Chrome antimony titanium buff rutile

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

(purity unknown)

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Reference 2

Reference Type:

secondary source

Title:

C.I. Pigment Brown 24

Author:

OECD

Year:

2002

Bibliographic source:

SIDS Initial Assessment Report for SIAM 15

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Principles of method if other than guideline:

Clive et al., Mutat. Res. 189, 143-156 (1987)

GLP compliance:

yes

Type of assay:

other: in vitro Mammalian Cell Gene Mutation Assay

Test material

Test material information

Constituent 1

Reference substance name:

Chrome antimony titanium buff rutile

EC Number:

269-052-1

EC Name:

Chrome antimony titanium buff rutile

Cas Number:

68186-90-3

Molecular formula:

(Ti, Sb, Cr) O2

IUPAC Name:

manganese(4+) trititanium(4+) pentaantimony(3+) chromium(3+) nickel(2+) octadecaoxidandiide

Test material form:

solid

Method

Target gene:

thymidine kinase (TK)

Species / strain

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

- Type and identity of media:
Culture medium: RPMI 1640 supplemented with PluronicF68, L-glutamine, sodium pyruvate, antibiotics and 10% horse serum;
treatment medium: Fischer´s medium with same supplements but 5% horse serum;
cloning medium: same culture medium but 20% horse serum and without PluronicF68 and addition of BBL purified agar (0.24%);
selection medium: cloning medium containing 3 µg/ml of TFT (5-trifluorothymidine)
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: yes
- Periodically "cleansed" against high spontaneous background: yes

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced rat liver

Test concentrations with justification for top dose:

3.13, 6.25, 12.5, 25, 50, 100 µg/mL

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 4 h
- Expression time (cells in growth medium): 2 h
- Selection time (if incubation with a selection agent): 10-14 h

SELECTION AGENT: 5-trifluorothymidine (TIFT)

NUMBER OF REPLICATIONS: 2

NUMBER OF CELLS EVALUATED: approx. 3*10e5

Evaluation criteria:

- The minimum criterion considered necessary to demonstrate mutagenesis for any given treatment is a mutant frequency that is ≥ 2 times the concurrent background mutant frequency (as the average of the vehicle control cultures).
- A dose-related or toxicity-related increase in mutant frequency should be observed.
- If the mutant frequency obtained for a single dose at or near the highest testable toxicity is about two or more times the minimum criterion, the test substance will be considered mutagenic in a single trial.
- Treatments that induce less than ten percent relative growth are included in the assay, but are not used as primary evidence for mutagenicity as it relates to risk assessment.

Results and discussion

Test results

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Trial 1 was not considered acceptable because of cell culture problems (slower growth; positive control cultures were excessively cytotoxic; the vehicle control mutant frequencies, while still in the acceptable range, were higher than usual). However, no mutagenicity of the test substance was observed.

Trial 2:

Treatment	Metabolic activation	Suspension growth *a	Cloning efficiency *b	Relative growth *c	Mutant frequency (10e^-6units)*d
3.13	no	117	79	82	74
	yes	101	76	78	110
6.25	no	116	72	84	76
	yes	74	97	71	106
12.5	no	129	78	100	64
	yes	102	80	82	97
25	no	127	87	110	68
	yes	88	105	93	93
50	no	119	102	122	69
	yes	89	93	83	107
100	no	88	102	90	74
	yes	107	79	84	115

*a = relative to vehicle control

*b = relative to vehicle control, total viable colony count/number of cells seeded * 100

*c = (relative suspension growth + relative cloning efficiency) / 100

*d = relative to vehicle control, (total mutant colonies/ total viable colonies) * 2 * 10e^-4, decimal is moved to express the frequency in units of 10e^-6.