Asphalt, oxidized

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study is considered reliable with restriction because it is a well conducted study published in scientific literature.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

64741-56-6

Cas Number:

64741-56-6

IUPAC Name:

64741-56-6

Constituent 2

Reference substance name:

Vacuum Residue API 81-14

IUPAC Name:

Vacuum Residue API 81-14

Test material form:

other: semi-solid

Details on test material:

Test substance: Vacuum residue API sample 81-14

Method

Species / strain

Species / strain / cell type:

other: L5178Y TK+/- mouse lymphoma cell line

Metabolic activation:

with and without

Metabolic activation system:

S9 fraction of Araclor-induced male mouse liver homogenate.

Test concentrations with justification for top dose:

0.061 to 1000 nL/mL

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: acetone

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: ethyl methane sulfonate (-S9) and dimethyl nitrosamine (+S9)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)
DURATION
- Exposure duration: 4 hours
- Expression time (cells in growth medium): 2-3 days

SELECTION AGENT (mutation assays): No data

NUMBER OF REPLICATIONS: 2

NUMBER OF CELLS EVALUATED: 3 x 10 + E6 cells

DETERMINATION OF CYTOTOXICITY
- Method: resistant (mutant) colonies

Evaluation criteria:

The minimum condition necessary to demonstrate mutagenesis for any given treatment is a mutant frequency that exceeds 150% of the concurrent background frequency by at least 10 x 10-6. The background frequency is defined as the average mutant frequency of the solvent and untreated controls. The following test results must also be obtained:

1) A dose-related or toxicity-related increase must be observed. (Usually over three doses)
2) An increase in mutant frequency may be followed by only a small or no further increase at higher concentrations or toxicities.
3) If an increase of about two times the minimum criterion or greater is observed for a single dose near the highest testable concentration, the test material shall be considered mutagenic.

Statistics:

The ratio of resistant colonies to total viable cell number was determined to be the mutant frequency.

Results and discussion

Test results

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

positive

Remarks:

weakly mutagenic in presence of metabolic activation (+S9)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: other: L5178Y TK+/- mouse lymphoma cell line

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

The sample was weakly mutagenic with metabolic activation.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive with metabolic activation weakly mutagenic in presence of S9

No evidence of mutagenic activity as observed in the absence of metabolic activation. However, weak activity was observed in the presence of metabolic activation.
 
Based on the results of the study, the test material (Vacuum Residue, API 81-14) is considered to be weakly mutagenic in the presence of metabolic activation in this mouse lymphoma forward mutation assay.

Executive summary:

In a supporting mouse lymphoma forward mutation assay, the mutagenic potential of the test material (Vacuum Residue, API 81-14) was evaluated using L5178Y TK+/- mouse lymphoma cells in the presence and absence of metabolic activation (±S9). The test material was tested at concentrations of 0.061 to 1000 nL/mL in the presence and absence of S9 in an acetone vehicle Ethyl methane sulfonate (EMS) was used as positive control in the absence of metabolic activation (-S9) while dimethyl nitrosamine (DMN) was used as positive control in the presence of metabolic activation (+S9).

No evidence of mutagenic activity as observed in the absence of metabolic activation. However, weak activity was observed in the presence of metabolic activation.

 

Based on the results of the study, the test material (Vacuum Residue, API 81-14) is considered to be weakly mutagenic in the presence of metabolic activation in this mouse lymphoma forward mutation assay.