Bis(2-(2-methoxyethoxy)ethyl) ether

Genetic toxicity: in vivo

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 from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

2 November - 10 November 1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The target chemical belongs to the homologues series of glymes, where there is an incremental increase in the number of CH2CH2O units. Therefore, it can be assumed that target and other glyme members (mono-, di-, and triglyme) share the same toxic mode action.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

early sample collection

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

1,2-dimethoxyethane

EC Number:

203-794-9

EC Name:

1,2-dimethoxyethane

Cas Number:

110-71-4

IUPAC Name:

1,2-dimethoxyethane

Constituent 2

Reference substance name:

Monoglyme

IUPAC Name:

Monoglyme

Details on test material:

colorless clear liquid
Purity: > 99%
- MW 90.12
- LogPow - 0.21
- Vapour pressure (20°C) 6600 Pa
- Water solubility miscible

Test animals

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

50 NMRI mice (Hoe NMRKf(SPF71, Breeder: Pharma Forschung Toxikologe, Kastengrund, Germany)
Age: 7-12 weeks
Body weight:
- male: 30-38 g (mean: 33 g)
- female: 23-27 g (mean: 25 g)
Housing: groups of five animals in Makrolon type-3 cages with wire mesh tops and softwood bedding
Diet: pelleted Altromin diet 1324 ad libitum
Water: Community tap-water, ad libitum
Room temperature: 22-24°C
Humidity: 41-49%

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

deionised water

Details on exposure:

A pre study revealed that 2000 mg/kg bw/d was the maximum tolerated dose.

Treatment:
Five males and five females were assigned to each test group. Animals were treated orally twice (one application per day) with either three doses of the test substance, the positive control (Cyclophosphamide) or the vehicle control (deinised water). Six hours after the last application the bone marrow of the animals was prepared.

Preparation of the animals:
The animals were killed and the femora were removed, the epiphyses were cut off and the marrow was flushed out with foetal calf serum using a syringe. The cell suspension was centrifuged at 1000 rpm for 5 min and the supernatant was discarded. A small drop of re-suspended cell pellet was spread on a slide. The smear was air-dried and stained with May-Grünwald/Giemsa.

Bone marrow smears were scored microscopically for micronucleated polychrmoatic erythrocytes. To analyse target organ cytotoxicity the ratio between polychrmoatic and normochromatic erythrocytes was determined. 2000 polychromatic erythrocytes per animal were analysed for appearance of micronuclei. The count of micronuclei containing normocytes was determined.

Duration of treatment / exposure:

2 applications (one per day)

Frequency of treatment:

daily

Post exposure period:

6 hours

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
20 mg/kg bw/d
Basis:
actual ingested

Doses / concentrations 2

Remarks:

Doses / Concentrations:
200 mg/kg bw/d
Basis:
actual ingested

Doses / concentrations 3

Remarks:

Doses / Concentrations:
2000 mg/kg bw/d
Basis:
actual ingested

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide 100 mg/kg bw/d

Examinations

Tissues and cell types examined:

Please refer to "Details on exposure"

Details of tissue and slide preparation:

Please refer to "Details on exposure"

Evaluation criteria:

5 animals per group and sex and 2000 polychromatic erythrocytes per animal were evaluated.

Statistics:

Performed by computer programm "Diamant" (Code: SG-PA Nr. 4453) programmed by the Department of Praktische Methamatik of the Hoechst AG, Frankfurt, Germany.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

Please refer to "Remarks on results"

Any other information on results incl. tables

Analogue approach Justification (target chemical: tetraglyme; source chemical: monoglyme):

a.   The target chemical belongs to the homologues series of glymes, where there is an incremental increase in the number of CH2CH2O units. Therefore, it can be assumed that target and other glyme members (mono-, di-, and triglyme) share the same toxic mode action.

b.   The findings in repeated dose toxicity studies are comparable for target and source chemicals: the target is the male reproductive organ. Further, findings in thymus and altered hematological values are indicative of altered blood system.

c.    The findings in reproductive performance are comparable: No live pubs and/or reduced number of pubs were the common finding.

d.   The findings in developmental toxicity studies are comparable: the most notable findings were paw skeletal malformations. These findings were observed also at dose levels not associated with apparent maternal toxicity.

Results ofin vivo Micronucleus Test in NMRI-Mice (males)

 

Dose [mg/kg bw/d]	Animal No.	MN^1/ 2000 PE^2	MN^1/ 1000 NC^3	Ratio PE^2/NC^3
Control	1	6	1	751:1000
	2	9	2	725:1000
	3	5	3	865:1000
	4	9	1	839:1000
	5	8	1	858:1000
20	11	6	1	966:1000
	12	10	4	748:1000
	13	7	1	823:1000
	14	10	3	823:1000
	15	8	2	607:1000
200	21	5	2	710:1000
	22	4	4	796:1000
	23	7	2	791:1000
	24	7	3	1063:1000
	25	9	1	663:1000
2000	31	5	2	969:1000
	32	3	2	1217:1000
	33	7	4	673:1000
	34	8	1	767:1000
	35	14	2	956:1000
Cyclophosphamide	41	154	2	649:1000
	42	184	3	343:1000
	43	162	3	489:1000
	44	165	4	440:1000
	45	211	4	450:1000

¹          Micronuclei

²          polychromatic erythrocytes

³          NormocytesResults ofin vivoMicronucleus Test in NMRI-Mice (females)

 

Dose [mg/kg bw/d]	Animal No.	MN^1/ 2000 PE^2	MN^1/ 1000 NC^3	Ratio PE^2/NC^3
Control	6	4	0	920:1000
	7	1	1	907:1000
	8	8	1	1126:1000
	9	6	2	891:1000
	10	9	2	1098:1000
20	16	8	5	1054:1000
	17	5	1	851:1000
	18	5	3	851:1000
	19	4	1	986:1000
	20	6	1	913:1000
200	26	5	1	928:1000
	27	5	4	1336:1000
	28	5	0	961:1000
	29	5	2	838:1000
	30	10	2	1195:1000
2000	36	8	1	991:1000
	37	5	2	1350:1000
	38	9	3	916:1000
	39	9	4	1223:1000
	40	10	2	1205:1000
Cyclophosphamide	46	122	2	496:1000
	47	70	1	563:1000
	48	148	1	345:1000
	49	134	2	512:1000
	50	146	4	446:1000

¹          Micronuclei

²          polychromatic erythrocytes

³          Normocytes

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
Based on the analogue approach using monoglyme as read-across supporting substance, tetralyme is not considered to be mutagenic.

Executive summary:

The mutagenicity of tetraglyme was assessed based on the analogue approach using monoglyme as read-across supporting substance.

Animals treated with monoglyme up to 2000 mg/kg bw/d (2 applications, one daily) did not show any clinical sign. All animals survived until the study termination.

The number of micronuclei containing polychromatic erythrocytes and normocytes were not influenced by the treatment with monoglyme. The ratio polychromatic erythrocytes/normocytes did not differ to the ratio obtained from the negative control animals.

Cyclophosphamide (positive control) showed a significant increase of induced mirconucleus frequency.

In conclusion, it can be stated that during the study monoglyme did not induce micronuclei as determined by the micronucleus test in the bone marrow cells of the mouse. Based on the analogue approach using monoglyme as read-across supporting substance, tetralyme is not considered to be mutagenic.