2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-methylphenyl acrylate

Endpoint summary

Description of key information

NOAEL (oral, rat, subchronic) = 2193.3 mg/kg bw/day

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 Feb - 15 May 1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

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

Version / remarks:

adopted Sep 1998

Deviations:

not specified

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

The strain of rat was selected as a series of studies with the test substance was already performed in rats of this strain and compiled data were available at the testing facility.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Japan, Inc.
- Age at study initiation: 5 weeks
- Weight at study initiation: 132 - 173 g (females) and 173 - 216 g (males)
- Housing: 3 rats per cage were housed in plastic cages (41 x 26 x 20 cm) with hardwood chip bedding.
- Diet: Powdered diet CE-2 (CLEA Jpan, Inc., Tokyo, Japan), ad libitum
- Water: Drinking water (Ichinomiya City tap water), ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2
- Humidity (%): 60 ± 10
- Air changes (per hr): more than 15 times
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 23 Nov 1983 To: 22 Dec 1983

Route of administration:

oral: feed

Vehicle:

corn oil

Details on oral exposure:

DIET PREPARATION
The test material was incorporated at the required levels (without correction for the purity) into basal diet and mixed with a blender.
- Rate of preparation of diet (frequency): Weekly

VEHICLE
- Justification for use and choice of vehicle: Corn oil was added to all diets before mixing in order to prevent contamination with test material as dust.
- Concentration in vehicle: 2%

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

In order to analyze the content of the test material in the prepared diet, samples of the prepared diets were shipped to the sponsor. Analyses of stability and homogeneity of test material in the prepared diet had been performed prior to the commencement of the study. The homogeneity was satisfactory, and it was confirmed that test material in the diet was stable for 3 weeks in a freezer. The content of test material in the prepared diets was analyzed at every preparation. The prepared diet was started to use when the content values were confirmed to be within the acceptable range. Average contents of the test material were 2431, 4809, 9854 and 29431 ppm for the nominal concentrations of 2500, 5000, 10000 and 30000 ppm in the prepared diet, respectively.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

7 days/week

Dose / conc.:

2 500 ppm

Remarks:

equivalent to 252.4 mg/kg bw/day for females and 175.1 mg/kg bw/day for males

Dose / conc.:

5 000 ppm

Remarks:

equivalent to 506.9 mg/kg bw/day for females and 344.1 mg/kg bw/day for males

Dose / conc.:

10 000 ppm

Remarks:

equivalent to 1019.3 mg/kg bw/day for females and 699.7 mg/kg bw/day for males

Dose / conc.:

30 000 ppm

Remarks:

equivalent to 3281.3 mg/kg bw/day for females and 2193.3 mg/kg bw/day for males

No. of animals per sex per dose:

24 (12 animals per group were euthanized and necropsied after 6 weeks treatment with the test substance)

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: The dietary levels in this study were set by considering the results of a previous 28 days repeated dose toxicity study entitled at the same testing facility. No treatment related changes were observed in the highest dietary level of 30000 ppm group, the dietary level of 30000 ppm was selected as the highest dose level for this study, then 10000, 5000, 2500 ppm were selected as higher middle, lower middle and low dietary levels, respectively.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes, all animals were checked for general conditions and mortality
- Time schedule: Once daily

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
Two-day food consumption per cage was measured weekly, and mean daily food consumption values per rat were calculated from the number of animals housed in one cage and the number of days. Test material intake was calculated from the nominal dietary levels, group means of food consumption and body weight data.

FOOD EFFICIENCY: Yes
Food efficiency was calculated according to a standard method.

WATER CONSUMPTION: Yes
Two-day water consumption per cage was measured weekly, and mean daily water consumption values per rat were calculated from the number of animals housed in one cage and the number of days.

HAEMATOLOGY: Yes, blood samples were collected via the abdominal aorta under ether anesthesia at pretreatment and after experimental week 6 or 13. EDTA-2K was used as anticoagulant. Wright-Diemsa solution was used for the determination of differential white blood cell percentages
- Anaesthetic used for blood collection: Yes (ether)
- Animals fasted: Yes, overnight
- How many animals: All
- Parameters checked: red blood cell count (RBC), white blood cell count (WBC), haemoglobin (HB), haematocrit (HT), platelet count (PLT), differential white blood cell percentages and differential count of WBC (myelocytes, neutrophils (stab), neutrophils (segment), lymphocytes, monocytes, eosinophils, basophils)

CLINICAL CHEMISTRY: Yes
- Animals fasted: Yes, overnight
- How many animals: All
- Parameters checked: Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total cholesterol, total proteins, albumin/globulin ratio (A/G), blood urea nitrogen, sodium (Na), potassium (K), Na/K ratio (Na/K), glucose and albumin

URINALYSIS: Yes
- Time schedule for collection of urine: Fresh urine samples were collected from the animals for scheduled necropsy at pretreatment and week 6 or 13, and were subjected to the urinalysis.
- Parameters checked: pH, proteins, glucose, ketones, bilirubin, occult blood and urobilinogen

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, all animals for scheduled necropsy were euthanized by exsanguination under ether anesthesia at pretreatment and after experimental week 6 or 13, and subjected to gross pathological examination for body surface and internal organs.
- Organs weights were recorded using an electric balance (1205MP, Sartorius K.K., Tokyo, Japan) after gross pathological examination: Brain, thymus, heart, lungs, liver, spleen, kidneys, adrenals, ovaries, testes and pituitary

HISTOPATHOLOGY: Yes, after fixation in 10% buffered formalin solution, the organs and tissues were routinely trimmed, embedded in paraffin wax, sectioned, and stained with hematoxylin and eosin (H&E), and then examined under light microscopically. In addition, bone tissues were decalcified by the rapid decalcification method, and processed for histopathological slides.
- Organs checked: Heart, lymph nodes (mandibular, mesenteric), spleen, bone and bone marrow (femur), thymus, adrenals, pituitary, lungs, stomach, small intestine (duodenum, jejunum, ileum), large intestine (cecum, colon, rectum), pancreas, liver, kidneys, ovaries, testes, spinal cord, brain (cerebrum, cerebellum), and any gross lesions

Statistics:

Statistical comparisons between control and test material treated groups of numerical data for body weights, hematology data, clinical chemistry data and organ weights (absolute and relative) were assessed using the Student’s t-test. The significances of intergroup differences in incidences of findings of gross- and histopathology were analyzed by the Fisher’s exact probability test. The significance of differences for each parameters were analyzed and evaluated at 5 % (p <0.05) or 1 % (p <0.01).

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

Males: Body weights in the 5000 ppm group were significantly lower than control values at weeks 7, 9 and 10.
Females: Body weights in the 10000 ppm group were significantly lower than control values at weeks 8 and 11, but within the control range at the end of treatment in week 13.
These effects were not considered to be related to the test material treatment, since these were transitory and not dose-dependent.

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

effects observed, non-treatment-related

Description (incidence and severity):

Males: Decreased water consumptions were noted in the 30000 ppm group when compared to the control values from week 7 to week 13.
Females: Decreasing trend in water consumptions were observed in the 30000 ppm group when compared to the control values during the course of the study.
In addition, overall average water consumptions in both sexes of the 30000 ppm dose group were also reduced compared with the control group.

Since no adverse effects on general conditions, body weight, urinalysis or clinical chemistry were noted, the reduction of water consumption was not considered to be related to the test substance.

Ophthalmological findings:

not examined

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Males:
A significantly decrease of haemoglobin values were observed in males of the 10000 ppm dose group after 6 weeks treatment with the test substance compared with the control group. After 13 weeks treatment with the test substance the hemoglobin values were within the range of the control animals.
Females:
In females of 5000, 10000 and 30000 ppm dose group a dose-dependent significantly reduced hemoglobin level after 6 weeks treatment with the test substance compared with the control group was determined.

However, the values were within the range of historical control data for rats of this strain according to data published by Charles River (reference: Charles River, Clinical Laboratory Parameters for Crl:CS (SD), March 2006). In addition, these changes were not considered to be treatment-related, since related parameters (RBC, WBC, HT and others) were not affected, and these alterations were reversible as the effects were not observed after 13-week treatment.
Please refer to Table 1 under "any other information on results incl. tables".

Reference: Charles River, Clinical Laboratory Parameters for Crl:CS (SD), March 2006; available online

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

Compared to control animals significant higher values of potassium (lower value of NA/K ratio) were noted in females of 10000 and 30000 ppm dose groups after 6-week treatment. Significant increased potassium levels and significant decreased Na/K ratio were observed in females of the 5000, 10000 and 30000 ppm dose group after 13 weeks treatment with the test substance compared with control group. This effect was not considered to be related to the treatment, since the values were within acceptable range based on historical control data determined at the testing facility.
A dose-dependent significant reduction of total-cholesterol values was determined in animals exposed to 5000, 10000 and 30000 ppm compared to control animals. This effect was not considered to be related to the treatment, since the values were within acceptable range based on historical control data determined at the testing facility.
Significant higher values of alkaline phosphatase in both sexes of the 30000 ppm dose group, significant higher values of blood urea nitrogen in females of all treatment groups and males of the 30000 ppm dose group, significant higher values of albumin in females of the 30000 ppm dose group were observed after 6-weeks treatment. However, these changes were not considered to be related to the treatment, since they were not observed after 13-weeks treatment, and no related changes were found after histopathological examination.

Please refer to Table 2 and 3 under "any other information on results incl. tables".

Urinalysis findings:

effects observed, non-treatment-related

Description (incidence and severity):

After 13 weeks treatment with the test substance only traces of occult blood were observed in 1/12 females of the control group and the 5000 ppm dose group, respectively, and in 1/12 males of the control group, 2500 and 10000 ppm dose group, respectively.
However, it was considered that these changes were not related to the treatment, and they were incidental, since dose-dependence was lacking, and any related renal change was not determined after histopathological examination.

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

Males:
Significant lower absolute spleen weights (11%) were noted in males of the 5000 ppm dose group compared to controls. Significant higher relative kidney weights (8% and 9%, respectively) were observed in males of the 5000 and 30000 ppm dose group, respectively. In males of the 10000 ppm dose group a significant increase of the relative testis weight (11%) was determined.

Females:
Significant lower absolute thymus weights (17%), and significant higher relative brain weights (7%) and relative heart weights (9%) were noted in females of the 10000 ppm dose group compared to controls.

The increase of the relative kidney weight was considered not to be related to the test material treatment, since absolute kidney weight was comparable to control value, and any related renal change was not observed after histopathological examination. The effects on absolute organ weights observed in the study were not considered to be related to the test material treatment, since there were no changes in the relative organ weights and the effects occurred at individual doses without dose-dependence.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Males:
Control: Single discolored spot (lung) in 7/12 males and small discolored testis in 1/12 males
2500 ppm: Single discolored spot (lung) in 3/12 males
5000 ppm: Crust cranium (skin/subcutis) in 1/12 males after 6-week treatment; single discolored spot (lung) in 1/12 males
10000 ppm: Single discolored spot (lung) in 2/12 males, small discolored testis, multiple discolored spots (lung) and discolored area (lung) each in 1/12 males
30000 ppm: Single discolored spot (lung) in 6/12 males, crust cranium (skin/subcutis) and reddened material perigenital (skin/subcutis) each in 1/12 males

Females:
Control: Single discolored spot (lung) in 4/12 females
2500 ppm: Single discolored spot (lung) in 4/12 females
5000 ppm: Single discolored spot (lung) in 2/12 females
10000 ppm: Single discolored spot (lung) in 3/12 females

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Heart, lymphocytic accumulation:
Control: 1/12 males (grade 1)
30000 ppm: 1/12 males (grade 1)

Pituitary, Cyst:
Control: 1/12 females (grade 1)
5000 ppm: 1/12 males (grade 1)
10000 ppm: 1/12 females (grade 1)

Lung, lymphocytic accumulation:
Control: 5/12 females (grade 1), 8/12 males (grade 1), 1/12 males (grade 2)
2500 ppm: 4/12 females (grade 1), 3/12 males (grade 1), 1/12 males (grade 2)
5000 ppm: 2/12 females (grade 2), 5/12 males (grade 1)
10000 ppm: 3/12 females (grade 1), 2/12 females (grade 2), 7/12 males (grade 1), 3/12 males (grade 2)
30000 ppm: 4/12 females (grade 1), 7/12 males (grade 1)

Lung, accumulation of foamy cells:
Control: 1/12 females (grade 1), 1/12 males (grade 1)
5000 ppm: 1/12 males (grade 1)
10000 ppm: 1/12 females (grade 1), 3/12 males (grade 1)

Lung, bronchopneumonia:
5000 ppm: 2/12 females (grade 1)

Lung, calcification arteria wall:
Control: 1/12 males (grade 1)
2500 ppm: 1/12 females (grade 1), 1/12 males (grade 1)
5000 ppm: 3/12 females (grade 1), 6/12 males (grade 1)
10000 ppm: 1/12 females (grade 1), 1/12 females (grade 2), 3/12 males (grade 1)
30000 ppm: 2/12 females (grade 1)

Large intestine, parasites in lumen:
Control: 1/12 females (grade 1), 3/12 males (grade 1)
2500 ppm: 3/12 females (grade 1), 3/12 males (grade 1)
5000 ppm: 1/12 females (grade 1), 3/12 males (grade 1)
10000 ppm: 2/12 females (grade 1)
30000 ppm: 1/12 females (grade 1), 3/12 males (grade 1)

Pancreas, atrophy of acinar cells:
5000 ppm: 1/12 females (grade 1)

Liver, fatty metamorphosis:
Control: 1/12 females (grade 1), 1/12 males (grade 1)
5000 ppm: 1/12 females (grade 1), 2/12 males (grade 1)

Adrenal, fatty metamorphosis:
Control: 1/12 males (grade 1)

Testis, atrophy:
Control: 1/12 males (grade 2)
1000 ppm: 1/12 males (grade 1)

Skin/subcutis, inflammation:
30000 ppm: 1/12 males (grade 1)

Preputial-clitoral gland, cyst:
30000 ppm: 1/12 males (grade 1)

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Key result

Dose descriptor:

NOAEL

Effect level:

>= 30 000 ppm

Based on:

test mat.

Remarks:

equivalent to 3281.3 mg/kg bw/day for females and 2193.3 mg/kg bw/day for males

Sex:

male/female

Basis for effect level:

other: No adverse and treatment-related effects observed up to and including the highest tested dose level.

Key result

Dose descriptor:

NOAEL

Effect level:

3 281.3 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No adverse and treatment-related effects observed up to and including the highest tested dose level.

Key result

Dose descriptor:

NOAEL

Effect level:

2 193.3 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: No adverse and treatment-related effects observed up to and including the highest tested dose level.

Key result

Critical effects observed:

no

Table 1: Summay of hematological data

Parameter		Control males	1000 ppm males	3000 ppm males	10000 ppm males	30000 ppm males	Control females	1000 ppm females	3000 ppm females	10000 ppm females	30000 ppm females
	N	12	12	12	12	12	12	12	12	12	12
Hemoglobin (g/dL) at week 7	Mean ± SD	14.5± 0.4	14.2± 0.6	14.1± 0.7	14.0± 0.4 *	14.2± 0.6	14.8± 0.7	14.7± 0.8	14.1± 0.5 **	14.1± 0.4 **	13.9± 1.3 *
Hemoglobin (g/dL) at week 13	Mean ± SD	16.2± 0.9	15.7± 0.7	15.7± 0.5	15.7± 0.7	15.4± 1.0	15.8± 0.9	15.4± 0.5	15.5± 0.8	15.1± 0.5 *	15.1± 0.9

* Significantly different from control group at p < 0.05

** Significantly different from control group at p < 0.01

Table 2: Summary of clinical chemistry data

Parameter		Control males	1000 ppm males	3000 ppm males	10000 ppm males	30000 ppm males	Control females	1000 ppm females	3000 ppm females	10000 ppm females	30000 ppm females
	N	12	12	12	12	12	12	12	12	12	12
Aspartate aminotransferase (KU) at week 7	Mean ± SD	127 ± 32	140 ± 36	124 ± 28	130 ± 34	141 ± 28	118± 23	125 ± 25	124 ± 22	132 ± 29	139 ± 30
Aspartate aminotransferase (KU) at week 13	Mean ± SD	131 ± 39	121 ± 24	133 ± 35	140 ± 35	134 ± 49	119 ± 35	110 ± 24	118 ± 21	114 ± 19	115 ± 21
Alanine aminotransferase (KU) at week 7	Mean ± SD	26 ± 6	29 ± 7	32 ± 6 *	29 ± 6	30 ± 7	23 ± 6	27 ± 4	28 ± 4 *	29 ± 8 *	28 ± 10
Alanine aminotransferase (KU) at week 13	Mean ± SD	25 ± 8	25 ± 4	28 ± 9	29 ± 9	26 ± 7	31 ± 14	29 ± 4	25 ± 6	26 ± 5	27 ± 6
Total cholesterol (mg/dL) at week 7	Mean ± SD	54 ± 8	55 ± 8	52 ± 11	55 ± 9	52 ± 6	62 ± 13	62 ± 13	63 ± 9	61 ± 12	58 ± 12
Total cholesterol (mg/dL) at week 13	Mean ± SD	73 ± 16	67 ± 20	57 ± 9 **	53 ± 16 **	57 ± 13 *	71 ± 8	80 ± 13	71 ± 8	75 ± 10	73 ± 17
Potassium (meq/L) at week 7	Mean ± SD	4.9 ± 0.3	5.1 ± 0.4	4.9 ± 0.3	5.2 ± 0.4	5.4 ± 0.4 **	4.6 ± 0.2	4.7 ± 0.3	4.7 ± 0.4	4.9 ± 0.4 *	4.9 ± 0.3 *
Potassium (meq/L) at week 13	Mean ± SD	4.8 ± 0.3	4.7 ± 0.5	4.8 ± 0.4	4.9 ± 0.3	5.0 ± 0.4	4.0 ± 0.2	4.2 ± 0.3	4.3 ± 0.4 *	4.4 ± 0.5 *	4.5 ± 0.3 **

* Significantly different from control group at p < 0.05

** Significantly different from control group at p < 0.01

Table 3: Historical control data of CD(SD) rats at week 13 from 2 different examinations

	K (meq/dL)	Na (meq/dL)	Total cholesterol (mg/dL)
Female
N	19	19	19
Mean	4.4	142	72
S.D.	0.3	3	14
N	12	12	12
Mean	4.4	143	78
S.D.	0.4	1	13
Male
N	20	20	20
Mean	4.7	143	49
S.D.	0.6	1	7
N	12	12	12
Mean	4.7	144	68
S.D.	0.5	1	7

Reference 2

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 Nov - 22 Dec 1983

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

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

Version / remarks:

adopted Oct 2008

Deviations:

not specified

GLP compliance:

no

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

The rat strain was selected due to availability of compiled data in our laboratory.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Japan, Inc.
- Age at study initiation: 5 weeks
- Weight at study initiation: 125 - 143 g (females) and 166 - 187 g (males)
- Housing: 3 rats per cage were housed in plastic cages (41 x 26 x 20 cm) with hardwood chip bedding.
- Diet: Powdered diet CE-2 (CLEA Jpan, Inc., Tokyo, Japan), ad libitum
- Water: Drinking water (Ichinomiya City tap water), ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2
- Humidity (%): 60 ± 10
- Air changes (per hr): more than 15 times
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 23 Nov 1983 To: 22 Dec 1983

Route of administration:

oral: feed

Vehicle:

corn oil

Details on oral exposure:

DIET PREPARATION
The test material was incorporated at the required levels (without correction for the purity) into basal diet and mixed with a blender.
- Rate of preparation of diet (frequency): Weekly

VEHICLE
- Justification for use and choice of vehicle: Corn oil was added to all diets before mixing in order to prevent contamination with test material as dust.
- Concentration in vehicle: 2%

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

In order to analyse the content of the test material in the prepared diet, samples were shipped to the sponsor. The content of test material in the prepared diets was analysed at the first preparation, and the homogeneity of test material in the prepared diet (1000 ppm) was also analysed at the first preparation. The results of content analyses were summarized as follows. Analyses were performed after 2-month storage in the freezer, since analytical method was not established at that time.
The contents of test material in the prepared diets were 978 ppm in the 1000 ppm diet, 2833 ppm in the 3000 ppm diet, 9651 ppm in the 10000 ppm diet, and 29260 ppm in the 30000 ppm diet. Analytical values for samples taken from three portions (top, middle and bottom) in the blender for the prepared 1000 ppm diet were ranged from 764 to 1203 ppm.

Duration of treatment / exposure:

28 days

Frequency of treatment:

7 days/week

Dose / conc.:

1 000 ppm

Remarks:

equivalent to 168 mg/kg bw/day for females and 99 mg/kg bw/day for males

Dose / conc.:

3 000 ppm

Remarks:

equivalent to 508 mg/kg bw/day for females and 298 mg/kg bw/day for males

Dose / conc.:

10 000 ppm

Remarks:

equivalent to 1788 mg/kg bw/day for females and 1012 mg/kg bw/day for males

Dose / conc.:

30 000 ppm

Remarks:

equivalent to 4863 mg/kg bw/day for females and 2792 mg/kg bw/day for males

No. of animals per sex per dose:

6

Control animals:

yes

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes, all animals were checked for general conditions and mortality
- Time schedule: Once daily

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
Two-day food consumption per cage was measured weekly, and mean daily food consumption values per rat were calculated from the number of animals housed in one cage and the number of days. Test material intake was calculated from the nominal dietary levels, group means of food consumption and body weight data.

WATER CONSUMPTION: Yes
Two-day water consumption per cage was measured weekly, and mean daily water consumption values per rat were calculated from the number of animals housed in one cage and the number of days.

HAEMATOLOGY: Yes, blood samples were collected via the abdominal aorta under ether anesthesia at pretreatment and after experimental week 4. EDTA-2K was used as anticoagulant. Wright-Diemsa solution was used for the determination of differential white blood cell percentages
- Anaesthetic used for blood collection: Yes
- Animals fasted: Yes, overnight
- How many animals: All
- Parameters checked: red blood cell count (RBC), white blood cell count (WBC), haemoglobin (HB), haematocrit (HT), platelet count (PLT), differential white blood cell percentages and differential count of WBC (myelocytes, neutrophils (stab), neutrophils (segment), lymphocytes, monocytes, eosinophils, basophils)

CLINICAL CHEMISTRY: Yes
- Animals fasted: Yes, overnight
- How many animals: All
- Parameters checked: Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total cholesterol, total proteins, albumin/globulin ratio (A/G), blood urea nitrogen, sodium (Na), potassium (K), Na/K ratio (Na/K), glucose and albumin

URINALYSIS: Yes
- Time schedule for collection of urine: Fresh urine samples were collected from the animals at experimental week 4.
- Parameters checked: pH, proteins, glucose, ketones, bilirubin, occult blood and urobilinogen

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, all surviving animals were euthanized by exsanguination under ether anesthesia after experimental week 4, and subjected to gross pathological examination for body surface and internal organs.
- Organs weights were recorded using an electric balance (1205MP, Sartorius K.K., Tokyo, Japan) after gross pathological examination: Brain, thymus, heart, lungs, liver, spleen, kidneys, adrenals, ovaries, testes and pituitary

HISTOPATHOLOGY: Yes, histopathological examination of organs was performed from both sexes of the control group and the highest dose group.
- Organs checked: Spleen, lungs, liver and kidneys

Statistics:

Statistical comparisons between control and test material treated groups of numerical data for body weights, hematology data, clinical chemistry data and organ weights (absolute and relative) were assessed using the Student’s t-test. The significances of intergroup differences in incidences of findings from gross pathology and histopathology were analyzed by the Fisher’s exact probability test. The significance of differences for each parameters were analyzed and evaluated at 5 % (p <0.05) or 1 % (p <0.01).

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):

effects observed, non-treatment-related

Description (incidence and severity):

Food consumptions in females and males of the treated groups were tended to be lower compared with the control groups. This effect was not considered to be related to the test substance treatment, since body weights in these groups were not affected by the treatment.

Food efficiency:

not examined

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

no effects observed

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Males:
A significantly decrease of haemoglobin values were observed in all male treatment groups compared with the control group. Since the levels of the red blood cells and haematocrit values did not exhibit any alteration and the histopathological examination of the spleen did not reveal any anemic change, the effect on haemoglobin was considered to be treatment-related, but without biological relevance.
Females:
In females of the highest dose group a significantly reduced haematocrit level compared with the control group was determined. However, the values were within the range of historical control data for rats of this strain according to data published by Charles River (reference: Charles River, Clinical Laboratory Parameters for Crl:CS (SD), March 2006) and were not considered to be dose-related.

Please refer to Table 1 under "any other information on results incl. tables".

Reference: Charles River, Clinical Laboratory Parameters for Crl:CS (SD), March 2006; available online

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

Females:
A significantly increase of aspartate aminotransferase levels were observed in females exposed to test substance concentrations of 3000, 10000 and 30000 ppm compared to control animals. Levels of aspartate aminotransferase were statistically increased in the 1000, 3000 and 10000 ppm dose groups compared with the control group. In the 1000 and 3000 ppm dose group total cholesterol was significantly reduced compared to control animals. However, all these levels were within the range of historical control data for rats of this strain according to data published by Charles River (reference: Charles River, Clinical Laboratory Parameters for Crl:CS (SD), March 2006). In addition, histopathological examination of the liver did not reveal any change related to the treatment. Therefore these effects were not treatment-related and considered to have no toxicological relevance.

Males:
In the highest dose group of 30000 ppm a significantly lower A/G ratio and albumin level was determined compared with the control group. Significant higher values of alanine aminotransferase were noted in all treatment groups compared to controls. Significant higher values of potassium and consequently significant lower values of Na/K were noted in males of the 10000 and 30000 ppm groups. Since histopathological examination of the kidney did not reveal any change related to the electrolyte imbalances in these dose groups, the effects were not treatment-related and considered to have no toxicological relevance.

Please refer to Table 2 under "any other information on results incl. tables".

Reference: Charles River, Clinical Laboratory Parameters for Crl:CS (SD), March 2006; available online

Urinalysis findings:

effects observed, non-treatment-related

Description (incidence and severity):

In the highest dose group 1/6 females and 1/6 males had trace positive reactions of occult blood. A slight positive reaction of occult blood was noted in 1/6 males of the highest dose group. Since the histological examination of the kidneys did not reveal any alteration in these animals, this effect effect was not treatment-related.

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

Females:
Significant lower values of absolute and relative spleen weights (18% reduction of the relative weight compared with the control group) were noted in females of the 1000 ppm dose group compared to controls.

Males:
Significantly lower values of absolute and relative heart weights (8% reduction of the relative weight compared with the control group) in males of the 3000 ppm dose group and significantly increased relative lung weights (13% increase compared with the control group) were noted in the 10000 and 30000 ppm dose group. The absolute and relative spleen weight in males of the 3000 ppm dose group was higher than in the control group, the 16% increase of the relative spleen weight was statistically significant compared with the control group. In the 10000 ppm dose group the absolute and relative spleen (increase of 22%) weight were significantly increased compared to controls.

These effects were not considered to be of toxicological relevance, since they were not dose-dependent and occurred without histopathological correlates.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

10000 ppm: A diverticulum of small intestine (ileum) was noted in 1/6 males.
30000 ppm: An enlargment of kidneys was observed in 1/6 males.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Males:
Slight calcification of artery wall and slight pneumonia was observed each in 1/6 animals of the control group. Slight hydronephrosis was noted in 1/6 animal of the 30000 ppm dose group.

Females:
Slight lymphocytic accumulations were observed each in 1/6 animals of the control and the 30000 ppm dose group, respectively.

Histopathological findings: neoplastic:

no effects observed

Other effects:

not examined

Key result

Dose descriptor:

NOAEL

Effect level:

>= 30 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse and treatment-related effects observed up to and including the highest tested dose level.

Key result

Dose descriptor:

NOAEL

Effect level:

4 863 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No adverse and treatment-related effects observed up to and including the highest tested dose level.

Key result

Dose descriptor:

NOAEL

Effect level:

2 792 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: No adverse and treatment-related effects observed up to and including the highest tested dose level.

Critical effects observed:

no

Table 1: Summary of hematology data

Parameter		Control males	1000 ppm males	3000 ppm males	10000 ppm males	30000 ppm males	Control females	1000 ppm females	3000 ppm females	10000 ppm females	30000 ppm females
Hemoglobin (g/dL)	Mean	15.3± 0.5	14.6± 0.4 *	14.3± 0.7 *	14.2± 0.7 *	14.3± 0.7 *	15.0± 1.4	14.3± 0.6	14.4± 0.6	14.3± 0.8	13.9± 0.5
	N	6	6	6	6	6	6	6	6	6	6
Haematocrit (%)	Mean	41.1± 2.2	40 5± 2.0	38.6± 2.4	39.8± 2.2	39.1± 2.0	41.3± 3.8	39.5± 4.1	37.8± 1.9	37.9± 1.8	37.1± 2.6 *
	N	6	6	6	6	6	6	6	6	6	6

* Significantly different from control group at p < 0.05

Table 2: Summary of clinical chemistry data

Parameter		Control males	1000 ppm males	3000 ppm males	10000 ppm males	30000 ppm males	Control females	1000 ppm females	3000 ppm females	10000 ppm females	30000 ppm females
Aspartate aminotransferase (KU)	Mean ± SD	107± 27	120± 37	118± 21	121± 24	111± 13	80± 7	97± 22	106± 24 *	102± 16 *	99± 17
	N	6	6	6	6	6	6	6	6	6	6
Alanine aminotransferase (KU)	Mean ± SD	27± 4	36± 3 **	37± 5 **	36± 8 *	40± 4 **	25± 5	32± 5 *	38± 5 **	33± 3 **	32± 8
	N	6	6	6	6	6	6	6	6	6	6

* Significantly different from control group at p < 0.05

** Significantly different from control group at p < 0.01

Table 3: Summary of absolute and relative organ weights

Parameter		Control males	1000 ppm males	3000 ppm males	10000 ppm males	30000 ppm males	Control females	1000 ppm females	3000 ppm females	10000 ppm females	30000 ppm females
	N	6	6	6	6	6	6	6	6	6	6
Spleen (absolute weight in g)	Mean ± SD	0.617 ± 0.054	0.681 ± 0.078	0.712 ± 0.133	0.734 ± 0.093 *	0.642 ± 0.051	0.490 ± 0.072	0.401 ± 0.035 *	0.422 ± 0.070	0.407 ± 0.061	0.444 ± 0.040
Spleen (relative weight)	Mean ± SD	0.1771 ± 0.0189	0.1966 ± 0.0146	0.2066 ± 0.0238 *	0.2162 ± 0.0234 *	0.1924 ± 0.0123	0.2338 ± 0.0307	0.1935 ± 0.0174 *	0.2076 ± 0.0322	0.2000 ± 0.0251	0.2128 ± 0.0241
Heart (relative weight)	Mean ± SD	0.3353 ± 0.0179	0.3257 ± 0.0114	0.3100 ± 0.0115 *	0.3346 ± 0.0187	0.3254 ± 0.0316	0.3422 ± 0.0346	0.3690 ± 0.0290	0.3446 ± 0.0175	0.3527 ± 0.0258	0.3395 ± 0.0432
Lung (relative weight)	Mean ± SD	0.3251 ± 0.0244	0.3450 ± 0.0262	0.3440 ± 0.0052	0.3692 ± 0.0200 **	0.3692 ± 0.0275	0.4352 ± 0.0375	0.4255 ± 0.0328	0.4612 ± 0.0370	0.4255 ± 0.0269	0.4354 ± 0.0405

* Significantly different from control group at p < 0.05

** Significantly different from control group at p < 0.01

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

2 193 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The selected study is the most adequate and reliable study with the lowest dose descriptor.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Subacute:

There is an oral 28-day repeated dose toxicity study in rats with CAS 61167-58-6 available (Daiyu-kai Institute of Medical Science, 1984). Male and female Sprague-Dawley rats were administered 1000, 3000, 10000 and 30000 ppm of the test substance in diet (corresponding to 99, 298, 1012 and 4863 mg/kg bw/day for females and 168, 508, 1788 and 2792 mg/kg bw/day for males). No mortality, no clinical signs and no adverse effects on body weight or body weight gain were observed in any of the dose groups during treatment. The slightly reduced food consumption was not considered to be treatment-related, since the body weights were not affected. In males, a significantly decrease of haemoglobin values were observed in all treatment groups when compared with the control group. Since the levels of the red blood cells and haematocrit values did not exhibit any alteration and the histopathological examination of the spleen did not determine any anaemic change, the effect on haemoglobin was considered to be treatment-related, but without biological relevance. In females of the highest dose group a significantly reduced haematocrit level compared with the control group was determined. However, the values were within the range of historical control data for rats of this strain. The observed effects on the clinical biochemistry findings in males and females were not treatment-related and considered to have no toxicological relevance. No adverse changes in organ weights in male or female rats and no toxicologically relevant macroscopic and histopathological changes were present in the study. Under the conditions of this study and based on the toxicological endpoints evaluated, the NOAEL was considered to be 2792 and 4863 mg/kg bw/day for male and female rats, respectively.

Subchronic:

An oral 13-weeks repeated dose toxicity study in rats with CAS 61167-58-6 is available (Daiyu-kai Institute of Medical Science, 1984). Male and female Crj: CD (SD) rats were administered 2500, 5000, 10000 and 30000 ppm of the test substance in diet (corresponding to 252.4, 506.9, 1019.3 and 3281.3 mg/kg bw/day for females and 175.1, 344.1, 699.7, 2193.3 mg/kg bw/day for males). No mortality and no clinical signs were observed in any of the dose groups during treatment. The effects on body weight or body weight gain were not considered to be related to the test material treatment, since these were transitory and not dose-dependent. In addition, no adverse effects in food consumption and dietary intake were seen. Decreased water consumptions were noted in the high-dose females and high-dose males, when compared with the control animals. However, since no adverse effects on general conditions, body weight, urinalysis or clinical chemistry were noted, the reduction of water consumption was not considered to be related to the test substance. No adverse changes in organ weights in male or female rats and no toxicologically relevant macroscopic and histopathological changes were present in the study. The observed effects on the clinical biochemistry findings in males and females were not treatment-related and considered to have no toxicological relevance. Under the conditions of this study and based on the toxicological endpoints evaluated, the NOAEL was considered to be 2193.3 and 3281.3 mg/kg bw/day for male and female rats, respectively.

Justification for classification or non-classification

The available data on repeated dose toxicity with the test substance (CAS 61167-58-6) do not meet the criteria for classification according to Regulation (EC) No 1272/2008, and are therefore conclusive but not sufficient for classification.