Ichthyolic acid, sodium salt

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:

From March 9th, 1993 to March 21st, 1993 (end of experimental phase)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

The study was performed according to the EEC guidelines L 251: part B: Methods for the Determination of Toxicity - Mutagnicity (Salmonella typhimurium - reverse mutation assay), dated September 19th, 1984, vol. 27, p. 143 and of the OECD Guidelines for Testing of Chemicals (No. 471, adopted 26 May 1983).

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Ichthyolic acid, sodium salt

EC Number:

215-671-7

EC Name:

Ichthyolic acid, sodium salt

Cas Number:

1340-06-3

IUPAC Name:

Identification of the UVCB substance by "Chemcial Abstracts Index Name", among others: Ichthyolic Acid, Sodium Salt. No IUPAC name known.

Test material form:

liquid

Method

Test concentrations with justification for top dose:

In a preliminary experiment using strain TA 100 a cytotoxic effect was observed at 31.6 microliters and 100.0 microliters/plate. Hence it was decided to use 100.0 microliters test substance as the top concentration in the main study.

Vehicle / solvent:

Aqua ad iniectabilia served as solvent (negative) control.

Controls

Untreated negative controls:

yes

Remarks:

Aqua ad iniectabilia served as solvent (negative) control.

Negative solvent / vehicle controls:

yes

Remarks:

Aqua ad iniectabilia served as solvent (negative) control.

True negative controls:

yes

Remarks:

Aqua ad iniectabilia served as solvent (negative) control.

Positive controls:

yes

Remarks:

with metabolic activation: sodium azide (in H2O), 2-nitrofluorene (in DMSO) and 9-aminoacridine (in ethanol) without metabolic activation: 2-aminoanthracene (in DMSO)

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

other: 2-aminoanthracene in DMSO (with metabolic activation)

Details on test system and experimental conditions:

The Salmonella typhimurium histidine (his) reversion system is a microbial essay which measures his- -> his+ reversion induced by chemicals which cause base changes or frameshift mutations in the genome of this organism.

Evaluation criteria:

A test chemical is considered to show a positive response if (i) the number of revertants is significantly increased (p <= 0.05, U-test) compared to the solvent control to at least 2-fold of the solvent control for TA 98 and TA 100 and 3-fold of the solvent control for TA 1535, TA 1537 and TA 1538 in both experiments, (ii) a significant (p <= 0.05) dose (log value)-related effect is observed, (iii) positive results have to be reproducible and the histidine independence of the revertants has to be confirmed by streaking random samples on histidine-free agar plates.

Statistics:

A test chemical is considered to show a positive response if (i) the number of revertants is significantly increased (p <= 0.05, U-test according to MANN and WHITNEY see reference below) compared to the solvent control to at least 2-fold of the solvent control for TA 98 and TA 100 and 3-fold of the solvent control for TA 1535, TA 1537 and TA 1538 in both experiments, (ii) a significant (p <= 0.05) dose (log value)-related effect (Spearman's rank correlation coefficient, see reference below) is observed, (iii) positive results have to be reproducible and the histidine independence of the revertants has to be confirmed by streaking random samples on histidine-free agar plates.

reference given for statistical evaluation (as mentioned above): COLQUHOUN, D., Lectures on Biostatistics, Clarendon Press, Oxford (1971)

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

A slight cytotoxic effect was observed at 31.6 microliter and 100.0 microliter/plate in a preliminary test. Hence 100.0 microliter/plate was chosen as top concentration for the main study.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

A slight cytotoxic effect was observed at 31.6 microliters and 100.0 microliters/plate. Hence 100.0 microliters/plate was chosen as top concentration for the main study.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

A slight cytotoxic effect was observed at 31.6 microliter and 100.0 microliter/plate in a preliminary test. Hence 100.0 microliter/plate was chosen as top concentration for the main study.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

A slight cytotoxic effect was observed at 31.6 microliter and 100.0 microliter/plate in a preliminary test. Hence 100.0 microliter/plate was chosen as top concentration for the main study.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

A slight cytotoxic effect was observed at 31.6 microliter and 100.0 microliter/plate in a preliminary test. Hence 100.0 microliter/plate was chosen as top concentration for the main study.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

No mutagenic effect was observed for ICHTHYOL PALE tested up to 100.0 microliter/plate in any of the tester strains in two independent experiments with and without metabolic activation.