy Ends did interact with MTT. In addition to the normal 1-hour procedure, two freeze-killed tissues treated with test substance and two freeze-killed non treated tissues were used for the cytotoxicity evaluation with MTT.

The non-specific reduction of MTT by SMPO Heavy Ends was 27% of the negative control tissues.

The net OD of the treated freeze-killed tissues was subtracted from the ODs of the test substance treated viable tissues.

The mean absorption at 540 nm measured after treatment with SMPO Heavy Ends and controls are presented in Table 2.

The individual OD540 measurements are presented in Table 3.

Table 4 shows the mean tissue viability obtained after 3-minute and 1-hour treatments with SMPO Heavy Ends compared to the negative control tissues. Skin corrosion is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after the 3-minute and 1-hour treatments with SMPO Heavy Ends compared to the negative control tissues was 94% and 29% respectively. Because the mean relative tissue viability for SMPO Heavy Ends was not below 50% after 3 minutes treatment and not below 15% after 1 hour treatment SMPO Heavy Ends is considered to be not corrosive.

The absolute mean OD540 (optical density at 540 nm) of the negative control tissues was within the laboratory historical control data range. The maximum inter-tissue variability in viability between two tissues treated identically was less than 33% and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues was less than 20%, which is just above the acceptance criteria. However, since the response of all individual positive control tissues was clearly positive this indicates that the test system functioned properly.

Finally, it is concluded that this test is valid and that SMPO Heavy Ends is not corrosive in the in vitro skin corrosion test under the experimental conditions described in this report. 

.

 

Table 2. Mean absorption in the in vitro skin corrosion test with SMPO Heavy Ends

	3-minute application				1-hour application
	A (OD540)	B (OD540)	Mean (OD540)	SD	A (OD540)	B (OD540)	Mean (OD540)	SD
Negative control	1.525	4.590	1.558	± 0.046	1.551	1.683	1.617	± 0.093
SMPO Heavy Ends^(1)	1.505	1.415	1.460	± 0.064	0.437	0.497	0.467	± 0.043
Positive control	0.287	0.195	0.241	± 0.065	0.159	0.226	0.192	± 0.048

SD = Standard deviation

Duplicate exposures are indicated by A and B.

⁽¹⁾ The values are corrected for the non-specific MTT reaction.

In this table the values are corrected for background absorption (0.043). Isopropanol was used to measure the background absorption.

 

Table 3. Individual OD measurements at 540 nm

	3-minute application (OD540)		1-hour application (OD540)		1-hour application freeze-killed (OD540) treated			1-hour application freeze-killed (OD540) Non-treated
	A	B	A	B		A	B		A	B
Negative control OD540 measurement 1 OD540 measurement 2 OD540 measurement 3	1.511 1.589 1.606	1.637 1.619 1.644	1.565 1.626 1.592	1.730 1.717 1.732
SMPO Heavy Ends OD540 measurement 1 OD540 measurement 2 OD540 measurement 3	1.980 1.992 1.970	1.894 1.878 1.900	0.922 0.903 0.912	0.973 0.969 0.977		0.455 0.455 0.455	0.666 0.667 0.658		0.1257 0.1246 0.1248	0.129 0.130 0.129
Positive control OD540 measurement 1 OD540 measurement 2 OD540 measurement 3	0.326 0.328 0.337	0.239 0.239 0.237	0.200 0.204 0.202	0.276 0.265 0.267

OD = Optical density

Duplicate exposures are indicated by A and B.

 

Table 4. Mean tissue viability in the in vitro skin corrosion test with SMPO Heavy Ends

	3-minute application viability (percentage of control)	1-hour application viability (percentage of control)
Negative control	100	100
SMPO Heavy Ends	94	29
Positive control	15	12

 

Applicant's summary and conclusion

Interpretation of results:

other:

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

SMPO Heavy Ends is not corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.

Executive summary:

An in vitro skin corrosion test with SMPO Heavy Ends was applied using a human skin model (EpiDerm; EPI-200). The possible corrosive potential of SMPO Heavy Ends was tested through topical application for 3 minutes and 1 hour.

SMPO Heavy Ends was applied undiluted (50 µL) directly on top of the skin tissue. The positive control had a mean relative tissue viability of 15% after 3 minutes exposure. The absolute mean OD540 (optical density at 540 nm) of the negative control tissues was within the laboratory historical control data range. The maximum inter-tissue variability in viability between two tissues treated identically was less than 33% and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues was less than 20%, which is just above the acceptance criteria. However, since the response of all individual positive control tissues was clearly positive this indicates that the test system functioned properly.

Skin corrosion is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 3-minute and 1-hour treatments with SMPO Heavy Ends compared to the negative control tissues was 94% and 29%, respectively. Because the mean relative tissue viability for SMPO Heavy Ends was not below 50% after the 3-minute treatment and not below 15% after the 1-hour treatment SMPO Heavy Ends is considered to be not corrosive.

Finally, it is concluded that this test is valid and that SMPO Heavy Ends is not corrosive in the in vitro skin corrosion test under the experimental conditions described in this report.