Distillates (coal tar), heavy oils

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 Aug. - 06 Sep. 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Distillates (coal tar), heavy oils

EC Number:

292-607-4

EC Name:

Distillates (coal tar), heavy oils

Cas Number:

90640-86-1

Molecular formula:

not applicable

IUPAC Name:

fluoranthene; phenanthrene; pyrene

Details on test material:

- Name of test material (as cited in study report): anthracene oil (> 50 ppm BaP)
- Molecular formula (if other than submission substance): not applicable
- Molecular weight (if other than submission substance): not applicable
- Substance type: organic
- Physical state: liquid
- Stability under test conditions: no measured data; based on chemical structure assumed to be stable
- Storage condition of test material: room temperature, exclusion of light

Method

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:

S. typhimurium TA 102

Metabolic activation:

with and without

Metabolic activation system:

Microsomal fraction prepared from induced livers of male Wistar rats, induced with phenobarbital (80 mg/kg bw) and ß-naphthoflavone (100 mg/kg bw) orally (3x)

Test concentrations with justification for top dose:

1st experiment: 3.16, 10, 31.6, 100, 316, 1000, 2500, and 5000 µg/plate (TA 98, TA 100, +/-S9)
1.0, 3.16, 10, 31.6, 100, 316, and 1000 µg/plate (TA 1535, TA 1537, - S9)
10, 31.6, 100, 316, 1000 and 2500 µg/plate (TA 1535, TA 1537, + S9)
3.16, 10, 31.6, 100, 316, and 1000 µg/plate (TA 102, +/-S9)
2nd experiment: with variations based on results of 1st experiment (Report, p. 11)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: compatible with survival of bacteria and S9 activity

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: see Report p. 15

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth/colony formation

Evaluation criteria:

Considered as mutagenic
- if a clear and dose-related increase in the number of revertants occurs in at least one tester with or without metabolic activation
and/or
- if a biologically relevant positive response for at least one of the dose groups occurs in at least one tester with or without metabolic activation.

An increase is considered relevant
- if in TA 100 and TA 102 mutation rate is at least twice as high as the rate of the solvent control;
- if in TA 98, TA 1535, and TA 1537 the mutation rate is at least 3x higher than that of the solvent control.

Statistics:

According to the OECD guidelines, the biological relevance is the criterion for the interpretation of the results: a statistical evaluation was not considered necessary under this premise (report p. 21).

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

reproducible in both tests

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at >= 31.6 µg/pl. (-S9); at >= 316 µg/pl. (+S9)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium, other: TA 98, TA 100, TA 1537

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

reproducible in both tests

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

not or weakly cytotoxic in the mutagenic concentration range

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium, other: TA 102

Metabolic activation:

with

Genotoxicity:

ambiguous

Remarks:

weak positive effect, not reproducible

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

not in the relevant mutagenic concentration range

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium, other: TA 98

Metabolic activation:

without

Genotoxicity:

positive

Remarks:

dose response positive

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

not cytotoxic in the relevant concentration range

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Summary:

The positive effects noted without S9 were weak and not reproducible in either experiment (see below).

In the presence of S9 clear dose-related increases in the mutation rates were found in TA 98 and 1537 and a weak positive correlation in TA 100 and TA 102, reproducible at non-cytotoxic concentrations in both experiments. The most responsive tester strain was TA 98.

[Mutation factors (+S9) = 3 - 14x above background with maximum in TA 98]

In either experiment, no biological relevant increases in the mutation rate were seen in TA 1535.

Experiment I:

No relevant increases in TA 98, TA 100, TA 1537, and TA 102 (-S9);

relevant increases in TA 98, TA 100, and TA 1537 (>= 10 µg/plate, +S9)

Experiment II:

Relevant increases in TA 98 (>= 15 µg/plate, -S9);

relevant increases in TA 98, TA 100, TA 1537, and TA 102 (>= 5 - 500 µg/plate, +S9)

Dose-response relationship of the reversion rate was observed with each tester strain.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive