Disodium peroxodisulphate

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-01-30 to 2004-12-13

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Test material form:

solid: crystalline

Test animals

Species:

rat

Strain:

other: Crl:CD (SD)IGS BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories; Raleigh; North Caroline (USA)
- Age at study initiation: (P) 11 wks
- Weight at study initiation: (P) Males: 359 - 436 g; Females: 212 - 280 g
- Fasting period before study: no
- Housing: Males and females were housed individually (except during mating)
- Diet: Powdered PMI Certified Rodent Diet #5002 (PMI Feeds, Inc.; St Louis, Missouri) ad libitum
- Water: ad libitum
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature: 18 - 26 °C
- Humidity: 30 - 70 % R.H.
- Air changes: a minimum of 10 air changes per hour
- Photoperiod: 12 hrs dark/12 hrs light

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

Study design:
Male and female Crl:CD (SD)IGS BR rats were assigned to 4 groups (12/sex/group). Each group received a control diet consisting of powdered PMI Certified Rodent diet #5002 (PMI Feeds Inc., St. Louis, Missouri) or the same diet containing diammonium persulfate at concentrations designed to provide target doses of 40, 100 250 mg/kg/day based on mean weekly body weight and mean weekly food consumption data for each sex at each dose level.
Dose administration:
Males were administered with test material in the diet for three weeks prior to mating, during the mating period (four days) and approximately five weeks after mating. Females were dosed throughout the 3-week pre-mating period, during the 4-day mating period, throughout gestation (22 days) and during the first four days of lactation. Depending on what day the female was confirmed pregnant, the total days of dose administration varied from 47 to 51 days. The animals were dosed until the day of sacrifice (prior to removal from the room).

Details on mating procedure:

Breeding:
Animals from respective groups were mated by placing one female in the breeding cage of a male from the same dose group. A record of mating pairs was maintained. Once mating occurred, the males and females were separated. The maximum mating period was 14 days. Females for which no evidence of mating was detected after a total of 14 days were placed in nesting boxes.
Confirmation of mating:
During mating, a daily inspection was be made for the presence of a retained copulatory plug, multiple copulatory plugs on the cage tray, or vaginal sperm. The day sperm or a plug was observed was designed to be day 0 of gestation.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Concentration of diammonium persulfate in rodent feed samples were determined using the measurement of the exothermic enthalpy delta H (J/g) by DSC of the test samples and comparison with a standard calibration curve. The method was evaluated and validated and found to be suitable for the analytical determination of diammonium persulfate in rodent diet.

Experimental procedures:
Sample preparation:
About 1 g to 10 g of sample was taken with a spatula from the container and ground for 3 minutes in a cleaned mortar and pestle. About 10 - 30 mg of the ground sample was transferred into a tared round DSC sample pan. By using a small steel cylinder, which was the same size as the pan, the powdery sample in the pan was compressed. The sample was weighed to ± 0.01 mg with an Autobalance AD 6. The weight of the sample was recorded on a sample weighing sheet. The sample pan containing the sample was then transferred into the sample holder of the DSC system for analysis immediately.
Instrumentation and Analysis:
DSC System:
Perkin Elmer Pyris 1 Differential Scanning Calorimeter; Serial Number: S73N0061703;
Balance:
PE AD 6 Autobalance; Balance Serial #: 655C04;
Sample Analysis:
DSC Mode used: Ice Bath;
Sample atmosphere: Nitrogen, 20 mL/min;
Sample pan: Aluminium, open pan;
Temperature Program: Hold at 30 °C for 1 minute; Heat from 30 °C to 220 °C with a rate of 10 °C/min;
Calculation:
Exothermic enthalpy delta H (J/g) of each sample in temperature range between 160 °C to 210 °C was calculated with Pyris Software provided by the DSC system.
A five point standard curve of ammonium persulfate concentration (ppm) versus delta H (J/g) was developed in a separate method development/validation procedure. The following equation, which was obtained with the five point standard curve, was used to calculate the ammonium persulfate concentration of each sample:
Concentration (ppm) = (delta H + 0.0052671)/0.0007350
where:
0.0052671 = Intercept of the standard curve
0.0007350 = Slope of the standard curve

Duration of treatment / exposure:

Not applicable

Frequency of treatment:

Not applicable

Details on study schedule:

The purpose of the study was to provide information regarding possible effects on mating, reproduction, and/or development in male and female rats. Males were administered with test substance in the diet three weeks prior to mating, during the mating period (four days) and approximately five weeks after mating.
Females were dosed throughout the 3-week pre-mating period, during the 4-day mating period, throughout gestation (22 days) and during the first four days of lactation. The total length of exposure was approximately 51 days for females (depending on when the female was confirmed pregnant) and 56 days for males.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Remarks:

in diet

Doses / concentrations 2

Dose / conc.:

40 mg/kg bw/day (nominal)

Remarks:

in diet

Doses / concentrations 3

Dose / conc.:

100 mg/kg bw/day (nominal)

Remarks:

in diet

Doses / concentrations 4

Dose / conc.:

250 mg/kg bw/day (nominal)

Remarks:

in diet

No. of animals per sex per dose:

12 animals per sex and per dose group

Control animals:

yes, plain diet

Details on study design:

Dietary formulations:
Diets were mixed at least weekly according to the mixing procedure approved by the sponsor. For each high-dose formulation prepared (whether for one or both sexes, depending on the phase of the study), the total amount of test substance needed for that high-dose stock formulation was weighed and the finely ground with a mortar and pestle. The finely ground test article was gradually mixed into approximately 200 g of the PMI powdered diet. This preliminary premixture of test article and powdered diet was then placed in a Hobart mixer, and the remaining powdered diet needed to achieve the high-dose stock formulation was gradually added to the test article and feed mixture. After completion of the additional powdered diet, the high dose stock formulation was mixed for at least 30 minutes. Once this mix was completed, the low and mid levels were prepared by taking the appropriate amount of the high-dose stock formulation and diluting it to the appropriate dietary concentration needed for each dose level by gradually adding powdered feed to achieve the correct precalculated weight. Calculated diet concentrations were based on historical body weight and food consumption data for Days 0 to 7 and based on current food consumption and body weight data for the appropriate sex after Day 7. All diet formulations were stored at room temperature until dosed. Dose concentrations were based on test article as supplied (i.e., no correction factor was used when calculating the amount of test article to be use).

Positive control:

Not indicated

Examinations

Parental animals: Observations and examinations:

Assessment of toxicity was based on mortality, clinical observations, body weights and weight change (during premating and mating for both sexes, during gestation and lactation for females, and postmating for males), food consumption (during premating for both sexes, during gestation and lactation for females, and postmating for males), pregnancy rates and maternal data, litter data (litter size, sex and weight of pups, live and dead pups), anatomic pathology, organ weights, histopathology of selected tissues, and staging of spermatogenesis.

Oestrous cyclicity (parental animals):

Not indicated

Sperm parameters (parental animals):

The following parameters were examined:
- Normal progression of spermatogenesis at necropsy.
- Stages of the spermatogenic cycle.
- Testicles examination.

Litter observations:

Litter size, sex and weight of pups, live and dead pups were examined.

Postmortem examinations (parental animals):

The necropsy included an examination of the external features of the carcass, external body orifices, the abdominal, thoracic, and cranial cavities, and organs/tissues.
At scheduled necropsy, the following organs were weighed: brain; liver; kidneys; prostate with seminal vesicles including secretions; testes, epididymides; ovaries; uterus (with cervix).
The following tissues from adult animals were preserved: cervix, caecum, coagulating gland, colon, duodenum; epididymides, oesophagus, ileum, jejunum, lesions, ovary with oviducts, prostate, rectum, seminal vesicle, stomach, testis, uterus, vagina.

Postmortem examinations (offspring):

At Day 4: Litter size and sex, weight, and abnormal observations of individual offspring were recorded. All dead pups were examined for cervical, thoracic and abdominal viscera abnormities and preserved in alcohol. Live pups were sacrificed, examined for gross external abnormalities, and discarded without necropsy.

Statistics:

Appropriate maternal and litter data were analyzed using analysis of variance (ANOVA) techniques; Levene's test was employed to analyze homogeneity of variances and Dunnett's t-test served as the post-hoc group comparison test. Calculated indices were analyzed using Fisher-Irwin exact test. Pup weights were analyzed by analysis of covariance (ANCOVA) techniques using the litter size as the covariate. Group comparisons were evaluated at the 5 % and 1 % two-tailed probability levels for all statistic analyses; a one-tailed analysis was used to determine significance for trend where appropriate.

Reproductive indices:

Fertility indices:
Female fertility = (number of females pregnant/total number females mated) x 100
Male fertility = (no. of males shown to be fertile/total number of males mated) x 100
Gestation index = (number of live litters born/number of pregnancies) x 100.

Offspring viability indices:

Viability index = (number of pups surviving to Day 4/number of pups born alive) x 100
Percent males (Days 0 and 4) = (number of males/total number of pups) x 100.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

not specified

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Details on results (P0)

There was no mortality. All animals survived to terminal sacrifice with the exception of two non pregnant females dosed at 100 and 250 mg/kg/day, respectively, which were sacrificed on day 26 due to their failure to deliver.
There were no treatment-related clinical signs of toxicity observed in F0 parents of either sex or in F1 pups at any treatment level. Remarkable clinical signs in the F0 parents and F1 pups were not attributed to treatment with diammonium persulfate, as they occurred sporadically, were of short duration, and did not demonstrate a dose response.
Normal progression of spermatogenesis was observed in male parental animals at necropsy. All stages of the spermatogenic cycle were present. In the testicles examination there was no indication of any test substance effects.

Effect levels (P0)

1

Key result

Dose descriptor:

NOAEL

Effect level:

>= 250 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: male and female toxicity

2

Key result

Dose descriptor:

NOAEL

Effect level:

>= 250 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: male and female fertility performance

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Details on results (F1)

There were no treatment-related clinical signs of toxicity observed in F1 pups at any treatment level. Remarkable clinical signs in the F1 pups were not attributed to treatment with diammonium persulfate, as they occurred sporadically, were of short duration, and did not demonstrate a dose response.

Effect levels (F1)

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

>= 250 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: pup viability and development

Overall reproductive toxicity

Key result

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

The NOAEL for male and female toxicity, for male and female fertility performance and for embryo/foetal viability and development was >= 250 mg/kg/day.

Executive summary:

Diammonium persulfate was tested for oral reproductive/developmental toxicity in a screening test with rats according to OECD guideline 421.The purpose of this study was to obtain initial information on the possible effects of the test item on reproduction and development when administered orally in the diet to Crl:CD (SD)IGS BR rats at doses of 40, 100 and 250 mg/kg bw/day compared to control animals (plain diet only).

There were no treatment-related clinical signs of toxicity observed in F0 parents of either sex or in F1 pups at any treatment level. Remarkable clinical signs in the F0 parents and F1 pups were not attributed to treatment with diammonium persulfate, as they occurred sporadically, were of short duration, and did not demonstrate a dose response. No significant changes were observed in male and female reproductive performance such as gonadal function, mating behaviour, conception, pregnancy, parturition and in development of the F1 offspring from conception to day 4 postpartum. In conclusion, under the conditions of this study, the NOAEL for male and female toxicity, the NOAEL for male and female fertility performance and the NOAEL for F1 viability and development was >= 250 mg/kg/day.