Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study did not identify if it was conducted in accordance with Good Laboratory Practices (GLP); however, quality assurance was equivalent. Purity of test material not reported.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report date:
1990

Materials and methods

Test guideline
Qualifier:
no guideline required
Principles of method if other than guideline:
Internal Method No. 185.3, Experimental Toxicology+
References:
- Schmid, W., The micronucleus test for cytogenetic analysis In: Hollaender, A. (ed.) Chemical Mutagens, vol. 4, Plenum Press, New York, 1976, p.31-53.
- Schmid, W., The micronucleus test In: Handbook of mutagenicity test procedures B.J. Kilbey et al. (eds.), Elsevier, Amsterdam, New York, Oxford, 1977, p.235-242.
GLP compliance:
no
Type of assay:
mammalian erythrocyte micronucleus test

Test material

Constituent 1
Reference substance name:
26385
IUPAC Name:
26385
Constituent 2
Reference substance name:
di-n-butyltin oxide
IUPAC Name:
di-n-butyltin oxide
Details on test material:
- Name of test material (as cited in study report): Di-n-butyltin oxide, ZK Number 26385
- Supplier: Witco GmbH, Bergkamen, Germany
- Physical state: Suspended in tap water
- Analytical purity: 99.38%

- Lot/batch No.: W 98/43
- Expiration date of the lot/batch: At least until May 1999 (according to information provided by sponsor)

- Stability under test conditions: At least until May 1999 (according to information provided by sponsor)
- Storage condition of test material: the tin-carbon bonds of the butyltin compound are stable in aqueous solutions

Water solubility : 4 mg/l at 20 degrees Celsius (according to information provided by sponsor)

Test animals

Species:
mouse
Strain:
NMRI
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
Test material vehicle:
- Vehicle(s)/solvent(s) used: arachis oil
- Justification for choice of solvent/vehicle: nda
- Concentration of test material in vehicle: 5, 10 and 20 mg/ml
- Amount of vehicle (if gavage or dermal): 10 ml/kg
- Lot/batch no.: 82207/2

Positive control vehicle:
- Vehicle(s)/solvent(s) used: physiol. saline
- Justification for choice of solvent/vehicle: nda
- Concentration of test material in vehicle: 0.015 mg/ml
- Amount of vehicle (if gavage or dermal): 10 ml/kg
- Lot/batch no. (if required): NAW 04 B
- Purity
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
The test material was dissolved in arachis oil.
Dosing concentrations are 50, 100 and 200 mg/kg. They were given by oral gavage once in the morning to 15 or 18 (3 reserve animals of each sex for the high-dose group) randomly selected male and female mice. Control animals (15 males and 15 females) were given the vehicles at 10 ml/kg in the same manner.
It was assumed from a preceeding acute toxicity study that 200 mg/kg would be a dose level at which toxic effects might be noted.
Duration of treatment / exposure:
5 males and 5 females from each of the negative control and the test material groups were killed by cervical dislocation 24, 48 or 72 hours after treatment (the positive control animals were killed 24 hours after treatment)
Frequency of treatment:
Single oral dose
Post exposure period:
Observed until termination
Doses / concentrationsopen allclose all
Dose / conc.:
50 other: mg/kg actual ingested
Dose / conc.:
100 other: mg/kg actual ingested
Dose / conc.:
200 other: mg/kg actual ingested
No. of animals per sex per dose:
15 males and 15 females (30 in total). 3 additional reserve animals of each sex for the high-dose group were also us
Control animals:
yes
Positive control(s):
- Positive control substance: Triaziquone
- Justification for choice of positive control(s): nda
- Route of administration: single i.p. treatment
- Doses / concentrations: 0.15 mg/kg, 10 ml/k

Examinations

Tissues and cell types examined:
Bone marrow erythrocytes
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION:
It was assumed from a preceeding acute toxicity study that 200 mg/kg would be a dose level at which toxic effects might be noted.

TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields):
Single oral doses of the concentrations were 50, 100 and 200 mg/kg. 5 males and 5 females from each the negative control and the test material groups were killed by cervical dislocation 24, 48 or 72 hours after treatment (the positive control animals were killed 24 hours after treatment)

DETAILS OF SLIDE PREPARATION:
Both femurs were dissected out from each animal. The bone marrow was flushed/aspirated into fetal calf serum. The resulting cell suspensions were centrifuged and smears were prepared from drops of the cell pellets which had been resuspended in a few drops of serum. The slides were air-dried and stained using May-Gruenwald and Giemsa solutions.

METHOD OF ANALYSIS:
The slides were coded and analyzed "blind" in random order. The stained smears were examined using oil immersion, high power magnification in regions where cells were well spread and stained. The slides were examined for the incidence of micronucleated cells per 2000 polychromatic (PCE) and 1000 normochromatic (NCE) erythrocytes per animal. The ratio of polychromatic to normochromatic erythrocytes was calculated on the basis of 1000 NCE scored.
Evaluation criteria:
Any toxic effect of the test material on the immature nucleated cells may lead either to a reduction in cell division or to cell death. These effects in turn lead to a reduction in cell numbers and to compensate for this, peripheral blood is shunted into the bone marrow. Therefore, a decrease in the frequency of polychromatic erythrocytes is taken as being indicative of toxicity.
Statistics:
The statistical analysis was conducted for each of the following variables:
p1: proportion of micronucleated PCE
p2: proportion of micronucleated NCE
p3: ratio of PCE/NCE

The analyses were conducted separately for the sample times. Regarding the first sample time one-sided t-tests were performed to assess the difference between positive and negative controls with pooled values for both sexes; thereafter the positive control group was excluded from further analysis. Thereafter in a two-factorial ANOVA (factors "sex", "treatment") for each sample time it was investigated as to whether any treatment effect was present. In case of significant interactions, comparisons between the control and each of the treatment groups were conducted separately for each sex. Where no significant interactions occurred, but a global treatment effect, comparisons were performed with values pooled for both sexes. The pair-wise comparisons were performed with one-sided t-tests (increase in p1 and p2, decrease in p3), using the error estimate of the ANOVA table. The test levels were always a = 0.05 (least significant differences test-LSD).

Results and discussion

Test results
Key result
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Vehicle controls validity:
valid
Negative controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
From the results obtained, it is concluded that the test material failed to produce any increase in the number of micronucleated polychromatic erythrocytes in male and female mice and so failed to show any evidence of mutagenic potential up to 200 mg/kg