[No public or meaningful name is available]

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No OECD guideline defined.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: EEC Directive 92/69, L 383 A, Annex V, B 12 dated December 29, 1992

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 3-methylphenyl diphenyl phosphate, 4-methylphenyl diphenyl phosphate, bis(3-methylphenyl) phenyl phosphate, 3-methylphenyl 4-methylphenyl phenyl phosphate and triphenyl phosphate

Molecular formula:

3-methylphenyl diphenyl phosphate: C19H17O4P 4-methylphenyl diphenyl phosphate´: C19H17O4P triphenyl phosphate: C18H15O4P bis(3-methylphenyl) phenyl phosphate: C20H19O4P 3-methylphenyl 4-methylphenyl phenyl phosphate: C20H19O4P

IUPAC Name:

Reaction mass of 3-methylphenyl diphenyl phosphate, 4-methylphenyl diphenyl phosphate, bis(3-methylphenyl) phenyl phosphate, 3-methylphenyl 4-methylphenyl phenyl phosphate and triphenyl phosphate

Constituent 2

Reference substance name:

chemical name: Diphenyl tolyl phosphate MCS

IUPAC Name:

chemical name: Diphenyl tolyl phosphate MCS

Details on test material:

Diphenyl cresylphosphate (BG-Chemie No. 195); 99.9% (GC) total of Phenyl cresylphosphate; on the day of the experiment.

Test animals

Species:

mouse

Strain:

NMRI

Sex:

male/female

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

The test article was formulated in corn oil. The vehicle was chosen to its reletive non-toxicity for the animals.

Duration of treatment / exposure:

single administration

Frequency of treatment:

All animals received a single standard volume of 10 ml/kg body weight intraperitoneally.

Post exposure period:

Sampling of the bone marrow from animals treated with the highest dose was done 16,24, 48 hours after treatment. Bone marrow samples from animals treated with the low and medium dose were taken only at preparation interval 24 hours.

Doses / concentrations

Remarks:

Doses / Concentrations:
100, 300, 1000 mg/kg
Basis:
other: intraperitoneally

No. of animals per sex per dose:

5

Control animals:

yes

Positive control(s):

CPA; Cyclophosphamide

Examinations

Tissues and cell types examined:

The bone marrow cells were collected for micronuclei analysis; 1000 polychromatic erythrocytes per animal were scored for micronuclei

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

Any other information on results incl. tables

Summary of results:

test group	dose (mg/kg bw)	sampling time (h)	PCEs with micronuclei (%)	range	PCE/NCE
test article	1000	16	0.17	0 -5	1000/ 801
vehicle	0	24	0.11	0 -5	1000/ 721
test article	100	24	0.09	0 -4	1000/ 746
test article	300	24	0.14	0 -3	1000/ 905
test article	1000	24	0.22	1 -5	1000/1033
cyclophosphamide	30	24	1.70	6 -31	1000/ 829
test article	1000	48	0.08	0 -2	1000/ 824

The animals treated with 1000 mg/kg bw Diphenyl cresylphosphate expressed toxic reactions. Reduction of spontaneous activity, eyelid closure, and convulsion (females only within the first hour after administration of the test article) followed by apathy were observed. One out of 18 femeles treated with 1000 mg/kg bw Diphenyl cresylphosphate died.

Applicant's summary and conclusion

Conclusions:

The in-vivo micronuleus test in male and female mice was negative. In comparison to the corresponding negative controls there was no significant enhancement in the frequency of the micronuclei at any preparation interval after application of the test article and with any dose level used.

Executive summary:

A micronucleus assay was performed to investigate the potential of Diphenyl cresyl phosphate to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the mouse. The test article was formulated in corn oil. This vehicle was used as negative control. The volume administered intraperitoneally was 10 ml/kg bw. 16h, 24h, and 48h after a single application of the bone marrow cells were collected for micronuclei analysis. The occurrence of micronuclei in ten animals (5males, 5 females) per test group was evaluated. 1000 polychromatic erythrocytes (PCE) per animal were scored for micronuclei. To describe a cytotoxic effect due to the treatment with the test article the ratio between polychromatic and normochromatic erythrocytes (NCE) was determined in the same sample and reported as the number of NCE per 1000 PCE.

The following dose levels of the test article were investigated:

16 h preparation interval: 1000 mg/kg bw;

24 h preparation interval: 100, 300, and 1000 mg/kg bw.;

48 h preparation interval: 1000 mg/kg bw.

In a pre-experiment the highest dose administered was estimated to be the maximum tolerated dose. The animals expressed toxic reactions. Reduction of spontaneous activity, eyelid closure, and convulsions (females only within the first hour after administration of the test article) followed by apathy were observed. In the micronucleus assay the same toxic symptoms occurred and 1 out of 18 females treated with 1000 mg/kg bw Diphenyl cresylphosphate died. After treatment with the highest test article dose at preparation interval 24 hours the number of NCEs was slightly increased as compared to the corresponding negative control thus indicating that Diphenyl cresylphosphate had a cytotoxic effect. In comparison to the corresponding negative controls there was no significant enhancement in the frequency of the micronuclei at any preparation interval after application of the test article and with any dose level used. 30 mg/kg bw cyclophosphamide administered intraperitoneally was used as positive control which induced a distinct increase of the micronucleus frequency. In conclusion it can be stated that during the study described and under the experimental conditions reported, the test article did not induce micronuclei as determined by the micronucleus test with bone marrow cells of the mouse. Therefore, Diphenyl cresylphosphate is considered to be nonmutagenic in this micronucleus assay.