2,4,8,10-tetra(tert-butyl)-6-hydoroxy-12H-dibenzo[d,g] [1,3,2]dioxaphosphocin, 6-oxide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2018-06-06 to 2018-06-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,4,8,10-tetra(tert-butyl)-6-hydoroxy-12H-dibenzo[d,g] [1,3,2]dioxaphosphocin, 6-oxide

EC Number:

829-608-1

Cas Number:

106396-29-6

Molecular formula:

C29 H43 O4 P

IUPAC Name:

2,4,8,10-tetra(tert-butyl)-6-hydoroxy-12H-dibenzo[d,g] [1,3,2]dioxaphosphocin, 6-oxide

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Purity: > 99%
Batch No.: 102Z4

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Beijing Vital River Laboratory Animal Technology Co., Ltd.
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 51-60 days on arrival, in the range of 57-68 days at the commencement of each animal’s dosing
- Weight at study initiation: 207-236 g
- Fasting period before study: fasted overnight prior to dosing
- Housing: in suspended, stainless steel cages (L 32.0 cm × W 28.0 cm × H 20.0 cm) on cage racks (L 167.0 cm × W 70.0 cm × H 171.0 cm)
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 23.5 °C
- Humidity (%): 47% - 75%
- Photoperiod (hrs dark / hrs light): 12 hours light, 12 hours dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: Ultra-purified water

Details on oral exposure:

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: According to the OECD Guideline for Testing of Chemicals: Acute Oral Toxicity-Acute Toxic Class Method (TG 423, adopted 2001) and relevant toxicity data (the acute oral LD50 of the active ingredient of test item in female rats is greater than 2000 mg/kg b.w.), the dose level of 2000 mg/kg b.w. was selected as the starting dose from one of four fixed dose levels (5, 50, 300, 2000 mg/kg b.w.)

Doses:

the first step dosing: 2000 mg/kg b.w.
the second step dosing: 2000 mg/kg b.w.

No. of animals per sex per dose:

three females in each dosing

Control animals:

no

Details on study design:

- Clinical observations: once during the first 30 minutes and at 1, 2 and 4 hours after application and then once each day for up to 14 days
- General observations: once daily for the animals which have not been administrated with the test item
- Frequency of weighing: on Day 0 (day of dosing), Day 7 and Day 14. At the end of the test surviving animals were weighed
- Necropsy of survivors performed: yes, including eye examinations of the abdominal, thoracic organs and their contents of all animals
- Moribund or Moritality inspection: made twice daily, morning and afternoon, during normal working days (except that it was made once in the dosing and necropsy days), and once daily at weekends and public holidays.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mL/kg bw

Based on:

test mat.

Mortality:

The first dosing (2000 mg/kg b.w.): All animals showed no deaths or moribund status during the test.
The second dosing (2000 mg/kg b.w.): All animals showed no deaths or moribund status during the test.

Clinical signs:

other: The first dosing (2000 mg/kg b.w.): All animals showed no abnormal symptoms during the course of the test. The second dosing (2000 mg/kg b.w.): All animals showed no abnormal symptoms during the course of the test.

Gross pathology:

No abnormalities were found in all animals under test at necropsy.

Applicant's summary and conclusion

Interpretation of results:

other: Category 5 or Unclassified

Conclusions:

The acute oral LD50 in rats for the test substance was estimated to be more than 2000 mg/kg b.w., and the cut-off value of LD50 was estimated to be 5000 or ∞ mg/kg b.w.

Executive summary:

The study was performed to assess the acute oral toxicity of the test substance in Sprague Dawley rats according to the OECD Guideline for Testing of Chemicals: Acute Oral Toxicity-Acute Toxic Class Method (TG 423, adopted 2001).

The test item was tested using a stepwise procedure and three female animals were used each group. The first and second step dosing were both 2000 mg/kg b.w.. Clinical observations and body weights were monitored during the study. All animals under test were subjected to a gross necropsy at the end of the study.

 

Both the first dosing and the second dosing, all animals showed no deaths or moribund status during the test. All animals showed no abnormal symptoms during the course of the test in both dosing groups. Most of the surviving animals gained body weights during the test. No abnormalities were found in all animals under test at necropsy.

 

Based on the results, the acute oral LD50 in rats for the test substance was estimated to be more than 2000 mg/kg b.w. and the cut-off value of LD50 was estimated to be 5000 or ∞ mg/kg b.w..