Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

Administrative data

Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
Deviations:
yes
Remarks:
Only one cultivation instead of two was conducted per test series (no duplicate).
GLP compliance:
no
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Creosote WEI-Type B
- Name of test material (as cited in study report): Creosote Spéciale 14130
- Molecular formula (if other than submission substance): not applicable, UVCB
- Substance type: organic
- Physical state: liquid
- Composition:

[w/w%]
=========================
Aromatic hydrocarbons 89.7
Phenols 6.8
N-Compounds 3.4
Benzene 0.04
Toluene 0.22
Ethyl-Benzene 0.21
m/p-Xylene 0.70
Styrene 0.12
o-Xylene 0.24
Indane 3.1
Indene 2.9
Naphthalene 12.2
2-Me-Naphthalene 5.3
1-Me-Naphthalene 3.3
Diphenyl 2.7
Acenaphthene 12.6
Fluorene 10.3
Phenanthrene 4.6
Anthracene 1.2
Fluoranthene 0.7
B(a)P 15 ppm
B(a)A 40 ppm
B(b)F 15 ppm
B(h)F + B(j)F 10 ppm
DiB(a, h)A < 5 ppm
Phenol 0.5
o-cresol 1.7
p-cresol 1.4
m-cresol 1.6
Xylenols 1.3
===========================

Method

Species / strain
Species / strain / cell type:
lymphocytes: human
Metabolic activation:
with and without
Metabolic activation system:
microsomes derived from Arochlor1254-induced rat liver (male SD rats, 500 mg/kg i.p. 5 d prior to sacrifice)
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Remarks:
+ S9: cyclophosphamide (0.02 mg/mL)- S9: methyl methanesulphonate (0.05 mg/mL)

Results and discussion

Test results
Species / strain:
lymphocytes: human
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
0.15 mg/mL and 0.25 mg/mL highest concentrations exhibiting a reduction of the mitotic index of about 50 % and between 90.5 and 82.6 %, respectively.
Vehicle controls validity:
valid
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

Summary of cytogenetic In-Vitro-Test: Chromosomal Analysis

Vehicle control

0.05 mg/ml

0.1 mg/ml

0.15 mg/ml

0.25 mg/ml

cytotoxicity 

no

no

no

Yes
(MI ~ -50%)

Yes
(MI < -80%)

Metaphases scored (1sttest / 2ndtest)

100 / 100

100 / 100

100 / 100

100 / 100

100 / 100

100 / 100

- / 100

- / 100

19 / 97

38 / 38

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

chromatid aberrations

Gaps (TG)1)2)

1 / 3

3 / 2

1 / 0

3 / 1

1 / 2

2 / 0

- / 1

- / 2

0 / 4

2 / 0

Breaks (TB)2)

0 / 0

3 / 1

0 / 1

1 / 2

1 / 1

0 / 4

- / 1

- / 1

0 / 0

1 / 0

interchanges

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

Isochromatid aberrations

Gaps (SG)1)2)

0 / 2

1 / 0

1 / 0

0 / 0

1 / 1

0 / 0

- / 0

- / 0

0 / 1

0 / 1

Breaks (SB)2)

1 / 1

2 / 1

2 / 1

0 / 1

0 / 1

0 / 1

- / 4

- / 6

0 / 4

0 / 0

interchanges

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

uncoiled chromatin (UC)2)

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

1 / 0

- / 0

- / 0

0 / 0

0 / 0

mitotic index

4.2 / 5.4

4.6 / 5.4

5.4 / 6.0

4.4 / 5.0

4.2 / 4.6

4.6 / 4.2

- / 2.4

- / 3.0

0.4 / 1.4

0.8 / 1.2

polyploidy

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

- / 0

- / 0

0 / 0

0 / 0

endo reduplication

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

- / 0

- / 0

0 / 0

0 / 0

Mean number of aberrations per cells

0.01 / 0.01

0.05 / 0.02

0.02 / 0.02

0.01 / 0.03

0.01 / 0.02

0.00 / 0.05

- / 0.05 

- / 0.07

0.00 / 0.04

0.03 / 0.00

CH2test results

--

--

0.34 / 0.34

1.85 / 0.21

0.00 / 0.34

4.08 / 1.33

- / 1.85

- / 0.69

0.19 / 1.94

0.15 / 0.77

MI = Mitotic index; 

1)not included in total aberration frequency

2)TB, TG, SB, SB, UC = Abbreviations used in tables of the test report

----------------------------------------

The selected test concentrations clearly covered a cytotoxic range, with about 50 % depression of the mitotic index at the additional concentration of 0.15 mg/ml, as compared to vehicle control and the lower test levels.

Under the test conditions, the creosote WEI Type B (containing <50 ppm BaP) did not induce chromosome aberrations in human lymphocytes in culture in the presence and absence of metabolic activation. Based upon the CHI-square test (p <0.01), no statistical significance was found as compared with the vehicle control. Metabolic activation had no noticeable influence on the aberration spectrum and yield. The positive controls showed significant increases in aberration frequencies.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative
Executive summary:

A creosote containing less than 50 ppm BaP was tested according to standard guidelinesOECD 473 (1983) and EEC Directive 84/449, B.10 (1984). Blood had been obtained from healthy non-smoking volunteers, and lymphocytes were proliferated and stimulated through cultivation with phytohaemagglutinin (48 h). Exposure time was 3 h, post-exposure time 22 h. Cell growth was stopped by addition of colchicine (2 h incubation). In a preliminary test, the cytotoxic potential of the creosote was estimated (mitotic index without S9, based on 500 cells per concentration). A confirmatory second independent main study was performed without variation of culture parameters (except a further test concentration: see below).

In the second test series, a further test concentration (0.15 mg/ml) was introduced as 3rdof 4 concentrations, because the highest one previously selected proved to be too cytotoxic in the 1sttest series.

Besides examination of chromosomal aberrations, the mitotic index was concurrently determined for each concentration tested. Gaps were recorded, but not included in the final result of aberration frequency. Under the test conditions, the creosote WEI Type B (containing <50 ppm BaP) did not induce chromosome aberrations in human lymphocytes in culture in the presence and absence of metabolic activation. Based upon the CHI-square test (p <0.01), no statistical significance was found as compared with the vehicle control. Metabolic activation had no noticeable influence on the aberration spectrum and yield. The positive controls showed significant increases in aberration frequencies.