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Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
two-generation reproductive toxicity
Remarks:
based on test type (migrated information)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1995
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995
Reference Type:
secondary source
Title:
O-Phenylphenol and its Sodium and Potassium Salts: A Toxicological Assessment
Author:
Bomhard, E. M. et al.
Year:
2002
Bibliographic source:
Crit. Rev. Toxicol. 32(6):551-626

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Version / remarks:
(1983)
Deviations:
yes
Remarks:
dose spacing >3-fold for dietary studies; P and F1 females rested for 2 and 3 weeks, respectively, before second mating (1 week recommended); no assessment of sperm parameters performed
Qualifier:
according to
Guideline:
EPA OTS 798.4700 (Reproduction and Fertility Effects)
Qualifier:
according to
Guideline:
EPA OPP 83-4 (Reproduction and Fertility Effects)
Version / remarks:
(1984)
Qualifier:
according to
Guideline:
other: MAFF, 59 NohSan No. 4200, (1985)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: flakes
Details on test material:
- Name of test material (as cited in study report): Ortho-phenylphenol, (1,1'-Biphenyl)-2-ol
- Physical state: white solid flakes
- Analytical purity: 99.5–100 %
- Lot/batch No.: S-01-93 (Mixture of test substance produced by DOW and Bayer)
- Stability: indefinitely in a cool environment, protected from light and moisture (not further specified)
- Storage condition of test material: at freezer conditions

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeders, Portage, MI, USA
- Age at study initiation: (P) 8 weeks
- Weight at study initiation: (P) Males: 279-340 g; Females: 180-229 g
- Housing: individually in stainless steel cages suspended over bedding of deotized animal cage board (DACB); during gestation and lactation females were housed individually in polycarbonate cages with Bed-O-Cobs bedding
- Diet: Purina Rodent Laboratory Chow 5001-4 Etts form, ad libitum
- Water: potable municiple water, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-26
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: feed
Vehicle:
other: acetone/ corn oil mix
Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): weekly
- Mixing procedure: The diet containing the test substance was prepared by disolving the appropriate amount of test substance for each dose level in acetone and corn oil. The corn oil mixture was then added to the diet, using acetone during diet preparation to rinse the equipment. Corn oil was added at 1% of the diet for all dose groups. To maintain the appropriate dose levels, the concentration of OPP in the diet was adjusted weekly during the premating period based on the group mean body weight and food consumption for each dose group. The concentration in the diet during the first week of the study was based on body weight and food consumption data collected during study week -1. During the mating periods, the males and females for each dose group received the concentration of OPP in the diet received by the females during the last week of the premating phase for the respective groups. (Note: The female concentration was used during the mating phase as the concentration in the diet was lower than for the males.) During the gestation and lactation periods the females from each dose group received diet which contained the concentration of OPP received during the last week of the premating period for the respective groups. Following completion of the F1a and F2a mating phases, the males received diet which contained the concentration of OPP received by the males during the last week of the premating period for the respective groups. As the dose during the lactation phase was not adjusted and food consumption during the lactation phase increases significantly, the dose during the lactation phase was approximately twice the dose received during the premating and gestation phases.
- Storage temperature of food: in a freezer at -23 °C
Details on mating procedure:
- M/F ratio per cage: 1/1
- Length of cohabitation: 21 days
- Proof of pregnancy: vaginal plug and/or sperm in vaginal smear referred to as Day 0 of pregnancy
- After 21 days of unsuccessful pairing females were treated as if pregnant (just in case insemination occurred but was not observed).
- After successful mating each pregnant female was caged in a plastic nesting cage.

A second mating was conducted in each generation. The F1b litter was then used to produce the F2 generation.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Stability and homogeneity were proven by liquid chromatographic analysis. OPP concentrations in rodent diet were varified for Weeks 1, 4, 8, 12, 16, 20, 24, 29, 32, 36, 40, 45, 49, 54, and 58.
Duration of treatment / exposure:
Duration of exposure before mating: 10 weeks
Duration of exposure in general: F0 parents: from study initiation until scheduled sacrifice, F1 parents: from weaning until scheduled sacrifice
Frequency of treatment:
daily
Details on study schedule:
- F1 parental animals not mated until 12 weeks after selected from the F1 litters.
- A rest period of 14 days (F1) and 20 days (F2), respectively, was initiated from the time the last respective litters were weaned.
Doses / concentrations
Remarks:
Doses / Concentrations:
20, 100, and 500 mg/kg bw/day
Basis:
nominal in diet
based on % a.i.
No. of animals per sex per dose:
30
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: based on the results of a previous 2-generation study with animals of the same strain

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily (once daily during weekends and holidays)

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once a week

BODY WEIGHT: Yes
- Time schedule for examinations: once a week

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
Oestrous cyclicity (parental animals):
Vaginal smears were taken for 3 weeks from 10 P and F1 females per dose level prior to mating. The vaginal smears were observed microscopically and classified as diestrous, proestrous, or estrous based on the cytology observed.
Sperm parameters (parental animals):
No sperm parameters were analysed.
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded.

PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was determined for pups born or found dead
Postmortem examinations (parental animals):
SACRIFICE
- Male animals: All surviving animals after completion of mating phase
- Maternal animals: All surviving animals after each dam's pups were weaned or died, respectively

GROSS NECROPSY
- For females, the uterus was examined for implantation sites and the number was recorded. However, due to 2 breedings per generation, this data was not used to determine pregnancy.

HISTOPATHOLOGY / ORGAN WEIGHTS
The terminal body weights, kidney weights with the attached ureter* and gonad weights were collected from all P and F1 adults. Relative organ weights were calculated for all organs weighed.
The following organs were collected from P and F1 adults and preserved: coagulation gland, cervix, epididymides, kidneys with the urether attached (right and left kidneys were identified), pituitary gland, prostate gland, seminal vesicles, uterus, vagina, gross lesions, physical identifier (tattoo), ovaries and testes. All tissues were examined histologically with the exception of the tattoo and the skulls containing maloccuded teeth without any other accompanying morphologic lesions.

* The kidney and the ureter were weighed and examined microscopically because these tissues have been identified to be a target organ in other studies.
Postmortem examinations (offspring):
SACRIFICE
- The F1 offspring not selected as parental animals were sacrificed at 4 days of age.
- These animals and F2 animals were subjected to postmortem examinations: No
Statistics:
Statistical significance was determined at p≤0.05 for all tests with the exception of Bartlett's test, in which a probability value of p≤0.001 was used. All tests were two-tailed, except for adult pathology evaluations.
Body weight (adults and pups), weight gain, and food consumption data were analysed by analyses of variance (ANOVA) and if significant differences were shown by ANOVA, Dunnett's test was used to identify significant differences from the control group. Number of estrous cycles and estrous cycle length were analysed by the Kruskal-Wallis test. If significance was shown by Kruskal-Wallis, the Mann-Whitney U-test was used to identify statistical significances between groups. Litter size, length of gestation, viability index, live birth index, % of male pups, insemination length, and number of implantation sites were analysed by the Kruskai-Wallis test. If significance was shown by Kruskai-Wallis, the Dunnett's test was used to identify significant differences from the control group.
The mating index, fertility index, gestation index, perinatal deaths, and pup gross necropsy lesions were analysed using Chi-square test. If significant diffferences were shown by Chi-square, Fisher's exact test was used to identify significant differences from control group. A Bonferroni adjustment to the p value was used with the Fisher's exact test. Terminal body weights and organ weights were evaluated by Bartlett's test for homogeneity. If the data were homogeneous, an ANOVA was performed followed by Dunnett's t-test on parameters showing a significant effect by ANOVA. If the data were non-homogeneous, a Kruskal-Wallis ANOVA was performed followed by the Mann-Whitney U-test to identify statistical significance between groups. Gross- and histopathologic lesion frequencies for adults were analysed using the Chi-square test. If significant differences were shown by Chi-square, Fisher's exact test was used to identify significant differences from control group.
Reproductive indices:
mating index, fertility index
Offspring viability indices:
gestation index , live birth index, viability index, lactation index

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
1 high dose male (P, 500 mg/kg bw/day) died on kidney failure; urine stain in high dose males (500 mg/kg bw/day, P + F1)
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
in high dose males and females (P and F1, 500 mg/kg bw/day)
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
in high dose males and females (P and F1, 500 mg/kg bw/day)
Organ weight findings including organ / body weight ratios:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
Compound-related lesions were noted in the kidney, urinary bladder, and ureter of high dose males (P and F1, 500 mg/kg bw/day)
Other effects:
not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
not examined
Reproductive performance:
no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
6 rats were sacrificed prior to scheduled sacrifice and 6 further rats died during the course of the study. However, only one death was considered compound-related: one high dose male (500 mg/kg bw/day) died of kidney failure.
The only clinical finding was a compound-related, though not statistically significant, increase in the number of P anf F1 males with urine stain. The urine staining was associated with gross and microscopic lesions in the urinary tract.

BODY WEIGHT (PARENTAL ANIMALS)
A compound-related decrease in body weights (as compared to controls) was noted for high dose males and females (500 mg/kg bw/day; P and F1):
- Females (P): 5-7% below the control group (statistically significant), beginning on Day 21 of pre-mating phase
- Males (P): not statistically significant, but biologically relevant because (1) high dose group body weights began diverging from control, low- and mid dose groups on study Day 77 and terminated 5% lower than control group; (2) the weight gain for the high dose group was decreased.
- Males (F1): 9-13% lower body weights as compared to controls (statistically significant), beginning on Day 0 of premating phase and reflecting lower F1b pup body weights accompanied with reduced body weight gain during growth phase following weaning
- Females (F1): 7-12% lower body weights as compared to controls (statistically significant), beginning on Day 0 of premating phase and reflecting lower F1b pup body weights accompanied with reduced body weight gain during growth phase following weaning

FOOD CONSUMPTION (PARENTAL ANIMALS)
There was no treatment-related effect noted in males throughout the study period. For females, there was an increase in food consumption during lactation.

REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS)
There was no treatment-related effect noted throughout the study period.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
There was no treatment-related effect noted on the mating index, the fertility index, the gestation index or gestation length.

GROSS PATHOLOGY (PARENTAL ANIMALS)
The only gross observation that was considered to be compound-related was a statistically significant increased incidence of urinary bladder calculi in the high-dose group F1 males.

HISTOPATHOLOGY (PARENTAL ANIMALS)
- Reproductive organs: There were no compound-related changes noted in the reproductive organs.
- Other: Compound-related lesions were noted in the kidney, urinary bladder, and ureter of both P and F1 high dose males (debris in the renal pelvis, chronic active inflammation, increase severity of background lesions in high-dose group P and F1 males, transitional cell hyperplasia, calculi and chronic inflammation in the urinary bladder of high-dose group P and F1 males, dilation and hyperplasia of the ureter in high-dose group P and F1 males)

ORGAN WEIGHTS (PARENTAL ANIMALS)
There were no biologically relevant and compound-related changes in organ weights noted.

Effect levels (P0)

open allclose all
Dose descriptor:
NOAEL
Remarks:
toxicity
Effect level:
100 mg/kg bw/day
Based on:
act. ingr.
Sex:
male/female
Remarks on result:
other: Generation: P, F1 and F2 (migrated information)
Dose descriptor:
LOAEL
Remarks:
toxicity
Effect level:
500 mg/kg bw/day
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: decreased body weights and toxicity to the urogenital tract in males
Remarks on result:
other: Generation: P, F1 and F2 (migrated information)
Dose descriptor:
NOAEL
Remarks:
fertility
Effect level:
> 500
Based on:
act. ingr.
Sex:
male/female
Remarks on result:
other: Generation: P, F1 (migrated information)

Results: F1 generation

General toxicity (F1)

Clinical signs:
no effects observed
Mortality / viability:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
significantly decreased in high dose pups (500 mg/kg bw/day) (F1 and F2)
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
no effects observed
Histopathological findings:
not examined

Details on results (F1)

VIABILITY (OFFSPRING)
There were no compound-related effects on live birth index, viability index, lactation index, or perinatal deaths.

CLINICAL SIGNS (OFFSPRING)
There were no compound-related clinical signs for pups.

BODY WEIGHT (OFFSPRING)
There was a statistically significant and compound-related decrease in pup weights (as compared to controls) in the high dose group. For the F1a and F1b pups the lower weight was observed on lactation Day 21 (-12% and -10%, respectively),while for the F2a and F2b pups the lower weight was observed on Day 14 (-6% and -7%, respectively) and on Day 21 (-11% and -12%, respectively).

GROSS PATHOLOGY (OFFSPRING)
No compound-related were observed at gross pathology.

Overall reproductive toxicity

Reproductive effects observed:
not specified

Any other information on results incl. tables

The following compound-related effects were found in the high-dose group:
- urine staining in P + F1 males
- decrease in bodyweight in P1 and F1 males and females
- decrease in pup bodyweights in the group
- increase in food consumption in females during lactation
The following findings were considered to be compound-related:
- one high-dose group male died from kidney failure
- urinary bladder calculi in high dose group males
- Debris in the renal pelvis, chronic active inflammation, increase severity of background lesions in high-dose group P and F1 males
- Transitional cell hyperplasia, calculi and chronic inflammation in the urinary bladder of high-dose group P and f1 males
- Dilation and hyperplasia of the ureter in high-dose group P and F1 males
No compound-related effects on reproductive and litter parameters, organ weights and clinical signs in pups were found.

Applicant's summary and conclusion

Conclusions:
The test item had no effect on reproductive performance.