Reaction product of 9-Octadecenoic acid, (Z)-, sulfonated, potassium salts, hydrogen peroxide and sulfuric acid

Endpoint summary

Description of key information

PSOA is corrosive in a in vitro study (OECD 431) by means of the Human Skin Model Test (human skin model EST-1000™). 

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-05-18 to 2011-05-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study with GLP

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for Testing of Chemicals 431: In vitro Skin Corrosion: Human Skin Model Test (Original Guideline adopted April 13, 2004).

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

Version / remarks:

May 31, 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: three-dimensional human epidermis skin model EST-1000™

Strain:

other: three-dimensional human epidermis skin model EST-1000™

Details on test animals or test system and environmental conditions:

EST-1000™kits were purchased from CellSystems® Biotechnologievertrieb GmbH (53842 Troisdorf, Germany). The EST-1000™ tissue consisted of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis. It consisted 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 EST-1000™ tissues (surface 0.6 cm²) were cultured on specially prepared cell culture inserts (MILLICELLs, 10 mm diameter).

Type of coverage:

other: human epidermis skin model

Preparation of test site:

other: human epidermis skin model

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

Due to its creamy consistency it was not possible to weigh in exact amounts of the test item. Therefore, an amount of about 110 mg was weighed, parted into four parts, and applied to the concerning tissues by means of the concave part of a bent spoon spatula and spread evenly over the surface of the tissue.

Duration of treatment / exposure:

3 minutes and 1 hour

Observation period:

Not applicable as in vitro test.

Number of animals:

Not applicable as in vitro test. Duplicate EST-1000™ tissues were exposed to the test item.

Details on study design:

Pre-warming of EST-1000™ Tissues

At least one hour before dosing the EST-1000™ tissues were removed from the refrigerator. Under sterile conditions using sterile forceps, the inserts were transferred into 6-well plates containing the pre-warmed medium.

Exposure

Duplicate EST-1000™ tissues were exposed to the test item, positive control or negative control for each of two different exposure periods: 3 minutes and 1 hour.
After the pre-incubation of the EST-1000™ tissues was completed (approximately 2 hours for the 1 hour exposure and 3 hours for the 3 minutes exposure) the medium in each well was replaced by 1.0 mL fresh medium per well. The negative control (50 μL deionised water) was added to the surface of duplicate EST-1000™ tissues. Subsequently, the remaining tissues were exposed to the test item and the positive control in the same
manner. At the end of the exposure period the tissues were gently rinsed using a wash bottle containing PBS to remove any residual test material.

MTT Assay

Two 24-well plates were prepared before the end of the tissue pre warming period. MTT solution (300 μL) was added to each well and the plates were kept in an incubator (37 ± 1.5 °C, 5 ± 0.5% CO2) until required.
After the exposure procedure was completed for all tissues of each time point, the cell culture inserts were transferred from the holding plates to the MTT-plates. After a 3 hour incubation period (37 ± 1.5 °C, 5 ± 0.5% CO2) the MTT solution was aspirated from the wells and the wells were rinsed three times with PBS. The inserts were transferred into new 24-well plates. The inserts were immersed in extractant solution by gently pipetting
2 mL of extractant solution (isopropanol) into each insert ensuring that the tissue was completely covered.
The formazan salt was extracted for about 18 hours. After the extraction period the inserts were pierced with an injection needle to allow the extract to run into the well from which the insert was taken, and the insert was discarded. 24-well plates were then placed on a shaker for approx. 15 minutes until the solution was homogeneous in colour. The optical density (OD) was read in a microplate reader (Versamax® Molecular Devices, 85737 Ismaning, Germany) at 570 nm (OD570) without reference filter. The mean values were calculated for each set of 3 wells per tissue
insert.

Irritation / corrosion parameter:

other: other: viabiliy

Value:

44

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 3 min. Max. score: 0.0. Reversibility: other: not applicable. Remarks: Score in % viability . (migrated information)

Irritation / corrosion parameter:

other: other: viability

Value:

1.2

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 1 hour. Max. score: 0.0. Reversibility: other: not applicable. Remarks: Score in % viability . (migrated information)

Interpretation of results:

corrosive

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In conclusion, it can be stated that in this study and under the reported experimental conditions, the test item PSOA was corrosive to skin.

Executive summary:

This in vitro study was performed to assess the corrosive potential of PSOA by means of the Human Skin Model Test. Independent duplicate tissues of the human skin model EST-1000™ were exposed to the test item, the negative control or the positive control for 3 minutes and 1 hour, respectively. The test item was applied to the concerning tissues and spread evenly over the surface of the tissue. A volume of 50 μL of either the negative control (deionised water) or the positive control (8.0 N KOH) was applied to each tissue. After exposure to the negative control the absorbance values exceeded the required acceptability criterion of mean OD570 ≥ 0.8 for both treatment intervals thereby confirming the acceptable quality of the tissues. Exposure to the positive control induced a decrease in the relative absorbance as compared to the negative control, both for the 3 minutes exposure period and for the 1 hour exposure period thus confirming the validity of the test system. After exposure to the test item PSOA the relative absorbance values decreased to 44.0% after 3 minutes. After the 1 hour exposure relative absorbance values were reduced to 1.2%. Both values exceeded the threshold for corrosivity of 50% for the 3 minutes exposure and 15% for the 1 hour exposure. Therefore, the test item was considered to be corrosive.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin

The corrosive potential of PSOA was assessed by means of an vitro study using the Human Skin Model Test according to OECD 431. Independent duplicate tissues of the human skin model EST-1000™ were exposed to the test item, the negative control or the positive control. The test item was applied to the concerning tissues and spread evenly over the surface of the tissue. A volume of 50 μL of either the negative control (deionised water) or the positive control (8.0 N KOH) was applied to each tissue. Exposure to the positive control induced a decrease in the relative absorbance as compared to the negative control. After exposure to the test item PSOA the relative absorbance values decreased to 44.0% after 3 minutes. After the 1 hour exposure relative absorbance values were reduced to 1.2%. Both values exceeded the threshold for corrosivity of 50% for the 3 minutes exposure and 15% for the 1 hour exposure. Therefore, the test item was considered to be corrosive, which is in line with prediction based on chemical composition and pH value.

Since the PSOA was determined to be corrosive in the in-vitro test, no study was performed in-vivo.

Eye

In accordance with column 2 of REACH Annex VII, the test on eye irritation (required in section 8.2) does not need to be conducted as the available information indicates that the criteria are met for classification as corrosive to the skin. In conclusion, no further testing is required in accordance with animal welfare reasons.

Justification for selection of skin irritation / corrosion endpoint:
Only one study is available

Effects on skin irritation/corrosion: corrosive

Justification for classification or non-classification

Based on positive in vitro skin corrosion test, PSOA is classified as skin corrosive (C, R35) according to Directive 67/548/EEC (DSD) and as skin corrosive cat. 1A (H314) according to Regulation (EC) No 1272/2008 (CLP).

Based on the skin corrosive effects PSOA is classified as severely eye damaging (Xi, R41) according to Directive 67/548/EEC (DSD) and as severely eye damaging cat. 1 (H318) according to Regulation (EC) No 1272/2008 (CLP).