Registration Dossier

Administrative data

Description of key information

In a subchronic study in Wistar rats following gavage administration of the

test compound for 90 days, the NOAEL and LOAEL was 100 and 300 mg/kg bw/day, respectively (BASF SE, 2014).

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records
Reference
Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Aug 2013 - May 2014
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
BASF SE
Limit test:
no
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services GmbH, Sulzfeld, Germany
- Age at study initiation: 42 ± 1 days
- Weight at study initiation: see results
- Housing: 5 animals per cage in polysulfonate (H-Temp) cages, floor area about 2065 cm2 (610×435×215 mm); TECNIPLAST, Hohenpeissenberg, Germany; Polycarbonate cages (floor area about 800 cm2) to measure the motor activity; TECNIPLAST, Hohenpeissenberg, Germany. Dust-free wooden bedding.
- Diet (e.g. ad libitum): ground Kliba mouse/rat maintenance diet “GLP”, meal, supplied by Provimi Kliba SA, Kaiseraugst, Switzerland, ad libitum
- Water (e.g. ad libitum): yes
- Acclimation period: yes

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70, 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 13.08.2014 To: 22.11.2014
Route of administration:
oral: gavage
Vehicle:
CMC (carboxymethyl cellulose)
Remarks:
1 % suspension in drinking water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Preparation frequency: test-substance preparations were prepared at least weekly.
Storage conditions: refrigerator
Route of administration: daily gavage using 3 or 5 mL syringes
Volume to be administered: 10 mL/kg body weight

VEHICLE
- Concentration in vehicle: 0, 1, 3, 10 g/100ml
- Amount of vehicle (if gavage): 10 ml/kg bw
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analyses confirmed (1) the stability of the test-substance preparations over a period of 7 days in the refrigerator, (2) the homogenous distribution of the test substance in the vehicle, and (3) the correctness of the prepared concentrations.
Duration of treatment / exposure:
90 days
Frequency of treatment:
daily
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
Dose / conc.:
600 mg/kg bw/day (actual dose received)
Remarks:
for males from day 70
No. of animals per sex per dose:
10
Control animals:
yes, concurrent vehicle
Details on study design:
4,4´-sulphonyldiphenol was administered by gavage to groups of 10 male and 10 female Wistar rats at dose levels of 0 (test group 0), 100 (test group 1), 300 (test group 2) and 1000 mg/kg bw/d (test group 3) over a period of 3 months. Due to severely impaired body weight development in male animals of test group 3 (1000 mg/kg bw/d), i.e. -20% on study day 63, the male animals were treated at a dose level of 600 mg/kg bw/d from study day 70 onwards. Female animals were continuously treated at limit dose.
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS:
- Time schedule: twice daily from monday to friday, once daily on saturdays and sundays

CLINICAL SIGNS:
- Time schedule: daily before and 2-5 h after test substance administration. Detailed clinical examinations in an open field prior to the start of the administration period and weekly thereafter.

DETAILED CLINICAL OBSERVATIONS:
- outside of cages once before the beginning of the administration period (day 0) and subsequently once a week (in the morning).

BODY WEIGHT: Yes
- Time schedule for examinations: before the start of the administration period, during the administration period the body weight on day 0 and thereafter at weekly intervals. The difference between the body weight on the respective day of weighing and the body weight on day 0 was calculated as body weight change.

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes, weekly over a period of 4 days

WATER CONSUMPTION AND COMPOUND INTAKE: Yes, daily by visual inspection

OPHTHALMOSCOPIC EXAMINATION: Yes,
- Time schedule for examinations: before beginning of administration, and at the end of the administration period.
- Dose groups that were examined: all animals of the control and highest dose group.

HAEMATOLOGY: Yes, towards the end of the administration period.
- Anaesthetic used for blood collection: Yes, blood samples were taken from fasted animals by puncturing the retrobulbar venous plexus under isoflurane anesthesia.
- Animals fasted: Yes
- Parameters checked: leukocytes, erythrocytes, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), platelets, differential blood count, reticulocytes, blood smear, prothrombin time

CLINICAL CHEMISTRY: Yes, towards the end of the administration period.
- Parameters checked: Alanine aminotransferase, Aspartate aminotransferase, Alkaline phosphatase, Serum gamma glutamyl transferase, Sodium, Potassium, Chloride, Inorg. Phosphate, Calcium, Urea, Creatinine, Glucose, Total bilirubin, Total protein, Albumin, Globulins, Triglycerides, Cholesterol,

URINALYSIS: Yes, towards the end of the administration period.
- Time schedule for collection of urine / metabolism cages used for collection of urine / animals fasted: Yes, on the afternoon preceding the day fixed for urinalysis, the animals were transferred individually into metabolism cages (no food or drinking water provided). Urine was sampled overnight. On the following day, the samples were examined.
- Parameters checked: Volume, Color, Turbidity, pH value, Protein, Glucose, Ketones, Urobilinogen, Bilirubin, Blood, Specific gravity, Microscopy of sediment.

NEUROBEHAVIOURAL EXAMINATION: Yes, functional observational battery (FOB) and measurement of motor activity (MA).
- Time schedule for examinations: in all animals once at the end of the administration period.
- Battery of functions tested: sensory activity / grip strength / motor activity / other:
FOB starts with passive home cage observation in the rack for a short period (about 10-30 seconds) in cages with the lids closed.
Followed by removal from the home cage for open field observation in a standard arena (50 × 50 × 25 cm).
Finally sensory motor tests as well as reflex tests. The findings were ranked according to the degree of severity, if applicable.
Motor activity (MA) was measured on the same day as the FOB was performed. The examinations was performed using the TSE Labmaster System supplied by TSE Systems GmbH, Bad Homburg, Germany. Animals were placed in new clean polycarbonate cages with a small amount of bedding for the duration of the measurement. Eighteen beams were allocated per cage. The number of beam interrupts were counted over 12 intervals for 5 minutes per interval.
Sacrifice and pathology:
Animals were sacrificed by decapitation under isoflurane anesthesia. The exsanguinated animals were necropsied and assessed by gross pathology.

GROSS PATHOLOGY and ORGAN WEIGHTS: Yes, Anesthetized animals, Adrenal glands, Brain, Epididymides, Heart, Kidneys, Liver, Ovaries, Spleen, Testes, Thymus, Thyroid glands, Uterus with cervix.

HISTOPATHOLOGY: Yes, All gross lesions, Adrenal glands, Aorta, Bone marrow (femur), Brain, Cecum, Cervix, Coagulating gland, Colon, Duodenum, Epididymides, Esophagus, Extraorbital lacrimal glands, Eyes with optic nerve (modified Davidson’s solution), Femur with knee joint, Harderian glands, Heart, Ileum, Jejunum (with Peyer’s patches), Kidneys, Larynx, Liver, Lungs, Lymph nodes (mesenteric and axillary lymph nodes), Mammary gland (male and female) , Nose (nasal cavity), Ovaries, Oviducts, Pancreas, Parathyroid glands, Pharynx, Pituitary gland, Prostate, Rectum, Salivary glands (mandibular and sublingual glands), Sciatic nerve, Seminal vesicles, Skeletal muscle, Skin, Spinal cord (cervical, thoracic and lumbar cord), Spleen, Sternum with marrow, Stomach (forestomach and glandular stomach), Testes, Thymus, Thyroid glands, Trachea, Urinary bladder, Uterus, Vagina.  

Hematoxylin and Eosin staining was performed at least from all animals of the high dose group. In liver sections of all dose groups cresyl violet stain was used for better classification of basophilic foci and GSTP immunohistochemistry was used to better detect GSTP positive (eosinophilic) hepatocellular foci.
Statistics:
Statistics of clinical examinations:
Body weight, body weight change was analysed by DUNNETT’s test.
Feces, rearing, grip strength of fore- and hindlimbs, landing foot-splay test, motor activity was analysed by KRUSKAL-WALLIS and WILCOXON test.
Statistics of clinical pathology:
Clinical pathology parameters (except for urine color and urine turbidity) were analysed by KRUSKAL-WALLIS and WILCOXON test.
Statistics of pathology
Weight of the anesthetized animals and absolute and relative organ weights were analysed by KRUSKAL-WALLIS and WILCOXON test.
Details on results:
CLINICAL SIGNS AND MORTALITY
No animal died prematurely.
Soft and discolored (light brown) feces were observed in all animals of the high and intermediate test groups. The discoloration was first observed on study day 15 in male and female animals of the high dose group and on study days 84 and 85 in male and female animals of the mid dose group, respectively. Soft consistency was observed towards the end of the treatment period.
Salivation after treatment from slight to moderate was observed in all male and in 9 of 10 female animals the high dose group, in 9 of 10 male and all female animals of the intermediate dose group as well as in 6 of 10 male and 4 of 10 female animals of the low dose group. This observation was temporary and short in appearance immediately after dosing.

BODY WEIGHT AND WEIGHT GAIN
Mean body weight of male animals in the high dose group (1000/ 600 [from day 70 onwards] mg/kg bw/d) was significantly lower during the entire administration period with a maximum of -20% on study day 70. In male animals of the intermediate dose group (300 mg/kg bw/d) mean body weight was also decreased up to nearly 10% on study days 84 and 91 (see table 2).
No deviations of toxicological concern in mean body weight were observed in male animals of the low dose group (100 mg/kg bw/d).
Relevant changes in mean body weight were not observed in female animals of all treatment-groups during the entire administration period.
(see table 2).
Mean body weight change values of male animals in the high dose group (1000/ 600 [from day 70 onwards] mg/kg bw/d) were significantly lower during the entire administration period with a maximum of -33% from study day 0 to 63. In male animals of the intermediate dose group (300 mg/kg bw/d) mean body weight change values were also decreased from study day 77 onwards with a maximum of -15% from study day 0 to 84 as well as study days 0 to 91.
No relevant deviations in mean body weight change were observed in male animals of low dose group (100 mg/kg bw/d).
Relevant changes in mean body weight change were also not observed in female animals of all treatment-groups during the entire administration period.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Food consumption in male animals of the high dose group (1000 mg/kg bw/d) was reduced from study day 7 to 70, with a maximum of -18% on study day 63 (see table 1). After the reduction of the dose (600 mg/kg bw/d from study day 70 onwards) the food consumption was within the usual range.
Food consumption of female animals and male animals of low and intermediate dose groups (100 and 300 mg/kg bw/d) was not influenced. (see Table 1)

WATER CONSUMPTION
No changes with regard to water consumption were observed.

OPHTHALMOSCOPIC EXAMINATION
No treatment-related findings were observed.

HAEMATOLOGY
At the end of the administration period in both sexes of the high dose group, red blood cell (RBC) counts and hemoglobin values were decreased (-7.2/-4.4% and -5.6/-9.1% in males and females, respectively). .
In high dose females hematocrit values were decreased (-6.8%).
In high dose males mean corpuscular volume (MCV) and relative reticulocyte counts were increased (+5.5/+21%, respectively).
In high dose females prothrombin time (Hepatoquick’s test, HQT) was prolonged.
Further statistically significant changes were identified to be within the range of historical controls and therefore considered to be not treatment related.

CLINICAL CHEMISTRY
At the end of the administration period, in males of the mid and high dose groups cholesterol levels were decreased (-34/-44.3%). This effect was regarded as treatment-related, but not adverse (ECETOC Technical Report No. 85, 2002).
Alterations in triglyceride levels in males were regarded as incidental.
In males of the high dose group creatinine values were increased (11%) and total bilirubin values were decreased (-22%). Alterations in the low dose group were considered to be not toxicologically relevant.
In females of the high dose group alkaline phosphatase activities were slightly increased (35%).

URINALYSIS
No treatment-related changes were observed.

NEUROBEHAVIOUR
Apart from incidental findings no dose- and test-substance related effects were observed in the Functional Observation battery of all dose groups (home cage observations, open-field observations and sensimotor rests/reflexes).
Likewise no dose- and test-substance related deviations to the control were noted in the motor activity measurements.

ORGAN WEIGHTS (relative)
For increased or decreased relative organ weights see Table 5.
Treatment-related and dose dependent decrease in terminal body weight in male animals.
Treatment-related increase in relative liver weights in mid and high dose group in females which correlated with histopathology. In males, the increase in relative liver weights in the high dose group was not accompanied by histopathologic findings but was outside the historical control range (This study: 2.676%, range of historical controls: 2.063% - 2.39%).
Weight increases in the adrenal gland of the high dose group of both sexes and the mid dose females were likely treatment-related although a histopathological correlate was only detected in males of the high dose group.
In the spleen relative weights were increased in high dose males and mid and high dose females, which correlated histopathologically with increased extramedullary hematopoiesis and were therefore considered treatment-related.
The decrease in thymus weight was not accompanied by histopathologic findings in females and was of questionable significance.
The statistically significant increase in relative weights of brain, epididymis, heart and testis in male animals of one or more treatment groups and increase of relative heart weights in females of the high dose was likely due to the decrease in terminal body weight.
The weight changes in the kidney were most likely also related to the decreased terminal body weight in males of all treatment groups as the histopathologically observed mineralization at the medulla/cortical junction was not believed to correlate with the weight change. In females, there was no histopathological correlate to the increased kidney weights in the mid and high dose group, therefore this was considered of equivocal significance.
The increased weights of the ovaries of high dose females were assessed as treatment-related as both absolute and relative weights were outwith the historical control range (this study absolute / relative 126 mg / 0.061%, historical control range absolute / relative 80.7 - 113.8 mg / 0.036 - 0.051%). There were no correlating histopathological findings.
There were no histopathological findings in the thyroid glands of high dose male and female animals. The weight change was therefore regarded as incidental.

GROSS PATHOLOGY
The cecum was dilated in all male animals of the high dose group.
The liver was enlarged in 8 of 10 females of the high dose group.

HISTOPATHOLOGY: NON-NEOPLASTIC
High dose male and female animals showed dilation of the cecum, characterized by a greater circumference of the cecal wall as compared to controls. A minimally increased number of apoptotic bodies were observed in the mucosa of treated animals.
Increased extramedullary hematopoiesis (mainly with reticulocytes) was observed in the spleen of both male and female animals (see table for incidence).
Male animals of the high dose group showed an increased thickness of the cortex of the adrenal gland, which was attributed to both hypertrophy and hyperplasia of cortical cells. This finding was assumed to have caused the weight increase of the adrenal glands in this test group.
Male animals of all test groups showed multifocal mineralization of tubules in the junction between cortex and medulla (termed “mineralization, medulla” in the incidence tables).
The mammary gland of mid and high dose group males showed a change from the physiological lobulo-alveolar morphology to a tubulo-alveolar appearance with smaller, more basophilic epithelial lining cells.
A dose-dependent increase in incidence and severity of centrilobular hypertrophy was noted as shown in the liver of females. Furthermore, there was an increased incidence of foci of hepatocellular alteration (especially the eosinophilic type) in the high dose females, which was also confirmed by an increased incidence of GSTP positive foci in immunohistochemistry.
Focal squamous metaplasia of the uterine glandular epithelium was noted with an increased incidence in treated female animals, which might be treatment-related.
Dose descriptor:
NOAEL
Effect level:
100 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male
Basis for effect level:
body weight and weight gain
organ weights and organ / body weight ratios
Dose descriptor:
NOAEL
Effect level:
300 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
female
Basis for effect level:
haematology
organ weights and organ / body weight ratios
Critical effects observed:
not specified

Table 1: Food consumption per day [g] 

males [g]

0

100

300

1000/600

d 3-7

18.5 +/-0

17.8 +/-0.9

18.4 +/-0.9

15.1 +/-0.1

d 10-14

21.6 +/-0.1

20.6 +/-1

22.6 +/-1.5

19.4 +/-2.8

d 17-21

23.5 +/-1.6

21.8 +/-0.4

24.4 +/-1.1

21.5 +/-0.5

d 24-28

23.1 +/-1

22.7 +/-0.4

25.9 +/-1.3

19.7 +/-1.3

d 31-35

22.5 +/-0.9

23.7 +/-1

24.9 +/-1.6

20.8 +/-1.2

d 38-42

23.6 +/-2.5

27 +/-1.6

22.9 +/-0.8

19.9 +/-0.4

d 45-49

20.7 +/-0.1

21 +/-0

20.1 +/-0.1

19.6 +/-1.2

d 52-56

20.7 +/-0.3

22.6 +/-0.6

21.4 +/-1.3

19.9 +/-1.1

d 59-63

22.4 +/-0.4

23 +/-3.3

21.9 +/-2.1

18.3 +/-2.1

d 66-70

22.5 +/-0.4

22.2 +/-1.8

22.8 +/-0.4

19.2 +/-2.3

d 73-77

21.1 +/-1.1

20.2 +/-0.6

22.1 +/-1.8

24.5 +/-5.9

d 80-84

21.1 +/-0.5

22.2 +/-0.4

21.1 +/-2.1

22.7 +/-4.4

d 87-91

22.1 +/-1.1

20.9 +/-0.8

21.5 +/-0.5

22.9 +/-4.1

females [g]

0

100

300

1000

d 3-7

12.9 +/-0.2

12.8 +/-0.39

12.6 +/-0

11.3 +/-1.1

d 10-14

14.7 +/-0.4

14 +/-0.1

14.5 +/-0.7

22.5 +/-4.7

d 17-21

14.9 +/-0.2

14.4 +/-0

15.1 +/-0.1

14.9 +/-0.5

d 24-28

16.4 +/-0.2

14.9 +/-0.5

15.6 +/-0.8

16.2 +/-0.4

d 31-35

15.2 +/-0.1

14.6 +/-0.1

14.9 +/-1

15.5 +/-0.7

d 38-42

15.6 +/-0.3

14.8 +/-0.1

15 +/-0.1

15.7 +/-0.2

d 45-49

14.7 +/-0.2

13.4 +/-0.3

16.9 +/-4.6

15.1 +/-0.2

d 52-56

16.2 +/-1.3

13.5 +/-0.1

14.1 +/-0.1

22.3 +/-9.9

d 59-63

16.3 +/-0.8

14.4 +/-0.2

15.3 +/-2.4

16 +/-4

d 66-70

17 +/-1.1

15.1 +/-0

14.8 +/-0.5

17.9 +/-2.4

d 73-77

16.2 +/-1

14.9 +/-1.5

15.1 +/-0.6

18.2 +/-5.3

d 80-84

15.7 +/-1

14.4 +/-0.2

14.9 +/-0.1

16.8 +/-0.6

d 87-91

15.1 +/-0.3

13.8 +/-0.3

14.6 +/-0.1

15.4 +/-0.4

Table 2: relative organ weights [%]

100, 300, 1000 mg/kg bw/d

males

females

Adrenals

96, 109, 177**

101, 121*, 131**

Brain

100, 103, 120**

No effect

Epididymes

101, 103, 112**

-

Heart

98, 101, 109*

101, 107, 109*

Kidneys

110*, 122**, 125**

112, 113*, 118**

Liver

No effect

109, 120**, 149**

spleen

97, 94, 119**

105, 113**, 111*

thyroid

89, 104, 116*

92, 105, 121**

thymus

No effect

100, 87, 79*

testes

104, 102, 116*

-

Ovaries

-

102, 109, 130*

uterus

-

124, 185, 95

 

Table 3: absolute body weights [g]

males [mg/kg bw]

0

100

300

1000/600

d 0

158.4 +/-6.4

157.1 +/-6.6

158.1 +/-5.5

158.2 +/-5.7

d 7

203.3 +/-9.5

199.9 +/-9.4

198 +/-9.4

189.9 +/-10**

d 14

246.7 +/-12.6

242.8 +/-14.9

240.6 +/-11.9

224.6 +/-15.4**

d 21

283.3 +/-16.9

276.7 +/-21.1

274.1 +/-11.4

253.7 +/-18.4**

d 28

311.7 +/-20

304.2 +/-26.3

298.1 +/-14.8

267.6 +/-20.1**

d 35

333 +/-23.8

328.6 +/-30.4

312.2 +/-17.2

282.1 +/-22.8**

d 42

351.4 +/-27.2

343.8 +/-33.9

326 +/-19.3

294.3 +/-26.5**

d 49

359 +/-23.1

355.8 +/-38.2

336.5 +/-19.5

302 +/-31.8**

d 56

375.1 +/-28.1

367.8 +/-40.3

345.3 +/-19.4

306.2 +/-32.3**

d 63

389.4 +/-31.6

377.8 +/-40.1

354.6 +/-19.7

312.4 +/-36.4**

d 70

396.6 +/-31.6

387.5 +/-45.4

362.3 +/-22.8

317.8 +/-36.6**

d 77

406.4 +/-31

390.6 +/-43.9

369.1 +/-22.5

326.6 +/-40.5**

d 84

413.4 +/-32.3

396.8 +/-45.4

373.8 +/-19.5

332.7 +/-42.2**

d 91

417.1 +/-31.8

400.7 +/-46.4

377.3 +/-21.7

334.7 +/-41.6**

females [mg/kg bw]

0

100

300

1000

d 0

126.1 +/-6.9

127 +/-6.9

126 +/-7.5

126.7 +/-7.8

d 7

143.7 +/-8.6

147 +/-8.2

144 +/-7.3

142.7 +/-7.9

d 14

162.9 +/-11.3

163.1 +/-10.2

162.4 +/-7.8

162.9 +/-8.8

d 21

180.1 +/-14.5

177.2 +/-9.5

173.7 +/-9.3

176.9 +/-9.4

d 28

191 +/-14.5

188.3 +/-10.7

187.6 +/-11.6

189.4 +/-11.6

d 35

201.1 +/-19

199 +/-11.8

196.4 +/-10.2

197.4 +/-11.9

d 42

208.4 +/-19.1

204.7 +/-13.8

202.8 +/-12.2

205.2 +/-12

d 49

216.8 +/-19.6

209.3 +/-13.2

207.2 +/-14.2

208.7 +/-13.6

d 56

219.3 +/-18.9

214.8 +/-13.1

212.5 +/-15.5

213.5 +/-13.8

d 63

227.2 +/-20.8

222.2 +/-13.7

216.1 +/-12.6

217.4 +/-14.4

d 70

230.2 +/-21

223.8 +/-16.2

220.6 +/-14.2

218.9 +/-15

d 77

235.5 +/-22.2

228.3 +/-14.2

222.1 +/-16.4

220.8 +/-16.6

d 84

236.1 +/-20.4

230.1 +/-13.9

224.9 +/-15.8

222.9 +/-15.9

d 91

237.3 +/-23.4

231.7 +/-14.2

225 +/-14.9

222.5 +/-15.3

Table 4: Observed effects in hematological parameters

Males [mg/kg bw/day]

0

100

300

1000

Red blood cell [tera/l]

8.71 +/-0.35

8.83 +/-0.32

8.46 +/-0.26

8.08 +/-0.39**

Hemoglobin [mmol/l]

9 +/-0.2

9 +/-0.4

8.8 +/-0.3

8.6 +/-0.2**

Hematocrit [L/L]

0.427 +/-0.014

0.426 +/-0.022

0.42 +/-0.018

0.412 +/-0.014

mean corpuscular volume [fL]

49.1 +/-1

48.2 +/-1.6

49.6 +/-1.5

51 +/-1.6**

reticulocyte counts [%]

1.5 +/-0.1

1.2 +/-0.5

1.6 +/-0.2

1.9 +/-0.4*

HQT [sec]

38.2 +/-2.2

39.2 +/-2.8

39.5 +/-2.7

40.5 +/-1.8

Females [mg/kg bw/day]

0

100

300

1000

Red blood cell [tera/l]

7.89 +/-0.31

7.832 +/-0. 2

7.76 +/-0.36

7.45 +/-0.25**

Hemoglobin [mmol/l]

8.8 +/-0.3

8.6 +/-0.2

8.5 +/-0.3

8 +/-0.3**

Hematocrit [L/L]

0.408 +/-0.012

0.406 +/-0.011

0.402 +/-0.015

0.38 +/-0.013**

mean corpuscular volume [fL]

51.8 +/-1.4

52 +/-2

51.8 +/-1.1

51 +/-1.8

reticulocyte counts [%]

1.8 +/-0.5

2 +/-0.5

2.2 +/-0.6

2.3 +/-0.5

HQT [sec]

35.5 +/-2.2

35.2 +/-1.3

36.8 +/-1.5

38.2 +/-1.2

 

Table 5: Observed effects in clinical chemistry

Males

[mg/kg bw/day]

0

100

300

1000

Cholesterol [mmol/l]

1.85 +/-0.29

1.65 +/-0.36

1.23 +/-0.29**

1.03 +/-0.17**

Creatinine [mmol/l]

30.53 +/-2.2

28.2 +/-1.4*

30.8 +/-2.7

34.2 +/-3.7*

total bilirubin [µmol/l]

1.62 +/-0.2

1.57 +/-0.15

1.49 +/-0.34

1.26 +/-0.36**

alkaline phosphatase activities [µkat/l]

0.68 +/-0.12

0.8 +/-0.47

0.91 +/-0.16**

0.92 +/-0.46

Females [mg/kg bw/day]

0

100

300

1000

Cholesterol [mmol/l]

1.62 +/-0.44

1.56 +/-0.26

1.3 +/-0.29

1.33 +/-0.32

Creatinine [mmol/l]

36.6 +/-5.9

35.9 +/-2.9

34.2 +/-3.8

32.1 +/-4

total bilirubin [µmol/l]

2.52 +/-0.45

2.18 +/-0.56

2.02 +/-0.39

2.32 +/-0.41

alkaline phosphatase activities [µkat/l]

0.66 +/-0.19

0.55 +/-0.09

0.69 +/-0.25

1.01 +/-0.37*

 * p<=0.05, ** p <=0.01

Table 6:  Histopath incedence

0, 100, 300, 1000(600) mg/kg

males

females

Cecum dilation

0, 0, 0, 10

0, 0, 1, 10

spleen

0, 0, 0, 8

2, 1, 4, 10

Mammary gland

0, 0, 0, 0

0, 0, 7, 10

Liver, hypertrophy

0, 0, 0, 0

0, 2, 5, 10

Liver, foci

0, 0, 0, 0

1, 1, 1, 6

Uterus

-

0, 2, 2, 5

Conclusions:
DHDPS was administered by gavage to groups of 10 male and 10 female Wistar rats at dose levels of 0, 100, 300 and 1000 mg/kg bw/d over a period of 3 months. Due to severely impaired body weight development in male animals of the high dose group, i.e. -20% on study day 63, the male animals were treated at a dose level of 600 mg/kg bw/d from study day 70 onwards.

Test substance related adverse signs of systemic toxicity were observed at a dose level of 300 mg/kg bw/d and above in male animals and at a dose level of 1000 mg/kg bw/d in female Wistar rats. Therefore, under the conditions of the present study the no observed adverse effect level (NOAEL) was 100 mg/kg bw/d in male and 300 mg/kg bw/d in female Wistar rats.
Executive summary:

Soft and discolored (light brown) feces were observed in all animals of mid and high dose groups starting on different days. These findings were assessed as being treatment-related.

Salivation after treatment was observed in most mid and high dose animals as well as in 6 of 10 male and 4 of 10 female animals of the low dose. From the temporary, short appearance immediately after dosing (or shortly before) it was concluded that salivation was induced by a bad taste of the test substance or local affection of the upper digestive tract. The effect was assessed to be non-adverse.

Cecum dilation was macroscopically identified in all high dose males. Histopathological cecum effects were noted in all male and female animals of the high dose group and in one mid dose female animal. Cecum dilation may have had a significant contribution to the decreased bw observed in the high dose males. Though the human relevance of these observations is questionable due to significant anatomical and functional differences of the cecum to rodents in which this structure is large and has a significant function in the digestion.

Regenerative anemia was identified in high dose animals (male and female) characterized by increased extramedullary hematopoiesis in the spleen correlated by findings in clinical pathology (decreased red blood cell counts and hemoglobin values, in females decreased hematocrit values, higher relative reticulocyte counts at least in males, low total bilirubin levels in males).

A weight increase of the adrenal glands of high dose male animals, which correlated with hypertrophy/hyperplasia in the cortex was regarded as adverse and treatment related.  

In absence of degenerative findings, multifocal mineralization of kidney tubules noted in males of all treatment groups was regarded as nonadverse.

In the mammary gland of male animals of the mid and high dose animals, a change from the physiological lobulo - alveolar morphology to a tubulo-alveolar appearance with smaller more basophilic epithelial lining cells (atrophy) was seen. In the literature (Rudmann et al., 2012; see also OECD, Series on Testing and Assessment, No. 106, 2009, Part4: Mammary gland [http://www.oecd.org/chemicalsafety/testing/43754898.pdf])), the occurrence of atrophy has been correlated to altered hormone levels (increased prolactin or decreased androgen) or with emaciation in male animals. This finding was regarded as adverse.

 

Increased liver weights in females of the mid and high dose was correlated with a dose-dependent centrilobular hypertrophy was seen in 2/10, 5/10, and 10/10 animals in low, mid and high dose group, respectively. Gradings were minimal in low to moderate in high dose animals correlating with the macroscopic finding “enlarged” in the high dose. In the livers of the high dose females, there was also an increased incidence of mainly eosinophilic foci of hepatocellular alteration, which were confirmed by GSTP immunohistochemistry, and considered to be adverse. Only the hypertrophy in the liver in combination with the increased liver weight of high dose females was assessed as adverse due to the presence of these foci. The hypertrophy alone in low and mid dose groups was assessed as non-adverse as no concurrent findings in clinical pathology were noted.

The increased relative liver weight in high dose males was assessed as adverse together with clinical pathology findings (lower cholesterol and higher triglyceride levels).

In the uterus, focal squamous cell metaplasia of glandular epithelium was observed in 2 females of low and mid dose group and in 5 of 10 females of the high dose group. In the high dose group this finding was assessed as possibly treatment-related and adverse due to the higher incidence. For low and mid dose group animals the finding was assessed as non-adverse as it can occur in single animals in control groups.

The increased weights of the ovaries of test group 3 females were assessed as treatment related although there were no correlating histopathological findings.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
100 mg/kg bw/day
Study duration:
subchronic
Species:
rat

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

Repeated dose toxicity: Oral

The key study is an OECD guideline 408 repeated-dose 90 day oral toxicity study. 4,4´-sulphonyldiphenol was administered by gavage to groups of 10 male and 10 female Wistar rats at dose levels of 0, 100, 300 and 1000 mg/kg bw/d (BASF SE, 2014). Due to a severely impaired body weight development in male animals of the high dose group, i.e. -20% on study day 63, the male animals were treated at a dose level of 600 mg/kg bw/d from study day 70 onwards. Female animals were continuously treated at the limit dose.

Temporary treatment related salivation was observed immediately after dosing. Furthermore soft and discolored (light brown) feces was observed in the mid and high dose groups. Both observations may result from treatment-related local effects in the digestive tract.

The observed body weight changes and cecum effects are likely to be secondary to these local effects in the digestive tract. Significant changes in mean body weights were identified in males of the mid and high dose groups. A dose dependent increase in histopathological cecum lesions was observed in all treatment groups (male and female), resulting in a macroscopical cecum dilation in all animals of the high dose group.

Besides the adverse decrease in body weights histopathological lesions in the mammary gland where observed in males of the mid and high dose groups, resulting in a NOAEL for male animals of 100 mg/kg bw.

Further organ effects were identified in the males of the high dose group, including a weight increase in adrenal glands, liver weight increase, and regenerative anemia.

In females no significant decrease in relative body weights was identified. However organ effects observed at the highest test dose are resulting in a NOAEL of 300 mg/kg bw.

Test substance induced adverse organ effects in females of the highest dose group include an increase in relative liver weights (correlated with histopathological lesions), histopathological changes in the uterus and a regenerative anemia.

 

A further study was performed according to guideline (Guidelines for 28-Day Repeat Dose Toxicity Testing of Chemicals, Japan, similar to OECD 407) and groups of 6 (control) or 12 (dose groups) Crj:CD (Sprague Dawley) rats per sex were daily gavaged with 0, 40, 200 and 1000 mg/kg bw of the test substance for 28 days followed by 14 days recovery period (Office of Environmental Chemicals Safety Environmental Health Bureau, 1999).

Mortality occurred in 2 males at the highest test dose. Both animals have shown caecum dilation accompanied by macroscopical and histopathological indications of intestinal damage. Intestinal heamorrhage centered around the caecum was therefore described to be the cause for mortality in these two animals. Abdominal distension observed in females of this dose group is regarded as a change reflecting the dilation in the cecum identified at necropsy. On a histopathological level cecum effects were described by mucosal hyperplasia and single cell necrosis in mucosal epithelium with a dose dependent incidence and severity in males and females of the 200 and 1000 mg/kg bw/day groups.

Further effects in the high dose group included a reduced body weight gain based on low food consumption, mild anemia and thymus, liver and kidney disorders. Furthermore adrenal weights of high dose males were increased. The effects observed in the mid dose group were decreased food consumption and body weight gain only in females, increase in incidences of proteinuria in both sexes and urobilinogen in males, decrease in urine pH in males and increase in kidney weight in males. Almost all the changes, except for those in the kidney, disappeared or were significantly diminished after a 14-day recovery period. Kidney effects were not accompanied by histopathological findings. Based on the effects on body weight gain, urinalysis (proteinuria, urobilinogen, pH) and kidney weight, the NOAEL was identified as 40 mg/kg bw/d.

 

In a subacute study with minimal description of methods and results, three groups of 5 male rats each were fed diets for 13 days containing 1 or 0.1% of the test compound with 1% corn oil (Eastman-Kodak, 1973). Rats consumed 810 or 97 mg/kg bw/day of the test compound. Effects on hematology, clinical chemistry, organ weight and adipose tissue were observed in the high dose group, which were most likely secondary to anorexia. Histological examination revealed cytoplamic basophilia of renal distal convoluted tubule epithelium in the high dose group indicating that the test compound was nephrotoxic. The site of toxicity was the kidney as noted in the 28 day study and the NOAEL was considered to be 97 mg/kg bw/d.

 

In an OECD guideline 421 study (Reproduction/Developmental Toxicity Screening Test) rats were gavaged with daily dose levels of 10, 60 and 300 mg/kg bw/day (see chapter 7.8.1, OECSEH, 2001). The total exposure period was 45 days for males and 53 days in females (from 14 days before mating to day 3 of lactation). Maternal toxicity was characterized by suppressed body weight gain and decreased food consumption in both genders of the high dose groups. Relative liver and pituitary weights were increased in high dose males only. Though histological hypertrophy of hepatocytes was indicated in both sexes of the 300 mg/kg bw group. Cecum distension was observed in both sexes from 60 mg/kg bw groups accompanied by diffuse hyperplasia of the cecum mucosal epithelium. Since the relevance of rat cecum effects is questionable for humans and no other adverse effects occurred at 60 mg/kg bw, this dose is considered to be the NOAEL for parental toxicity in this study. No kidney effects were reported in the study report. 

 

The available studies with subchronic and subacute exposure of rats with 4,4’-sulfonyldiphenol well reflect common toxicological features for repeated dose oral toxicity. Mild differences in severity were described, which may reflect a rat strain specificity (Wistar - Sprague Dawley) and differences in the experimental study design.

Temporary treatment related salivation and a different appearance of feces compared to the control group are indicative for test substance related alterations of the gastrointestinal content. This may result in local effects and/or an effect on the bacterial flora of the gastrointestinal tract. Decrease in food consumption resulting in body weight changes and cecum effects can be addressed as secondary to these changes in the content of the gastro-intestinal tract. However, due to significant anatomical and functional differences of the cecum, these effects observed in rats can not be equally considered relevant for humans. In rodents this anatomical structure is large and in comparison to humans has a significant function in digestion. Nevertheless these disturbances in the content and structure of the gastrointestinal tract in rats may have a significant impact on organ effects observed at these or higher dose levels.

The 90 day study was identified to be the most reliable repeated dose study for oral exposure. Therefore the overall NOAEL for repeated dose toxicity, oral exposure was derived as 100 mg/kg bw. 

Repeated dose toxicity: Dermal and Inhalation

No subacute or subchronic repeated dose studies with dermal and inhalation exposure are available for 4,4´-sulphonyldiphenol. Repeated dose toxicity testing by dermal and inhalation routes was waived for 4,4`-sulphonyldiphenol.

Dermal:

In accordance with column 2 of REACH Annex IX, the test repeated dose toxicity after dermal exposure (required in section 8.6) does not need to be conducted as repeated dose toxicity studies for oral application are available or proposed. 4,4'-sulphonyldiphenol is not irritating and not sensitizing to the skin. Due to the low skin penetration rate, systemic toxicity after dermal exposure is considered significant less present as after oral application. Therefore oral repeated dose tests provide a reliable basis for the extrapolation of effects after dermal application.

Inhalation:

In accordance with column 2 of REACH Annex IX, the test repeated dose toxicity after inhalation (required in section 8.6) does not need to be conducted as repeated dose toxicity studies for oral application are available or proposed.

For the organic solid 4,4'-sulphonyldiphenol, inhalative exposure via aerosols/dust is not relevant during production and processing (polymerization) as both uses are conducted in closed systems. Only approx. 1.7% of the particles have a particle size below 10 µm, indicating that no or only a very limited amount of the substance can reach the lung (see IUCLID5 section 4.5). In addition, due to the very low vapor pressure (25°C; < 1 mbar) exposure towards gaseous 4,4'-sulphonyldiphenol can practically be excluded.

Justification for classification or non-classification

Due to significant anatomical and functional differences of the cecum, effects observed in rats can not be equally considered relevant for humans. In rodents this anatomical structure is large and in comparison to humans has a significant function in digestion.

Further organ effects were observed in both studies but occurred well above the guidance values for specific target organ toxicity repeated dose (GHS 3.9.2.9).

Proteinuria observed in a subacute (28 -day) study from a dose level of 200 mg/kg bw (OECSEH, 1999) were neither observed in an OECD guideline 421 reproduction/developmental toxicity screening test (OECSEH, 2001) nor in an oral subchronic (90 day) study.nor in an oral subchronic (90 day) study (BASF, 2014). Therefore this effect was not considered as relevant for classification.

Summarized 4,4`-sulphonyldiphenol is not classified for repeated dose toxicity according to 67/548/EEC (DSD) and Regulation (EC) No 1272/2008 (CLP, GHS).