Reaction products of triphenyl phosphite and isodecanol (1:2)

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD 422

Deviations:

yes

Remarks:

(This protocol exceeded the OECD 422 study design by following the F1 offspring to weaning.)

Principles of method if other than guideline:

This study was performed in compliance with OECD Guideline 422, (1996) and was performed under OECD (1998), and EPA TSCA (1989) Good Laboratory Practice regulations. This study exceeded the OECD 422 study design by following the F1 offspring to weaning.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Triisodecyl phosphite

EC Number:

246-998-3

EC Name:

Triisodecyl phosphite

Cas Number:

25448-25-3

Molecular formula:

C30H63O3P

IUPAC Name:

Phosphorus acid, triisodecyl ester

Details on test material:

- Name of test material (as cited in study report): TDP
- Analytical purity: > 99%
- Lot/batch No.: Doverphos 6, Batch 162T041801

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Raleigh, NC (males and females both from Area RIO) on June 3, 2003.
- Age at study initiation:
- Weight at study initiation:
- Fasting period before study:
- Housing: animals were individually housed upon arrival, during the acclimation period, and upon the initiation of the treatment period in solid-bottom polycarbonate cages with stainless-steel wire lids (Laboratory Products, Rochelle Park, NJ) with Sani-Chip® cage litter (P.J. Murphy Forest Products Corp., Montville, NJ). Study animals were housed 2 per cage (1 male: 1 female from the same dose group) during the mating period. Females were caged individually once they were successfully mated (or at the end of the mating period) and throughout gestation. Females were housed with their litters throughout the lactation period. Randomly selected F1 weanlings (10/sex/group), males, and females were singly housed during the postweaning exposure period.
- Diet: Pelleted Purina Certified Rodent Diet® (No. 5002, PMI Feeds, Inc., St. Louis, MO) ad libitum
- Water: Tap water (source: City ofDurham, Department of Water Resources, Durham, NC) was available ad libitum in plastic water ·bottles with butyl rubber stoppers and stainless-steel sipper tubes.
- Acclimation period: ~ 1 week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 71.1 to 76.2°F
- Humidity (%):37.2% to 69.6%.
- Air changes (per hr): 12-hour light cycle per day
- Photoperiod (hrs dark / hrs light):


IN-LIFE DATES: From: To:

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: Mazola® corn oil

Details on exposure:

Male and female CD (Sprague-Dawley(SD)) F0 rats were administered TDP orally by gavage at 0, 50, 250 and 1000 mg/kg/day at a dose volume of 5 ml/kg/day in Mazola® corn oil, 10 animals/sex/dose, for 2 weeks of prebreed exposure (males and females), 2 weeks of mating (males and females) and 3 weeks of gestation and lactation each (F0 females).

Analytical verification of doses or concentrations:

yes

Details on mating procedure:

After the 2-week prebreed exposure period, animals were randomly mated within treatment groups for a 2-week mating period to produce the F1 generation, with continuing exposure.
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Length of cohabitation: 14 days
- Proof of pregnancy: vaginal plug / sperm in vaginal smear referred to as day 0 of pregnancy.
- Once vaginal sperm were observed, the male and female from that mating pair were individually housed.

Duration of treatment / exposure:

8 weeks. 2 weeks of prebreed exposure (males and females), 2 weeks of mating (males and females), and 3 weeks of gestation and lactation each (FO females).

Frequency of treatment:

Once a day/7days/week

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

50 mg/kg bw/day (actual dose received)

Doses / concentrations 2

Dose / conc.:

250 mg/kg bw/day (actual dose received)

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

10 animals/sex/dose

Control animals:

yes

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Cage side observations: changes in skin and fur, eyes, mucous membranes, respiratory and circulatory systems, autonomic and central nervous systems, somatomotor activity, and behavior pattern. Beginning ongd 20, each female was observed twice daily (a.m. and p.m.) for evidence of littering.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least once daily for F0 males and females until necropsy.

BODY WEIGHT: Yes
- Time schedule for examinations: F0 males and females were recorded weekly during the prebreed period for both sexes and for F0 females during gestation and lactation. During gestation, F0 females were weighed on gestational days (gd) 0, 7, 14, and 20. Dams producing litters were weighed on pnd 0, 4, 7, 14, and 21.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- F0 males and females were recorded weekly during the prebreed period for both sexes and for F0 females during gestation and lactation. During pregnancy of F0 females, feed consumption was recorded for gd 0-7, 7-14, and 14-20. During lactation ofFllitters, maternal feed consumption was measured for pnd 0-4, 4-7, 7-14, and 14-21, although maternal feed consumption after pnd 14 was confounded by the contribution from the pups, since pups are self-feeding by this time. Feed consumption was not measured during the period of cohabitation, since 2 adult animals (1 male and 1 female) were in the same cage. Feed consumption was not measured for the recovery animals during or post dosing. Any female that did not show evidence of successful mating after 14 days of cohabitation continued on the original weekly weighing schedule and was monitored for evidence ofpregnancy and littering.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day #
- Organs examined: examination of the external surfaces, all orifices, the carcass, the thoracic, abdominal, and pelvic cavities and their viscera, and cervical tissues and organs. Gross lesions were recorded and retained in 10% neutral buffered formalin, with selected organs weighed and retained or discarded, as appropriate

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No data
- Number of corpora lutea: No data
- Number of implantations: Yes
- Number of early resorptions: No data
- Number of late resorptions: No data
- Other

Fetal examinations:

On the day of birth (postnatal day [pnd] 0), anogenital distance was measured and body weights recorded for all live F1 pups in all litters. F1 litters were culled on pnd 4 to yield as nearly as possible 5 males and 5 females per litter. The culled F1 pups were weighed, euthanized, and necropsied with complete external and visceral examinations. For the remaining F1 pups, survival indices were calculated at least weekly through weaning (pnd 21). In addition, hematology, clinical biochemistry and urinalysis assays were performed at necropsy for 5 randomly selected F0 males. Clinical biochemistry was also assessed for the 28-day females.
- Body Weight: All F1 pups were individually counted, sexed, weighed, and examined grossly at birth (pnd 0), at pnd 4,7, and 14, and at weaning (pnd 21).
- Observations: The presence or absence of retained nipples and areolae on the ventrum was recorded for F1 offspring males at ~pnd 11-13
- External examinations: Yes: all per litter
- Other: All retained F1 weanlings were weighed and feed consumption measured once per week until their scheduled demise. Daily F1
mortality and clinical. observations were conducted as described for the F0 animals. All nonselected FI weanlings were subjected to a complete gross necropsy (external and visceral) examination, with gross lesions retained in IO% neutral buffered formalin. The retained FI offspring were sacrificed at ~70 days of age and subjected to the same assessments as the FO parents (except for evaluation of nidation scars, which are not relevant to the F1 females because they are not mated).

Statistics:

The unit of comparison was the male, female, pregnant female, or the litter, as appropriate. Treatment groups were compared to the concurrent control group using either parametric ANOVA under the standard assumptions or robust regression method, which do not assume homogeneity of variance or normality. The homogeneity of variance assumption was examined via Levene's Test. If (p<0.05), robust regression methods were used to test all treatment effects, which use variance estimators that make no assumptions regarding homogeneity of variance or normality of the data. If Levene's Test did not reject the hypothesis of homogeneous variances, standard ANOVA techniques were applied for comparing the treatment groups. The GLM procedure in SAS® Release 8 was used to evaluate the overall effect of treatment and, when a significant treatment effect was present, to compare each exposed group to the control via Dunnett's Test. A one-tailed test (i.e., Dunnett's Test) was used for all pairwise comparisons to the vehicle control group, except that a two-tailed test was used for parental and pup body weight and organ weight parameters, feed consumption, percent males per litter, and anogenital distance. Student's t-test was used for analysis ofbody weight and organ weights from the recovery males and females and the 28-day females. All indices were analyzed by Chi-Square Test for Independence. When Chi-Square revealed significant (p<0.05) differences among groups, then a Fisher's Exact Probability Test, with adjustments for multiple comparisons, w':!s used for pairwise comparisons between each treatment group value and the control group value. Acquisition of developmental landmarks as well as anogenital distance, was also analyzed by Analysis of Covariance. For correlated data SUDAAN® software (RTI, 2001) was used for analysis of overall significance and pairwise comparisons to the control group values.

Indices:

Survival indices were calculated on pnd 0, 4, 7, and 14 and at weaning. The precoital interval and gestational length were equivalent across all groups. There were also no statistically significant changes across groups for the number of total implantation sites per litter and for the number of total and live pups per litter at birth. There were also no significant differences across groups for percent postimplantation loss per litter. Sex ratio (% males) per litter was unaffected across all groups for all lactational intervals. There were 34, 36, 27, and 38 F1 male offspring and 36, 32, 23, and 42 F1 female offspring evaluated at scheduled sacrifice on pnd 21 at 0,50,250, and 1000 mg/kg/day,

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
There were no effects on prenatal (postimplantation) loss or on total live or dead pups per litter in any group throughout lactation. No litters were lost during lactation.

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: No signs of reproductive or developmental toxicity up to 1000 mg/kd/day

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
There was no evidence ofFl offspring toxicity either at birth or during lactation. There were no effects on survival indices, litter size, sex ratio/litter, or pup deaths across any groups. Body weights of pups per litter (all pups or separately by sex) were equivalent across all groups for all time points, except for significant increases in female and all pup (but not male pup) body weights/litter at 50 mg/kg/day on pnd 0, most likely due to the slightly reduced live litter size (13.1) at this dose relative to the control live litter size (15.8). There were no effects on anogenital distance for either sex at birth. There was also no Fl treatment- or dose-related systemic or developmental toxicity at any dose at any time.

Effect levels (fetuses)

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No signs of reproductive or developmental toxicity up to 1000 mg/kd/day

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

TDP administered by gavage once daily at 0, 50, 250 and 1000 mg/kg/day to parental F0 CD (SD) rats, 10/sex/group through prebreed, mating, gestation and lactation resulted in essentially no treatment- or dose-related adult F0 parental toxicity at any dose at any time. Reproductive toxicity was not present in F0 males and females. There was also no F1 offspring toxicity observed postnatally through the weanling necropsy. Therefore, the F0 male and female systemic no observable adverse effect level (NOAEL) was at or above 1000 mg/kg/day. The NOAELs for F0 reproductive toxicity during lactation were also at or above 1000 mg/kg/day for males and females.

F0 Gestation:

- 9, 9, 7, and 10 females were identified as sperm positive and confirmed pregnant at 0, 50, 250, and 1000 mg/kg/day, respectively.

- Clinical Observations: alopecia in 2, 2, 1, and 0 females at 0, 50, 250, and 1000 mg/kg/day, respectively; efflux of the dosing solution in 1, 0, 1, and 1 females each at 0, 50, 250, and 1000 mg/kg/day, respectively; rooting postdosing in 1, 1, 6, and 8 females at 0, 50, 250, and 1000, respectively; and salivating prior to dosing in 5 females at 1000 mg/kg/day. One female at 50 mg/kg/day displayed a swollen left hindlimb, and 1 female at 1000 mg/kg/day had overgrown incisors that were trimmed. Rooting postdosing is considered related to taste aversion and not to toxicity, per se.

F0 Lactation

F0 maternal body weight change was significantly increased for pnd 4-7, 14-21, and 0-21 at 1000 mg/kg/day. As anticipated, maternal feed consumption was increased in all groups from pnd 14-21 due to the pups selffeeding.

- Clinical Observations: alopecia in 3, 1, 2, and 1 females at 0, 50, 250, and 1000 mg/kg/day, respectively. Chromodacryorrhea was observed in 1 female at 50 mg/kg/day and 2 females at.1000 mg/kg/day. Efflux of the dosing solution was observed in 1 female at 1000 mg/kg/day. Rooting postdosing was observed in 0, 1, 4, and 10 females at 0, 50, 250, and 1000 mg/kg/day, respectively. Salivation prior to dosing was observed in 1 female at 50 mg/kg/day and 7 females at 1000 mg/kg/day. One female at 1000 mg/kg/day exhibited blood in mouth prior to dosing on pnd 19. The 1 female at 50 mg/kg/day still exhibited a swollen left hindlimb.

Applicant's summary and conclusion

Conclusions:

TDP administered by gavage once daily at 0, 50, 250 and 1000 mg/kg/day to parental F0 CD (SD) rats, 10/sex/group through prebreed, mating, gestation and F1 lactation resulted in essentially no treatment or dose related adult F0 parental toxicity at any dose at any time. Reproductive toxicity was not present in F0 males or females. There was also no F1offspring toxicity observed postnatally through the weanling necropsy. Therefore, the F0 male and female systemic no observable adverse effect level (NOAEL) was at or above 1000mg/kg/day for males and females. The NOAELs for F0 reproductive toxicity were observed at or above 1000 mg/kg/day for males and females. The NOAELs for F1 offspring toxicity during lactation were also at or above 1000 mg/kg/day for males and females. (Author)