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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: DNA damage and/or repair
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The work described was performed in compliance with UK GLP standards (Schedule 1, Good Laboratory Practice Regulations 1997 (SI 1997/654)). These Regulations are in accordance with GLP standards published as OECD Principles on Good Laboratory Practice (revised 1997, ENV/MC/CHEM(98)17); and are in accordance with, and implement, the requirements of Directives 87/18/EEC and 88/320/EEC.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Qualifier:
according to
Guideline:
EU Method B.12 (Mutagenicity - In Vivo Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes (incl. certificate)
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Sponser's identification: Ethyl Tetrahydrofurfuryl Ether
- Date Received: 18 November 1998
- Description: colourless liquid
- Storage conditions: room temperature in the dark under nitrogen

Data relating to the identity, purity and stability of the test material are the respsonibilty of the Sponser.

For the purpose of this study the test material was freshly prepared as required as a solution at the appropriate concentration in arachis oil.

With it not being a requirement of the test method the concentration, homogeneity and stability of the test material preparations were not determined by analysis.

Test animals

Species:
mouse
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River (UK) Limited, Margate, Kent.
- Age at study initiation: 5 - 8 weeks old.
- Weight at study initiation: 23 - 30g
- Assigned to test groups randomly: Yes - given a unique number within the study by ear punching and a number written on a colour coded cage card.
- Housing: In groups of upto 7, in solid-floor polypropylene cages with woodflake bedding.
- Diet): Free access to food (Rat and Mouse Expanded Diet No.1, Special Diets Services Limited, Witham, Essex, UK) was allowed troughout the study.
- Water: Free access to maine drinking water
- Acclimation period: five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 24°
- Humidity (%): 49 to 70%
- Air changes (per hr): approx. 15 changes
- Photoperiod (hrs dark / hrs light): Lighting controlled by a time switch to give twelve hours light and twelve hours darkness.

Administration / exposure

Route of administration:
oral: gavage

Examinations

Details of tissue and slide preparation:
Immediately following sacrifice (ie. 24 or 48 hours following dosing), both femurs were dissected from each animal, aspirated with foetal calf serum and bone marrow smears prepared following centrifugation and re- suspension. The smears were air-dried, fixed in absolute methanol and stained in May-Griinwald/Giemsa, allowed to air-dry and coverslipped using mounting medium.
Evaluation criteria:
Stained bone marrow smears were coded and examined blind using light _ microscopy at x1000 magnification. The incidence of micronucleated cells
per 2000 polychromatic erythrocytes (PCE-blue stained immature cells) per animal was scored. Micronuclei are normally circular in shape, although occasionally they may be oval or half-moon shaped, and have a sharp contour with even staining. In addition, the number of normochromatic erythrocytes (NCE-pink stained mature cells) associated with 1000 erythrocytes were counted; these cells were also scored for incidence of micronuclei.
The ratio of polychromatic to normochromatic erythrocytes was calculated together with appropriate group mean values and standard deviations.

Results and discussion

Additional information on results:
A comparison was made between the number of micronucleated polychromatic erythrocytes occurring in each of the test material groups and the number occurring in the corresponding vehicle control group.
A positive mutagenic response was demonstrated when a statistically significant dose-responsive increase in the number of micronucleated polychromatic erythrocytes was observed for either the 24 or 48-hour kill times when compared to their corresponding control group.
If these criteria were not demonstrated, then the test material was considered to be non-genotoxic under the conditions of the test.
A positive response for bone marrow toxicity was demonstrated when the dose group mean polychromatic to normochromatic ratio was shown to be statistically significantly lower than the concurrent vehicle control group.

All data were statistically analysed using appropriate statistical methods as recommended by the UKEMS Sub-committee on Guidelines for Mutagenicity Testing Report, Part III (1989). The data was analysed following a v/(x + 1) transformation using Student's t-test (two tailed) and any significant results were confirmed using the one way analysis of variance.

Applicant's summary and conclusion

Conclusions:
ETHYL TETRAHYDROFURFURYL ETHER was considered to be non-genotoxic under the conditions of the test.