Naphthalene

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:

1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study, basic data given, part of a comprehensive test programme

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

1986

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

1981

Reference 3

Reference Type:

publication

Title:

Unnamed

Year:

1992

Report date:

1992

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:

No guideline stated, but study was conducted according to Ames et al. (1975), Mutat. Res. 31, 347-364; comparable to guideline study and in accordance with OECD Guideline 471

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Naphthalene

EC Number:

202-049-5

EC Name:

Naphthalene

Cas Number:

91-20-3

Molecular formula:

C10H8

IUPAC Name:

naphthalene

Details on test material:

- Name of test material (as cited in study report): naphthalene (obtained from Fisher Scientific)
- Physical state: white crystalline powder
- Analytical purity: 99.8%

Method

Target gene:

his¯

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:

S9 mix from livers of Aroclor 1254 induced male Sprague-Dawley rats or Syrian hamsters

Test concentrations with justification for top dose:

0 (solvent control), 0.3, 1.0, 3.3, 10.0, 33.0, 100.0 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: acetone
- Justification for choice of solvent/vehicle: no data

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: without S9 mix: TA98 4-nitro-o-phenylenediamine, TA100 and TA1535 sodium azide, TA1537 9-aminoacridine; with S9 mix: 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min at 37°C
- Exposure duration: 48 h
- Expression time (cells in growth medium): 48 h at 37°C

NUMBER OF REPLICATIONS: triplicate plating

DETERMINATION OF CYTOTOXICITY
- Method: no data

Evaluation criteria:

Mutagenic response: a dose-related, reproducible increase in the number of revertants over background;
nonmutagenic response: when no increase in the number of revertants was elicited by the chemical;
questionable response: when there was an absence of a clear-cut dose-related increase in revertants,
when the dose related increases in the number of revertants were not reproducable,
when the response was of insufficient magnitude to support a determination of mutagenicity.

Statistics:

Mean and standard error of the mean of replicate plates were calculated.

Results and discussion

Test results

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:

cytotoxicity

Remarks:

in tests with the highest concentrations, toxicity was observed.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Detailed results of the NTP Ames test of naphthalene

Data of both experiments are reported. Individual strain data is presented as mean ± standard error. Abbreviations are noted below the tables. Study number is 471098. Study was completed in 1981.

 

 

Strain: TA1535

 

Dose	No Activation		No Activation		10% HLI		10% HLI		10% RLI		10% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
Protocol	Preincubation		Preincubation		Preincubation		Preincubation		Preincubation		Preincubation
µg/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0 (solvent control)	22	1.5	19	2.6	11	2.3	8	0.6	9	0.6	12	2.4
0.3			24	3.1
1	21	3	26	2.7	10	3.3	11	2.9	13	1.2	16	1.5
3.3	22	5.2	23	2.3	10	0.9	11	3.8	9	0.7	10	1.7
10	30	2.6	20	1.2	12	0.6	11	0.3	8	0.7	10	2.6
33	20s	1.2	15	2.3	13	1	11	1.7	11	1.5	13	1.2
100	15t	3.5			6s	1.9	10s	3.2	13s	3.4	11s	2.9
Positive Control	1258	18.8	687	6.4	126	1.7	75	8.9	63	8	48	1.9

 

 

Strain: TA100

 

Dose	No Activation		No Activation		10% HLI		10% HLI		10% RLI		10% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
Protocol	Preincubation		Preincubation		Preincubation		Preincubation		Preincubation		Preincubation
µg/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0 (solvent control)	143	4.5	141	4.2	143	11.9	128	6.2	144	2.4	137	8.2
0.3			121	3.5
1	146	5.8	124	3.6	143	13.2	115	7.9	130	2.7	143	16
3.3	124	12	117	8.5	155	4.9	135	2.4	133	13.2	133	5.9
10	145	5.8	113	6.2	140	3.5	118	9.8	135	8.7	121	6.6
33	141s	9.4	113	5.1	147	5.7	133	6.8	142	6.6	121	7.3
100	t				141s	2	145s	9	104s	0.6	127s	5.4
Positive Control	1636	45.5	801	28.7	2534	77.9	754	19.2	1074	13.2	792	26.4

 

 

Strain: TA98

 

Dose	No Activation		No Activation		10% HLI		10% HLI		10% RLI		10% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
Protocol	Preincubation		Preincubation		Preincubation		Preincubation		Preincubation		Preincubation
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0 (solvent control)	14	3.8	17	1	35	4.8	20	3.1	29	4.1	23	0.3
0.3			12	2.2
1	15	2.2	17	1.5	30	2.6	29	2.1	27	1.8	23	2.2
3.3	22	2.3	12	2.6	42	5.5	21	1.9	32	1.7	24	0.7
10	16	3.3	12	2.6	32	4.2	26	1.2	25	2.6	21	0.9
33	19s	2.5	12	3.2	32	3.1	21	1.2	29	1.9	24	2.8
100	14s	0.3			34s	1.5	23	2.4	22s	1.2	24	1.2
Positive Control	1772	9.6	1072	40.3	2064	71.4	183	10.1	982	43.1	176	16.6

 

 

Strain TA1537

 

Dose	No Activation		No Activation		10% HLI		10% HLI		10% RLI		10% RLI
	(Negative)		(Negative)		(Negative)		(Negative)		(Negative)		(Negative)
Protocol	Preincubation		Preincubation		Preincubation		Preincubation		Preincubation		Preincubation
ug/Plate	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
0 (solvent control)	8	1.8	8	1.9	10	1.2	6	2.4	11	3.8	10	2.3
0.3			7	1.2
1	8	0.6	5	0.6	11	1.2	8	0.3	10	0.9	8	0.7
3.3	7	1.5	9	0.6	9	3.2	7	0.9	9	0.9	9	0.9
10	8	0.7	9	1.5	12	2	10	1.5	8	1.7	5	2.2
33	6s	2	4	0.9	12	1.5	10	1.5	10	1.9	7	1.5
100	t				10s	1	5s	0.6	5s	1.9	4s	0.6
Positive Control	1010	39.4	185	12	205	22.1	77	5.3	87	5.2	86	2.9

 

 

Abbreviations:

RLI = induced male Sprague Dawley rat liver S9

HLI = induced male Syrian hamster liver S9

 

s = slight toxicity; p = precipitate; x = slight toxicity and precipitate; t = toxic; c = contamination

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

In a reverse gene mutation assay in bacteria according to Ames (1975) using four strains of S. typhimurium (TA 97, TA 98, TA 100, TA 1535, and TA 1537), naphthalene was tested negative at concentrations of 0.3, 1.0, 3.3, 10, 33, and 100 µg/plate in the presence and absence of mammalian metabolic activation (S9 mix from Arochlor 1254 induced rat and hamster liver). At the highest concentration some cytotoxicity was observed. Under the conditions of this test, naphthalene is not mutagenic to bacteria in vitro.