Tall oil, sodium salt

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

3 August 2011 to 5 August 2011

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

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

13 April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Tall oil, sodium salt

EC Number:

266-037-1

EC Name:

Tall oil, sodium salt

Cas Number:

65997-01-5

Molecular formula:

Not applicable. UVCB substance.

IUPAC Name:

Alkaline Aqueous Extraction of sodium salts of fatty acids and rosin acids from the Kraft Pulping Process

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature in the dark
- Stability under test conditions: not specified
- Solubility and stability of the test substance in the solvent/vehicle: not specified
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not specified

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: no further treatment occurred.
- Preliminary purification step: n/a
- Final dilution of a dissolved solid, stock liquid or gel: n/a
- Final preparation of a solid: n/a

OTHER SPECIFICS:
- measurement of pH, osmolality, and precipitate in the culture medium to which the test chemical is added: n/a
- other information:

In vitro test system

Test system:

human skin model

Remarks:

Epiderm

Source species:

human

Details on animal used as source of test system:

EpiDerm Skin Model
Supplier: MatTek Corporation, Ashland, MA, USA
Date received: 3rd of August 2011
Lot number of the tissue: 15168
Lot number of the assay medium: 072811TTA

Justification for test system used:

N/a

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm
- Tissue batch number(s): 15168
- Production date: not specified
- Shipping date: not specified
- Delivery date: Received 3rd of August 2011
- Date of initiation of testing: 3rd of August 2011

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37°C
- Temperature of post-treatment incubation: 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: one time, unknown volume.
- Observable damage in the tissue due to washing: not specified
- Modifications to validated SOP: not specified

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 5.0 mg/ml
- Incubation time: 3 hours
- Spectrophotometer: yes
- Wavelength: 540 nm
- Filter: not specified
- Filter bandwidth: not specified
- Linear OD range of spectrophotometer: not specified

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: yes, viable
- Barrier function: not specified
- Morphology: not specified
- Contamination: not specified
- Reproducibility: not specified

NUMBER OF REPLICATE TISSUES: Duplicate tissues used in 3-minute and 60-minute exposure. Duplicate negative and positive control tissues were also used.

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- Fresh tissues / killed tissues : Freeze-killed tissue were used for the MTT viability assay
- Procedure used to prepare the killed tissues: untreated EpiDerm tissues were placed in a freezer (-14 to -30°C) at least overnight
- No of replicates: Duplicate
- Method of calculation used: the relative mean viability was the mean obtained OD540 of the test item divided by the obtained mean of OD540 of the negative control and multiplied by 100.

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: Two

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the viability is ≥50 % after 3 minutes exposure and ≥15 % after 60 minutes exposure.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied: 50 µL of test item

NEGATIVE CONTROL
- Sterile distilled water

POSITIVE CONTROL
- 8 N potassium hydroxide

Duration of treatment / exposure:

3 and 60 minutes respectively

Duration of post-treatment incubation (if applicable):

Straight after exposure period, the tissues were rinsed and incucated for 3 hours during the MTT assay

Number of replicates:

duplicate cultures

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min exposure

Value:

101.9

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 min exposure

Value:

55.9

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
- Direct-MTT reduction: yes
- Colour interference with MTT: not specified

DEMONSTRATION OF TECHNICAL PROFICIENCY: Yes

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes
- Acceptance criteria met for variability between replicate measurements: yes
- Range of historical values if different from the ones specified in the test guideline: n/a

Any other information on results incl. tables

Direct MTT Reduction:

The MTT solution containing the test item turned purple which indicated that the test item directly reduced MTT and therefore, the MTT viability assay was performed in parallel on viable and freeze-killed tissues.

Test item, positive control item and negative control item:

The mean OD540 values for the negative control, test item and positive control for the 3-Minute exposure period are given in Table 1 and for the 60-Minute exposure period in Table 2. The mean viabilities of the test item and positive control, relative to the corresponding negative control (i.e. same exposure time) are also given in each corresponding Table.

The relative mean viability of the test item treated tissues was 101.9% after the 3-Minute exposure period and 55.9% after the 60-Minute exposure period.

Quality criteria:

The mean OD540 of the two negative control tissues were 1.564 for the 3-Minute exposure period and 1.604 for the 60-Minute exposure period. These both met the test acceptance criteria.

A 3-Minute exposure period of 8.0 N Potassium Hydroxide revealed a mean relative tissue viability of 20.7%. The positive control acceptance criterion was therefore satisfied.

Table 1 - Mean OD540 Values and Percentage Viabilities for the Negative Control Item, Positive Control Item and Test Item (3-Minute exposure period)

Treatment	OD540 of individual tissues	Mean OD540 of duplicate tissues (tvt)	Mean OD540 of tissues corrected for MIT direct reduction tkt-ukt	Relative Mean Viability %
Negative Contr019	1.621	1.564	na	100*
	1.506
Positive Controlo	0.358	0.324	na	20.7
	0.289
Test Item	1.641	1.662	1.593	101.9

Corrected viability of treated killed tissues 0.152 (tkt) - 0.083 (ukt) = 0.069

 

Table 2 - Mean OD540 Values and Percentage Viabilities for the Negative Control Item, Positive Control Item and Test Item (60-Minute Exposure Period

Treatment		OD540 of individual tissues	Mean OD540 of duplicate tissues (tvt)	Mean OD540 of tissues corrected for MTT direct reduction tkt-ukt	Relative Mean Viability %
Negative ControlC		1.609	1.604	na
		1 598
Positive ControlC		0.199	0.169	na	10.5
		0.139
Test Item		0.907	1.066	0.896	55.9

Corrected viability of treated killed tissues 0.313 (tkt) - 0.143 (ukt) = 0.170

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an in vitro skin corrosion study using Epiderm Human Skin Models, conducted according to OECD Test Guideline 431 and in compliance with GLP, it was concluded that TOS E is not corrice to skin.

Executive summary:

In an in vitro skin corrosion study using Epiderm Human Skin Models, conducted according to OECD Test Guideline 431 and in compliance with GLP, it was concluded that TOS E is not corrosive to skin. This was based on obtained values of 101.9 % tissue viability following 3 minutes exposure and 55.9 % tissue viability following 60 minutes exposure. To be considered as non-corrosive, a cell viability of ≥ 50% is required following 3 minutes exposure and ≥15 % following 60 minutes exposure. The tested positive and negative controls were considered to be valid.