Hydrocarbons, C17-30, hydrotreated distillates, distn. lights

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 from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

No data reported

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study is classified as reliable without restriction because it was carried out according to OECD TG 471.

Data source

Reference

Reference Type:

publication

Title:

Estimation of the dermal carcinogenic activity of petroleum fractions using a modified Ames assay

Author:

Blackburn GR, Deitch RA, Schreiner CA, Mehlman MA, and Mackerer CR

Year:

1984

Bibliographic source:

Cell Biol Toxicol, Vol 1(1), pp 67-80

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

not specified

Type of assay:

other: modified bacterial reverse mutation assay (modified Ames test)

Test material

Test material information

Constituent 1

Reference substance name:

Solvent refined/Hydrotreated heavy naphthenic distillate, (CAS # 64741-96-4/CAS # 64742-52-5)

IUPAC Name:

Solvent refined/Hydrotreated heavy naphthenic distillate, (CAS # 64741-96-4/CAS # 64742-52-5)

Details on test material:

Read Across to Unrefined/Acid Treated Oils

The following substances were tested:

Number 7, Solvent refined/Hydrotreated heavy naphthenic distillate, CAS # 64741-96-4/CAS # 64742-52-5.
Number 9, 10, and 11, Solvent refined/hydrotreated heavy paraffinic distillate, CAS # 64741-88-4/CAS # 64742-54-7.
Number 13: Solvent refined/dewaxed heavy paraffinic distillate, CAS # 64741-88-4/CAS # 64742-65-0.

Method

Target gene:

Not applicable.

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 specified

Metabolic activation:

with

Metabolic activation system:

Aroclor 1254-induced rat or hamster liver S9

Test concentrations with justification for top dose:

50 ul

Vehicle / solvent:

dimethyl sulphoxide

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: benzo(a)pyrene at 5 μg/plate and 2-aminoanthracene at 2 μg/plate

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: not reported
- Exposure duration: not reported
- Expression time (cells in growth medium): not reported
- Selection time (if incubation with a selection agent): not reported
- Fixation time (start of exposure up to fixation or harvest of cells): not reported

NUMBER OF REPLICATIONS: not reported

NUMBER OF CELLS EVALUATED: not reported

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index

Evaluation criteria:

Mutagenicity Index

Statistics:

No data reported.

Results and discussion

Test results

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Additional information on results:

No data reported.

Remarks on result:

other: other: Modified Ames Test using Salmonella typhimurium strain TA 98 and Aroclor 1254-induced hamster liver S-9

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

The modified assay was used to rank the test samples, and a corn oil control, for relative mutagenic activity.  The ranking correlated closely  (r=0.97) with potency ratings from previously determined carcinogenicity bioassays.  Samples subjected to solvent refining were non-carcinogenic.

In the table below, the sample number in the study report along with the study ID and mutagenicity index of each substance is listed.

Sample Number	Sample ID	CAS#	Mutagenicity Index
7	Solvent-Refined/Hydrotreated Heavy Naphthenic Distillate	64741-96-4/ 64742-52-5	0
9	Solvent-Refined/Hydrotreated Heavy Paraffinic Distillate	64741-88-4/ 64742-54-0	0
10	Solvent-Refined/Hydrotreated Heavy Paraffinic Distillate	64741-88-4/ 64742-54-0	0
11	Solvent-Refined/Hydrotreated Heavy Paraffinic Distillate	64741-88-4/ 64742-54-0	0
13	Solvent-Refined/Dewaxed Heavy Paraffinic Distillate	64741-88-4/ 64742-65-0	0

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

All five solvent refined samples had mutagenicity indices of 0 and are therefore not considered positive in the AMES test for bacterial mutagenicity.

Executive summary:

In an in vitro modified Ames assay, five lubricating base oils were tested using S. typhimurium strain TA98 at concentrations of 50 micrlitres per plate. The solvent-refined samples tested were not mutagenic and had mutagenicity indices of 0. This study received a Klimisch score of 1 and is classified as reliable without restriction because it was carried out according to OECD TG 471.