6H-Dibenz[c,e][1,2]oxaphosphorin-6-propanoic acid, butyl ester, 6-oxide

Endpoint summary

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January - March 2014

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: Crl:(WI)BR rats

Sex:

female

Details on test animals or test system and environmental conditions:

Experimental Animals:
Species and strain: Crl:(WI)BR rats
Source: TOXI COOP ZRT. Cserkesz u. 90.
1103 Budapest, Hungary
Hygienic level at arrival: SPF
Hygienic level during the study: Good conventional
Justification of strain: The Wistar rats as a rodent is one of the standard species
of acute toxicity studies
Number of animals: 3 animals/group
Sex: Female, nulliparous and non pregnant animals
Age of animals: Young adult rat, 9 weeks old in first and second step
Body weight range
at starting (first step): 150 - 155 g
Body weight range
at starting (second step): 150 - 155 g
Acclimatization time: 5 days in first step and 6 days in second step

Husbandry:
Animal health: Only healthy animals were used for the study. Health
status was certified by the study director.
Room: 5/II (E building)
Housing: Group caging (3 animals/cage)
Cage type: Type II polypropylene/polycarbonate.
Bedding: Laboratory bedding.
Light: Artificial light, from 6 a.m. to 6 p.m.
Temperature: 22 ± 3 °C
Relative humidity: 30 - 70 %
Ventilation: 10-15 air exchanges/hour by central air-condition system.
The temperature and relative humidity were recorded daily during the study.
Before housing the animals the microbiological status of the room was checked.

Food and Water Supply
Animals received ssniff® SM R/M-Z+H complete diet for rats and mice produced by ssniff Spezialdiäten GmbH, D-59494 Soest Germany and tap water from municipal supply, as for human consumption from bottle ad libitum.
The diet and drinking water are periodically analysed and are considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study. Copies of the relevant Certificates of Analysis are maintained in Toxi-Coop Zrt.’s archive.
Contents of ssniff® SM R/M-Z+H complete diet are presented in Appendix V.

Identification
The individual identification was performed by numbers on the tail written by a permanent marker. The numbers were given on the basis of Toxi-Coop Zrt.'s master file, for each animal allocated to the study. The boxes were identified by cards, holding information about study number, sex, dose group, cage number and individual animal numbers.

Characteristics of article used for anesthesia:
Name: Isofluran
Batch number: B14C10A
Expiry date: 02/2015
Manufactured by: CP-Pharma
Ostlandring 13, 31303 Burgdorf
Storage conditions: Below 30 °C, protected from light.
Purpose of use: for euthanasia

Route of administration:

oral: gavage

Vehicle:

other: Helianthi annui ol. raffinat; Batch number: 1305-4630; Date of expiration: 22.04. 2014; Suplier: Parma Produkt Kft.

Details on oral exposure:

A single oral administration - followed by a fourteen-day observation period - was performed by gavage. The day before treatment the animals were fasted. The food but not water was withheld overnight. Animals were weighed before the application and the food was given back 3 hours after the treatment.

Doses:

All doses were formulated in the vehicle. Concentration of formulations was adjusted to maintain a treatment volume of 10 mL/kg bw. The test item was applied in a concentration of 200 mg/mL. Formulations were prepared just before the administration and stirred continuously during the treatment.

Starting dose was selected on the basis of the available information about the test item. The acute toxic class method was carried out involving a stepwise procedure with the use of 2000 mg/kg bw as the starting dose in three female rats. No animal died in the first step at 2000 mg/kg bw dose level, so treatment with 2000 mg/kg bw was repeated on further three female rats. No animal died in the second step, too, so the test was finished, the stopping criteria of Annex 2d of OECD Guideline No. 423 (presented in Appendix VII) was met.

No. of animals per sex per dose:

6

Control animals:

no

Sex:

female

Dose descriptor:

other: No lethality was noted at single oral dose of 2000 mg/kg bw.

Effect level:

> 2 000 mg/kg bw

Based on:

dissolved

Remarks on result:

other: The method used, was not intended for the precise calculation of a precise LD50 value.

Mortality:

Animals were observed individually after dosing at least once during the first 30 minutes, then 1 h, 2 h, 3 h, 4 h after the treatment and twice each day for 14 days thereafter.

Clinical signs:

other: Animals were observed individually after dosing at least once during the first 30 minutes, then 1 h, 2 h, 3 h, 4 h after the treatment and once each day for 14 days thereafter. Individual observations were performed on the skin and fur, eyes and mucous me

Gross pathology:

All animals survived until the scheduled necropsy on Day 15. No pathological changes were found related to the effect of the test item during the macroscopic examination of animals.

Other findings:

Necropsy
At the end of the observation period all rats were sacrificed under isofluran anaesthesia. After examination of the external appearance, the cranial, thoracic and abdominal cavities were opened and the appearance of the tissues and organs was observed, and any abnormality was recorded with details of its location, colour, shape and size.

Lethality

No death occurred at 2000 mg/kg bw single oral dose of KCCS DOB11. All female rats in step 1 and step 2 survived until the end of the 14-day observation period.

Clinical symptoms

No treatment related symptoms were observed throughout the 14-day post-treatment period at any groups of the female animals.

Body weights

The mean body weight of the animals corresponded to their species and age throughout the study.

Evaluation

No death occurred after the single 2000 mg/kg bw oral dose of KCCS DOB11. There were no toxic clinical signs and any related to the effect of the test item found in body weights and body weight gains during the study. Autopsy revealed no treatment related pathological changes.

Interpretation of results:

other: GHS category 5

Remarks:

Criteria used for interpretation of results: expert judgment

Conclusions:

The method used is not intended to allow the calculation of a precise LD50 value.
The test item was ranked into classes of Globally Harmonized Classification System (GHS) described in the OECD Guideline No. 423 as below:
Dose (mg/kg bw): 2000
Mortality (dead/treated): 0/6
LD50 (mg/kg bw): above 2000
GHS category: 5

In conclusion, the LD50 of the test item “KCCS DOB11” is higher than 2000 mg/kg bodyweight by oral route in the rat.
In accordance with the OECD Guideline No. 423 (Annex 2d), the LD50 cut-off of the test item may be considered to be 5000 mg/kg body weight by oral route inthe rat.

Executive summary:

General information

An acute toxic class method was carried out involving a stepwise procedure with the use of 2000 mg/kg bw as the starting dose in three female rats. No animal died in the first step at 2000 mg/kg bw dose level, therefore treatment with 2000 mg/kg bw was repeated on further three female rats. No animal died in the second step, too, so the test was finished, the stopping criteria of Annex 2d of OECD Guideline No. 423 (presented in Appendix VII) was met. Animals were weighed, observed for lethality and toxic symptoms for 14 days after the treatment. Gross pathological examination was carried out on the 15th day after the treatment.

Lethality, Clinical symptoms and Body weight

No lethality was noted at single oral dose of 2000 mg/kg bw. No clinical symptoms were observed on the day of the treatment and during the 14-day observation period, the general state and behaviour of experimental animals were normal. The body weight development was undisturbed in all animals.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Justification for classification or non-classification

Acute toxicity (oral) / OECD 423

The LD₅₀ of the test item “KCCS DOB11” is higher than 2000 mg/kg bodyweight by oral route in the rat. In accordance with the OECD Guideline No. 423 (Annex 2d), the LD50 cut-off of the test item may be considered to be 5000 mg/kg body weight by oral route in the rat.