Registration Dossier

Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was conducted in a manner similar to existing testing guidelines with extensive documentation. However, the study was no performed under the GLP regulations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979

Materials and methods

Test guideline
Qualifier:
no guideline available
Guideline:
other: The study was conducted in a manner similar to O.E.C.D. Test Guideline 408, 90-Day oral toxicity in rodents.
Deviations:
yes
Remarks:
there was no assessment for neurotoxicity.
GLP compliance:
no
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
As per IUCLID5 Sections 1.1. -1.4. for Bisphenol A.

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
Weanhing SPF rats (Wistar wu, Random) were obtained from the Central Institute for the Breeding of Laboratory Animals TNO, Zeist, The Netherlands.
The rats were 3 1/2 weeks old and weighed 35 to 50 grams. Upon arrival they were randomly divided into 4 groups of 15 males and 15 females. The rats were housed under conventional conditions, 5 per sex per cage, in suspended, stainless steel cages, fitted with wire mesh floors and fronts, in a well—ventilated room at 24 + I °C, humidity 40 — 70 % and a 12 hour light—dark cycle. The rats were fed ad libitum from weighed feeders which were filled twice weekly with the meal diets. Drinking water was supplied by bottles which were filled daily with fresh tap water and cleaned once weekly.

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
The test substance Bisphenol A was added to the rodent diet at levels of 100, 500 or 2500 ppm for the test groups. The highest dietary level was prepared first; the lower levels were prepared by diluting with stock diet. Homogeneity was achieved by mixing for 2 minutes in a mechanical blender (Stephan). The stability of Bisphenol A in stock diet had been examined in the a 4—week feeding study in rats. It appeared that at dietary levels of up to 10,000 ppm no loss of Bisphenol A occurred after storage for 4 weeks at ambient temperature. In the present 90-study 10 kg batches of the test diets were freshly prepared 5 times during the three months’ feeding period and stored at ambient temperature. The prepared diets were offered to the animals daily ad libitium.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
No data
Duration of treatment / exposure:
90-days
Frequency of treatment:
Daily
Doses / concentrations
Remarks:
Doses / Concentrations:
100, 500 or 2500 ppm (90-110, 410-510, 2420-2650 measured).
Basis:
nominal in diet
No. of animals per sex per dose:
15
Control animals:
yes, plain diet
Details on study design:
The general condition and behaviour of the animals was checked daily. All signs of ill health or reaction to treatment were recorded. The individual body weights were recorded once weekly. The food consumption of each cage was measured weekly during the first 12 weeks of the study. The water consumption of each cage of animals was measured in weeks 0 — 2, 6 — 7 and 11 — 12.

Samples of blood were collected from the tip of the tail of 10 rats of each sex and group in week 13. Differential white blood cell count was restricted to 10 male and 10 female rats of the control and top dose group (2500 ppm). At study termination in week 14, blood samples were collected in heparinized plastic tubes from the aorta of 10 rats/sex/group under ether anaesthesia. The blood samples were centrifugated at 2,000 rpm for 15 minutes using Sure-.Sep®from General Diagnostics for good separation of the plasma. Individual urine samples were collected from 10 rats/sex/group during the last 16 hours of a 24—hour period of deprivation of food and water in week 13.


Positive control:
No

Examinations

Observations and examinations performed and frequency:
See Details on study design above. Observation for clinical signs, body weight, feed and water consumption were made during the in-life phase of the study. Hematological, clinical chemistry and urinalyses parameters were assessed at study termination.
Sacrifice and pathology:
At day 91 and 92 all male rats and at day 92 and 95 all female rats were anaesthetized by ether, exsanguinated by cannulating the aorta and then examined grossly for pathological changes. The following organs were weighed: heart, testes, kidneys, ovaries, liver, uterus, spleen, thymus, brain thyroid, pituitary, and adrenals. Tissue samples as per the study protocol of all animals were preserved in a 4 % aqueous neutral phosphate—buffered formaldehyde solution. Detailed microscopic examinations were carried out on all male and female rats of the top dose group (2500 ppm) and on all control rats. The fixed tissues were embedded in Paraplast® and sections were cut at 5 .im; the sections were stained with haema— toxylin and eosin.
Statistics:
Body weight and organ weight data were analysed statistically by the Student—t—test. Haematological findings, blood biochemical values and urinalyses were evaluated by the Wilcoxon test.

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
effects observed, treatment-related
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):
WBCs in females only at 2500 ppm.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Mean Fasting glucose was decreased and mean BUN increased at 2500 ppm in males and females.
Urinalysis findings:
no effects observed
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
Mean body weights were significantly decreased at the 2500 ppm level in males from week 2 and onwards and in females from week 4 and onwards. The relative decrease in male body weight at 2500 ppm at study termination was 17% and in females the relative decrease was 9%. Mean food intake was diminished at the 2500 ppm level in both sexes and at 500 ppm only in females.

In males there were no significant or dose—related differences in haematological findings. In females total white blood cell counts were significantly increased in the 2500 ppm group, but no noticeable change occurred in the differential counts. Fasting blood glucose levels were decreased at 2500 ppm in both sexes and in females also at 500 ppm. Blood urea nitrogen levels were statistically significantly increased at 100 and 2500 ppm but not at 500 ppm. However, there were no dose—related differences in serum enzyme and protein levels in any of the groups.

There were no significant dose-related differences in group mean organ weights. At autopsy, treatment—related gross alterations were found in the skin and in the caecum. The changes consisted of enlarged caeca in two males of the mid—dose group and in seven males and nine females of the top—dose 2500 ppm group. Alopecia of the skin was observed in one male and six females of the top—dose group, in three females of the mid—dose group, and in one female of the low—dose group.


Effect levels

Dose descriptor:
NOAEL
Effect level:
ca. 500 ppm
Based on:
test mat.
Remarks:
in the diet
Sex:
male/female
Basis for effect level:
other: see 'Remark'

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
On the basis of the results obtained it appears that Bisphenol A did not induce any signs of overt toxicity even at the top—dose level of 2500 ppm in the diet. The changes observed at this level which may be of toxicological relevance consisted of reduced body weight gain accompanied by decreased feed consumption. The increased incidence of alopecia was not accompanied by morphological changes. Since no changes of toxicological significance were found in the mid—dose group, 500 ppm is considered a no—toxic effect level. In the present study this level was equivalent to a daily intake of 37 mg Bisphenol /kg body weight/day. These data suggest that 2-Acetone polymer with phenol (BPA-Tars) would have a similar No Observed Adverse Effect Level (NOAEL) under the conditions of this study.
Executive summary:

Bisphenol A, a structural analog for 2 -Acetone polymer with phenol (BPA-Tars) was assessed for systemic adverse effects in a 90 -day subchronic feeding study with rats in a manner similar to O.E.C.D. Test guideline No. 408. On the basis of the results obtained it appears that Bisphenol A did not induce any signs of overt toxicity even at the top—dose level of 2500 ppm in the diet. The changes observed at this level which may be of toxicological relevance consisted of reduced body weight gain accompanied by decreased feed consumption. The increased incidence of alopecia was not accompanied by morphological changes. Since no changes of toxicological significance were found in the mid—dose group, 500 ppm is considered a no—toxic effect level. In the present study this level was equivalent to a daily intake of 37 mg Bisphenol /kg body weight/day. These data suggest that BPA-Tars would have a similar No Observed Adverse Effect Level (NOAEL) under the conditions of this study.