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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study with acceptable restrictions. Restrictions: no details about the purity of the TS.

Data source

Referenceopen allclose all

Reference Type:
study report
Reference Type:
Toxicity Assessment of Thiodiglycol
Reddy G, Major MA, Leach GJ
Bibliographic source:
International Journal of Toxicology, 24:435–442

Materials and methods

Test guideline
according to guideline
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Principles of method if other than guideline:
adopted 1997
GLP compliance:
Type of assay:
micronucleus assay

Test material

Constituent 1
Reference substance name:
Reference substance 001
Details on test material:
Lot No. 05701EQ, further data available from the sponsor

Test animals

Details on test animals or test system and environmental conditions:
- Strain: Crl:CD-1(ICR) BR
- obtained from Charles River Lab, Raleigh (North Carolina) (preliminary study) or St. Constant (Quebec) (main study)
- at least 6 days acclimatization period
- randomization of animals
- at start of treatment period in the main study males ca. 8 weeks old, bw range 30.0-34.5 g; in the preliminary study males and females ca. 8 weeks old, bw range
30.2-34.8 g and 22.8-25.4 g, respectively

- animals housed in dose groups; polycarbonate cages used with hardwood chip laboratory bedding.
- temperature 18-26°C; 30-70% relative humidity; light/dark cycle 12h/12h; ventilation at least 10 air changes per h;
- certified rodent diet #5002 and tap water ad libitum; no contaminants in diet, water and wood chips (analysed)

Administration / exposure

Route of administration:
oral: gavage
sterile deionized water
Details on exposure:
- Formulation procedure (main study)
Test substance (TS) dissolved in the vehicle (sterile deionized water) immediatly before use; concentrations of 0, 50, 100, 200 mg/ml TS or 8 mg/ml cyclophosphamide (positive control); administration volume 10 ml/kg bw in all groups.
Duration of treatment / exposure:
Single exposure
Frequency of treatment:
Post exposure period:
24 and 48 h
Doses / concentrations
Doses / Concentrations:
0, 500, 1000, 2000 mg/kg bw
actual ingested
No. of animals per sex per dose:
6 males in the main study
Control animals:
yes, concurrent vehicle
Positive control(s):
gavaged once with 80 mg/kg bw cyclophosphamide


Tissues and cell types examined:
Bone marrow smears prepared (air dried, fixed with methanol)
Details of tissue and slide preparation:
Slides stained with May-Grünwald followed by Giemsa staining) for microscopic examination. Evaluation of slides on a blind basis; for each mouse, the number of micronucleated polychromatic erythrocytes (MPE) counted in 2000 polychromatic erythrocytes (PE); the ratio of PE versus normochromatic erythrocytes (NE) determined by scoring 500 erythrocytes per mouse; historical background frequency of micronuclei in this strain at this lab is 0.0 to 0.4%.
Evaluation criteria:
A statistical significant increase in the frequency of MPE must be demonstrated for at least one dose level, and a statistically significant dose-related response; historical data and other considerations of biological relevance were taken into account.
Data analysed by using an analysis of variance (Winer, 1971) on untransformed proportions of cells with micronuclei per mouse and on untransformed PE:NE ratios when the variances were homogeneous; ranked proportions used for heterogeneous variances; differences from control analysed by Dunnett's t-test; parametric and nonparametric tests used for trend analysis.

Results and discussion

Test results
no effects
Vehicle controls validity:
Positive controls validity:
Additional information on results:
- Preliminary toxicity test
no clinical signs at any dose level; 2000 mg/kg bw used for the main study

- Clinical signs in the main study
no clinical signs observed in any group
- Cytogenetic in the main study
no significant differences in MPE values between vehicle controls and TS treated males of all dose groups; the PN/NE ratio was also not significantly altered in any TS treatment group; valid positive and negative control (also in comparison with historical data)

Any other information on results incl. tables

Cytogenetic summary table
Dose in mg/kg bw % MPE (SE) PE/NE ratio (SE)
and harvest time
vehicle 24 h 0.13 (0.02) 0.91 (0.03)
vehicle 48 h 0.09 (0.01) 0.84 (0.06)
500 24 h 0.09 (0.03) 0.79 (0.03)
1000 24 h 0.12 (0.03) 0.79 (0.04)
2000 24 h 0.11 (0.02) 0.82 (0.05)
2000 48 h 0.10 (0.02) 0.91 (0.04)
control 24 h 3.07 (0.35)** 0.67 (0.04)*

SE: standard error; *: p<0.05; **: p<0.01

Applicant's summary and conclusion

Interpretation of results (migrated information): negative
No mutagenic activity in the mouse bone marrow micronucleus test at dose levels up to 2000 mg/kg bw.
Executive summary:

Guideline study with acceptable restrictions (no details about the test substance).

In the mouse bone marrow micronucleus assay 6 male mice per dose were gavagaed once with 0, 500, 1000, or 2000 mg/kg and bone marrow prepared for evaluation 24 and 48 h after application. No increase in the frequency of micronuclei was detected. No clinical toxicity or cytotoxic effects on the bone marrow were found even at 2000 mg/kg bw, the highest test dose recommended by the current guideline. The positive controls were valid.

Conclusion: No mutagenic activity in the mouse bone marrow micronucleus test at dose levels up to 2000 mg/kg bw.