Octan-1-ol, ethoxylated

Endpoint summary

Description of key information

Skin irritation / corrosion (in vitro, OECD 431): corrosive

Conclusion based on data obtained with octan-1-ol, ethoxylated (CAS No. 27252-75-1, EC No. 500-058-1).

Eye irritation: serious eye damage

A study for eye irritation is not required for octan-1-ol, ethoxylated (CAS No. 27252-75-1, EC No. 500-058-1) according to the REACH Regulation (EC) No. 1907/2006, Annex VII, Section 8.2, Column 2, because the substance is classified as skin corrosion, leading to classification as serious eye damage (Category 1).

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:

06 - 08 Mar 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

adopted 29 Jul 2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Medicines and Healthcare Products Regulatory Agency, Department of Health, London, United Kingdom

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

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: EpiDermTM reconstituted three-dimensional human epidermis (EPI-200)

Source strain:

not specified

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDermTM tissues (MatTek Corporation)
- Tissue batch number: 28646

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 °C for 3 min and 37 °C for 60 min in the incubator

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: Washing was achieved by filling and emptying each tissue under a constant soft stream of Dulbecco’s Phosphate Buffered Saline (DPBS) (without Ca2+ Mg2+) for approximately 40 seconds, to gently remove any residual test item. Excess DPBS was removed by blotting the bottom of the tissue insert with tissue paper. Each tissue was placed into the prepared holding plate until all tissues were rinsed.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 h at 31 °C
- Spectrophotometer: Labtech LT-4500 microplate reader
- Wavelength: 570 nm

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
The test item was able to directly reduce MTT. Therefore, an additional test using freeze-killed tissues was performed. The results obtained showed negligible interference due to direct reduction of MTT. It was therefore considered unnecessary to quantitatively correct the results.

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount applied: 50 µL

NEGATIVE CONTROL
- Amount applied: 50 µL

POSITIVE CONTROL
- Amount applied: 50 µL
- Concentration: 8.0 N in deionised water

Duration of treatment / exposure:

3 and 60 min

Number of replicates:

duplicates for each treatment and control group (3 and 60 min

Irritation / corrosion parameter:

% tissue viability

Remarks:

mean value of 2 tissues

Run / experiment:

3 min exposure

Value:

34.7

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Remarks:

mean value of 2 tissues

Run / experiment:

60 min exposure

Value:

9.4

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

OTHER EFFECTS:
- Direct-MTT reduction: The test substance was directly reducing MTT. Therefore, an additional test with freeze-killed tissues was performed. The interference was considered negligible, thus a correction of results has not been performed.
- Colour interference with MTT: The test substance was not colour interfering with water. Thus, an additional test with viable tissues was not performed.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The mean OD 570 nm of the tissue replicates treated with the negative control is 2.079 for the 3 min exposure and 2.044 for the 60 min exposure and matches the required acceptability criterion.
- Acceptance criteria met for positive control: Mean relative tissue viability is ≤ 20%. Treatment with the positive control for 60 min resulted in a relative mean tissue viability of 2.9% and matches the required acceptability criterion.
- Acceptance criteria met for variability between replicate measurements: In the range 20 to 100% viability the coefficient of variation between the two tissue replicates did not exceed 30% and matches the acceptability criterion.

Table 1: Relative mean viabilities for all treatment groups:

Exposure Period	Percentage Viability
	Negative Control	Positive Control	Test Item
3 minute	100*	3.0	34.7
60 minute	100*	2.9	9.4

* The mean viability of the negative control tissues was set to 100%

Table 2: Mean OD570 and viabilities for the negative control, positive control and the test item

Tissue	Exposure Period	MeanOD570of individual tissues	Mean OD570of duplicate tissues	Standard Deviation	Coefficient of Variation (%)	Relative Mean Viability (%)
Negative Control	3 Minutes	2.043	2.079	0.051	5.4	100*
		2.115
	60 Minutes	2.042	2.044	0.002	0.1
		2.045
Positive Control	3 Minutes	0.061	0.063	0.003	na	3.0
		0.065
	60 Minutes	0.059	0.060	0.001	na	2.9
		0.061
Test Item	3 Minutes	0.697	0.722	0.035	4.9	34.7
		0.747
	60 Minutes	0.210	0.192	0.026	13.7	9.4
		0.173

OD = Optical density

* = The mean percentage viability of the negative control tissue is set at 100%

na = Not applicable

Interpretation of results:

other: Skin corr. 1, H314. Classification according to Regulation (EC) No. 1272/2008 (CLP/EU GHS).

Conclusions:

CLP: Skin corrosive category 1 (H314). Classification according to Regulation (EC) No. 1272/2008 (CLP/EU GHS).

Executive summary:

Under the conditions of the test, the test item was shown to have a corrosive potential towards reconstructed human epidermis tissue in the EpiDerm^TM prediction model. Based on this result, the substance is considered to meet the criteria for classification as Skin corrosive 1, H314, according to the CLP Regulation (EC) No. 1272/2008.

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 irritation / corrosion

The skin corrosive properties of octan-1-ol, ethoxylated (CAS No. 27252-75-1, EC No. 500-058-1) were tested in an EpiDerm™ in vitro assay performed according to OECD guideline 431 under GLP conditions (Croda, 2019a). In this assay, skin corrosion is directly related to cytotoxicity which is determined by the reduction of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to formazan by viable cells in the test item treated tissues relative to the corresponding negative control. Duplicate tissues were treated with the test item for exposure periods of 3 and 60 minutes.  Negative and positive control groups were treated for each exposure period. The test item was found to directly reduce MTT and therefore additional non-viable tissues were used for correction purposes. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT loading. After MTT loading each tissue was placed in 2 mL of isopropanol to extract the MTT. At the end of the formazan extraction period each well was mixed thoroughly and triplicate 200 µL samples were transferred to the appropriate wells of a pre-labelled 96 well plate.  The optical density (OD) was measured at 570 nm (OD570). Data are presented in the form of percentage viability (MTT reduction in the test item-treated tissues relative to negative control tissues). The relative mean viabilities of the tissues treated with the test item were 34.7% and 9.4% for the 60 and 3 min exposure, respectively. The positive control substance (8.0N potassium hydroxide, KOH) reduced the cell viability to 3.0% and 2.9% after 60 and 30 min exposure, respectively. All quality criteria required for acceptance of results were satisfied. Based on the reduced cell viabilities observed, the test item was considered to be corrosive in this in vitro assay.

Eye irritation

Data on eye irritation are not required for octan-1-ol, ethoxylated (CAS No. 27252-75-1, EC No. 500-058-1) because the substance is classified as corrosive to skin, leading to classification as serious eye damage (Category 1). For a detailed evaluation of the eye irritation potential of the substances in the AE category, please refer to the category justification attached to the category object.

Justification for classification or non-classification

The available data on skin corrosion obtained with octan-1-ol, ethoxylated (CAS No. 27252-75-1, EC No. 500-058-1) meet the criteria for classification according to the CLP Regulation (EC) No. 1272/2008. As a result of the classification for skin corrosion, the substance needs also to be classified for serious eye damage. In conclusion, octan-1-ol, ethoxylated (CAS No. 27252-75-1, EC No. 500-058-1) is therefore classified as Skin Corr. 1 and Eye Damage 1 (H314).