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Administrative data

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
17 Oct - 14 Nov 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline conform GLP-study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report date:
1992

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)
Deviations:
no
GLP compliance:
yes
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
1,2-bis(2-methoxyethoxy)ethane
EC Number:
203-977-3
EC Name:
1,2-bis(2-methoxyethoxy)ethane
Cas Number:
112-49-2
Molecular formula:
C8H18O4
IUPAC Name:
2,5,8,11-tetraoxadodecane
Constituent 2
Reference substance name:
Triethylene glycol dimethyl ether
IUPAC Name:
Triethylene glycol dimethyl ether
Constituent 3
Reference substance name:
2,5,8,11-Tetraoxadodecan
IUPAC Name:
2,5,8,11-Tetraoxadodecan
Details on test material:
clear, colorless liquid

Test animals

Species:
rat
Strain:
other: Hoe: WISKf (SPF71)
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Hoechst AG, Kastengrund, Germany
- Age at study initiation: 6 weeks
- Weight at study initiation: 104-118 g
- Housing: Group housing of 5 animals per sex in Macrolon cages with wodden granulate as bedding material
- Diet (e.g. ad libitum): Altromin 1324, ad libitum (except of duration of metabolism study)
- Water (e.g. ad libitum): tap water, ad libitum (except of duration of metabolism study)
- Acclimation period: at least 5 days before start of treatment under laboratory conditions

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 50 +/- 20%
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 17. October To: 14. November 1991

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Formulations (w/v) were prepared daily and were homogenized to visually acceptable levels.

- Concentration in vehicle: 0, 1.25, 5 and 20% (w/v)
- Amount of vehicle (if gavage): 5 ml/kg
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
29 days
Frequency of treatment:
Once daily, 7 days per week, approximately the same time each day with a maximum of 2.5 hours difference between the earliest and latest dose.
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0 mg/kg bw/d
Basis:
actual ingested
Remarks:
Doses / Concentrations:
62.5 mg/kg bw/d
Basis:
actual ingested
Remarks:
Doses / Concentrations:
250 mg/kg bw/d
Basis:
actual ingested
Remarks:
Doses / Concentrations:
1000 mg/kg bw/d
Basis:
actual ingested
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Details on study design:
Please refer to "Examinations"
Positive control:
No

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily mortality and viability

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least once daily

Weekly examination of eyes, oral mucosa, neurological anomalies and teeth

BODY WEIGHT: Yes
- Time schedule for examinations: twice weekly

FOOD CONSUMPTION: twice weekly
- Food consumption calculated as g food/100 g body weight/day
- Water consumption: weekly

HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to scheduled post mortem examination at the end of the treatment
- Anaesthetic used for blood collection: Yes (Ketanest)
- Animals fasted: no
- How many animals: all animals
- Parameters examined: Red blood cells, Haemoglobin, Haematocrit, Mean corpuscular volume, Mean corpuscular haemoglobin, Mean corpuscular haemoglobin concentration, White blood cells, Differential leucocyte count (neutrophils, lymphocytes, monocytes, eosinophils, basophils), Thrombocyte count, Reticulocytes, Heinz' bodies, Activated Partial thromboplastin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: prior to scheduled post mortem examination at the end of the treatment
- Animals fasted: no
- How many animals: All animals
- Parameters examined: Sodium, Potassium, Inorganic Phosphate, Urea, Total Bilirubin, Creatinine, Glucose, Chloride, Calcium, Alanine aminotransferase, Aspartate aminotransferase, Alkaline phosphatase, gamma-Glutamyl transpeptidase, Total Protein, Albumin,

URINALYSIS: Yes
- Time schedule for collection of urine: overnight 16 hours (day 26-27)
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters examined: Appearance, Clarity, Colour, pH, Blood, pH, Red blood cells, Protein, Glucose, Ketones, Bilirubin, Urobilinogen, Specific gravity, Sediment













Sacrifice and pathology:
Sacrifice by exsanguination

GROSS PATHOLOGY: Yes (skin, eyes, teeth, oral mucosa, all organs)

ORGAN WEIGHTS: Yes, absolut and relative organ weights were determined for the following organs:
Heart, liver, kidneys, adrenals, spleen, lung, brain, thymus, ovaries, testes, epididymides

HISTOPATHOLOGY: Yes
The following slides were examined by a pathologist:
- all tissues collected at the scheduled sacrifice from all groups
Adrenal glands, Brain [cerebellum, mid-brain, cortex], Colon, Jejunum, Heart, Liver, Kidneys, Spleen, Lung, Thymus, Ovaries, Uterus, Testes, Epididymides, Prostate, Seminal vesicle, Urinary bladder, Trachea, Stomach, Skeletal muscle, Nervus ischiadicus, Bone marrow (cervical, thoracal, lumbal), Lymph nodes (cervical, iliacal)



,
Statistics:
Body weight gain, urainalysis, hematology, clinical chemistry, absolute/relative organ weights:
One-way analysis of variance with sequentially rejective multiple comparisons

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
decreased weight gain
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
no effects observed
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
decreased thrombocyte and leucocyte count
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
increased Bilirubine and creatinine concentration
Urinalysis findings:
effects observed, treatment-related
Description (incidence and severity):
decreased pH
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
decreased thymus and testes weight
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
changes in testes tissue, oligo/aspermia, thymus involution
Histopathological findings: neoplastic:
no effects observed
Details on results:
Mortality/Viability:
All animals survived and no clinical signs were noted at any dose level. No neurological or ophthalmological effects or changes in mucosa were noted.

Body weight:
Except of the males of the 1000 mg/kg bw/d group which showed a decreased body weight gain, the body weight gain of all animals was not affected.

Food/water consumption:
There were no effects upon the mean daily food and water consumption observed in all test groups.

Haematology/clinical chemistry:
There were no changes noted at 62.5 and 250 mg/kg bw/d dose groups. At 1000 mg/kg bw/d the leucocyte count was decreased in male rats; the thrombocyte count was decreased in all animals of the high dose group.
At 1000 mg/kg bw/d the bilirubin and creatinin concnetration was significantly inctreased.

Urinalysis:
The pH of all animals of the high dose group was decreased.

Organ weights:
Relative organ weights were within the control range with the exception of a decreased testis and epididymides weight (absolut and relative) of the males in the high dose group. The absolut and relative thymus weight was also significantly decreased in all animals of the 1000 mg/kg bw/d group. Females of the 250 mg/kg bw/d group had decreased thymus weight.

Macroscopic/microscopic findings:
The size of testes was reduced in males of the 1000 mg/kg bw/d dose group.
No microscopic changes occurred at any dose level with the exception of changes of the testes, epididymides and spermatogenesis in male rats of the 1000 mg/kg bw/d dose group which caused oligo- and aspermia. In both males and females involution of thymus was observed in the high dose group.

Effect levels

Dose descriptor:
NOAEL
Effect level:
250 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: changes in thymus and testes/spermatogenesis at 1000 mg/kg bw/d

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Based on the changes in thymus and testes/spermatogenesis in male and female rats at 1000 mg/kg bw/d, the NOAEL is considered to be 250 mg/kg bw/d.
Executive summary:

A 29 day oral toxicity study was performed in rats. The animals were exposed to 0, 62.5, 250 and 1000 mg/kg bw/d.

All animals survived and no clinical signs were noted at any dose level. No neurological or ophthalmological effects or changes in mucosa were noted. Except of the males of the 1000 mg/kg bw/d group which showed a decreased body weight gain, the body weight gain of all animals was not affected. There were no effects upon the mean daily food and water consumption observed in all test groups. There were no changes in haematology and clinical chemistry noted at 62.5 and 250 mg/kg bw/d dose groups. At 1000 mg/kg bw/d the leucocyte count was decreased in male rats; the thrombocyte count was decreased in all animals of the high dose group. At 1000 mg/kg bw/d the bilirubin and creatinin concentration was significantly inctreased. Relative organ weights were within the control range with the exception of a decreased testis and epididymides weight (absolute and relative) of the males in the high dose group. The absolute and relative thymus weight was also significantly decreased in all animals of the 1000 mg/kg bw/d group. Females of the 250 mg/kg bw/d group had decreased thymus weight. The size of testes was reduced in males of the 1000 mg/kg bw/d dose group. No microscopic changes occurred at any dose level with the exception of changes of the testes, epididymides and spermatogenesis in male rats of the 1000 mg/kg bw/d dose group which caused oligo- and aspermia. In both males and females involution of thymus was observed in the high dose group.