2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptan-1-ol

Endpoint summary

Description of key information

OECD Toolbox v. 4.3.1: no alert for skin sensitization in silico

DPRA (OECD TG 442C): no peptide reactivity in chemico

h-CLAT (OECD TG 442D): no activation of dendritic cells in vitro

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in chemico

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))

Version / remarks:

adopted in June 2019

Qualifier:

according to guideline

Guideline:

other: EU Method B.59

Version / remarks:

adopted in February 2017

GLP compliance:

yes (incl. QA statement)

Type of study:

direct peptide reactivity assay (DPRA)

Details on the study design:

Skin sensitisation (In chemico test system) - Details on study design:
The Direct Peptide Reactivity Assay (DPRA) is an in chemico procedure proposed to address the molecular initiating event leading to skin sensitization, namely protein reactivity, by quantifying the reactivity of test chemicals towards model synthetic peptides containing either lysine or cysteine. Cysteine and lysine percent peptide depletion values are then calculated and used in a prediction model to categorize a substance in one of four classes of reactivity for supporting the discrimination between skin sensitizers and non-sensitizers.
For comparison, tests were performed with the test item, the vehicle (solvent control = negative control) and the known sensitizer Cinnamic aldehyde (positive control).

The DPRA quantifies the remaining concentration of cysteine- or lysine-containing peptide following 24 hours incubation with the test item at 25 +/-2.5 ºC. Relative peptide concentration is measured by reversed phase (C18) high-performance liquid chromatography (HPLC) with gradient elution and UV detection at 220 and 258 nm. The synthetic peptides contain phenylalanine to aid in the detection.
The test item was dissolved and tested according to the given test procedure. Cinnamic aldehyde was used as positive control at a concentration of 100 mmol/L in acetonitrile.

Cysteine and lysine peptide solutions were incubated at 1:10 and 1:50 ratio in glass auto sampler vials with the test item solution for 24 hours at 25 ± 2.5 °C in the dark. Samples were visually inspected for precipitation or phase separation before HPLC analysis. The test item was analyzed in triplicate for both peptides. The HPLC run sequence was set up in order to keep the HPLC analysis time less than 30 hours. HPLC analysis for the cysteine and lysine peptides were performed on separate days with the test item solutions freshly prepared for both assays on each day.

The concentrations of cysteine or lysine peptide were photometrically determined at 220 nm in each sample by measuring the peak area (area under the curve, AUC) of the appropriate peaks and by calculating the concentration of peptide using the linear calibration curve derived from the standards. Percent peptide depletion is calculated according to OECD Guideline.

Acceptance criteria:
The following criteria must be met for a run to be considered valid:
a) The standard calibration curve should have an r2 > 0.99.
b) The mean percent peptide depletion value of the three replicates for the positive control cinnamic aldehyde should be between 60.8% and 100% for the cysteine peptide and between 40.2% and 69.0% for the lysine peptide and the maximum standard deviation (SD) for the positive control replicates should be < 14.9% for the percent cysteine depletion and < 11.6% for the percent lysine depletion.
c) The mean peptide concentration of reference controls A should be 0.50 ± 0.05 mM and the coefficient of variation (CV) of peptide peak areas for the nine reference controls B and C in acetonitrile should be <15.0%.
If one or more of these criteria is not met, the run would have been repeated.
The following criteria must be met for a test item’s results to be considered valid:
a) The maximum standard deviation for the test item replicates should be < 14.9% for the percent cysteine depletion and < 11.6% for the percent lysine depletion.
b) The mean peptide concentration of the three reference controls C in the appropriate solvent should be 0.50 ± 0.05 mM.
If these criteria were not met, the data would have been rejected and the run have been repeated for that specific test item.

According to the study protocol the mean percent cysteine and percent lysine depletion value was calculated for the test item and the positive control. Negative depletion was considered as “0” when calculating the mean. By using the cysteine 1:10/lysine 1:50 prediction model, the threshold of 6.38 % average peptide depletion can be used to support the discrimination between skin sensitizers and non-sensitizers in the framework of an IATA.

Positive control results:

The positive control cinnamic aldehyde led to a depletion of 69.52 % cysteine peptide and 55.87 % lysine peptide. These values are within the required range of 60.8% and 100% for the cysteine peptide and between 40.2% and 69.4% for the lysine peptide. The maximum standard deviation (SD) for the positive control replicates was < 14.9% for the percent cysteine depletion and < 11.6% for the percent lysine depletion.

Run / experiment:

other: mean of 2 runs

Parameter:

other: % depletion in the cysteine 1:10/lysine 1:50 prediction model:

Value:

1.43 %

Vehicle controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Remarks:

DPRA prediction: negative

Parameter:

cysteine depletion

Value:

2.86 %

Vehicle controls validity:

valid

Positive controls validity:

valid

Parameter:

lysine depletion

Value:

0 %

Vehicle controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

DEMONSTRATION OF TECHNICAL PROFICIENCY:
The acceptance criteria for a DPRA test to be considered valid were met.
The linearity of the standard calibration curve was r2 = 1.0000 for cysteine peptide and r2 = 0.9999 for lysine peptide. Hence the requirement of r2 > 0.99 was met.
The mean peptide concentrations of reference control A were 0.505 mM for cysteine peptide or 0.493 mM for lysine peptide, and, hence well within the accepted range of 0.50 ± 0.05 mM and the coefficient of variation (CV) of peptide peak areas for the nine reference controls B and C was <15.0%.
The acceptance criteria of validity described were fulfilled in this test system.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for vehicle control: yes
- Acceptance criteria met for positive control: yes

The test item was completely dissolved and stable in acetonitrile at a concentration of 100 mM. The formulation analysis performed at LPT resulted in actual levels of 1H,1H,7H-perfluoroheptane-1-ol of 93.9% of the nominal concentrations determined via GC-FID.
No precipitate in the reaction mixture at the end of the incubation time and no co-elution were observed.

Results of the DPRA:

Test item	Mean % Cysteine peptide depletion	Mean % Lysine peptide depletion	Mean % Cysteine/Lysine peptide depletion	reactivity class	DPRA prediction
positive control (cinnamic aldehyde)	69.52	55.87	62.70	high	positive
test item	2.86	0	1.43	minimal	negative

No precipitation was observed after the incubation period.

Interpretation of results:

other: negative

Executive summary:

The Direct Peptide Reactivity Assay (DPRA; OECD 442C) is an in chemico procedure proposed to address the molecular initiating event leading to skin sensitization, namely protein reactivity, by quantifying the reactivity of test chemicals towards model synthetic peptides containing either lysine or cysteine. Cysteine and lysine percent peptide depletion values are then calculated and used in a prediction model to categorize a substance in one of four classes of reactivity for supporting the discrimination between skin sensitizers and non-sensitizers.

Since the test item visually appeared a clear solution in acetonitrile at the test concentration of 100 mmol/L this solvent was used in the DPRA. No precipitaton of the test item occured after incubation and no co-elution was observed. The cysteine 1:10/lysine 1:50 prediction model was applied to the test item. No relevant depletion of cysteine and lysine peptides became obvious in the DPRA (1.43 % peptide depletion). According to the prediction model “minimal reactivity” was derived for the test item in water, leading to a DPRA prediction of “negative“.

Reference 2

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD TG 442E (In vitro skin sensitization: human cell line activation test (h-CLAT)

Version / remarks:

adopted in June 2018

GLP compliance:

yes (incl. QA statement)

Type of study:

activation of dendritic cells

Details on the study design:

Skin sensitisation (In vitro test system) - Details on study design:
The h-CLAT assay is an in vitro assay that quantifies changes of cell surface marker expression (i.e. CD86 and CD54) on a human monocytic leukaemia cell line, THP-1 cells, following 24 hours exposure to the test chemical. These surface molecules are typical markers of monocytic THP-1 activation and may mimic DC activation, which plays a critical role in T-cell priming. The changes of surface marker expression are measured by flow cytometry following cell staining with fluorochrome-tagged antibodies. Cytotoxicity measurement (by analysing the propidium iodide (PI) uptake) is also conducted concurrently to assess whether upregulation of surface marker expression occurs at sub-cytotoxic concentrations. The relative fluorescence intensity of surface markers compared to the solvent/vehicle control are calculated and used in the prediction model to support the discrimination between sensitisers and non-sensitisers.

Specifications:
The human monocytic leukaemia cell line, THP-1 (TIB-202™, ATCC) was used for performing the h-CLAT assay.

Preparation of Cultures:
THP-1 cells were incubated at 37 °C under 5 % CO2 and humidified atmosphere in RPMI-1640 medium2 supplemented with 10 % fetal calf serum (FCS)3, 0.1 % 2-mercaptoethanol4, 100 units/mL penicillin5, and 100 μg/mL streptomycin4. THP-1 cells were routinely seeded every 2-3 days at the density of 0.1 to 0.2 x 10 EE6 cells/mL. They were maintained at densities of 0.1 to 1.0 x 106 cells/mL. Prior to using them for testing, the cells were qualified by conducting a reactivity check. The reactivity check of the cells was performed using the positive controls (2,4-dinitrochlorobenzene (DNCB) and nickel sulfate (NiSO4)) and the negative control (lactic acid (LA)) at the earliest two weeks after thawing. Both DNCB and NiSO4 produce a positive response (upregulation) of both CD86 and CD54 cell surface markers; LA produces a negative response of both CD86 and CD54 cell surface markers. Only the cells which have passed the reactivity check were used for the assay. Cells can be propagated up to two months after thawing. Cells should not exceed 30 passages after thawing. The reactivity check was performed according to the procedures described below.
For testing, THP-1 cells were seeded at a density of either 0.1 x 10 EE6 cells/mL or 0.2 x 10 EE6 cells/mL, and pre-cultured in culture flasks for 72 or 48 hours, respectively. It is important that the cell density in the culture flask just after the pre-culture period is as consistent as possible in each experiment, because the cell density in the culture flask just after pre-culture could affect the CD86/CD54 expression induced by allergens. On the day of testing, cells harvested from the culture flask were resuspended with fresh culture medium at 2 x 106 cells/mL. Then, cells were distributed into a 24-well flat-bottom plate with 500 μL per well (1 x 10 EE6 cells/well).

Dose finding assay:
A dose finding assay was performed to determine the CV75, being the test item concentration that results in 75 % cell viability (CV) compared to the solvent/vehicle control. The CV75 value was used to determine the concentration of test items for the CD86/CD54 expression measurement. The CV75 was calculated as 218.8 μg/mL and 262.6 μg/mL (1,2 x CV75) was chosen as the maximum test concentration for the main experiment.

Preparation of test and control items:
1H,1H,7H-perfluoroheptane-1-ol was completely dissolved in dimethyl sulfoxide (DMSO). Fresh preparations of the test and control items were used for the treatment. The final concentration of the vehicle in the culture system did not affect cell viability or growth rate.

For the h-CLAT assay, the stock solution of the test item in DMSO was diluted as follows: A solution of 500 mg/mL was prepared and then further diluted 250-fold into culture medium (working solutions). Inhomogeneous test item precipitation was noted macroscopically after addition at 2000 μg/mL. This working solution was homogenised using a 20 g cannula. Due to the limited solubility of the test item an expanded testing of the temporal stability and solubility of the test item in the solvent DMSO in treatment medium was analysed after 3, 8 and 24 h incubation at 37 °C for 2000, 1000 and 500 μg/mL. At 1000 μg/mL the test item was dissolved after 24 h incubation, but not after 3 and 8 h incubation time. The test item was dissolved at concentrations 500 μg/mL and lower. Therefore, 1000 μg/mL was chosen as top concentration. Based on the working solution of 2000 μg/mL seven additional dilutions (in total eight concentrations) were prepared, by two-fold serial dilution using the corresponding solvent/vehicle (medium with DMSO). The working solutions were used for exposure by adding an equal volume of working solution to the volume of THP-1 cell suspension in the plate to achieve a further two-fold dilution and a final range of concentrations in the plate of 7.8 – 1000 μg/mL. At 1000 μg/mL medium test item precipitation was noted macroscopically at the start of the incubation.

The solvent DMSO was tested at a single final concentration in the plate of 0.2%. The control had undergone the same dilution steps as described for the working solutions which is known to not affect cell viability and corresponds to the same concentration of DMSO found in the test item and in the positive control.

Treatment:
The culture medium or working solutions described in section 5.2.1 were mixed 1:1 (v/v) with the cell suspensions prepared in the 24-well flat-bottom plate. The treated plates were incubated for 24 ± 0.5 hours at 37°C under 5% CO2.

Propidium ioidide (PI) staining:
After 24 ± 0.5 hours of exposure 200 μL of each cell-preparation was transferred into a 96-well round-bottom plate and cells were collected by centrifugation (at 250 g for 5 minutes at 4°C). The supernatants were discarded and the remaining cells were washed twice with washing buffer (0.1% BSA7 in DPBS8). Cell pellets were resuspended in 200 μL washing buffer. Shortly prior to analysis propidium iodide solution was added (final concentration of PI: 1 μg/mL).

Cytotoxicity Assessment:
The propidium iodide (PI) uptake was analysed using flow cytometry10 with the acquisition channel B3-A. A total of 10 000 living cells (PI negative) were acquired. When the cell viability is low, up to 30 000 cells including dead cells were acquired. Alternatively, data can be acquired for one minute after the initiation of the analysis. The cell viability was calculated using the following equation by the cytometer analysis program.

Cell viability = Number of living cells/Total number of acquired cells x 100

The CV75 value, i.e. a concentration showing 75% of THP-1 cell survival (25% cytotoxicity), was calculated by log-linear interpolation using the following equation:

Log CV75 = (75 - c) x log (b) - (75 - a) x log (d) / a - c
where:
a is the minimum value of cell viability over 75%;
c is the maximum value of cell viability below 75%;
b and d are the concentrations showing the value of cell viability a and c respectively.

Preparation of the test and control items
The solvent/vehicle DMSO as determined in the dose finding assay was used to dissolve the test item. An average CV75 of 218.8 μg/mL and a 1.2 × CV75 of 262.6 μg/mL was determined in the dose finding assay. As the determined concentration inducing cytotoxicity in the preliminary experiment did not reveal cytotoxicity in a first main experiment (not included for evaluation), a higher concentration had to be set in the following repetitions. Hence, 1.2 × 1.2 × CV75 = 315.1 μg/mL was chosen as top concentration for the following repetitions. The test item was first diluted to the concentration corresponding to 2-fold of the 1.2 × 1.2 × CV75 in culture medium (stock solution). This stock solution was homogenised using a 20 g cannula. Then, 1.2-fold serial dilution was made using the corresponding solvent/vehicle (medium with DMSO) to obtain eight working dilutions in the range of 2 x 1.2 x 1.2 x CV75 to 2 x 1.2 x 1.2 x 0.279 x CV75. The working solutions were further diluted two-fold for use for exposure. 24-well plates were used for CD86/CD54 expression measurement.
Vehicle control: DMSO
Positive control: DNCB (2,4-dinitrochlorobenzene) was used as the positive control for CD86/CD54 expression measurement at a final single concentration of 4.0 μg/mL in the plate. To obtain a 4.0 μg/mL concentration of DNCB in the plate, a 2 mg/mL stock solution of DNCB in DMSO was prepared and further diluted 250-fold with culture medium to a 8 μg/mL working solution. The run acceptance criteria were the same as those described for the test item, except for the last acceptance criterion since the positive control is tested at a single concentration.

Application of test and control items:
For each test and control item, one experiment was needed to obtain a prediction. Each experiment consists of at least two independent runs for CD86/CD54 expression measurement. Each independent run was performed either on a different day or on the same day provided that for each run: a) independent fresh stock solutions and working solutions of the test item and antibody solutions were prepared and b) independently harvested cells were used (i.e. cells were collected from different culture flasks); however, cells may come from the same passage. Test and control items prepared as working solutions (500 μL) were mixed with 500 μL of suspended cells (1 x 106 cells) at 1:1 ratio, and cells were incubated for 24 ± 0.5 hours. In each run, a single replicate for each concentration of the test and control items were sufficient because a prediction was obtained from at least two independent runs.

Cell staining and analysis:
After 24 ± 0.5 hours of exposure, cells were transferred from the 24-well plate into sample tubes, collected by centrifugation (at 250 g for 5 minutes at 4 °C), and then washed with washing buffer. After washing, cells were blocked with 600 μL of blocking solution (washing buffer containing 0.01 % (w/v) globulin (Cohn fraction II, III, Human)) and incubated at 4 °C for 15 minutes. After blocking, cells were divided into three aliquots of 180 μL into a 96-well round-bottom plate or microtube.
After centrifugation, cells were stained with 50 μL of FITC-labelled anti-CD86, anti-CD54, or mouse IgG1 (isotype) antibodies at 4 °C for 30 minutes in the dark.
After washing with 200 μL of washing buffer twice, cells were resuspended in 200 μL washing buffer and stored until analysis at 4 °C. Shortly prior to analysis, PI solution (final concentration of PI is 1 μg/mL) were added. The expression levels of CD86 and CD54, and cell viability were analysed using flow cytometry.

Positive control results:

The assay aceptance criteria for the positive controls were met:
DNCB (2,4-dinitrochlorobenzene) was used as the positive control for CD86/CD54 expression measurement at a final single concentration of 4.0 μg/mL in the plate. The positive control was run in both experiments. All quality criteria for the vehicle control and the positive control required were fulfilled.
The RFI of the positive control was > 200 for CD 54 and > 150 for CD86 at viabilities of > 50%.

Run / experiment:

other: mean of 3 experiments

Parameter:

other: RFI (relative fluorescence intensitiy) of CD54

Value:

200

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Run / experiment:

other: mean of 2 experiments

Parameter:

other: RFI (relative fluorescence intensity) of CD86

Value:

150

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Other effects / acceptance of results:

DOSE RANGE FINDER:
A dose finding assay was performed to determine the CV75, being the test item concentration that results in 75% cell viability (CV) compared to the solvent/vehicle control. 1H,1H,7H-perfluoroheptane-1-ol was completely dissolved in DMSO. Eight dilutions (eight concentrations) were prepared and a final range of concentrations in the plate of 7.8 - 1000 μg/mL culture medium were tested. At 1000 μg/mL medium test item precipitation was noted macroscopically at the start of the incubation. DMSO was used as solvent control. The CV75 value was used to determine the concentration of test item for the CD86/CD54 expression measurement. In this preliminary experiment (consisting of two independent runs) a CV75 of 218.8 μg/mL and a maximum test concentration for the main experiment of 262.6 μg/mL was calculated. As the determined concentration inducing cytotoxicity in the preliminary experiment did not reveal cytotoxicity in a first main experiment (not included for evaluation), a higher concentration had to be set in the following repetitions. Therefore, 1.2 × 1.2 × CV75 = 315.1 μg/mL was chosen as top concentration for the following repetitions.

MAIN EXPERIMENT:
Hence, 1H,1H,7H-perfluoroheptane-1-ol was tested at 8 concentrations in the range from 88.8 to 315.1 μg/mL.

OTHER EFFECTS:
- Visible damage on test system: none

DEMONSTRATION OF TECHNICAL PROFICIENCY: proven

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

All assay acceptance criteria were met.

The h-CLAT prediction was considered negative as:

• The RFI of CD86 was below 150% at any tested concentration (with cell viability ≥ 50%) in all experiments;

• The RFI of CD54 was below 200% in the third and fourth experiment at any tested concentration (with cell viability ≥ 50%).

Table 1: Results of the h-CLAT assay

	RFI CD54*^1	RFI CD86*^1	MFI relative to IgG (%) CD54	MFI relative to IgG (%) CD86	Viability Mean of IgG, CD54 and CD86 (%)
Medium control	<150	<150	>105	>105	>90
Vehicle control (DMSO)	100	100	>105	>105	>90
test item	<200*^2	<150	>105	>105	>50*^3
positive control DCNB (4 µg/mL)	>200	>150	>105	>105	>50

*1 = compared to the vehicle control

*2 = conclusion of 3 main experiments

*3 = >50% in at least 4 concentrations

In conclusion, the test item did not reveal any sensitising properties in the h-CLAT method.

Interpretation of results:

GHS criteria not met

Remarks:

based on DPRA and h-CLAT

Executive summary:

The study was conducted to investigate the potential of the test item to induce changes in surface marker expression (CD54 and CD86) of dendritic cells in the human Cell Line Activation Test (h-CLAT). The h-CLAT was performed acording to OECD 442E.

The test substance was solved in DMSO and tested at final concentrations of 88 to 315.1 µg/mL, determined in a dose finding assay. The assay acceptance criteria for the positive control DNCB (2,4 -dinitrochlorobenzene) and the vehicle control DMSO were met in this test. Treatment of the cell cultures with the test item led to the following results:

The h-CLAT prediction was considered negative as:

• The RFI of CD86 was below 150% at any tested concentration (with cell viability ≥ 50%) in all experiments;

• The RFI of CD54 was below 200% in the third and fourth experiment at any tested concentration (with cell viability ≥ 50%).

In conclusion, the test item did not reveal any sensitising properties in the h-CLAT.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The structure activity relationship of the substance was investigated by using the OECD Toolbox 4.3.1 (released 2019). No protein binding alerts for skin sensitization were identified in silico by the OECD QSAR Toolbox. A moderate skin permeability is predicted in the Toolbox (Schlecker, 2019).

The Direct Peptide Reactivity Assay (DPRA; OECD 442C) is an in chemico procedure proposed to address the molecular initiating event leading to skin sensitization, namely protein reactivity, by quantifying the reactivity of test chemicals towards model synthetic peptides containing either lysine or cysteine. Cysteine and lysine percent peptide depletion values are then calculated and used in a prediction model to categorize a substance in one of four classes of reactivity for supporting the discrimination between skin sensitizers and non-sensitizers. Since the test item visually appeared a clear solution in acetonitrile at the test concentration of 100 mmol/L this solvent was used in the DPRA. No precipitaton of the test item occured after incubation and no co-elution was observed. The cysteine 1:10/lysine 1:50 prediction model was applied to the test item. No relevant depletion of cysteine and lysine peptides became obvious in the DPRA (1.43 % peptide depletion). According to the prediction model “minimal reactivity” was derived for the test item in water, leading to a DPRA prediction of “negative“.

An in vitro study was conducted to investigate the potential of the test item to induce changes in surface marker expression (CD54 and CD86) of dendritic cells in the human Cell Line Activation Test (h-CLAT). The h-CLAT was performed acording to OECD 442E. The test substance was dissolved in DMSO and tested at final concentrations of 88 to 315.1 µg/mL, determined in a dose finding assay. The assay acceptance criteria for the positive control DNCB (2,4 -dinitrochlorobenzene) and the vehicle control DMSO were met in this test. The h-CLAT prediction was considered negative as the RFI of CD86 was below 150% at any tested concentration (with cell viability ≥ 50%) in all experiments, and the RFI of CD54 was below 200% in the third and fourth experiment at any tested concentration (with cell viability ≥ 50%).

In conclusion, the test item did not reveal any skin sensitising properties in the h-CLAT.

Based on the results of the OECD Toolbox, the Direct Peptide Reactivity Assay (DPRA, OECD TG 442C) and the human Cell Line Activation Assay (h-CLAT, OECD 442E) and taking into account the 2 out or 3 Defined Approach (Draft OECD Guideline Defined Approaches for Skin Sensitisation of December 2020), the registered substance has no skin sensitizing potential

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the results of the Direct Peptide Reactivity Assay (DPRA, OECD TG 442C) and the human Cell Line Activation Assay (h-CLAT, OECD 442E) and taking into account the 2 out of 3 Defined Approach (Draft OECD Guideline Defined Approaches for Skin Sensitisation of December 2020) the registered substance has no skin sensitizing potential and thus, no classification is warranted.