Diisopropylbiphenyl and triisopropylbiphenyl

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:

Aug 14, 1991 - Nov 22, 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted 1983

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted 1997

Deviations:

yes

Remarks:

no strain to detect cross-linking mutagens included

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Diisopropylbiphenyl and triisopropylbiphenyl

EC Number:

915-589-8

Molecular formula:

not applicable for UVCB substance

IUPAC Name:

Diisopropylbiphenyl and triisopropylbiphenyl

Details on test material:

- Name of test material (as cited in study report): Sure Sol®-300 (provided by Koch Chemical Company., Wichita, Kansas, USA)
= compound of diisopropyl-1,1'-biphenyl [CAS no. 69009-90-1] and tris(1-methylethyl)-1,1'-biphenyl [CAS no. 29225-91-0],
~60% and ~35%, resp., plus other alkylbiphenyls (not specified: ~5% (acronym: di-IPB/tri-IPB, not specified in the report)
- Reference: Koch Chem. Comp USA 1999: Sure Sol 300 - MSDS 10 Feb. 1999
- Substance type: organic
- Physical state: clear, colorless liquid
- Analytical purity: no data
- Impurities (identity and concentrations): no data
- Lot/batch No.: 1581-47
- Expiration date of the lot/batch: 01/01/1993
- Storage condition of test material: room temperature, protected from exposure to 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 1538

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat liver S9 (prepared from male Sprague-Dawley rats)

Test concentrations with justification for top dose:

Range finding test (tester strain TA 100, with and without S9 mix): 6.7, 10, 33, 67, 100, 333, 667, 1000, 3333, 5000 µg per plate and vehicle control
(vehicle: DMSO)
Main experiment and confirmatory assay: 100, 333, 1000, 3333, 5000 µg per plate and vehicle control (vehicle: ethanol)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO (range finding test), ethanol (main experiment)
- Justification for choice of solvent/vehicle: In the range finding test precipitation but no appreciable toxicity was observed.
Therefore ethanol was chosen as an appropriate solvent in the main experiment.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: see table below

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

NUMBER OF REPLICATIONS: 3 per tester strain and concentration, with or without S9 mix

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

Evaluation criteria:

A test substance is 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 98 and TA 100 mutation rate is at least twice as high as the rate of the solvent control;
- if in TA 1535, TA 1537, and TA 1538 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.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Yes (Range finding test with DMSO as solvent)

RANGE-FINDING/SCREENING STUDIES: Results indicated that precipitate of test item but no appreciable toxicity was observed.

Any other information on results incl. tables

A 1.8 -fold dose-responsive increase with tester strain TA98 (with S9) was not reproducible. Also a 2.3 -fold dose-responsive increase in tester strain TA1537 (with S9) was not reproducible.

Applicant's summary and conclusion

Conclusions:

Interpretation of results:
negative with metabolic activation
negative without metabolic activation

Under the conditions of the study, alkylation and transalkylation products of biphenyl with propene did not cause a positive response with any of the tester strains with or without metabolic
activation.