Alcohols, C16-18 and ethoxylated C16-18 , phosphates (20 moles ethoxylation)

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From March 28, 2007 to April 16, 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Alcohols, C16-18 and ethoxylated C16-18 , phosphates (20 moles ethoxylation)

Molecular formula:

C18H39O4P1 (monoester representative, i.e., mono- C18 PSE) C56H115O24P1 (ethoxylated monoester representative, i.e., mono- C16 AE20 PSE) C32H67O4P1 (diester representative, i.e., di- C18 PSE) C112H227O44P1 (ethoxylated diester representative, i.e., di- C16 AE20 PSE)

IUPAC Name:

Alcohols, C16-18 and ethoxylated C16-18 , phosphates (20 moles ethoxylation)

Test material form:

solid

Method

Target gene:

Histidine

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Aroclor-induced rat liver S9

Test concentrations with justification for top dose:

- In the initial toxicity-mutation assay, the maximum dose tested was 5000 μg per plate; this dose was achieved using a concentration of 100 mg/mL and a 50 μL plating aliquot. The dose levels tested were 6.7, 10, 33, 67, 100, 333, 667, 1000, 3333 and 5000 μg per plate. A mutagenic response (reductions in revertant counts) was observed in strains TA1535 and TA1537 in the absence of S9 activation. Precipitate was observed at 1000 or 3333 μg per plate. No toxicity was observed. Based on the findings of the initial toxicity-mutation assay, the maximum dose plated in the confirmatory mutagenicity assay was 5000 μg per plate.
- In the confirmatory mutagenicity assay, the dose levels tested were 15, 50, 150, 500, 1500 and 5000 μg per plate. Precipitate was observed at 1500 and 5000 μg per plate. No toxicity was observed but reductions in revertant counts were observed in strains TA1535 and TA1537 and WP2 uvrA in the absence of S9 activation beginning at 1500 or at 5000 µg per plate.

Vehicle / solvent:

Ethanol (solution in EtOH at a concentration of approximately 500 mg/mL)

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

methylmethanesulfonate

other: 2-aminoanthracene

Details on test system and experimental conditions:

- The assay was performed in two phases, using the plate incorporation method. The first phase (1.), the initial toxicity-mutation assay, was used to establish the dose-range for the confirmatory mutagenicity assay and to provide a preliminary mutagenicity evaluation. The second phase (2.), the confirmatory mutagenicity assay, was used to evaluate and confirm the mutagenic potential of the test substance.
1. Vehicle control, positive controls and eight dose levels of the test substance were plated, two plates per dose, with overnight cultures of TA98, TA100, TA1535, TA1537 and WP2 uvrA on selective minimal agar in the presence and absence of Aroclor-induced rat liver S9.
2. Six dose levels of test substance along with appropriate vehicle control and positive controls were plated with overnight cultures of TA98, TA100, TA1535, TA1537 and WP2 uvrA on selective minimal agar in the presence and absence of Aroclor-induced rat liver S9. All dose levels of test substance, vehicle control and positive controls were plated in triplicate.
- The plates were inverted and incubated for 48 to 72 h at 37±2°C. Plates that were not counted immediately following the incubation period were stored at 2-8°C until colony counting could be conducted.

Rationale for test conditions:

Dose-range finding test
Cytotoxicity

Evaluation criteria:

- Scoring:
The condition of the bacterial background lawn was evaluated for evidence of test substance toxicity by using a dissecting microscope. Precipitate was evaluated after the incubation period by visual examination without magnification. Toxicity and degree of precipitation were scored relative to the vehicle control plate using the codes. As appropriate, colonies were enumerated either by hand or by machine.
- Evaluation:
For the test substance to be evaluated positive, it must cause a dose-related increase in the mean revertants per plate of at least one tester strain over a minimum of two increasing concentrations of test substance.

Statistics:

For each replicate plating, the mean and standard deviation of the number of revertants per plate were calculated and are reported.

Results and discussion

Test results

Key result

Species / strain:

other: S. typhymurium TA98, TA100, TA1535 and TA1537 + 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:

1. Initial Toxicity-Mutation Assay:
No positive mutagenic responses were observed with any of the tester strains in either the presence or absence of S9 activation. Precipitate was observed at 1000 and 3333 μg per plate. No toxicity was observed but a mutagenic response (reductions in revertant counts) was observed in strains TA1535 and TA1537 in the absence of S9 activation.
2. Confirmatory Mutagenicity Assay:
No positive mutagenic responses were observed with any of the tester strains in either the presence or absence of S9 activation. Precipitate was observed at 1500 and 5000 μg per plate. No toxicity was observed but reductions in revertant counts were observed in strains TA1535 and TA1537 and WP2 uvrA in the absence of S9 activation.
- All criteria for a valid study were met as described in the protocol.

Remarks on result:

other: precipitation at 1500 and 5000 µg/plate

Applicant's summary and conclusion

Conclusions:

Under the study conditions, the test substance was determined to be non-genotoxic with and without metabolic activation.

Executive summary:

A study was conducted to determine the in vitro genetic toxicity of the test substance, 'mono- and di- C16 -18 PSE and C16 -18 AE20 PSE', using bacterial reverse mutation assay (Ames test), according to OECD Guideline 471, in compliance with GLP. Salmonella typhimurium strains TA 98, TA100, TA 1535 and TA 1537 as well as Escherichia coli strain WP2 uvr A were used in this experiment. The assay was performed in two phases, using the plate incorporation method. In the first phase, a preliminary toxicity assay was conducted to establish the dose-range for the mutagenicity assay. In the second phase, the mutagenicity assay was conducted to evaluate the mutagenic potential of the test substance. In the preliminary toxicity-mutation assay, the maximum dose tested was 5000 μg per plate; this dose was achieved using a concentration of 100 mg/mL (in ethanol) and a 50 μL plating aliquot. The tested dose levels in this assay included 6.7, 10, 33, 67, 100, 333, 667, 1000, 3333 and 5000 μg per plate with and without metabolic activation (S9 -mix). Precipitate was observed at 1000 and 3333 μg per plate. No background lawn toxicity was observed but reductions in revertant counts were observed with tester strains TA1535 and TA1537 in the absence of S9 activation beginning at 1000 or at 5000 µg per plate. Based on the findings of the preliminary toxicity assay, the maximum dose plated in the confirmatory mutagenicity assay was 5000 μg per plate. In the mutagenicity assay, the tested dose levels included 15, 50, 150, 500, 1500 and 5000 μg per plate with and without metabolic activation. No positive mutagenic responses were observed in any of the tester strains, with and without metabolic condition. Precipitate was observed at 1500 and 5000 μg per plate. No background lawn toxicity was observed but reductions in revertant counts were observed with strains TA1535 and TA1537 and WP2 uvrA in the absence of S9 activation beginning at 1500 or at 5000 µg per plate. All criteria for a valid study were met as described in the protocol. Under the study conditions, the test substance was determined to be non-genotoxic with and without metabolic activation (BioReliance, 2007).