Residues (petroleum), heavy coker gas oil and vacuum gas oil

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Near-guideline, GLP-compliant study. Adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

Salmonella typhimurium TA98 exposed using either a standard plate incorporation assay or a modified protocol (8-fold increase in S9; 3-fold increase in NADP)

GLP compliance:

yes

Type of assay:

bacterial gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

64741-62-4

Cas Number:

64741-62-4

IUPAC Name:

64741-62-4

Test material form:

other: Viscous hydrocarbon liquid

Details on test material:

Catalytic cracked clarified oil (CCCO), CAS No. 64741-62-4.
Sample No API 81-15
Gravity degrees API: 0.1
Specific gravity: 1.0753
Viscosity in SUS 210 °F: 56.1
Flash Pt °F: 396
Ash, weight %: 0.05
Sulfur weight %:1.1
Pour Pt °F: 35
Asphaltenes (MM-596): 4.2 %
Carbon residue in weight %: 4.6

Method

Target gene:

hisD3052

Species / strain

Species / strain / cell type:

S. typhimurium TA 98

Details on mammalian cell type (if applicable):

not applicable

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with

Metabolic activation system:

Aroclor 1254-induced rat S9

Test concentrations with justification for top dose:

Trial 1: 1000, 5000, 10000, 25000, 50000 ug/plate
Trial 2: 33, 100, 333, 1000, 3333 ug/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (4 ug); perylene (50 ug)

Details on test system and experimental conditions:

Standard plate incorporation assay: 10% Aroclor 1254- induced rat S9 homogenate mix per ml; 4 mM NADP
Modified protocol: 80% S9 homogenate per ml; 12 mM NADP
Testing performed twice (independent repeat)
2-aminoanthracene and perylene used as positive control substances

Evaluation criteria:

Doubling in mutation frequency

Statistics:

None reported

Results and discussion

Test results

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

>10000 ug/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

other: strain/cell type: Modified Ames assay using Salmonella typhimurium strain TA98

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

In both cases, significant and reproducible dose-dependent increases in the number of revertants were obtained.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive

positive in Salmonella typhimurium TA98 in vitro with and without metabolic activation

Executive summary:

The mutagenic potential of catalytic cracked clarified oil (up to 50000 µg/plate; sample API 81-15) was investigated in a non-guideline GLP-compliant study. Four separate tests were conducted in duplicate using S. typhimurium strain TA 98 in the presence of either 10% Aroclor 1254-induced rat liver S9 mix and 4 mM NADP or 80% S9 mix and 12 mM NADP; 2-aminoanthracene and perylene were used as positive control substances. A two-fold increase in revertants per plate was regarded as a positive response.

The test substance was positive in all 4 tests, with the number of revertants increased maximally 13.1, 27.8, 44 and 46.3-fold, respectively over solvent controls. The largest increase in revertants occurred in the assays activated with 80% S-9 and 12 mM NADP. A satisfactory response was obtained with the positive control substances.