2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-((hexyl)oxy)phenol

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992 - 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Reference 2

Reference Type:

other: amendment to CIBA-GEIGY924088 ["Summary of 14 days range finding study"]

Title:

Unnamed

Year:

1994

Report date:

1994

Reference 3

Reference Type:

other: Expert statement to to CIBA-GEIGY924088 ["(Histo)Pathology"]

Title:

Unnamed

Year:

1995

Report date:

1995

Reference 4

Reference Type:

other: Expert statement to CIBA-GEIGY924088 ["Dissected organs/tissues"]

Title:

Unnamed

Year:

1994

Report date:

1994

Reference 5

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Reference 6

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Reference 7

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Reference 8

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Revised Chemical Substance Law (1987), Japan

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-((hexyl)oxy)phenol

EC Number:

411-380-6

EC Name:

2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-((hexyl)oxy)phenol

Cas Number:

147315-50-2

Molecular formula:

C27 H27 N3 O2

IUPAC Name:

2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyloxy)phenol

Test animals

Species:

rat

Strain:

other: Sprague-Dawley derived

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: CIBA-GEIGY Limited, Stein, Switzerland
- Age at study initiation: approximately 4 weeks at delivery
- Weight at study initiation: 97.3 - 118.8 g in males; 91.6 - 115.4 g in females
- Housing: in groups of 5 in Macrolon cages (type 4) with wire mesh tops and standardised granulated soft wood bedding
- Diet: Pelleted, certified standard diet ad libitum
- Water: ad libitum
- Acclimation period: 10 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/- 2 °C
- Humidity: 55 +/- 10 %
- Air changes (per hr): 16 - 20
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 1992-08-31 To: 1992-09-29 (treatment group); From: 1992-08-31 To: 1992-10-27 (recovery group)

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: admixed to pelleted food

Details on oral exposure:

DIET PREPARATION
The test item was weighed on a balance. The pulverized food was then homogeneously mixed with the appropriate concentrations of the test substance and about 25% water was added before pelleting. The pellets were subsequently airdried. The diet was stored in stainless steel containers at room temperature.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Control analyses of the test item content were undertaken with diet used for treatment weeks 1 to 4.

Analytical method: KBB-284/1 (named in CIBA-GEIGY-Report "ANALYTICAL REPORT ON THE CONTENT OF TEST MATERIAL IN RAT FEED /28-DAYS STUDY")

Duration of treatment / exposure:

28 days

Frequency of treatment:

regular

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0 ppm (= mg/kg food)
Basis:
other: analytically determined value in the diet

Doses / concentrations 2

Remarks:

Doses / Concentrations:
8.95, 59.1, 1130 mg/kg bw/day in males
Basis:
other: analytically determined value in the diet

Doses / concentrations 3

Remarks:

Doses / Concentrations:
8.62, 55.5, 1090 mg/kg bw/day in females
Basis:
other: analytically determined value in the diet

No. of animals per sex per dose:

5 males, 5 females per dose group; additionally 5 males, 5 females for recovery assessment in the control and high dose group

Control animals:

yes

Details on study design:

- Dose levels were based on the results of a 14-days range-finding study described elsewhere.
- Randomization: Computer-generated random algorithm
- Post-exposure recovery period in satellite groups: 28-day recovery period

Positive control:

no

Examinations

Observations and examinations performed and frequency:

MORTALITY: Yes
- Time schedule: evaluated on a daily basis

IN-LIFE OBSERVATIONS: Yes
- Time schedule: evaluated on a daily basis, observations were recorded at least weekly
- Observations performed to detect changes in state of health or behaviour

BODY WEIGHT: Yes
- Time schedule for examinations: recorded individually at weekly weighing sessions.

FOOD CONSUMPTION: Yes
- recorded weekly (cagewise) and calculated for periods of one week
- individual food consumption values: calculated from the food consumption per cage and the number of animals
- Food consumption ratios: weekly food consumption (g)/midweek bw (g) x (1000/7) [g food/kg bw per day]
- Test item intake: food consumption ratio x nominal dose (ppm)/1000 [mg test item/kg bw per day]

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the treatment period; additionally at the end of the recovery period
- Anaesthetic used for blood collection: Yes, ether anesthesia, blood samples were drawn from the retro-orbital plexus
- Animals fasted: Yes
- How many animals: all animals
- Parameters examined:
Red blood cells: Erythrocyte count, Hemoglobin, Hematocrit, Mean corpuscular volume, Red cell volume distribution width, Mean corpuscular haemoglobin, Mean corpuscular haemoglobin concentration, Hemoglobin concentration distribution width; Differential leukocyte count; Thrombocyte count; Prothrombin time; Methemoglobin

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the end of the treatment period; additionally at the end of the recovery period
- Animals fasted: Yes
- How many animals: all animals
- Parameters examined: Glucose, Urea, Creatinine, Total Bilirubin, Total Protein, Albumin, Globulins, A/G Ratio, Cholesterol, Triglycerides, Sodium, Potassium, Calcium, Chloride, Phosphorus inorganic, Aspartate aminotransferase, Alanine aminotransferase, Alkaline phosphatase, Gamma-glutamyl transpeptidase

URINALYSIS: No

OPHTHALMOSCOPIC EXAMINATION: No

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY/NECROPSY: Yes
At the end of 28-day treatment and of additional 4-week recovery period all control and treated animals were bled under ether anesthesia and subjected to detailed autopsy. A complete autopsy with tissue preservation was performed also on one control animal, which died on day 9 of the study. The weights of body (exsanguinated) adrenals, liver, kidneys, ovaries, testes, thyroid with parathyroid gland, and mesenteric lymph node were recorded. Samples of the following tissues and organs were preserved in neutral buffered 4% formalin: Skin, mammary area, spleen, mesenteric lymph node, axillary lymph node, sternum with bone marrow, femur with joint, skeletal muscle, trachea, lung, heart, aorta, submandibular salivary gland (both), liver, pancreas, esophagus, stomach, small intestine, large intestine, kidney (both), urinary bladder, prostate, seminal vesicle, testis (both), epididymis (both), uterus, vagina, ovary (both), pituitary gland, adrenal gland (both), thyroid with parathyroid gland, thymus, peripheral nerve, brain, spinal cord, eye with optic nerve (both), orbital gland (both), extraorbital lacrimal gland (both), Zymbal gland (both), muzzle, tongue, and any tissue with gross lesions. All organ and tissue samples were processed, embedded, cut at a thickness of 3-5 micrometers, and stained with hematoxylin and eosin (only main group to evaluate toxicity).

HISTOPATHOLOGY: Yes
Spleen, heart, liver, kidney (both), adrenal gland (both), thyroid with parathyroid gland, and any organ with gross lesions

Statistics:

For each time point and parameter an univariate statistical analysis was performed. Nonparametric methods were applied, to allow for non normal as well as normal data distribution. Each treated group was compared to the control group by Lepage's two-sample test and tested for increasing or decreasing trends from control up to the respective dose group by Jonekheere's test for ordered alternatives.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food efficiency:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Details on results:

IN-LIFE OBSERVATIONS AND MORTALITY:
No relevant clinical signs were observed during the study.
No treatment-related death occurred during the study.

BODY WEIGHT:
Mean bodyweight development in both sexes was not affected by treatment.

FOOD CONSUMPTION AND FOOD CONSUMPTION RATIOS:
Mean food intake was not influenced by treatment.
Mean food consumption ratios were comparable to control values

HAEMATOLOGY:
The treatment had no influence on the hematological profile.

CLINICAL (BLOOD) CHEMISTRY:
The treatment had no influence on blood chemistry parameters.

ORGAN WEIGHTS:
All organ weights were considered not to be influenced by treatment.

GROSS PATHOLOGY:
No treatment-related changes were observed.

HISTOPATHOLOGY:
No treatment-related changes were observed.

Effect levels

1

Dose descriptor:

NOEL

Effect level:

1 130 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: No treatment-related changes up to and including the highdose level.

2

Dose descriptor:

NOEL

Effect level:

1 090 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No treatment-related changes up to and including the highdose level.

3

Dose descriptor:

NOAEL

Effect level:

1 130 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: No treatment-related changes up to and including the highdose level.

4

Key result

Dose descriptor:

NOAEL

Effect level:

1 090 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No treatment-related changes up to and including the highdose level.

Target system / organ toxicity

Key result

Critical effects observed:

no

Any other information on results incl. tables

In a previous subacute 14-day range-finding study the test item was administered in the diet for 2 weeks at doses of 0, 100, 1000 and 10000 ppm (= mg/kg food) to a total of 40 albino rats , 5 males and 5 females per dose group. Corrected for the analytically determined test item concentrations in the diet , the mean daily intakes were 16.2 , 98.1, and 1050 mg/kg bw in males, and 16.1, 93.3 , and 966 mg/kg bw in females, respectively. No clinical signs were observed and no animal died during the study. Neither mean bodyweight development nor food intake were affected by treatment. Treatment did not influence the hematological or blood chemistry profiles of the rats. Mean organ weights were not influenced by treatment and no treatment-related changes were detected at necropsy. This study is listed above as further reference (CIBA-GEIGY924087).

Applicant's summary and conclusion

Executive summary:

In a repeated toxicity study the test item (as described in section 1.2) was administered to five rats/sex/dose level by feeding at dose levels of 0, 100, 650, and 12000 ppm for a period of 28 days. The analytically determined mean daily intake was 8.95, 59.1, and 1130 mg/kg bw in males, and 8.62, 55.5, and 1090 mg/kg bw in females. In addition, a 28-day recovery testing was performed with five male/female rats at dose levels of 0 and 12000 ppm. No test item-related effects in mortality, clinical signs, body weight, food consumption, hematology, clinical chemistry, organ weights, gross pathology, and histopathology were observed. However, one female from the control group died accidentally. No other death occurred during the study. The NO(A)EL is 1130 mg/kg bw/d in males and 1090 mg/kg bw/d in females. This repeated toxicity study in the rat is acceptable and satisfies the guideline requirement for a repeated dose 28-day oral toxicity study (OECD 407) in rodents.