Reaction mass of m-terphenyl and o-terphenyl

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:

1982- 1983

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study, GLP-compliant, available as unpublished report, no restrictions, adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Ames, B. N., McCann, J., and Yamasaki, E. (1975). Methods for Detecting Carcinogens and Mutagens with the Salmonella Mammalian-Microsome Test. Mutat. Res. 31, 347-364.

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: MRC's standard operating procedure for Salmonella typhimurium (Document #B002R3).

Deviations:

no

Test guideline 3

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Terphenyl

EC Number:

247-477-3

EC Name:

Terphenyl

Cas Number:

26140-60-3

Molecular formula:

C18H14

IUPAC Name:

terphenyl

Details on test material:

- Name of test material: toluol soluble terphenyl and quarterphenyls
- Substance type: mixed-terphenyls, -quaterphenyls
- Physical state: solid
- Storage condition of test material: test materials were stored in the dark at refrigeration temperature prior to testing.

Method

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix

Test concentrations with justification for top dose:

0.01, 0.04, 0.2, 1.0, 3.0, 10.0 mg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: the test material is not soluble in water, partially soluble in ethanol, soluble in DMSO

Controls

Controls 1

Negative solvent / vehicle controls:

yes

Remarks:

100 µL of solvent per plate

Controls 2

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

TA1535, TA1537; with metabolic activation

Controls 3

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA1537; without metabolic activation

Controls 4

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

TA98, TA100; with metabolic activation

Controls 5

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

TA98, TA100; without metabolic activation

Controls 6

Positive controls:

yes

Positive control substance:

other: sodium nitrite

Remarks:

TA1535; without metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: Plates were incubated at 37°C (±1°C) for 48 hours

NUMBER OF REPLICATIONS: Three replicate plates for each strain/microsome/dose level combination

DETERMINATION OF CYTOTOXICITY
- Method: results indicating any effect on the growth of background lawns or any detectable plating interferences

Statistics:

Analysis included Bartlett's test for homogeneity of variance and comparison of treatments with controls uing within-levels pooled variance and a one-sided t-test.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 100

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

between 10-0.04 mg

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility: not soluble in water
- Precipitation: sample precipitates out on plates at 10, 3 and 1 mg/plate

ADDITIONAL INFORMATION ON CYTOTOXICITY:
In the toxicity screen, a concentration of > or = 1mg of sample per plate expressed a slight level of toxicity in the presence and absence of microsomal activation.

Any other information on results incl. tables

The plate incorporation assay: Summary

With microsomal activation
Amount/plate (mg)	Revertants/plate
	TA98			TA100			TA1535			TA1537
10.0	42	32	40	138	170	128	10	10	10	9	7	6
3.0	50	35	35	124	154	144	10	7	8	3	6	6
1.0	37	49	43	107	128	124	12	18	14	7	6	5
0.2	46	34	38	128	123	133	16	8	13	10	2	6
0.04	45	47	38	132	126	125	16	9	14	8	7	10
0.01	41	35	33	99	99	81	5	15	8	5	10	4
Controls
Solvent	29	39	38	119	84	81	14	10	12	10	11	11
Negative	45			75			6			8
Positive		861			1159			280			342

   

Without microsomal activation
Amount/plate (mg)	Revertants/plate
	TA98			TA100			TA1535			TA1537
10.0	25	28	28	97	74	73	12	4	12	8	5	4
3.0	27	20	34	77	83	86	5	11	9	5	5	7
1.0	25	29	31	69	60	93	12	7	11	8	6	4
0.2	27	24	30	97	50	58	8	9	6	12	10	5
0.04	27	29	35	78	74	61	11	16	6	12	9	4
0.01	28	30	26	74	77	68	7	5	6	7	6	7
Controls
Solvent	29	27	29	89	63	79	8	8	7	11	19	8
Negative	28			91			14			8
Positive		667			1174			535			1564

Applicant's summary and conclusion

Conclusions:

Interpretation of results: equivocal (overall result).
Individual results: negative without metabolic activation for TA98, TA100, TA1535 and TA1537; negative with metabolic activation for strain TA98, TA1535 and TA 1537; positive with metabolic activation only for strain TA100
The Ames test indicated that there was no activation without metabolic activation. With metabolic activation, one strain showed positive results (TA100) while all other strains were negative. However, this single positive result in TA100 has to be judged carefully when taking a closer look at the mean values of the plates of TA100+S9: 93/ 128 / 128 / 120 / 141 / 145 revertants per plate (solvent: 95 revertants/plate). As such, the test item showed only a slight increase by a factor of 1.5 which can not clearly be judged as biologically relevant (an increase of more than 12 times was found for the positive control). A report of the U.S. Environmental Protection Agency Gene-Tox-Program (Kier et al., 1986, [1]) points out that a biologically relevant increase in tester strain TA100 requires the number of reversions to be at least twice as high. As such, taking into account the information given in the guidance on the application of the CLP criteria and in the publication of Kier et. al, 1986, the obtained results do not allow for a clear derivation of a positive result and are considered as equivocal and questionable.
[1] Kier, L.E., Brusick, D.J., Auletta, A.E., von Halle, E.S., Brown, M.M., Simmon, V.F., Dunkel, V., McCann, J., Mortelmans, K., Prival, M., Rao, T.K. and Ray, V. (1986), The Salmonella typhimurium/mammalian microsomal assay. A report of the U.S. Environmental Protection Agency Gene-Tox–Program, Mutat. Res. 168, 69-240

Executive summary:

Mixture of terphenyls and quarterphenyls was not mutagenic with and without metabolic activation in Salmonella strains TA98, TA1535 and TA1537. The Mixture of terphenyls and quarterphenyls was not mutagenic without metabolic activation in Salmonella strain TA100. The experiments with the Mixture of terphenyls and quarterphenyls with metabolic activation revealed equivocal results in Salmonella strain TA100. A slight increase of the number of revertants per plate (factor of 1.5) was observed. However, this single positive result in TA100 has to be judged carefully when taking a closer look at the mean values of the plates of TA100+S9: 93/ 128 / 128 / 120 / 141 / 145 revertants per plate (solvent: 95 revertants/plate). As such, the Mixture of terphenyls and quarterphenyls showed only a slight increase by a factor of 1.5 which can not clearly be judged as biologically relevant (an increase of more than 12 times was found for the positive control). A report of the U.S. Environmental Protection Agency Gene-Tox-Program (Kier et al., 1986, [1]) points out that a biologically relevant increase in tester strain TA100 requires the number of reversions to be at least twice as high. As such, taking into account the information given in the guidance on the application of the CLP criteria, the obtained results do not allow for a clear derivation of a positive result and are considered as equivocal and questionable.

[1] Kier, L.E., Brusick, D.J., Auletta, A.E., von Halle, E.S., Brown, M.M., Simmon, V.F., Dunkel, V., McCann, J., Mortelmans, K., Prival, M., Rao, T.K. and Ray, V. (1986), The Salmonella typhimurium/mammalian microsomal assay. A report of the U.S. Environmental Protection Agency Gene-Tox–Program, Mutat. Res. 168, 69-240