2-(1-methylethoxy)ethyl acetate

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP-Guideline study, tested with the source substance 2-(1-Methylethoxy)ethanol (CAS No. 109-59-1). According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2003

Reference 2

Reference Type:

secondary source

Title:

SIDS Initial Assessment Report For SIAM 28 Paris, France, 15-17 April 2009, Chemical Name: 2-(1-methylethoxy)ethanol, CAS Number: 109-59-1

Author:

OECD SIDS

Year:

2009

Bibliographic source:

http://webnet.oecd.org/Hpv/UI/SIDS_Details.aspx?id=C1C0D516-D068-4A01-B34D-7C61F59A21D1

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

no opthalmoscopic and neurobehavioural examinations.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-isopropoxyethanol

EC Number:

203-685-6

EC Name:

2-isopropoxyethanol

Cas Number:

109-59-1

IUPAC Name:

2-isopropoxyethanol

Details on test material:

Name of test material (as cited in study report): 2-(1-Methylethoxy)ethanol
- Molecular formula: C5H12O2
- Molecular weight: 104.15
- Analytical purity:>/= 99.5%
- Impurities (identity and concentrations): water (<0.1%)
- Lot No.: 30321
- Stability under test conditions: The stability of test material was identified by analysis of the remainder.
- Storage condition of test material: at room temperature

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan, Inc. Atsugi
- Age at study initiation: 5 weeks
- Weight at study initiation:
- Fasting period before study: 18 h
- Housing: animals were housed individually in metallic cages with wire mesh bottoms.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 8 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-25
- Humidity (%): 40-75
- Air changes (per hr):15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

28 days

Frequency of treatment:

daily, 7 days/week

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 30, 125 and 500 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: A preliminary test was conducted to determine the doses to be employed. Reddish urine was observed after the first administration, and inhibition of body weight gain recognized on days 1-2 at doses more than 500 mg/kg bw/d.
Based on this result, the test substance was administered in a volume of 10 mL/kg bw/d at doses of 30, 125 and 500 mg/kg bw/d by gavage for 28 days.
-Post-exposure recovery period: 14 d

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily, before-dosing and after-dosing and daily day during the 14 day recovery period

BODY WEIGHT: Yes
- Time schedule for examinations: twice a week and at termination administration, recovery period, and necropsy

FOOD CONSUMPTION:
- Food consumption: Yes, once a week

WATER CONSUMPTION: Yes

HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to necropsy
- Anaesthetic used for blood collection: Yes
- Animals fasted: Yes
- How many animals: 5 per sex per dose

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: prior to necropsy
- Animals fasted: Yes
- How many animals: 5 per sex per dose

URINALYSIS: Yes
- Time schedule for collection of urine: samples were collected for a 4 and 24 h period during the last week of administration and in the last week of the 14 d recovery period.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
Organs examined at necropsy: organ weight for both sexes, brain, lung, thyroid gland, liver, kidney, spleen, adrenal, thymus, ovaries and testes.

HISTOPATHOLOGY: Yes
All animals in control and in the high dose group: spleen, bone marrow of Femur, esophagus, liver and kidney
All animals: spleen, bone marrow of Femur, liver, kidney ovary and brain.

Statistics:

Dunnett´s test, Student´s test, Aspin-Welch´s t-test, chi square test, Mann-Whitney U-test

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

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

no effects observed

Ophthalmological findings:

not specified

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

effects observed, treatment-related

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not specified

Details on results:

CLINICAL SIGNS AND MORTALITY
No deaths in any group occurred through the administration and the recovery periods. Reddish urine was observed in both sexes from the first day of the administration until the following day at a dose of 500 mg/kg bw/day. As a result of urinary examination, this was proved to be haematuria. After the second day of administration, no clinical signs were observed.
BODY WEIGHT AND WEIGHT GAIN
There were no treatment-related changes in body weight during administration periods, however, high values of body weight continued during the recovery period in the female group at 500 mg/kg bw/day, and the value showed statistical significance on day 14 of the recovery period.
FOOD CONSUMPTION AND COMPOUND INTAKE
Food intake was significantly decreased in male and female groups at 500 mg/kg bw/day on day 1 of administration.
WATER CONSUMPTION AND COMPOUND INTAKE
There were no treatment-related changes in water consumption during the administration and recovery periods.
HAEMATOLOGY
Decreases in red cell count, haemoglobin content, haematocrit value and mean corpuscular haemoglobin concentration (MCHC), and increases in mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), reticlulocyte were recognized in male and female groups at 500 mg/kg bw/day, and it was considered the animals were in anemic condition. Furthermore, increase of reticulocyte in males and decreases of red cell count, haemoglobin, MCHC in females were also recognized at 125 mg/kg bw/day, and it was considered the animals at this dosage were in anemic condition. Increases of MCV and MCH in both sex groups, and decrease of MCHC in males were found.
CLINICAL CHEMISTRY
Increases of inorganic phosphorus and potassium in males and increases of A/G ratio and creatinine in females were found in the group at 500 mg/kg bw/day. However, the changes of inorganic phosphorus were without change of blood calcium concentration, and the changes of potassium were without change of blood sodium, and not present in females. Therefore it was considered not to be related to treatment. Increase of total cholesterol was observed in the group at 500 mg/kg bw/day. Increase in total cholesterol was not observed at the end of the administration period, and not present in female. Therefore, it was taken as accidental changes.
URINALYSIS
In urinalysis, dark blown-coloured urine was observed in 4 males and 2 females at 500 mg/kg bw/day on day 1 of administration, and there were 8 males and 7 females including them which occult blood was strongly positive. Additionally, yellowish brown urine, protein and bilirubin were observed in both sexes at 500 mg/kg bw/day. One each of male and female animals showed strong positive occult blood at the end of the administration period (day 23 of administration). There were no treatment-related changes at the end of the recovery period (day 9 of recovery).
ORGAN WEIGHTS
Increase of absolute and relative weights of spleen were found in both sex groups at 500 mg/kg bw/day, and increase of relative weight was also found in females at 125 mg/kg bw/day. In addition, increases of relative weight of liver in both sexes, and relative weight of kidney in males were observed at 500 mg/kg bw/day. Increase of absolute weight of spleen and increase of absolute and relative weight of liver was observed in females at 500 mg/kg bw/day. Decrease in absolute weight of thyroid gland was observed in males at 500 mg/kgbw/day. However, the change of thyroid gland was not observed at the end of the administration period. Therefore, it was taken as accidental changes. Relative weight of kidney was significantly reduced due to increase of body weight measured at sacrifice.
GROSS PATHOLOGY
Enlargement of the spleen was observed in all males and 3 females, and dark reddish change of the spleen was observed in one male and 3 females at 500 mg/kg bw/day. Enlargement of the liver was observed in 2 males at 500 mg/kg bw/day, and yellowish change of the liver was observed in 3 females at 500 mg/kg bw/day. Enlargement of the kidney was observed in 3 males at 500 mg/kg bw/day. The enlargement of the spleen was examined in 2 males at 500mg/kg bw/day, and the enlargement of the liver or enlargement of the kidney was observed in these 2 examples.
HISTOPATHOLOGY: NON-NEOPLASTIC
The following changes were observed: In spleen, enhancement of extramedullary haematopoiesis in all animals of male and female groups at more than 125mg/kg bw/day, and deposition of brown pigment in almost all animals of both sex groups at more than 125 mg/kg bw/day. This brown pigment was demonstrated as hemosiderin deposition by Berlin Blue staining. In bone marrow, increased haematopoiesis of erythrocyte was found in males at 500 mg/kg bw/day and females at doses more than 125 mg/kg bw/day. In liver, extramedullary haematopoiesis was observed in 3 males and 2 females at 500 mg/kg bw/day, but such change was not found in the groups less than 125 mg/kg bw/day. Otherwise, some changes were recognized in liver and kidney; however, they were not treatment-related changes. The changes observed at the end of administration became slight.
OTHER FINDINGS
In bone marrow myelogram findings at 500 mg/kg bw/day, increase of rate of erythroid cells and decrease of rate of myeloid cells were significantly observed, Namely, increases of rates of polychromatic erythroblast in males and erythroblasts from basophilic erythroblast to normoblast in females, decreases of rates of promyeloblast, neutrophil, eosinophil and lymphocyte in males, myeloblast and eosinophilic myelocyte in females were found. As a result, the myeloid/erythroid ratio was reduced in both sexes. At doses less than 125 mg/kg bw/day, though the degree became mild as compared with the findings of the group at 500 mg/kg bw/day, some findings were observed at 125 mg/kg bw/day, and increase in rate of polychromatic erythroblast and decreases of neutrophil, eosinophil in males, and decrease of rate of myeloblast in females were observed at 30 mg/kg bw/day. After the recovery period, the changes observed at the end of administration reduced, and decrease of rate of promyelocyte was found in females, but increase of rate of neutrophilic myelocyte, myeloid/erythroid ratio were found, and these changes were opposite as compared with the findings observed at the end of the administration period.

Effect levels

1

Dose descriptor:

LOAEL

Effect level:

30 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: haematuria

2

Dose descriptor:

NOAEL

Effect level:

< 30 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: haematuria

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Table 1. Results of urinalysis in male and female rats on Day 1 of the dosing period.

		Male				Female
Dose (mg/kg bw/day)		control	30	125	500	control	30	125	500
Number of animals in group		10	5	5	10	10	5	5	10
Red blood cells, not observed		10	5	5	10	10	5	5	10
Crystals, a few observed		10	4	5	9	8	5	4	10
Cast, not observed		10	5	5	10	10	5	5	10
Protein	-	5	4	3	1	8	4	5	3
	+/-	3	1	0	1	1	1	0	0
	+	2	0	2	0	1	0	0	0
	++	0	0	0	5	0	0	0	4
	+++	0	0	0	3**	0	0	0	3**
Bilirubin	-	10	5	5	2	10	5	5	5
	+	0	0	0	7	0	0	0	5**
	++	0	0	0	1	0	0	0	0
Occult blood	-	10	5	5	2	10	5	5	3
	+++	0	0	0	8	0	0	0	7**
Color	Light yellow	9	5	5	1	10	5	5	3
	Yellow	1	0	0	1	0	0	0	2
	Yellowish brown	0	0	0	4	0	0	0	3
	Dark brown	0	0	0	4**	0	0	0	2**

**: p<0.01

 - negative; ± trace; +: slight; ++: moderate; +++: marked

Table 2. Results of haematological examinations in male rats at the end of the dosing period and at the end of the recovery period.

Dose (mg/kg bw/day)	End of administration period				End of recovery period
	0	30	125	500	0	500
RBC (x10xE4/µL)	737 ± 29	720 ± 24	718 ± 31	571 ± 25**	793 ± 43	751 ± 21
Haemoglobin (g/dL)	14.7 ± 0.5	14.2 ± 0.3	14.4 ± 0.4	12.6 ± 0.5**	14.8 ± 0.4	15.0 ± 0.3
Haematocrit (%)	44.3 ± 2.0	43.2 ± 1.0	43.7 ± 1.8	39.1 ± 1.5**	44.1 ± 1.4	45.0 ± 1.2
MCV (fL)	60.1 ± 1.9	60.0 ± 1.1	60.8 ± 1.7	68.6 ± 2.9**	55.6 ± 2.5	59.9 ± 1.6*
MCH (pg)	19.9 ± 0.7	19.8 ± 0.4	20.0 ± 0.6	22.1 ± 0.9**	18.7 ± 0.8	20.0 ± 0.6*
MCHC (g/dL)	33.2 ± 0.3	33.0 ± 0.3	32.9 ± 0.4	32.2 ± 0.3**	33.6 ± 0.1	33.4 ± 0.1*
Platelet (x10xE4/µL)	100.0 ± 10.6	108.4 ± 5.7	98.6 ± 15.7	95.6 ± 14.8	99.4 ± 4.5	95.2 ± 10.3
Reticulocyte (%)	3.5 ± 0.8	3.5 ± 0.5	5.3 ± 1.4*	14.8 ± 1.3**	3.1 ± 0.6	2.7 ± 0.4
WBC (x100/µL)	88.6 ± 35.4	67.8 ± 20.9	79.7 ± 25.6	77.2 ± 32.4	101.1 ± 36.9	76.9 ± 10.7

*: p<0.05, **:p<0.01

Table 3. Results of haematological examinations in female rats at the end of the dosing period and at the end of the recovery period.

Dose (mg/kg bw/day)	End of administration period				End of recovery period
	0	30	125	500	0	500
RBC (x10xE4/µL)	724 ± 31	672 ± 55	655 ± 31*	548 ± 24**	744 ± 28	742 ± 32
Haemoglobin (g/dL)	14.4 ± 0.5	13.5 ± 0.9	13.2 ± 0.4*	12.3 ± 0.4**	14.3 ± 0.8	15.3 ± 0.6
Haematocrit (%)	42.6 ± 1.4	40.4 ± 2.7	39.9 ± 1.3	38.4 ± 1.1**	42.7 ± 2.4	45.6 ± 1.8
MCV (fL)	58.9 ± 1.3	60.2 ± 2.1	61.0 ± 1.5	70.2 ± 1.3**	57.2 ± 1.3	61.5 ± 1.2**
MCH (pg)	19.9 ± 0.5	20.1 ± 0.6	20.1 ± 0.5	22.5 ± 0.3**	19.2 ± 0.3	20.6 ± 0.5**
MCHC (g/dL)	33.7 ± 0.2	33.5 ± 0.2	33.0 ± 0.3**	32.1 ± 0.3**	33.6 ± 0.4	33.5 ± 0.4
Platelet (x10xE4/µL)	110.9 ± 4.1	108.6 ± 15.6	104.5 ± 9.6	102.3 ± 10.9	102.3 ± 11.7	99.0 ± 4.3
Reticulocyte (%)	2.2 ± 0.6	4.5 ± 4.7	5.8 ± 1.9	15.4 ± 2.5**	3.7 ± 1.6	2.1 ± 0.6
WBC (x100/µL)	43.7 ± 9.2	31.0 ± 18.2	40.7 ± 15.2	39.2 ± 8.7	48.9 ± 5.5	56.5 ± 4.0*

*: p<0.05, **:p<0.01

Table 4. Myelogram findings in male rats.

	End of administration period				End of recovery period
Dose (mg/kg bw/day)	Control	30	125	500	Control	500
Myeloblast (%)	2.2 ± 0.9	2.3 ± 0.4	2.2 ± 0.5	1.9 ± 1.3	2.5 ± 0.9	2.3 ± 1.0
Promyelocyte (%)	2.6 ± 0.9	2.8 ± 0.4	2.6 ± 0.7	1.4 ± 0.4*	3.1 ± 0.8	3.1 ± 1.4
Neutrophilic myelocyte (%)	5.4 ± 1.0	6.0 ± 0.5	7.2 ± 2.4	5.0 ± 1.0	8.2 ± 1.9	6.5 ± 1.8
Neutrophil (%)	25.8 ± 1.8	21.7 ± 2.1**	19.3 ± 1.7**	16.3 ± 1.7**	22.9 ± 4.9	22.7 ± 5.4
Eosinophilic myelocyte (%)	1.0 ± 0.5	1.0 ± 0.4	1.2 ± 0.5	0.9 ± 0.6	0.6 ± 0.4	0.9 ± 0.3
Eosinophil (%)	1.6 ± 0.5	0.7 ± 0.3*	0.8 ± 0.7*	0.5 ± 0.3**	0.9 ± 0.6	0.6 ± 0.2
Total granulocyte(%)	50.3 ± 1.5	47.5 ± 3.4	43.5 ± 2.9**	35.4 ± 3.2**	48.7 ± 6.4	48.1 ± 7.5
Basophilic erythroblast (%)	2.8 ± 1.1	3.7 ± 1.1	3.4 ± 1.1	6.3 ± 4.1	4.5 ± 1.3	4.8 ± 2.8
Polychromatic erythroblast (%)	11.9 ± 2.4	15.8 ± 1.0*	17.1 ± 2.8**	25.2 ± 2.4**	11.8 ±2.2	12.7 ± 3.0
Normoblast (%)	14.1 ± 4.1	13.4 ± 2.3	14.4 ± 4.5	17.5 ± 3.1	13.0 ± 2.2	11.6 ± 3.0
Total erythroblast(%)	29.0 ± 2.5	32.9 ± 2.5	35.2 ± 5.8*	49.4 ± 3.0**	29.9 ± 4.6	29.5 ± 8.3
Myeloid/Erythroid	1.8 ± 0.2	1.4 ± 0.2*	1.3 ± 0.3**	0.7 ± 0.1**	1.7 ± 0.4	1.8 ± 0.8
Lymphocyte	17.2 ± 2.6	17.0 ± 2.9	17.9 ± 4.7	11.5 ± 2.6*	18.3 ± 3.5	18.2 ± 4.8

*: p< 0.05, **:p<0.01

Table 5. Myelogram findings in female rats.

	End of administration period							End of recovery period
Dose (mg/kg bw/day)	Control	30		125			500	Control	500
Myeloblast (%)	3.8 ± 0.9		1.3 ± 0.8**		1.4 ± 0.3**	1.5 ± 1.3**		1.7 ± 0.9	2.6 ± 0.8
Promyelocyte (%)	2.2 ± 1.1		2.8 ± 0.9		2.7 ± 0.6	1.4 ± 0.8		3.5 ± 0.7	2.5 ± 0.3*
Neutrophilic myelocyte (%)	5.8 ± 0.9		7.1 ± 1.5		5.2 ± 2.2	5.7 ± 2.2		6.1 ± 1.2	8.0 ± 1.2*
Neutrophil (%)	19.9 ± 5.6		18.4 ± 2.0		18.3 ± 4.1	15.7 ± 2.8		20.3 ± 4.8	23.6 ± 1.6
Eosinophilic myelocyte (%)	1.7 ± 0.6		1.6 ± 0.2		1.0 ± 0.3*	0.6 ± 0.3**		1.5 ± 0.5	1.4 ± 0.4
Eosinophil (%)	1.0 ± 0.5		1.1 ± 0.4		0.8 ± 0.4	0.8 ± 0.3		1.5 ± 0.4	1.4 ± 0.6
Total granulocyte(%)	45.0 ± 6.8		44.0 ± 3.9		41.9 ± 5.2	34.4 ± 5.6*		46.9 ± 4.5	51.5 ± 3.4
Basophilic erythroblast (%)	3.6 ± 1.6		4.8 ± 1.7		2.0 ± 0.9	6.4 ± 2.2*		3.3 ± 1.7	2.8 ± 1.0
Polychromatic erythroblast (%)	13.2 ± 3.8		15.2 ± 2.7		16.8 ± 5.3	21.9 ± 2.4**		13.4 ± 1.4	10.5 ± 3.3

*: p< 0.05, **:p<0.01