Ethylene diformate

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions. No food consumption reported and no ophthalmological examination performed.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

no food consumption reported and no ophthalmological examination performed.

GLP compliance:

yes

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:

Ethane-1,2-diol

Details on test material:

- Name of test material (as cited in study report): ethylene glycol
- Physical state: colourless liquid
- Analytical purity: > 99%
- Lot Number: A021180
- Stability as bulk chemical: 2 weeks at temperatures up to 60 °C when stored protected from light
- Storage condition of test material: Stored at 5 °C prior to use and at room temperature during use for up to 14 days.

Test animals

Species:

mouse

Strain:

B6C3F1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Industries, Indianapolis, USA
- Age at study initiation: 63 days
- Weight at study initiation: 22.8-23.1 g (males) and 18.0-18.7 g (females)
- Housing: Animals were housed in groups of five per cage in solid-bottom polycarbonate cages (Lab Products, Inc., Garfield, USA) with Betachips betting (Northeastern products Corp., Warrensburg, USA).
- Diet: NIH-07 Open formula mash diet (Zeigler Brothers, Inc., Gardners, USA), ad libitum
- Water: ad libitum
- Acclimation period: 19 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-22
- Humidity (%): 37-58
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 1981-05-25 To: 1981-08-28

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatographic methods were used to confirm homogeneity as well as the stability of dose formulations. The dose formulations were analyzed at the initiation and the mid-point of the study.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

daily, 7 days/week

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
3200, 6300, 12500, 25000 and 50000 ppm
Basis:
nominal in diet

Doses / concentrations 2

Remarks:

Doses / Concentrations:
640, 1260, 2500, 5000 and 10000 mg/kg bw/day
Basis:
other: calculated assuming a daily food consumption of 6 g and a mean adult body weight of 30 g (Derelanko, 2008)

No. of animals per sex per dose:

10

Control animals:

yes

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: weekly and at the end of the study

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the study
- How many animals: all animals
- Parameters checked: erythrocytes, haemoglobin, haematrocrit, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, total and differential leukocyte counts.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the end of the study
- How many animals: all animals
- Parameters checked: blood urea nitrogen, creatinine, sodium, potassium, chloride, partial carbon dioxide, calcium, phosphorus (inorganic), total protein, albumin, albumin/globulin ratio, total bilirubin, pH-value

URINALYSIS: Yes
- Time schedule for collection of urine: at the end of the study
- Parameters checked: glucose, protein, specific gravity, pH-value, urobilinogen, bilirubin, blood (haemoglobin), ketones and nitrite.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes. Necropsy performed on all animals. Organ weights: Brain, heart, right kidney, liver, lungs, thymus, right testis
HISTOPATHOLOGY: Yes. Complete histopathology on all control and high-dose animals: Tissue masses, gross lesions, associated lymph nodes, adrenal gland, brain, colon, oesophagus, femur including marrow, gallbladder, heart, kidney, liver, lung, mammary gland, mandibula and mesenteric lymph nodes, nose, ovary, pancreas, parathyroid gland, pituitary gland, prostate gland, small intestine, spleen, stomach, testis, thymus, thyroid gland, trachea, urinary bladder, uterus. 12500 and 25000 ppm dose group (males): liver and kidneys.

Statistics:

Significant differences from the control group were calculated using the William', Dunnett's test or Fisher exact test. Wheights and weight changes were given as mean and standard error.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

see Table 2 under "Any other information on results incl. tables", non adverse.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

high-dose (males): one animal had a crystal in the wall of a meningeal artery

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

mid- and high-dose group (males): kidney and liver effects

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortalities were observed during the study period. No chemical-related clinical findings were observed, fighting was observed among all exposed and control male mice.

BODY WEIGHT AND WEIGHT GAIN
Body weight and body weight gains of male groups that received 12500 and 50000 ppm were significantly reduced (see Table 1 under "Any other information on results incl. tables").

HAEMATOLOGY
No biologically significant changes in haematology were observed in any dose group.

CLINICAL CHEMISTRY
No biologically significant changes in clinical chemistry were observed in any dose group.

URINALYSIS
No biologically significant changes in urinalysis were observed in any dose group.

ORGAN WEIGHTS
No biologically significant changes were observed in absolute and relative organ weights (see Table 2 under "Any other information on results incl. tables").

GROSS PATHOLOGY
No treatment related lesions were seen in any organ in females. One male in the high dose group had a small birefringent crystal resembling an oxalate crystal in the wall of a meningeal artery.

HISTOPATHOLOGY
Treatment-related histopathologic lesions were noted only in the kidneys and livers of male mice in the 25000 and 50000 ppm group. Hyaline degeneration in the liver occured in the cetrilobular hepatocytes. Affected cells contained cyoplasmic accumulations of nonbirefringent, eosinophilic (hyaline), globular, or crystalline material which resembled erythrocytes in size, shape and tinctorial properties. In some cases, only one or two hepatocytes around cetral veins were affected; in more severe cases, affected hepatocytes were present in several layers of the hepatic cords adjacent to central veins. Nephropathy was characterized by several renal tissue changes that included tubule dilatation, cytoplasmic vacuolation, or regenerative hyperplasia of tubule epithelial cells. These changes were focal, randomly distributed and of minimal to mild severity (see Table 3 under "Any other information on results incl. tables").
No treatment related lesions were seen in any organ in females.

OTHER
All serologic analyses for murine viruses were negative.

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

male

Basis for effect level:

other: Liver hyaline degeneration and kidney nephrophathy in higher concentrations.

2

Dose descriptor:

NOAEL

Effect level:

2 500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: calculated assuming a daily food consumption of 6 g and a mean adult body weight of 30 g (Derelanko, 2008)

3

Dose descriptor:

NOAEL

Effect level:

50 000 ppm

Based on:

test mat.

Sex:

female

Basis for effect level:

other: overall effects

4

Dose descriptor:

NOAEL

Effect level:

10 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: calculated assuming a daily food consumption of 6 g and a mean adult body weight of 30 g (Derelanko, 2008)

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Table 1. Body Weights and Weight Changes (Males).

	Body Weights and Weight Changes (g)
	Males
	Survival	Initial	Final	Change
Control	10/10	23.0 ± 0.3	32.5 ± 0.6	9.5 ± 0.5
3200 ppm	10/10	22.8 ± 0.4	32.4 ± 0.8	9.6 ± 0.6
6300 ppm	10/10	23.1 ± 0.4	32.4 ± 1.0	9.3 ± 0.8
12500 ppm	10/10	23.0 ± 0.4	30.2 ± 1.0	7.2 ± 0.9*
25000 ppm	10/10	22.8 ± 0.4	31.1 ± 0.6	8.3 ± 0.6
50000 ppm	10/10	23.0 ± 0.3	30.4 ± 0.6	7.4 ± 0.6*

*: Significantly different (P≤0.05) from the control group by Williams' or Dunnett's test.

Table 2. Significant changes in organ weights and Organ to body weight ratios.

	Control	3200 ppm	6300 ppm	12500 ppm	25000 ppm	50000 ppm
	Males
Necropsy body weights	32.4 ± 0.6	31.8 ± 0.7	32.0 ± 1.0	29.4 ± 0.9*	32.0 ± 0.6	30.3 ± 0.6*
Heart absolute	0.156 ± 0.008	0.158 ± 0.006	0.139 ± 0.006	0.134 ± 0.005*	0.142 ± 0.004*	0.140 ± 0.006*
Liver absolute	1.49 ± 0.05	1.70 ± 0.10	1.50 ± 0.10	1.26 ± 0.04*	1.46 ± 0.04	1.37 ± 0.05
Liver relative	46.0 ± 1.43	53.2 ±2.5*	46.8 ± 1.6	42.9 ±1.27	45.8 ± 1.05	45.2 ± 1.51
	Females
Liver absolute	1.23 ± 0.06	1.07 ± 0.03*	1.12 ± 0.04	1.13 ± 0.03	1.24 ± 0.05	1.14 ± 0.04
Liver relative	48.4 ± 2.01	43.3 ± 1.37*	45.1 ± 0.75	45.1 ± 1.07	47.6 ± 1.20	45.8 ± 0.71

*Significantly different (P≤0.05) from the control group by Williams' or Dunett's test

Table 3. Selected non neoplastic lesions in male mice.

	Control	3200 ppm	6300 ppm	12500 ppm	25000 ppm	50000 ppm
Liver: Hyaline Degeneration Overall rates^b	0/10	-^c	-	0/10	10/10**	10/10**
Kidney: Nephropathy^d Overall rates	0/10	-	-	0/10	1/10	5/10*

*: Significantly different (P≤0.05) from the control group by the Fisher exact test.

**: P≤0.01

b: Number of affected animals/number of animls necropsied or number of animals with tissues examined microscopically