Registration Dossier

Toxicological information

Genetic toxicity: in vivo

Currently viewing:

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
not stated
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The study was conducted according to a test protocol that is comparable to the appropriate OECD test guideline, with acceptable restrictions. Only 1000 erythrocytes were scored per animal, full experimental details were not reported, toxicity details were lacking. It was not compliant with GLP. Read across to the registered substance is considered scientifically justified.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
The toxicity of behenyl alcohol: I. Genotoxicity and subchronic toxicity in rats and dogs
Author:
Iglesias G, J J Hlywka, J E Berg, M H Khalil, L E Pope and D Tamarkin
Year:
2002
Bibliographic source:
Regulatory Tox. and Pharm. 36, 69-79 2002a

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
yes
Remarks:
(only 1000 PCEs per animal scored for micronuclei)
Principles of method if other than guideline:
Well-conducted study according to protocol very similar to OECD guideline 474
GLP compliance:
not specified
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): behenyl alcohol
- Substance type: colourless, waxy solid
- Physical state: solid
- Analytical purity: no data, but for repeated dose toxicity (oral), 98%
- Impurities (identity and concentrations): no data
- Composition of test material, percentage of components: no data
- Isomers composition: no data
- Purity test date: no data
- Lot/batch No.: no data, but for repeated dose toxicity (oral), obtained from Condea, Germany
- Expiration date of the lot/batch: no data
- Stability under test conditions: no data
- Storage condition of test material: no data
- Other:
- Melting point: 70 deg C
- Soluble in: ethanol and chloroform
- Insoluble in: water

Test animals

Species:
mouse
Strain:
NMRI
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: BRL Tierfarm Fullinsdorf, Switzerland
- Age at study initiation: >=10 weeks
- Weight at study initiation: no data
- Assigned to test groups randomly: no data
- Fasting period before study: 18 hours, but continued to receive water ad libitum
- Housing: Markrolon Type 1 cages with wire mesh tops and granulated soft wood bedding
- Diet (e.g. ad libitum): standard pellet diet, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21
- Humidity (%): not regulated
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: no data

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle(s)/solvent(s) used: polyethylene glycol
- Justification for choice of solvent/vehicle: no data
- Concentration of test material in vehicle: no data [calculated: 5, 15 and 50 mg/ml]
- Amount of vehicle (if gavage or dermal): 10 ml/kg bw
- Lot/batch no. (if required): no data
- Purity: no data
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: few details; test material suspended in vehicle
Duration of treatment / exposure:
single administration
Frequency of treatment:
single administration
Post exposure period:
none
Doses / concentrations
Remarks:
Doses / Concentrations:
50, 150, 500 mg/kg bw
Basis:
nominal conc.
No. of animals per sex per dose:
6
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide
- Justification for choice of positive control(s): no data
- Route of administration: presumably oral gavage
- Doses / concentrations: 40 mg/kg bw

Examinations

Tissues and cell types examined:
bone marrow cells
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: based on previous study - 500 mg/kg bw estimated to be the "maximum attainable dose"
TREATMENT AND SAMPLING TIMES (in addition to information in specific fields): 24, 48 and 72 hours after dosing

DETAILS OF SLIDE PREPARATION: femurs removed, marrow flushed out with foetal calf serum, cell suspension centrifuged and supernatant discarded, small drop of cell pellet spread on slide, air dried, stained with May-Grunwald, mounted; 1 slide/sample

METHOD OF ANALYSIS: 1000 polychromatic erythrocytes (PCEs) scored for micronuclei; polychromatic:normochromatic (PCE:NCE) ratio scored

OTHER: only 5/sex per dose level evaluated
Evaluation criteria:
To be considered positive, either a statistically significant dose-related increase in the number of micronucleated PCEs or a reproducible, statistically significant positive response for at least one dose level
Statistics:
Mann-Whitney test

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
not specified
Remarks:
presumably toxic at >500 mg/kg bw
Vehicle controls validity:
valid
Negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Dose range: no data
- Solubility: no data
- Clinical signs of toxicity in test animals: no data
- Evidence of cytotoxicity in tissue analyzed: no data
- Rationale for exposure: no data
- Harvest times: no data
- High dose with and without activation: no data
- Other: presumably toxic above 500 mg/kg bw since this maximum dose was chosen for the main study on the basis of the results of the range-finding study

RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): 0.03-0.09% for vehicle controls, 0.04-0.10% for test material treated, 0.71% for positive control
- Ratio of PCE/NCE (for Micronucleus assay): 1.05-1.27 for vehicle controls, 0.98-1.55 for test material treated, 0.93 for positive control
- Appropriateness of dose levels and route: appropriate (top dose was apparently the maximum tolerated dose, oral route relevant to humans)
- Statistical evaluation: no statistically significant increases in the frequency of micronuclei in mice treated with the test material; statistical significance not presented for positive control

Any other information on results incl. tables

Toxicity unclear, but possibly one male and one female mouse [per group?] died either spontaneously or due to gavage error.

Table 1 Results of micronucleus assay 24 hour sampling time

Treatment

Suspending agent

Low dose

Mid dose

High dose

Concentration mg/kg bw

0

40

50

150

Harvest time

24

24

24

24

Micronucleated PCE (%)

0.03

0.71

0.07

0.08

Ratio PCE/NCE

1.27

0.93

0.98

1.07

Table 2 Results of micronucleus assay 48 hour sampling time

Treatment

Suspending agent

Test substance

Test substance

Test substance

Concentration mg/kg bw

0

50

150

500

Harvest time

48

48

48

48

Micronucleated PCE (%)

0.09

0.1

0.04

0.05

Ratio PCE/NCE

1.05

1.06

1.01

1.23

Table 3 Results of micronucleus assay 72 hour sampling time

Treatment

Suspending agent

Low dose

Mid dose

High dose

Concentration mg/kg bw

0

50

150

500

Harvest time

72

72

72

72

Micronucleated PCE (%)

0.09

0.09

0.05

0.07

Ratio PCE/NCE

1.41

1.33

1.55

1.46

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
In a reliable study, behenyl alcohol (C22) did not increase the incidence of micronuclei in mouse bone marrow cells after a single oral gavage dose of up to 500 mg/kg bw.