2,6-bis[[bis(2-hydroxyethyl)amino]methyl]-4-nonylphenol

Endpoint summary

Description of key information

The substance was concluded to be sensitizer.

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:

April to May 2019

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Type of study:

direct peptide reactivity assay (DPRA)

Specific details on test material used for the study:

The Poliol MB 600 was found to be soluble in acetonitrile at 100 mM, therefore, acetonitrile was selected as the vehicle for this study.

Key result

Parameter:

other: Depeletion Cysteine

Remarks:

%

Value:

49

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Key result

Parameter:

other: Depletion Lysine

Remarks:

%

Value:

0

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Key result

Parameter:

other: Mean depletion (Cysteine and Lysine)

Remarks:

%

Value:

24.5

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Key result

Parameter:

other: Maximum standard deviation (cysteine)

Value:

4.69

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Key result

Parameter:

other: Maximum standard deviation (lysine)

Value:

0.05

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Other effects / acceptance of results:

Results of the present study indicate that, Poliol MB 600 met all the evaluation criteria to conclude as sensitisers in DPRA assay. Reference controls and positive controls met all the acceptance criteria for the controls. The cysteine peptide, used for the study, was stable throughout the study. This showed the suitability of test system and procedures used in the test facility.

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

From the results of this study, under the specified experimental conditions, Poliol MB 600 was concluded as sensitizer in DPRA assay.

Executive summary:

EXECUTIVE SUMMARY:This study was conducted to evaluate the skin sensitisation potential of
Poliol MB 600using synthetic heptapeptides. The method followed was as per the OECD TG 442C.

Poliol MB 600was found to be soluble in acetonitrile at 100 mM.Thereforeacetonitrilewas selected as vehicle for this study.

Synthetic heptapeptides containing Lysine (Ac-RFAAKAA-COOH) or Cysteine (Ac-RFAACAA-COOH) were used as the test system in this assay.Cysteine and lysine containing peptides were incubated with positive control and test item for 24 ± 2 hours at 25 ± 2.5 ºC (in dark), separately.Relative peptide concentration was measured by high-performance liquid chromatography (HPLC) with gradient elution and UV detection at 220 nm. Cysteine and lysine peptide percent depletion values were calculated and used in a prediction model which allow assigning the test item to one of four reactivity classes used to support the discrimination between sensitisers and non-sensitisers (OECD, 2015).

HPLC system suitability was determined by the standard calibration curve and value of r²obtained was 0.99974 for cysteine and 0.99994 for lysine peptides, against set standard of r²> 0.99. The mean percent peptide depletion value of positive control,viz., cinnamic aldehyde was 72% for cysteine peptide and 41 % for lysine peptide. The Relative Coefficient of Variability (RCV) for the reference control B was 1.67 for cysteine peptide and 0.63 for lysine peptide. The mean peptide concentration of reference control A and B was 0.50 ± 0.05 mM. The relative coefficient of variability (RCV) for the stability of cysteine peptide in acetonitrile was 3.52 against set standard of <15%, indicating that cysteine is stable in acetonitrile. Percent peptide depletion values of Poliol MB 600 for cysteine and lysine were 49% and 0%, respectively. Mean percent depletion for Poliol MB 600 was 24.5%.

From results of this study, under specified experimental conditions, Poliol MB 600 was positive (moderate reactivity) in the DPRA assay. 

Reference 2

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April to May 2019

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 442D (In Vitro Skin Sensitisation: ARE-Nrf2 Luciferase Test Method)

GLP compliance:

yes (incl. QA statement)

Type of study:

activation of keratinocytes

Specific details on test material used for the study:

The Poliol MB 600 was found to be soluble in dimethyl sulfoxide at 200 mM, Therefore, DMSO was selected as the vehicle for this study.

Positive control results:

The gene induction for positive control (i.e., trans cinnamaldehyde) was found to be >1.5 at concentrations of 16 µM, 32 µM and 64 µM in both the repetitions. The E.C1.5 value for positive control was found to be 14.44 µM and 10.36 µM in experiment 2 and 3, respectively. The mean value of E.C1.5 for positive control was found to be 12.23 µM in experiment 2 and 3, respectively. The average gene induction for positive control at 64 µM was found to be 4.06 and 5.18 for experiment 2 and 3, respectively (which lies between acceptable range of 2 and 8). Dose response with increasing gene induction at increasing dose was also observed for trans-cinnamaldehyde in experiment 2 and experiment 3.

Key result

Parameter:

other: Imax

Value:

1.86

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Key result

Parameter:

other: EC1.5

Remarks:

mM

Value:

1.8

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Key result

Parameter:

other: IC50

Remarks:

mM

Value:

-2.64

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Key result

Parameter:

other: IC30

Remarks:

mM

Value:

3.95

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of skin sensitisation

Other effects / acceptance of results:

The EC1.5 mean value for Poliol MB 600 was 1.80 mM, which was less than 200 mM. The value of maximum induction (Imax) for Poliol MB 600 was 1.92 at the tested concentration of 3.13 mM in experiment 2 and 1.80 at the tested concentration of 1.56 mM in experiment 3, which was higher than 1.5 fold. The cellular viability was 101.02% at the tested concentration of 3.13 mM in experiment 2 and 89.12% at the tested concentration of 1.56 mM in experiment 3, with induction of luciferase activity above 1.5 fold.
 
For Poliol MB 600 three experiments were conducted and out of these two valid experiments (experiment 2 and 3) were considered for final evaluation. As the results of experiment 1 and 2 were not comparable to each other, experiment 3 was performed for confirmation of the results.
Results of the present study indicate that, Poliol MB 600 met all the evaluation criteria to conclude as sensitisers in KeratinoSens assay. Negative and positive controls met the acceptance criteria for the controls and were correctly identified as non-sensitiser and sensitiser, respectively. This showed the suitability of test system and procedures used in the test facility.

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

From the results of this study, under the specified experimental conditions, Poliol MB 600 was concluded as sensitisers in KeratinoSens assay.

Executive summary:

EXECUTIVE SUMMARY:This study was conducted to evaluate the skin sensitization potential of
Poliol MB 600 based onKeratinocyte-Based ARE-Nrf2 Luciferase Reporter Gene methodas recommended by OECD Test guideline 442D.

Poliol MB 600 was found to be soluble at 200 mM in dimethyl sulfoxide. Therefore dimethyl sulfoxide was selected as a vehicle.Test item was tested in two independent experiments.Keratinosens^TM(HaCaT) cellswereexposed to Poliol MB 600 between test concentrations of 2000 µM to 0.98 µM and positive control between concentrations of 4 to 64 µM for 48 ± 2 hours in 5+1% CO₂at 37 ± 1^oC. After incubationcells were analyzed for luciferase activity.Cell viability of the concurrently treated cells was also evaluated using MTT test with separate set of plate. I_maxand EC_1.5values were calculated based on luciferase activity i.e., luminescence measured (reading of three plates) while IC₅₀and IC₃₀were calculated based on results of cytotoxicity (OD values, reading of one plate).

For positive control trans cinnamldehyde, EC_1.5value was found to be12.23 µM,when run concurrently. The IC₅₀and IC₃₀values for Poliol MB 600 werefound to be 46.68 and 40.16 µM.

The EC_1.5mean value for Poliol MB 600 was 17.96µM, which was less than 1000 µM. The value of maximum induction (I_max) for Poliol MB 600 was 1.92 at the tested concentration of 31.25µMin experiment 2 and 1.80 at the tested concentration of 15.63µMin experiment 3, which was higher than 1.5 fold. The cellular viability was 102.12% at the tested concentration of 31.25µMin experiment 2 and 89.12% at the tested concentration of 15.63µMin experiment 3, with induction of luciferase activity above 1.5 fold. Observed dose response for luciferase induction was also statistically significant.

All criteria for a valid study were met as described in the study plan.From the results of this study, under the specified experimental conditions,Poliol MB 600 wasconcluded as sensitiser in KeratinoSens assay.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)