Reaction mass of ethane-1,2-diol and 2-hydroxyethyl formate and ethylene diformate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Toxicology and carcinogenesis studies of ethylene glycol (CAS No. 107-21-1) in B6C3F1 mice (feed studies)

Author:

US NTP

Year:

1993

Bibliographic source:

NIH Publication NO.93-314, NTP TR 413

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Version / remarks:

1983

Deviations:

not specified

GLP compliance:

not specified

Type of assay:

other: Chromosomal aberration in vitro

Test material

Test material information

Constituent 1

Reference substance name:

Ethane-1,2-diol

EC Number:

203-473-3

EC Name:

Ethane-1,2-diol

Cas Number:

107-21-1

Molecular formula:

C2H6O2

IUPAC Name:

ethylene glycol

Method

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Cytokinesis block (if used):

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 mix from Aroclor 1254 induced rat livers

Test concentrations with justification for top dose:

Test concentrations with and without S9: 160, 500, 1600, 5000 µg/mL ethane-1,2-diol

Vehicle / solvent:

Since ethan-1,2-diol was soluble in the culture medium (McCoy's 5A medium) no vehicle was used.

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

-S9

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

+S9

Details on test system and experimental conditions:

Total cells counted: 100 per concentration

Without S9:
Cells were incubated in McCoy's 5A medium with the ethylene glycol for 10 hours; Colcemid was added and incubation continued for 2 hours. The cells were then harvested by mitotic shake-off, fixed, and stained with Giemsa.

With S9:
Cells were treated with ethylene glycol and S9 for 2 hours, after which the treatment medium was removed and the cells incubated for 10 hours in fresh medium, with Colcemid present for the final 2 hours. Cells were harvested in the same manner as for the treatment without S9.

Evaluation criteria:

Cells were selected for scoring on the basis of good morphology and completeness of karyotype (21 ± 2 chromosomes). All slides were scored blind and those from a single test were read by the same person.

Classes of aberrations: simple (breaks and terminal deletions), complex (rearrangements and translocations), and other (pulverized cells, despiralized chromosomes, and cells containing 10 or more aberrations).

Statistics:

Statistical analyses were conducted on both the slopes of the dose-response curves and the individual dose points. Data are presented as percentage of cells with aberrations.

For a single trial, a statistically significant (P≤0.05) difference for one dose point and a significant trend (P≤0.015) were considered weak evidence for a positive response (+w); significant differences for two or more doses indicated the trial was positive (+)

Results and discussion

Test results

Key result

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

see attached background material

Applicant's summary and conclusion

Conclusions:

Ethane-1,2 -diol was considered to be negative in the chromosome aberration assay in CHO cells under the conditions of the study.

Executive summary:

Ethane-1,2 -diol was tested in Chinese hamster ovary cells with and without metabolic activation for its potential to induce chromosomal aberrations. Cells were incubated in culture medium with ethane-1,2 -diol at 0, 160, 500, 1600, 5000 µg/mL. Appropriate negative and positive controls were used in parallel.

No cytotoxicity was seen even at the highest dose tested. The negative and positive controls showed the expected results. The number of aberrations/cell and percent cells with aberrations were not increased.

It can be concluded that ethane-1,2 -diol is not clastogenic.