Pentan-2-one

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in chemico

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 442C (In Chemico Skin Sensitisation Assays addressing the Adverse Outcome Pathway key event on covalent binding to proteins)

GLP compliance:

yes (incl. QA statement)

Type of study:

direct peptide reactivity assay (DPRA)

Justification for non-LLNA method:

The DPRA is one in a trio of non-animal screen studies required to be conducted in order to determine if an LLNA needs to be conducted.

Test material

Test material information

Constituent 1

Reference substance name:

Pentan-2-one

EC Number:

203-528-1

EC Name:

Pentan-2-one

Cas Number:

107-87-9

Molecular formula:

C5H10O

IUPAC Name:

pentan-2-one

Constituent 2

Reference substance name:

Methyl n-Propyl Ketone

IUPAC Name:

Methyl n-Propyl Ketone

Constituent 3

Reference substance name:

2-Pentanone

IUPAC Name:

2-Pentanone

Test material form:

liquid

Details on test material:

MPK (purity 99.7%)
Batch/Lot no. 7054784
Exp. date: March 2001
CAS no. 107-87-9
Clear, colorless liquid

Specific details on test material used for the study:

Name: Methyl Propyl Ketone
Batch No.: TD21033302
CAS No: 107-87-9
Molecular Weight: 86.13 g/mol
Purity: 94.79%
Physical State: liquid
Colour: colourless
Stability: stable
Storage Conditions: ambient
Expiry Date: 01 January 2023
Safety Precautions: The routine hygienic procedures will be sufficient to assure personnel health and safety.

In chemico test system

Details of test system:

cysteine peptide, (Ac-RFAACAA-COOH)

lysine peptide (Ac-RFAAKAACOOH)

Vehicle / solvent:

water

Positive control:

cinnamic aldehyde

Results and discussion

In vitro / in chemico

Results

Results 1

Group:

test chemical

Run / experiment:

mean

Parameter:

mean lysine depletion

Value:

0.53 %

At concentration:

0.5 mM

Vehicle controls validity:

valid

Remarks:

Reference control

Negative controls validity:

valid

Remarks:

Co-elution control

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Remarks:

The data generated with this method may be not sufficient to conclude on the absence of skin sensitisation potential of chemicals and should be considered in the context of integrated approach such as IATA.

Results 2

Group:

test chemical

Run / experiment:

mean

Parameter:

mean cystein depletion

Value:

1.18 %

At concentration:

0.5 mM

Vehicle controls validity:

valid

Remarks:

Reference control

Negative controls validity:

valid

Remarks:

Co-elution control

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Remarks:

The data generated with this method may be not sufficient to conclude on the absence of skin sensitisation potential of chemicals and should be considered in the context of integrated approach such as IATA.

Outcome of the prediction model:

negative [in vitro/in chemico]

Any other information on results incl. tables

The in chemico direct peptide reactivity assay (DPRA) enables detection of the sensitising potential of a test item by quantifying the reactivity of test chemicals towards synthetic peptides containing either lysine or cysteine.

In the present study Methyl Propyl Ketone was dissolved in dist. water, based on the results of the pre-experiments.

Based on a molecular weight of 86.13 g/mol a 100 mM stock solution was prepared. The test item solutions were tested by incubating the samples with the peptides containing either cysteine or lysine for 24 ± 2 h at 25 ± 2.5 °C. Subsequently samples were analysed by HPLC.

All test item solutions were freshly prepared immediately prior to use.

For the 100 mM stock solution of the test item no turbidity or precipitation was observed when diluted with the cysteine peptide solution.After the 24 h±2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. No precipitation, turbidity or phase separation was observed for any of the samples.

For the 100 mM stock solution of the test item no turbidity or precipitation was observed when diluted with the lysine peptide solution.After the 24 h±2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. No precipitation, turbidity or phase separation was observed for any of the samples.

No co-elution of test item with the peptide peaks was observed. Sensitising potential of the test item was predicted from the mean peptide depletion of both analysed peptides (cysteine and lysine) by comparing the peptide concentration of the test item treated samples to the corresponding reference control C (RC C_{dist. water}).

The 100 mM stock solution of the test item showed minimal reactivity towards the synthetic peptides. The mean depletion of both peptides was ≤ 6.38% (0.86%). Based on the prediction model 1 the test item can be considered as non-sensitiser.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this study under the given conditions the test item showed minimal reactivity towards both peptides. The test item is considered as a “non-sensitiser”.
The data generated with this method may be not sufficient to conclude on the absence of skin sensitisation potential of chemicals and should be considered in the context of integrated approach such as IATA.

Executive summary:

The in chemicodirect peptide reactivity assay (DPRA) enables detection of the sensitising potential of a test item by quantifying the reactivity of test chemicals towards synthetic peptides containing either lysine or cysteine.

In the present study Methyl Propyl Ketone was dissolved in dist. water, based on the results of the pre-experiments.

Based on a molecular weight of 86.13 g/mol a 100 mM stock solution was prepared. The test item solutions were tested by incubating the samples with the peptides containing either cysteine or lysine for 24 ± 2 h at 25 ± 2.5 °C. Subsequently samples were analysed by HPLC.

All test item solutions were freshly prepared immediately prior to use.

For the 100 mM stock solution of the test item no turbidity or precipitation was observed when diluted with the cysteine peptide solution.After the 24 h±2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. No precipitation, turbidity or phase separation was observed for any of the samples.

For the 100 mM stock solution of the test item no turbidity or precipitation was observed when diluted with the lysine peptide solution.After the 24 h±2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. No precipitation, turbidity or phase separation was observed for any of the samples.

No co-elution of test item with the peptide peaks was observed. Sensitising potential of the test item was predicted from the mean peptide depletion of both analysed peptides (cysteine and lysine) by comparing the peptide concentration of the test item treated samples to the corresponding reference control C (RC C_{dist. water}).

The 100 mM stock solution of the test item showed minimal reactivity towards the synthetic peptides. The mean depletion of both peptides was ≤ 6.38% (0.86%). Based on the prediction model 1 the test item can be considered as non-sensitiser.

 Conclusion

In this study under the given conditions the test item showed minimal reactivity towards both peptides. The test item is considered as a “non-sensitiser”.

The data generated with this method may be not sufficient to conclude on the absence of skin sensitisation potential of chemicals and should be considered in the context of integrated approach such as IATA.