Pentatriacontan-18-one

Endpoint summary

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

11.1 Deviations from the Study Plan
The following deviation from the study plan was documented:
The pre-incubation time was 1 hour, instead of 18 ± 3 hours overnight. This can be seen as uncritical, because the pre-incubation time must be at least 1 hour (in consultation with the tissue supplier; MatTek In Vitro Life Science Laboratories).

The deviation was assessed and signed by the study director on 08. Oct. 2018.
11.2 Deviations from the Guideline
The following deviation from the guideline was documented:
The pre-incubation time was 1 hour, instead of 18- 24 hours. This can be seen as uncritical, because the pre-incubation time must be at least 1 hour (in consultation with the tissue supplier; MatTek In Vitro Life Science Laboratories).

The deviation was assessed and signed by the study director on 08. Oct. 2018

Deviations:

yes

Remarks:

see Version/ remarks

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on animal used as source of test system:

The test system is a commercially available EpiDermTM-Kit, procured by MatTek.
The EpiDermTM tissue consists of human-derived epidermal keratinocytes which have been cultured to form a multi-layered, 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 representing main
lipid classes analogous to those found in vivo. The EpiDermTM tissues are cultured on specially prepared cell culture inserts.

Vehicle:

unchanged (no vehicle)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Tissue Amount
1 26.3 mg
2 25.5 mg
3 26.5 mg

Duration of treatment / exposure:

1 hour

Duration of post-treatment incubation (if applicable):

23 hours

Number of replicates:

3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Mean

Value:

107.6

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Designation Stearone Positive Control
% Tissue viability (tissue 1) 106.7% 4.1%
% Tissue viability (tissue 2) 110.6% 3.7%
% Tissue viability (tissue 3) 105.5% 3.3%
% Tissue viability (mean) 107.6% 3.7%
± SD of mean tissue viability (%) 2.7% 0.4%

  

  Skin Irritation Potential of the Test Item

The mean value of relative tissue viability of the test item was increased to 107.6% after the treatment. This value is above the threshold for skin irritation (50%). Therefore, the test item is considered as non-irritant to skin.

Validity criteria and results are stated in the following table:

Table 9.3-a     Validity

Criterion	Demanded	Found
Mean OD of negative control	≥ 0.8 and ≤ 2.8	1.6
Mean % tissue viability of positive control SDS	< 20% of negative control	3.7%
SD of mean viability of the tissue replicates (%)	≤ 18%	5.5% (negative control) 0.4% (positive control) 2.7% (test item)

 

All validity criteria were met.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item Stearone is considered as non-irritant to skin.
After the treatment, the mean value of relative tissue viability was increased to 107.6%. This value is above the threshold for skin irritation (50%). negative control was well within the required acceptability criterion

The positive control has met the acceptance criterion too, for thus ensuring the validity of the test system.
Variation within replicates was within the accepted range for negative control, positive control and test item (required: ≤ 18%).
For these reasons, the result of the test is considered valid.

Executive summary:

One valid experiment was performed.

Three tissues of the human skin model EpiDerm^TMwere treated with the test item for 60 minutes.

The test item was applied directly to each tissue and spread to match the tissue size (0.63 cm²; as indicated by the supplier).

DPBS-buffer was used as negative control and 5% SDS solution was used as positive control.

After treatment with the negative control, the mean absorbance value was within the required acceptability criterion of 0.8 ≤ mean OD ≤ 2.8, OD was 1.6. 

The positive control showed clear irritating effects. The mean value of relative tissue viability was reduced to 3.7% (required:<20%).

The variation within the tissue replicates of negative control, positive control and test item was acceptable (required: ≤ 18%). 

 

After the treatment with the test item, the mean value of relative tissue viability was increased to 107.6%. This value is above the threshold for skin irritation potential (50%). Test items that induce values above the threshold of 50% are considered non-irritant to skin. 

 

 

Therefore, the test item Stearone is considered non-irritant to skin in the Reconstructed human Epidermis (RhE) Test Method.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

human

Details on test animals or tissues and environmental conditions:

The EpiOcularTM tissue consists of normal, human-derived keratinocytes which have been cultured to form a stratified squamous epithelium similar to that found in the human cornea. It consists of highly organized basal cells. These cells are not transformed or transfected with genes to induce an extended life span. The EpiOcularTM tissues are cultured in specially prepared cell culture inserts with a porous membrane through which nutrients can pass to the cells. The tissue surface is 0.6 cm2.

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

Replicate Amount
Tissue 1 50.0 mg
Tissue 2 50.3 mg

Duration of treatment / exposure:

6 hours

Duration of post- treatment incubation (in vitro):

18 hours

Number of animals or in vitro replicates:

2

Irritation parameter:

in vitro irritation score

Run / experiment:

% Viability Mean

Value:

101.3

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Designation	Positive Control	Stearone
% Viability (Tissue 1)	39.3%	101.7%
% Viability (Tissue 2)	37.9%	100.9%
% Viability Mean	38.6%	101.3%

Criterion	Demanded	Found
Mean OD of negative control	>0.8 and < 2.5	1.6
% mean relative viability of positive control	< 50% of negative control	38.6%
Variation within replicates	< 20%	1.2% (negative control) 1.4% (positive control) 0.8% (test item)

 

Values for negative control and for positive control were within the range of historical data of the test facility .

 

Therefore, the experiment is considered valid.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the test, Stearone is considered non-eye irritant in the EpiOcular Eye Irritation Test.
After treatment with the test item, the mean value of relative tissue viability was 101.3%.
This value is well above the threshold for eye irritation potential (≤ 60%).
All validity criteria were met. The criterion for optical density of the negative control was fulfilled: The OD value was 1.6 (> 0.8 and < 2.5).
The positive control induced a decrease in tissue viability as compared to the negative control to 38.6%. Variation within the replicates of the controls and the test item was acceptable (< 20%).
For these reasons, the result of the test is considered valid

Executive summary:

One valid experiment was performed.

The test item Stearone was applied to a three-dimensional human cornea tissue model in duplicate for an exposure time of 6 hours.

 

After treatment, the respective substance was rinsed from the tissue; then, cell viability of the tissues was evaluated by addition of MTT, which can be reduced to formazan. The formazan production was evaluated by measuring the optical density (OD) of the resulting solution.

Demineralised water was used as negative control and methyl acetate was used as positive control.

The controls showed the following results: After treatment with the negative control, the absorbance values were within the required acceptability criterion of mean OD>0.8 and < 2.5, OD was 1.6. The positive control showed clear eye irritating effects, the mean value of the relative tissue viability was 38.6% (< 50%). 

Variation within tissue replicates of the controls and the test item was acceptable (< 20%).

 

After treatment with the test item, the mean value of relative tissue viability was 101.3%. This value is well above the threshold for eye irritation potential (≤ 60%). Test items that induce values above the threshold are considered non-eye irritant.

 

Under the conditions of the test, Stearone is considered non- eye irritant in the EpiOcular^TMEye Irritation Test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Skin irritation:

After the treatment with the test item, the mean value of relative tissue viability was increased to 107.6%. This value is above the threshold for skin irritation potential (50%). Test items that induce values above the threshold of 50% are considered non-irritant to skin. Therefore, the test item Stearone is considered non-irritant to skin in the Reconstructed human Epidermis (RhE) Test Method.

Eye irritation:

After treatment with the test item, the mean value of relative tissue viability was 101.3%. This value is well above the threshold for eye irritation potential (≤ 60%). Test items that induce values above the threshold are considered non-eye irritant. Under the conditions of the test, Stearone is considered non- eye irritant in the EpiOcular^TMEye Irritation Test.