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Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
three-generation reproductive toxicity
Remarks:
based on test type (migrated information)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1968
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report which meets basic scientific principles: pre-GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1968
Report date:
1968

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)
Deviations:
yes
Remarks:
3 generations used, dietary administration
GLP compliance:
no
Limit test:
no
Justification for study design:
This study was conducted to evaluate the effects of long-term ingestion of the test substance on reproduction in rats. The test material
at dietary levels of 100, 500, and 1500 ppm was fed to the rats through two parental and two two-litter filial generations. Following nine weeks of
dietary administration to the F2B weanlings designated as the third parental generation, the study was terminated.

Test material

Constituent 1
Details on test material:
TS-Freetext:
CAS No. 26896-20-8; Neodecanoic acid (2,2-dimethyloctanoic acid)
- Name of test material (as cited in study report): MRD-67-21
- Physical state: clear liquid with a faint odor
- Analytical purity: assumed 100%

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River
- Age at study initiation: (P) young
- Weight at study initiation: (P) Males: 108-164 g; Females: 101-144 g;
- Diet (e.g. ad libitum): prepared, ad libitum
- Water (e.g. ad libitum): ad libitum

Administration / exposure

Route of administration:
oral: feed
Vehicle:
other:
Remarks:
Basal Diet
Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): Fresh diets were prepared every 2 weeks or weekly as needed.
- Mixing appropriate amounts with (Type of food): Purina Laboratory Chow
- Storage temperature of food: Room temperature

Control rats were fed a basal diet of Purina Laboratory Chow. The test material was incorporated into the basal diet on a weight-perweight basis and thoroughly mixed in a Hobart blender to provide the desired dietary level for each test group. Fresh diets were prepared every two weeks or weekly as needed, and the appropriate diets and water were available to the animals at all times.
Details on mating procedure:
- M/F ratio per cage: 1/2
- Length of cohabitation: week
- After successful mating each pregnant female was caged (how): individually
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
Premating exposure period (males): P1: 9 weeks
Premating exposure period (females): P1: 9 weeks
Duration of test: 3 generations
Frequency of treatment:
Continuous
Details on study schedule:
P1 GENERATION
Prior to initiation of the first and second breeding phases, the parental generation animals were maintained in individual cages and fed the appropriate diets until they reached maturity, 9 weeks. At the end of the ninth week, two females and one male within each group were mated. Males were rotated for 3 weeks.

F1A GENERATION
Twenty-four hours after birth, the F1A litters were arbitrarily reduced to a maximum of eight pups for nursing. After 21 days, representative pups from each litter were sacrificed and gross necropsies were performed. All other weanlings were discarded.

F1B GENERATION
One week after weaning the last F1A litter, the P1 parents were re-mated are previously described to produced the F1B generation. After a 21-day nursing period, 20 female and 10 male weanlings were designated as the P2 generation. One third of the remaining weanlings were gross necropsied, the remaining were discarded.

P2 GENERATION
The P2 animals were individually hosed until they reached 100 days of age. Mating occurred as described previously.

F2A GENERATION
As described previously – F1A

F2B GENERATION
As described previously – F1B
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 100, 500, 1500 ppm in diet
Basis:
nominal in diet
approximately 5, 25 and 75 mg/kg/day, respectively
No. of animals per sex per dose:
20 Females, 10 Males per dose group
Control animals:
yes
Details on study design:
Rationale for Dose Selection: A preliminary three-month subacute toxicity study (i.e., mortality, body weight, food consumption, physical appearance, behavioral signs, gross examination, organ weight, histopathology, clinical biochemistry) in rats fed daily dietary dose levels of ~500, 1500, 5000, and 15000 ppm neodecanoic acid was performed (15 rats/sex/group) to select doses for a three-generation reproductive toxicity study. No compound effects were noted in regard to physical appearance and behavior of the test rats at the dose levels of 500 ppm and 1500 ppm. However, in the 15,000 ppm group, there was mortality (73% survival: 4 males/5 females) and all rats exhibited clinical signs of thin and hunched; the majority of the rats also had a pale appearance. In the 5,000 ppm and 15,000 ppm dose groups, there was significantly decreased mean body weight gain in male/female rats at the end of the study (10%/14% and 73%/57% below control, respectively). Also, food consumption for the 5,000 ppm females and 15,000 ppm male and female rats was significantly lower compared with control values (7% and 42% below control, respectively. Also, there were gross examination findings in liver and kidneys. Hepatotoxic changes were seen in the male and female rats at 15,000 and 5,000 ppm. There were renal changes affecting the tubules of both the male and female rats who were
dosed with 15,000, 5,000 and 1500 ppm of neodecanoic acid. Therefore, based on mortality, clinical signs, decreased body weight gain and decreased food consumption at 5000 ppm and 15,000 ppm, 1,500 ppm was selected as the high dose for the definitive three-generation reproductive toxicity study.

Examinations

Parental animals: Observations and examinations:
Observations were made at 5 and 9 weeks
Oestrous cyclicity (parental animals):
No data
Sperm parameters (parental animals):
No data
Litter observations:
Immediately after birth
Postmortem examinations (parental animals):
All parent animals
Necropsies were performed on all parent animals which died during the study, gross observations were recorded, and tissues taken from these
animals were preserved in 10% neutral buffered formalin.
Postmortem examinations (offspring):
All offspring
Litter size, mortality, pup body weights, clinical signs
Statistics:
N/A
Reproductive indices:
The reproductive indices were derived as follows: fertility index, number of pregnancies divided by the number of matings; gestation index, number of litters born divided by the number of pregnancies observed; live birth index, number of pups born alive divided by the number of pups born; lactation index, number of pups weaned divided by the number of pups nursed.
Offspring viability indices:
Fertility, gestation, live birth, lactation.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
no effects observed
Description (incidence and severity):
There were no test substance-related clinical observations in any dose group of the parental generation. The appearance and behavior of the rats in the test groups were generally comparable with that of the controls.
Mortality:
mortality observed, non-treatment-related
Description (incidence):
One control P1 female was found dead following the second mating period (F1B). The right adrenal was enlarged and dark red in color, and the lungs were dark red in color. The observation was not considered treatment-related.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
There were no test substance-related body weight changes in any dose group of the parental generation. Body weight gain changes of the test animals were similar to the controls. See information panel for tables.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
There were no test substance-related food consumption in any dose group of the parental generation. Food consumption changes of the test animals were similar to the controls. See information panel for tables.
Food efficiency:
not specified
Ophthalmological findings:
not specified
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
There were no behavioral findings in any dose group.
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
There were no test substance-related neuropathological findings in any dose group.
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
There were no test substance-related histopathologic changes in any dose group of the parental generation. The variations in histopathological findings w comparable with that of the controls, were observed in a single animals and/or were common findings in this species.
Histopathological findings: neoplastic:
no effects observed
Description (incidence and severity):
There were no test substance-related histopathologic changes in any dose group of the parental generation. The variations in histopathological findings w comparable with that of the controls, were observed in a single animals and/or were common findings in this species.

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
not examined
Reproductive function: sperm measures:
not examined
Reproductive performance:
no effects observed
Description (incidence and severity):
There were no test substance-related effects on reproductive performance in any group. For the first reproduction phase, the various Indices, litter size, and pup body weights were comparable among the control and test groups for both cycles. The appearance and behavior of the newborn and of the F1A and F1B pups during lactation were comparable to controls. See information panel for tables.

P0 to F1A:
Dose Level (ppm)
0 100 500 1500

No. of Matings 20 20 20 20
No. of Pregnancies 20 20 20 20
Fertility Index % 100 100 100 100
No. of Litters Born 20 20 20 20
Gestation Index 100 100 100 100
Live Birth Index% 98.8 99.2 98.7 96.6

P0 to F1B:
No. of Matings 20 20 20 20
No. of Pregnancies 19 19 19 20
Fertility Index % 95 95 95 100
No. of Litters Born 18 19 19 20
Gestation Index 94.7 100 100 100
Live Birth Index% 99.6 99.2 99.6 99.6


Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)


BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
No effects noted

TEST SUBSTANCE INTAKE (PARENTAL ANIMALS)
No effects noted

REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS)
No effects noted

REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS)
No effects noted

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
No effects noted

ORGAN WEIGHTS (PARENTAL ANIMALS)
No effects noted

GROSS PATHOLOGY (PARENTAL ANIMALS)
No effects noted

HISTOPATHOLOGY (PARENTAL ANIMALS)
No effects noted

OTHER FINDINGS (PARENTAL ANIMALS)
No effects noted

Effect levels (P0)

Key result
Dose descriptor:
NOAEL
Effect level:
1 500 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no adverse general toxicity, reproductive toxicity and fertility effects observed in P0 males or females at any dose level during the premating, mating or weaning phases. This study was conducted prior to GLP guidelines.

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:
no effects observed
Description (incidence and severity):
There were no test substance-related clinical observations in any dose group of the parental generation. The appearance and behavior of the rats in the test groups were generally comparable with that of the controls.
Mortality:
mortality observed, non-treatment-related
Description (incidence):
Two intermediate dose P1 males were found dead following the first (F2A) mating period. The gastrointestinal tract of both animals was filled with gas, the lungs of one were dark gray in color, and the lungs of the other were distended and dark red with grayish areas. One control P1 female was found dead following weaning of the F2B litter. Necropsy findings included advanced autolysis; pituitary and thymus dark red consolidated and abscessed areas on lungs; liver and kidneys dark red with dark black areas; poor differentiation between cortex and medulla of kidneys; pyloric portion of stomach red; and intestinal tract red and contained blackish red, semithick material. The observations were not considered treatment-related.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
There were no test substance-related body weight changes in any dose group of the parental generation. Body weight gain changes of the test animals were similar to the controls. See information panel for tables.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
There were no test substance-related food consumption in any dose group of the parental generation. Food consumption changes of the test animals were similar to the controls. See information panel for tables.
Food efficiency:
not specified
Ophthalmological findings:
not specified
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
no effects observed
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
There were no behavioral findings in any dose group.
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
There were no test substance-related changes in organ weights in any dose group.
Gross pathological findings:
no effects observed
Description (incidence and severity):
There were no test substance-related gross examination findings in any dose group.
Neuropathological findings:
no effects observed
Description (incidence and severity):
There were no test substance-related neuropathological findings observed in any dose level.
Histopathological findings: non-neoplastic:
no effects observed
Description (incidence and severity):
There were no test substance-related histopathology findings observed in any dose level.

Histopathological evaluation was performed on sections of the above listed tissues from five female and five male animals in the control (0 ppm) and high level (1500 ppm) groups. In addition, sections of thyroid, lung, liver, kidney, adrenal, and trachea from five female and five male animals in the low level (100 ppm) and intermediate level (500 ppm) groups were examined microscopically.
Histopathological findings: neoplastic:
no effects observed
Description (incidence and severity):
There were no test substance-related histopathology findings observed in any dose level.
Other effects:
no effects observed

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:
not examined
Reproductive function: sperm measures:
not examined
Reproductive performance:
no effects observed
Description (incidence and severity):
There were no test substance-related effects on reproductive performance in any group. For the first reproduction phase, the various Indices, litter size, and pup body weights were comparable among the control and test groups for both cycles. The appearance and behavior of the newborn and of the F2A and F2B pups during lactation were comparable to controls. See information panel for tables.
Dose Level (ppm)
0 100 500 1500

No. of Matings 20 20 20 20
No. of Pregnancies 20 20 20 20
Fertility Index % 100 100 100 100
No. of Litters Born 20 20 20 20
Gestation Index 100 100 100 100
Live Birth Index% 100 99.6 98.2 99.6

P1 to F2B:
Dose Level (ppm)
0 100 500 1500

No. of Matings 20 20 20 20
No. of Pregnancies 20 20 20 19
Fertility Index % 100 100 100 95
No. of Litters Born 20 20 20 19
Gestation Index 100 100 100 100
Live Birth Index% 100 99.2 99.6 98.4

Effect levels (P1)

Key result
Dose descriptor:
NOAEL
Effect level:
1 500 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no adverse general toxicity, reproductive toxicity and fertility effects observed in P1 males or females at any dose level during the premating, mating or weaning phases. This study was conducted prior to GLP guidelines.

Results: F1 generation

General toxicity (F1)

Clinical signs:
no effects observed
Description (incidence and severity):
There were no test substance-related clinical observations in any dose group of the parental generation. The appearance and behavior of the rats in the test groups were generally comparable with that of the controls.
Mortality / viability:
mortality observed, non-treatment-related
Description (incidence and severity):
Mutilation of pups found dead at birth was noted in one control and two high level F1 litters. The observation was not considered treatment-related.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
There were no test substance-related body weight changes in any dose group of the F1 generation. Body weight gain changes of the test animals were similar to the controls. See information panel for tables.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):

There were no test substance-related food consumption in any dose group of the F1generation. Food consumption changes of the test animals were similar to the controls. See information panel for tables.
Food efficiency:
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not examined
Anogenital distance (AGD):
not examined
Nipple retention in male pups:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):

There were no test substance-related changes in organ weights in any dose group.
Gross pathological findings:
no effects observed
Description (incidence and severity):

There were no test substance-related gross examination findings in any dose group.
Histopathological findings:
no effects observed
Description (incidence and severity):

There were no test substance-related histopathologic changes in any dose group of the F1 generation. The variations in histopathological findings w comparable with that of the controls, were observed in a single animals and/or were common findings in this species.
Other effects:
no effects observed

Developmental neurotoxicity (F1)

Behaviour (functional findings):
not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:
not examined

Details on results (F1)

F1A and F1B – The various indices, litter size, pup body weights, appearance, and behavior of the newborn and of the pups during lactation were comparable among the control and test groups for both cycles. The pups from one high level F1A litter were noted to be cold to the touch at birth. During delivery of this litter, a bloody-appearing vaginal discharge was observed in the dam. Pups noted to be thin and/or small in size at birth or during lactation were found in all of the groups. Sings of nasal discharge and wheezing were observed in a few pups. Spasmodic breathing was noted in one intermediate level F1A pup which was gray in color. In the F1B litters, a few control and test pups were found with eyes squinted and eyelids red in color. One low level F1B pup had enlarged eyes. No adverse effects were noted during necropsy.

F2A and F2B – The various indices, litter size, pup body weights, appearance, and behavior of the newborn and of the pups during lactation were comparable among the control and test groups for both cycles. At birth, two pups from one high level F2A litter were found cold to the touch. Minor incidental findings were also noted.

Effect levels (F1)

open allclose all
Key result
Dose descriptor:
NOAEL
Generation:
F1a
Effect level:
1 500 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no adverse general and reproductive toxicity effects observed in F1a males or females at any dose level. This study was conducted prior to GLP guidelines.
Key result
Dose descriptor:
NOAEL
Generation:
F1b
Effect level:
1 500 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no adverse general and reproductive toxicity observed in F1b males or females at any dose level. This study was conducted prior to GLP guidelines.

Results: F2 generation

General toxicity (F2)

Clinical signs:
no effects observed
Description (incidence and severity):
There were no test substance-related clinical observations in any dose group of the F2 generation. The appearance and behavior of the rats in the test groups were generally comparable with that of the controls.
Mortality / viability:
mortality observed, non-treatment-related
Description (incidence and severity):
Mutilation of pups found dead at birth or during the nursing period was noted in one control F2 litter and in one low level litter in the F2A and F2B cycles each. The observation was not considered treatment-related.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
There were no test substance-related body weight changes in any dose group of the F2 generation. Body weight gain changes of the test animals were similar to the controls.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):

There were no test substance-related food consumption in any dose group of the F2 generation. Food consumption changes of the test animals were similar to the controls.
Food efficiency:
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not examined
Anogenital distance (AGD):
not examined
Nipple retention in male pups:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):

There were no test substance-related changes in organ weights in any dose group.
Gross pathological findings:
no effects observed
Description (incidence and severity):
There were no test substance-related gross examination findings in any dose group.
Histopathological findings:
no effects observed
Description (incidence and severity):

There were no test substance-related histopathologic changes in any dose group of the F2 generation. The variations in histopathological findings w comparable with that of the controls, were observed in a single animals and/or were common findings in this species.

Developmental neurotoxicity (F2)

Behaviour (functional findings):
not examined

Developmental immunotoxicity (F2)

Developmental immunotoxicity:
not examined

Effect levels (F2)

open allclose all
Key result
Dose descriptor:
NOAEL
Generation:
F2a
Effect level:
1 500 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no test substance-related adverse effects on F2a generation pups.
Key result
Dose descriptor:
NOAEL
Generation:
F2b
Effect level:
1 500 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: There were no test substance-related adverse effects on F2b generation pups.

Overall reproductive toxicity

Key result
Reproductive effects observed:
no
Lowest effective dose / conc.:
1 500 ppm

Applicant's summary and conclusion

Conclusions:
No adverse effects on general toxicology, reproduction or development were noted.
Executive summary:

These studies were conducted in 1968, prior to the GLP guidance.

A dose range-finding three-month subacute toxicity study in rats fed daily dietary dose levels of ~500, 1500, 5000, and 15000 ppm neodecanoic acid was performed (15 rats/sex/group) to select doses for a three-generation reproductive toxicity study. The following parameters were examined: mortality, body weight, food consumption, physical appearance, behavioral signs, gross examination, organ weight, histopathology, clinical biochemistry.

In the 15,000 ppm group, there was mortality (73% survival: 4 males/5 females) and all rats exhibited clinical signs of thin and hunched; the majority of the rats also had a pale appearance. In the 5,000 ppm and 15,000 ppm dose groups, there was significantly decreased mean body weight gain in male/female rats at 13 weeks, end of the study (10%/14% and 73%/57% below control, respectively).  Also, food consumption for the 5,000 ppm females and 15,000 ppm male and female rats was significantly lower compared with control values (7% and 42% below control, respectively. Also, there were gross examination findings in liver and kidneys. Hepatotoxic changes were seen in the male and female rats at 5,000 and 15,000 ppm dose groups. There were renal changes affecting the tubules of both the male and female rats who were dosed with 1500, 5,000 and 15,000 ppm of neodecanoic acid.  No test substance effects were noted in regard to physical appearance and behavior of the test rats at the dose levels of 500 ppm and 1500 ppm. Therefore, based on mortality, clinical signs, decreased body weight gain, decreased food consumption, and gross / histopathologic examination changes at 5000 ppm and 15,000 ppm, 1,500 ppm was selected as the high dose for the definitive three-generation reproductive toxicity study.

A definitive modified three-generation reproductive toxicity study was performed to evaluate the effects of long-term ingestion of neodecanoic acid on reproduction in albino rats.  Neodecanoic acid was administered in the diet at levels of 100, 500, and 1500 ppm fed to the rats through two parental and to two-litter filial generations.  Following nine weeks of dietary administration to the F2B weanlings designated as the third parental generation, the study was terminated.  There was no evidence at any test level of an adverse effect on the survival, appearance, behavior, body weight gain, and food consumption of the parental generations; on the reproductive performance of the parents reflected by the various indices; or on the growth, appearance, and behavior of the offspring.  Gross and macroscopic pathological findings revealed no evidence of a compound-related effect at any of the dietary levels.