Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1983
Report Date:
1983

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EU Method B.11 (Mutagenicity - In Vivo Mammalian Bone-Marrow Chromosome Aberration Test)
Version / remarks:
rules of GLP practice (Fed. Register, 22.12.78 and 11.04.80)
GLP compliance:
yes
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): HF 0021 , Glyoxylic Acid 50%
- Physical state: clear, yellowish liquid
- Composition of test material, percentage of components: 50 % aqueous solution
- Lot/batch No.: Bac 203 A (5.10.82)

Test animals

Species:
mouse
Strain:
CD-1
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River France breeding center
- Age at study initiation: 11-12 weeks
- Housing: animalös were kept 2 and/or 4 to a sterilisable polycarbonate cage
- Diet: pellet feed ad libitum
- Water: sterilised by filtration (millipore) ad libitum
- Acclimation period: 11 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 2 °C
- Humidity (%): 50 ± 20 %
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- clear, sterile pyogen-free water
Details on exposure:
Administraton:

Oral route (negative control and HF0021):
- orally by intubation in the volume of 25 ml/kg bw using a stainless steel, curved oesophagial cannula 16/10 mm in diameter and
40 mm long mounted on aq syringe

Intraperitoneal route (positive controls):
- intraperitoneally using a disposable 25 G needle 0.5 mm in diameter and 1.6 mm long
Duration of treatment / exposure:
48 hours
Frequency of treatment:
- 2 doses were administererd at an intervall of 24 hours, in the morning between 8.30 and 9.30 a.m.
Post exposure period:
24 hours
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 183, 366 or 914 mg/kg bw
Basis:
nominal conc.
gavage
No. of animals per sex per dose:
4
Control animals:
yes
yes, concurrent vehicle
Positive control(s):
- benzo(a)pyrene : 500 mg/kg bw
- cyclophosphamide: 100 mg/kg bw

- Route of administration: intraperitoneally

Examinations

Tissues and cell types examined:
1) Hematological investigations
- a blood sample was collected by puncture of the retro-orbital sinus before sacrifice
performed: red blood count, haematokrit, haemoglobin, mean corpuscular volume, white blood count

2) Counting the micronuclei:
- femurs were removed after killing and bone marrow smears were prepared on a slide and stained
- The counts are based on examination of 1000 polychromatic erythrocytes
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION:
The doses were set at 1/2, 1/5 and 1/10 of the LD50 of HF 0021 administered by oral route to the mouse

Statistics:
The values obtained for treated animals were compared with those obtained for control animals by means of a Student' t test.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Remarks:
(but highest dose level corresponded to half ot the mouse LD50)
Vehicle controls validity:
valid
Negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
The substance HF 0021 (Glyoxylic Acid 50 %) was tested for mutagenicity in the mouse using the micronucleus test.

The results of the haematological investigations showed that the red cell parameters were normal for the animals treated with HF 0021.

The number of micronuclei found in the polychromatophilic erythrocytes of animals treated with the test substance was no greater than the number found in the negative control group.

The mutagenicity of benzo(a)pyrene and of cyclophophamide was confirmed by this test.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
Under the experimental conditions, the substance HF 0021 (Glyoxylic Acid 50%) was found to have no mutagenic properties.
Executive summary:

In a Crl:Cobs CD-1 (1 CR) mouse bone marrow micronucleus assay, 4 animals/sex/dose were treated by gavage with Glyoxylic Acid 50% at doses of 0, 183, 366, or 914  mg/kg bw.  Bone marrow cells were harvested 24 hours post-treatment. The vehicle was water. The highest dose corresponded to 1/2 of the mouse LD50 and thus represents the maximum tolerable dose.

There were no signs of toxicity during the study. The positive controls (Benzo(a)pyrene and Cyclophosphamide) induced the appropriate response. There was not a significant increase in the frequency of micronucleated polychromatic erythrocytes in bone marrow up to the dose of 914 mg/kg bw after treatment time.