Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Developmental toxicity / teratogenicity

Currently viewing:

Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2021
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2021
Report date:
2021

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Version / remarks:
June 25, 2018
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Limit test:
yes

Test material

Constituent 1
Reference substance name:
Triisotridecyl phosphite
EC Number:
278-758-9
EC Name:
Triisotridecyl phosphite
Cas Number:
77745-66-5
Molecular formula:
C39H81O3P
IUPAC Name:
triisotridecyl phosphite
Test material form:
liquid
Specific details on test material used for the study:
NAME OF TEST MATERIAL (as stated in the study report): Trisisotridecylphosphite

SOURCE OF TEST MATERIAL
- Source of test material: Valtris Specialty Chemicals Ltd.
- Batch No. W057094
- Expiration date of the lot/batch: March 15, 2022
- Purity: 98%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature in original container.
- Stability under test conditions: The stability of the test item in dose formulations was determined using a validated analytical method. The test item was found stable up to 24 hours under use conditions (i.e., room temperature). Dose formulations were prepared every day and used within 4 hours of preparation.

Test animals

Species:
rat
Strain:
Wistar
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Jai Research Foundation Animal Breeding Facility.
- Age at study initiation: At the initiation of the acclimatisation female rats were 11-13 weeks old.
- Weight at study initiation: 199.4 – 232.8 g at beginning of acclimatisation.
- Housing: female rats were housed individually, except during the mating period.
- Diet (e.g. ad libitum): standard rodent pellet diet (Certified Teklad Global 14% Protein Rodent Diet, Batch No 2014SC-090920MA,, procured from Envigo Laboratories, Inc., USA), ad libitum
- Water (e.g. ad libitum): filtered drinking water (filtered through Reverse Osmosis water filtration system) in polypropylene bottles, ad libitum.
- Acclimation period: 6 days prior to mating

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 - 24
- Humidity (%): 65 - 68
- Air changes (per hr): 16
- Photoperiod (hrs dark / hrs light): 12 hours fluorescent light and 12 hours darkness, light hours were approximately 06.00 - 18.00 hours.

IN-LIFE DATES: Acclimatisation start March 05, 2021; Experiment Completion June 23, 2021.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
PREPARATION OF DOSING SOLUTIONS: Dose formulations were prepared every day prior to the dosing and were used within 4 hours of preparation. Dose formulations were thoroughly mixed using a magnetic stirrer.

VEHICLE
- Justification for use and choice of vehicle (if other than water): solubility

DOSE VOLUME: 4 mL/kg b.w.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The test item concentration and homogeneity of test item in samples of the control and dose formulations were analysed once prior to initiation of treatment and once during the treatment period. The samples were analysed at JRF using validated analytical method (JRF Study N° 228-2-13-18511).

Two sets of samples (4 samples per set) were collected by sampling three aliquots (upper, middle and lower layers) from each concentration except control (only one aliquot). One set of samples was used for analyses and the other set of samples was stored at refrigerated. On each occasion, the mean concentration was determined and compared with the nominal value and the coefficient of variation calculated. The acceptance criteria was ±15% deviation from nominal value and %CV <10.
Details on mating procedure:
After the acclimatisation period, each female rat was cohabitated with an untreated male rat (1:1) until the requisite numbers of mated female rats (25/group) were obtained. Detection of mating was confirmed by evidence of a copulatory plug in the vagina or by sperm positive vaginal smear. After confirmation of mating, each the female rats were returned to an individual cage, assigned to a group and that day was designated as the day 0 of gestation (GD 0).
Duration of treatment / exposure:
Days 5 - 19 of gestation
Frequency of treatment:
Once daily
Duration of test:
Day 20 of gestation
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day
Dose / conc.:
1 000 mg/kg bw/day
No. of animals per sex per dose:
25 mated females per group
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: The limit dose was chosen based on a testing requirement from ECHA following submission of a multi dose level OECD 414 guideline GLP study (JRF, 2018), which reported a NOAEL at the highest level tested (375 mg/kg/day).

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily, for mortality and morbidity

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: During the study period, visible clinical signs, such as changes in the skin, fur, eye, mucous membranes, as well as the behavioural pattern of the mated female rats, were recorded twice daily.

BODY WEIGHT: Yes
- Time schedule: on gestation days 0, 3, 5, 8, 11, 14, 17, and 20.

FOOD CONSUMPTION: Yes
- Time schedule: for the periods 0–3, 3–5, 5–8, 8–11, 11–14, 14–17, 17–20, and 5-20 days of gestation.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- All female rats were weighed, euthanised by carbon dioxide asphyxiation, dissected and examined macroscopically.

ORGAN WEIGHTS AND HISTOPATHOLOGY: Yes
- At the time of terminal sacrifice, the weight of the liver, kidney, brain, and thyroid gland was taken
after collection from all female rat and preserved in 10% neutral buffered formalin for histopathology.
Organ weights relative to terminal body weight and brain weight were calculated. Detailed histological examination of liver, kidney, and thyroid gland was performed in high and control dose groups. Brain was collected and preserved but histopathology was not performed.
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Number of live fetuses: Yes
- Number of dead fetuses: Yes

Non-gravid uteri were further examined by immersing in 5% ammonium sulphide solution for confirming the non-pregnant status.
Blood sampling:
At the time of terminal sacrifice on GD 20, blood (approximately 3 mL) was collected from all-female
rats under anaesthesia (isoflurane) by orbital plexus puncture.

Serum thyroid hormones (T4, TSH, and T3) were analysed from all female rats at the terminal sacrifice.

Serum samples were also analysed for UDP Glucuronosyltransferase (UDPG) and clinical chemistry
parameters (alanine aminotransferase, aspartate aminotransferase, creatinine, total protein, albumin,
and urea) of liver and kidney.
Fetal examinations:
- External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [approximately half per litter]
- Skeletal examinations: Yes: [remaining half per litter]
- Head examinations: Yes: [approximately half per litter]
- Fetus sex (based on anogenital distance): Yes [all per litter]
- Fetuses body weight: Yes [all male fetuses per litter, all female fetuses per litter]
Statistics:
TYPE OF DATA:
Parametric: Body weight, body weight change, food consumption, corrected body weight,
absolute and relative uterine weight, organ weight, organ weight ratio, male sex ratio,
pre-and postnatal loss (%), live foetus (%), and resorption (%), ano-genital distance
Non-parametric: Mortality rate, pregnancy rate, foetal observation, litter size, number of corpora lutea, number of implants, number of a live foetus, number of pre-and postnatal losses,
number of resorptions

SIGNIFICANCE LEVEL:
Parametric: 5% and 1% level between control and treated group
Non-parametric: 5% level between control and treated group
Indices:
Pre-implantation loss (%)
Post-implantation loss (%)
Live fetuses (%)
Dead fetuses (%)
Male Sex ratio
Resorptions (%)
Historical control data:
No

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
no effects observed
Description (incidence and severity):
No clinical signs of toxicity were observed during the experimental period in any dose group.
Mortality:
no mortality observed
Description (incidence):
No mortality or morbidity was observed in any dose group.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
The mean body weight and Day 20 corrected body weight of the pregnant female rats were comparable between the control and the test item treated group.


Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
The mean food consumption of the pregnant female rats was comparable between the control, and the test item treated group.
Food efficiency:
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Statistically, a significant increase in the serum ALT level was observed in the 1000 mg/kg b. wt./day
dose group. This alteration is considered an effect of the test item treatment but non-adverse in
nature in the absence of histopathological alterations in the liver.

Statistically, a significant increase in the serum UDP Glucuronosyltransferase (UDPG) level was
observed in the 1000 mg/kg b. wt./day dose group. This alteration reveals enzyme induction activity
of the test item and considered as an effect of the test item treatment but non-adverse in nature in the
absence of the histopathological alteration in the liver.
Endocrine findings:
effects observed, non-treatment-related
Description (incidence and severity):
Serum TSH and T4 levels were comparable with that of the control group.

Statistically, a significant decrease in serum T3 level was observed in pregnant female rats belonging
to 1000 mg/kg b. wt./day dose group. This finding could be related to the induction of UDP
Glucuronosyltransferase (UDPG) seen in the liver, and associated increased clearance of the thyroid
hormones. In the absence of corresponding changes in TSH, and in the absence of histopathological alterations in thyroid, this finding is considered to be non-adverse.
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
The mean absolute and relative uterine weight of the pregnant female rats were comparable between the control and the test item treated group.

Statistically, a significant increase in the absolute (around 13% increase vs control) and relative
liver weights (vs terminal body weight and brain weight) were noted in the 1000 mg/kg b. wt./day
dose group. Similarly, statistically, a significant increase in the absolute (around 15% increase vs
control) and relative (vs brain weight) thyroid gland weights were observed in the 1000 mg/kg b. wt./day dose group. These effects were considered to be related to treatment but were considered nonadverse in nature in the absence of the treatment-related histopathological alterations in these organs.
Gross pathological findings:
no effects observed
Description (incidence and severity):
External and internal (gross) examination of the terminally sacrificed female rats did not reveal any lesion of pathological significance.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, non-treatment-related
Description (incidence and severity):
Histological examination of liver, kidney, and thyroid gland did not reveal any treatment-related lesion
in rats of the control as well as the high dose group. The lesions observed, ectopic thymus and kidney pelvis dilation, were considered to be congenital/spontaneous as the lesions were present in both the treated and control group rats.
Other effects:
no effects observed

Maternal developmental toxicity

Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
no effects observed
Changes in number of pregnant:
no effects observed
Other effects:
no effects observed
Details on maternal toxic effects:
The mean numbers of corpora lutea, implantation sites, live foetuses, dead foetuses, resorptions (early, late, and total), pre-implantation loss, and post-implantation loss, the mean percent of live foetuses, dead foetuses, pre-implantation loss, post-implantation loss, and total resorptions were comparable between the control, and test item treated group.

Effect levels (maternal animals)

open allclose all
Dose descriptor:
NOEL
Remarks:
Maternal Developmental Toxicity
Effect level:
>= 1 000 mg/kg bw/day
Based on:
test mat.
Remarks on result:
other: No treatment related effect observed at the limit dose of 1000 mg/kg/day.
Dose descriptor:
NOAEL
Remarks:
Maternal Systemic Toxicity
Effect level:
>= 1 000 mg/kg bw/day
Based on:
test mat.
Remarks on result:
other: No adverse effects were observed at the limit dose of 1000 mg/kg/day.

Maternal abnormalities

Abnormalities:
no effects observed
Description (incidence and severity):
No adverse effects were observed at the limit dose of 1000 mg/kg/day.

Results (fetuses)

Fetal body weight changes:
no effects observed
Description (incidence and severity):
The mean body weight of male, female and total fetuses (male + female) was comparable between the control and the test item treated groups.
Reduction in number of live offspring:
no effects observed
Description (incidence and severity):
The mean number of corpora lutea, implantation sites, live foetuses, dead foetuses, resorptions (early, late, and total), pre-implantation loss, and post-implantation loss, as well as the mean percent of live foetuses, dead foetuses, pre-implantation loss, post-implantation loss, and total resorptions were comparable between the control, and test item treated group.
Changes in sex ratio:
no effects observed
Description (incidence and severity):
The male sex ratio was comparable between the control and the test item treated group.
Changes in litter size and weights:
no effects observed
Description (incidence and severity):
The mean count of male, female and total foetuses (male + female) was comparable between the
control group, and the test item treated group.
Anogenital distance of all rodent fetuses:
no effects observed
Description (incidence and severity):
The mean anogenital distance of male and female foetuses was comparable
between the control and the test item treated group.
Changes in postnatal survival:
not examined
External malformations:
no effects observed
Description (incidence and severity):
No treatment-related external anomalies were observed.
Skeletal malformations:
no effects observed
Description (incidence and severity):
No treatment-related increases in the incidence of skeletal malformations were observed. Findings were similar in the treated and control group, and at incidences within the range of historical control data.
Visceral malformations:
no effects observed
Description (incidence and severity):
No treatment-related visceral anomalies were observed. Spontaneous findings in the treated and control group were within the historical control data range.

No treatment-related anomalies were observed in the head razor sections.
Other effects:
no effects observed
Details on embryotoxic / teratogenic effects:
No effects were observed in this study.

Effect levels (fetuses)

Dose descriptor:
NOEL
Effect level:
>= 1 000 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Remarks on result:
other: No effects were observed at the limit dose of 1000 mg/kg/day.

Fetal abnormalities

Abnormalities:
no effects observed
Description (incidence and severity):
No effects were observed at the limit dose of 1000 mg/kg/day.

Overall developmental toxicity

Developmental effects observed:
no

Any other information on results incl. tables

The following tabluar results and Appendices are provided in two separate attachments:


Table 2: Pregnancy Data Summary


Table 3: Clinical Observations Summary (Maternal)


Table 4: Body Weight Summary (Maternal)


Table 5: Body Weight Gain Summary (Maternal)


Table 6: Food Consumption Summary


Table 7: Prenatal Data Summary


Table 8: Foetal Data Summary


Table 9: Foetal Gross External Observation Summary


Table 10: Foetal Visceral Observations Summary


Table 11: Foetal Head Razor Section Observation Summary


Table 12: Foetal Skeletal Observation Summary


Appendix 11: Pathology Report


Appendix 12: Thyroid Hormone Analysis Report (TSH)


Appendix 13: Thyroid Hormone Analysis Report (T3 and T4)


Appendix 14: UDPG Analysis Report

Applicant's summary and conclusion

Conclusions:
In this OECD 414 guideline GLP limit study of trisisotridecyl phosphite, no adverse maternal systemic effects were observed at the limit dose of 1000 mg/kg bw/day, and no treatment-related effects were observed on maternal reproduction or fetal development. Therefore, the NOAEL for maternal systemic toxicity is considered to be 1000 mg/kg bw/day. This dose in considered to be a NOEL for maternal and fetal developmental toxicity.
Executive summary:

An enhanced OECD 414 guideline GLP limit study was conducted on tris isotridecyl phosphite. Groups of 25 female Wistar rats were treated by oral gavage on gestation days (GD) 5 to 19, by at  dose levels of 0 (corn oil vehicle), or 1000 mg/kg b. wt./day. Rats were observed twice daily for mortality and clinical signs. Maternal body weights and food consumption were recorded throughout the gestation period.


All rats were sacrificed on GD 20 and assessed for gross pathological changes. The uteri were excised, weighed, and examined for the numbers of implantation sites, early and late resorptions, and numbers of live and dead foetuses. The ovaries were excised, and the number of corpora lutea counted. The foetuses were identified for sex, weighed, and examined for external findings. The anogenital distance was measured for all foetuses. At the time of terminal sacrifice, the weight of the thyroid gland, liver, kidney, and brain was recorded from all-female rats and preserved for histopathology. Detailed histological examination of the liver, kidney, and thyroid gland was performed in control and high dose group female rats. Serum thyroid hormones T3 (liothyronine), T4 (levothyroxine), and TSH (thyroid-stimulating hormone) were analysed from all pregnant female rats during the terminal sacrifice. UDP Glucuronosyltransferase (UDPG) and clinical chemistry parameters (alanine aminotransferase, aspartate aminotransferase, creatinine, total protein, albumin, and urea) of liver and kidney were also analysed from all pregnant female rats.  The maternal liver evaluations were included to aid interpretation of thyroid findings. Following appropriate fixation, foetuses were examined for visceral abnormalities, including razor sectioning of the head and skeletal abnormalities.


No treatment-related effects were seen on maternal reproduction parameters, or on fetal development.


Treatment-related effects were limited to liver and thyroid findings in maternal animals.  Nonadverse effects seen in the 1000 mg/kg b. wt./day dose group animals included:


- Statistically significant increase in the serum ALT level vs controls.


- Statistically significant increase in the serum UDP Glucuronosyltransferase (UDPG) vs controls. This finding indicates enzyme induction activity in the liver and and has been  associated with increased clearance of the thyroid hormones.


 - Statistically significant decrease in serum T3 level vs controls. This finding could be related to the induction of UDP Glucuronosyltransferase (UDPG) seen in the liver.

- Statistically significant increase in the absolute and relative liver and thyroid weights vs controls.


Because no treatment-related histopathological alterations were seen in the liver or thyroid, these findings were considered to be non-adverse in nature.





Based on these results, the NOAEL for maternal systemic toxicity is considered to be 1000 mg/kg bw/day. This dose in considered to be a NOEL for maternal reproduction and fetal developmental toxicity.