Tetradecan-1-ol, propoxylated, esters with propionic acid

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

PPG-2 myristyl ether propionate has been determined to be non-mutagenic to Salmonella typhimurium and Escherichia coli bacterial strains under the conditions of an in vitro test system, with no biologically relevant increase in the frequency of revertant colonies observed with or without metabolic activation.

The constituents of PPG-2 myristyl ether propionate are not expected to induce structural chromosomal aberration or gene mutation in mammalian cells according to QSAR predictions in the OECD QSAR Toolbox.

Subsequently, the substance can be regarded as non-mutagenic.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

March 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
(Q)SAR

2. MODEL (incl. version number)
OECD QSAR Toolbox v4.2

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
SMILES notation for individual constituents was input:
One propoxyl group - CCCCCCCCCCCCCCOCC(C)OC(=O)CC
Two propoxyl group - CCCCCCCCCCCCCCOCC(C)OCC(C)OC(=O)CC
Three propoxyl group - CCCCCCCCCCCCCCOCC(C)OCC(C)OCC(C)OC(=O)CC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: In vitro gene mutation in mammalian cells
- Unambiguous algorithm: OECD principle 2 (takes the highest mode value from
the nearest 6 chemical neighbour)
- Defined domain of applicability: OECD principle 3, Analogue selection.
- Appropriate measures of goodness-of-fit and robustness and predictivity: Prediction determined by comparison to other chemicals identified with similar structures, prediction confidence measured by the p-value (must be below/equal to 0.05 to be viable).
- Mechanistic interpretation: Not provided by the user

5. APPLICABILITY DOMAIN
- Descriptor domain: Active descriptor: Log Kow
- Structural and mechanistic domains: Aquatic toxicity classification by ECOSAR and 'in vivo mutagenicity (Micronucleus) alerts by ISS'
- Similarity with analogues in the training set: In all cases predictions were all equal to the predicted values.

6. ADEQUACY OF THE RESULT
In accordance with Annex XI of REACH, reliable and adequate results obtained from valid Qualitative or Quantitative Structure-Activity Relationship models ((Q)SARs) may indicate the presence or absence of certain dangerous properties. These results may be used instead of testing, provided the substance falls within the applicability domain of the (Q)SAR model.

Qualifier:

according to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Version / remarks:

Predictions of potential to induce gene mutation were based on experimental data from the in vitro mammalian cell gene mutation assay of structurally similar substances conducted in accordance with the OECD Testing Guideline 476, including Chinese hamster lung fibroblasts (V79), Chinese hamster Ovary (CHO), and Mouse lymphoma L5178Y cells.

Deviations:

no

Principles of method if other than guideline:

- Software tool(s) used including version: OECD QSAR Toolbox v4.2
- Justification of QSAR prediction: A literature search was conducted to identify studies on gene mutation in mammalian cells for the registered substance and its constituents, but no relevant studies were identified.

GLP compliance:

no

Type of assay:

other: OECD QSAR Toolbox v4.2 read-across analysis

Key result

Genotoxicity:

negative

Remarks:

Predictions were based on experimental data from the in vitro mammalian cell gene mutation assay of structurally similar substances.

Remarks on result:

other: Quantative results not determined as no test was performed for this endpoint.

Conclusions:

Based on the OECD QSAR Toolbox v4.2 results PPG-2 myristyl ether propionate is not expected to induce gene mutation in mammalian cells.

Executive summary:

The OECD QSAR Toolbox v4.2 predictions of gene mutation in mammalian cells were performed for the three constituents of PPG-2 myristyl ether propionate (tetradecan-1-ol, propoxylated, esters with propionic acid (one, two and tree propoxyl groups). The predictions were based on experimental data from the in vitro mammalian cell gene mutation assay of structurally similar substances conducted in accordance with the OECD Testing Guideline 476. The mechanistic and endpoint specific profilers for tetradecan-1-ol, propoxylated, esters with propionic acid identified no alerts for gene mutation with the exception of the profiler “in vivo mutagenicity (Micronucleus) alerts by ISS” which showed an alert, H-Acceptor-path-H-acceptor. The profiler “in vivo mutagenicity (Micronucleus) alerts by ISS” was then used to define the category for the prediction and group chemicals that show that same specific mechanism (H-Acceptor-path-H-acceptor) for in vivo mutagenicity (Micronucleus) alerts by ISS and for which experimental results on genotoxicity were available. All constituents were found to have a negative result in relation to the potential to induce gene mutation in mammalian cells. All results were statistically significant (prediction confidence of p < 0.05).

Reference 2

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

March 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
(Q)SAR

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Version / remarks:

Predictions of potential to induce gene mutation were based on experimental data from the in vitro cytogenicity test in mammalian cells of structurally similar substances conducted in accordance with the OECD Testing Guideline 473 and an in vivo micronucleus test that is equivalent to the OECD Guideline 474.

Deviations:

no

Principles of method if other than guideline:

To determine the potential of PPG-2 myristyl ether propionate to induce chromosomal aberration in mammalian cells, an expert assessment was performed. This was achieved by an evaluation of a number of Quantitative Structure–Activity Relationship (QSAR) predictions performed in the OECD QSAR Toolbox for Grouping of Chemicals into Categories for the three proproxylated constituents of PPG-2 myristyl ether propionate that contain one, two, and three propoxyl groups, and by using experimental data for analogous substances. QSAR modelling is an accepted prediction technique from which to derive non-test information for a number of genotoxicity endpoints.

GLP compliance:

no

Type of assay:

other: OECD QSAR Toolbox v4.2 read-across analysis

Key result

Species / strain:

other: not applicable

Metabolic activation:

not applicable

Genotoxicity:

other: not applicable

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not applicable

Untreated negative controls validity:

not applicable

Positive controls validity:

not applicable

Remarks on result:

no mutagenic potential (based on QSAR/QSPR prediction)

Conclusions:

The constituents of PPG-2 myristyl ether propionate are not expected to induce structural chromosomal aberration in mammalian cells according to QSAR predictions in the OECD QSAR Toolbox. Subsequently, the registered substance can be regarded as non-mutagenic.

Executive summary:

An assessment was undertaken to evaluate the potential of PPG-2 myristyl ether propionate, a Substance of Unknown or Variable composition, Complex reaction products or Biological materials (UVCB), to induce structural chromosomal aberration potential in mammalian cells. As experimental data was not available for the registered substance, a number of QSAR predictions were performed in the OECD QSAR Toolbox for Grouping of Chemicals into Categories for the three proproxylated constituents of PPG-2 myristyl ether propionate (ECHA 2008). The OECD QSAR Toolbox can be applied to fill in data gaps for genotoxic endpoints using experimental data for analogous substances.

Except for one prediction that was inconclusive (PPG-2 myristyl ether propionate (Two Propoxyl Groups): p = 0.188), all constituent predictions were negative for structural chromosomal aberration in mammalian cells. As the negative predictions were statistically significant (p = 0.0313), they can be regarded as suitable for the purpose of endpoint assessment. Therefore, the constituents of PPG-2 myristyl ether propionate are non-mutagenic based on QSAR prediction and, therefore, the registered substance is not expected to induce structural chromosomal aberration in mammalian cells.

Reference 3

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From June 07, 2017 to July 02, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

Commission Regulation (EC) No. 440/2008 of 30 May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

Version / remarks:

EPA OCSPP harmonised guideline

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Economy, Trade and Industry, Japanese Ministry of Health, Labour and Welfare and Japanese Ministry of Agriculture, Forestry and Fisheries

Deviations:

no

Principles of method if other than guideline:

During test item preparation and analysis, all formulations were used within four hours of preparation and were assumed to be stable for this period. Analysis for concentration, homogeneity, and stability of the test item formulations is not a requirement of the test guidelines and was, therefore, not determined. This is an exception with regard to Good Laboratory Practise (GLP) and has been reflected in the GLP compliance statement.

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Target gene:

Histidine locus in the genome of Salmonella typhimurium, or tryptophan for Escherichia coli

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

other: Strain is histidine-dependent

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

other: Strain is tryptophan-dependent

Metabolic activation:

with and without

Metabolic activation system:

10% liver S9 in standard co-factors (S9-mix), prepared from rats pre-treated with a mixture known to induce an elevated level of these enzymes

Test concentrations with justification for top dose:

Experiment 1 (plate incorporation method) had a pre-determined dose range of 1.5 to 5000 µg/plate (1.5, 5, 15, 50, 150, 500, 1500, and 5000 µg/plate). 5000 µg/plate was the maximum recommended dose level. A repeat experiment was undertaken, Experiment 2 (pre-incubation method), with fresh bacteria and test item and an adapted dose range of 15 to 5000 µg/plate (15, 50, 150, 500, 1500, and 5000 µg/plate). Six test item concentrations were selected in Experiment 2 in order to achieve both four non-toxic dose levels and the potential toxic limit of the test item following the change in test methodology.

Vehicle / solvent:

- Vehicle used: Acetone, Fisher Scientific (Batch No. 1679355; purity: 99.98%; expiry: 2021-11)
- Justification for choice of vehicle: The test item was noted as immiscible in sterile distilled water and dimethyl sulphoxide at 50 mg/mL but was fully miscible in acetone at 100 mg/mL in solubility checks performed in-house

Untreated negative controls:

yes

Remarks:

Untreated to assess spontaneous revertant colony rate

Negative solvent / vehicle controls:

yes

Remarks:

Acetone

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

N-ethyl-N-nitro-N-nitrosoguanidine

benzo(a)pyrene

other: 2-Aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: Experiment 1 followed the plate-incorporation method with Vogel-Bonner agar. As this experiment was deemed to be negative, a second was performed (Experiment 2) in line with the pre-incubation method (described by Ames et al. 1975; Maron and Ames 1983; Mortelmans and Zeiger 2000)

EXPOSURE DURATION: In Experiment 1, all plates were incubated at 37 ± 3 °C for approximately 48 hours and scored for revertant colonies. In Experiment 2, plates containing the bacterial strain culture; phosphate buffer (without activation) or S9-mix (with activation); and test item, solvent vehicle, or positive control were incubated at 37 ± 3 °C for 20 minutes (with shaking). This was followed by the addition of molten, trace amino-acid supplemented media and plating onto Vogel-Bonner plates, which were then incubated at 37 ± 3 °C for approximately 48 hours and scored for the presence of revertant colonies

NUMBER OF REPLICATIONS: Assays were performed in triplicate for the test item and the positive, negative, and solvent controls

Evaluation criteria:

There are several criteria for determining a positive result. Any, one, or all of the following can be used to determine the overall result of the study:

1. A dose-related increase in mutant frequency over the dose range tested (De Serres and Shelby, 1979).
2. A reproducible increase at one or more concentrations.
3. Biological relevance against in-house historical control ranges.
4. Statistical analysis of data as determined by UKEMS (Mahon et al., 1989).
5. Fold increase greater than two times the concurrent solvent control for any tester strain (especially if accompanied by an out-of-historical range response (Cariello and Piegorsch, 1996)).

A test item will be considered non-mutagenic (negative) in the test system if the above criteria are not met.

Although most experiments will give clear positive or negative results, in some instances the data generated will prohibit making a definite judgment about test item activity. Results of this type will be reported as equivocal.

Statistics:

Statistical significance was confirmed by using Dunnetts Regression Analysis (* = p < 0.05) for those values that indicate statistically significant increases in the frequency of revertant colonies compared to the concurrent solvent control.

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

In the first mutation test (plate incorporation method), a test item precipitate (fine and particulate in appearance) was noted under an inverted microscope from 1500 µg/plate and by eye at 5000 µg/plate. In the second mutation test (pre-incubation method), a test item precipitate (fine and particulate in appearance) was only noted under an inverted microscope at 5000 µg/plate. The precipitate observations did not prevent the scoring of revertant colonies.
No biologically relevant increase in the frequency of revertant colonies was recorded for any of the bacterial strains, with any dose of the test item, either with or without metabolic activation (S9-mix) in Experiment 1 (plate incorporation method) or Experiment 2 (pre-incubation method). A small, statistically significant increase in TA1535 revertant colony frequency was observed in the second mutation test at 5000 µg/plate (presence of S9-mix). This increase was considered to be of no biological relevance because there was no evidence of a dose-response relationship or reproducibility. Furthermore, the individual revertant colony counts at the statistically significant dose level was within the inhouse historical untreated/vehicle control range for the tester strain and the maximum fold increase was only 1.2 times the concurrent vehicle control.

Conclusions:

PPG-2 myristyl ether propionate was shown not to increase the frequency of revertant colonies to a biologically significant degree in Salmonella typhimurium and Escherichia coli bacterial strains with or without metabolic activation. The substance is subsequently considered to be non-mutagenic to bacteria under the conditions of this test.

Executive summary:

An in vitro gene mutation test in bacteria was performed with Salmonella typhimurium and Escherichia coli to determine the genetic toxicity of PPG-2 myristyl ether propionate. The following guidelines and regulations were adhered to without deviation: OECD Guideline 471 (Bacterial Reverse Mutation Assay); EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria) of Commission Regulation (EC) No. 440/2008 of 30 May 2008; EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998); and Japanese Ministry of Economy, Trade and Industry, Japanese Ministry of Health, Labour and Welfare and Japanese Ministry of Agriculture, Forestry and Fisheries. The study was compliant with Good Laboratory Practise (GLP).

S. typhimurium strains TA1535, TA1537, TA98, and TA100 and E. coli strain WP2uvrA were treated with PPG-2 myristyl ether propionate using the plate incorporation method (Experiment 1) and pre-incubation method (Experiment 2) at up to eight dose levels, in triplicate, both with and without the addition of a rat liver homogenate metabolizing system (10% liver S9 in standard co-factors). The dose range for Experiment 1 was predetermined: 1.5, 5, 15, 50, 150, 500, 1500, and 5000 µg/plate. The experiment was repeated on a separate day using fresh bacterial cultures and fresh test item formulations. The pre-incubation method was followed in Experiment 2 as the results of Experiment 1 were found to be negative. The dose range was amended to 15, 50, 150, 500, 1500, and 5000 µg/plate. Six test item concentrations were selected in order to achieve both four non-toxic dose levels and the potential toxic limit of the test item following the change in test methodology.

No biologically relevant increase in the frequency of revertant colonies was recorded for any of the bacterial strains, with any dose of the test item, either with or without metabolic activation (S9-mix) in Experiment 1 (plate incorporation method) and Experiment 2 (pre-incubation method). A small, statistically significant increase in TA1535 revertant colony frequency was observed in the second mutation test at 5000 µg/plate (presence of S9-mix). This increase was considered to be of no biological relevance because there was no evidence of a dose-response relationship or reproducibility. Furthermore, the individual revertant colony counts at the statistically significant dose level was within the inhouse historical untreated/vehicle control range for the tester strain and the maximum fold increase was only 1.2 times the concurrent vehicle control.

Under the conditions of this in vitro test system, PPG-2 myristyl ether propionate was concluded to be non-mutagenic.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The endpoint conclusion determined for genetic mutation in bacteria (in vitro) was derived from QSAR predictions and a GLP-compliant study that followed standard guidelines and regulations without deviation, namely, OECD Guideline 471 (Bacterial Reverse Mutation Assay); EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria) of Commission Regulation (EC) No. 440/2008 of 30 May 2008; EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998); and Japanese Ministry of Economy, Trade and Industry, Japanese Ministry of Health, Labour and Welfare and Japanese Ministry of Agriculture, Forestry and Fisheries. A Klimisch score of 1 (reliable without restriction) has been assigned to the final result.