Reaction products of dimethyl phosphonate with 2-alkyl-2-alkylpropanediol and alkanediol

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 January 2017 to 30 January 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid: viscous

Details on test material:

- Appearance/physical state: Clear viscous liquid
- Storage conditions: Room temperature in the dark

Test animals

Species:

rat

Strain:

other: Crl:CD(SD)

Remarks:

albino

Sex:

female

Details on test animals or test system and environmental conditions:

TEST SYSTEM, ANIMAL RECEIPT AND ACCLIMATION
- Crl:CD(SD) rats from Charles River Laboratories, Inc., Raleigh, NC were used as the test system on this study. The animal model, the Crl:CD(SD) albino rat, is generally recognized as appropriate for acute oral toxicity studies, and was selected because it is a widely used strain for which significant historical control data are available. The number of animals selected for the study was the minimum necessary to yield scientifically meaningful results. No information exists to indicate a difference in sensitivity between the sexes. Therefore, only females will be used to reduce variability and as a means of minimizing the number of animals used. The experimental design used the general procedures and standards required by the current federal and international test guidelines.
- The albino rats utilized for this study were received in good health from Charles River Laboratories, Inc., Raleigh, NC, on 03 Jan 2017. The rats were inspected by a qualified technician upon receipt, weighed and uniquely identified by a subcutaneous microchip (BMDS) implanted in the dorsoscapular area. The rats were acclimated to laboratory conditions for a minimum of 6 days. During this period, each animal was observed twice daily for mortality and changes in general appearance or behaviour.

ANIMAL HOUSING
- Upon arrival, all animals were housed individually in clean, stainless steel, wire-mesh cages suspended above cage-board. The animals were maintained by the animal husbandry staff of Charles River in accordance with SOPs. The animal facilities at Charles River are accredited by AAALAC International.
- Enrichment devices were provided to all animals as appropriate throughout the study for environmental enrichment and to aid in maintaining the oral health of the animals, and were sanitised weekly.

DIET DRINKING WATER AND MAINTENANCE
- The basal diet used in this study, PMI Nutrition International, LLC, Certified Rodent LabDiet 5002, is a certified feed with appropriate analyses performed by the manufacturer and provided to Charles River. Municipal water supplying the facility was analysed for contaminants according to Charles River SOPs. The results of the diet and water analyses are maintained at Charles River.
- No contaminants were present in animal feed or water at concentrations sufficient to interfere with the objectives of this study.
- The basal diet and municipal water, delivered by an automatic watering system, were provided ad libitum, except during the overnight fasting period prior to dosing and the 4-hour period after dosing when food was withheld.

ENVIRONMENTAL CONDITIONS
- All animals were housed throughout the acclimation period and during the study in an
environmentally controlled room. The room temperature and humidity controls were set to
maintain environmental conditions of 68 °F to 78 °F (20 °C to 26 °C) and 30 % to 70 %,
respectively.
- Room temperature and relative humidity data were monitored continuously and were scheduled for automatic collection on an hourly basis. Mean daily temperature ranged from 72.2 °F to 72.5 °F (22.3 °C to 22.5 °C) and mean daily relative humidity ranged from 36.4 % to 50.9 % during the study. – Fluorescent lighting provided illumination for a 12-hour light (0600 hours to 1800 hours)/12-hour dark photoperiod. Lighting conditions were recorded every 15 minutes.
- Air handling units were set to provide a minimum of 10 fresh air changes per hour.

ASSIGNMENT OF ANIMALS TO TREATMENT GROUPS
- Animals used in the study were randomly selected based on health and body weight from available stock and assigned to groups by use of WTDMS.
- The selected animals were approximately 8–9 weeks old at initiation of dosing; body weight values ranged from 158 g to 190 g.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

PREPARATION
- Prior to use, the bulk test substance was transferred into a storage container for dispensation.

TEST SUBSTANCE ADMINISTRATION
- The rats were fasted overnight prior to dosing. Food was returned approximately 4 hours after dosing. The test substance was administered once orally by gavage to 1 fasted female albino rat at a dose level of 300 mg/kg. No mortality was observed, and another female rat was dosed at 2000 mg/kg (limit dose). No mortality was observed, and 4 additional female rats were dosed at 2000 mg/kg.
- The test substance was dosed undiluted based on its density. The dose volume was determined by dividing each dose level, expressed as g/kg, by the density (1.1093 g/mL; as determined by the Charles River Formulations Department). Individual doses were calculated based on fasted body weights taken just prior to dosing and dose volumes of 0.270 and 1.803 mL/kg for the 300 and 2000 mg/kg groups, respectively. See Appendix 3 (attached) for the dosing regimen used for the sighting and main studies.

Doses:

300 mg/kg bw and 2000 mg/kg bw

No. of animals per sex per dose:

- One animal doses at 300 mg/kg bw
- Five animals dosed at 2000 mg/kg bw

Control animals:

no

Details on study design:

PARAMETERS EVALUATED
- Mortality: The rats were observed twice daily, once in the morning and once in the afternoon, for mortality and moribundity.
- Clinical observations: The rats were observed at the time of dosing, 15 ± 5 minutes and approximately 1, 2, and 4 hours post-dosing on Study Day 0, and once daily thereafter for 14 days. Observations included, but were not limited to, evaluation for changes in appearance of skin and fur, eyes, mucous membranes, respiratory and circulatory systems, autonomic effects, and central nervous system effects.
- Body weights: Body weights were obtained and recorded on Study Days 0 (initiation), 7, and 14 (termination).
- Necropsy: Upon termination, all rats were euthanised by carbon dioxide inhalation. The major organ systems of the cranial, thoracic, and abdominal cavities were examined for all animals. Tissues were discarded.

DATA ACQUISITION AND ANALYSIS
- The major computer systems used on this study include, but are not limited to, the systems listed in the attached table. All computerized systems used for data collection during the conduct of this study have been validated (with the exception of Microsoft Office); when a particular system has not satisfied all requirements, appropriate administration and procedural controls were implemented to assure the quality and integrity of the data.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

- All animals survived to the scheduled necropsy.

Clinical signs:

- There were no clinical observations noted at 300 mg/kg.
- Test substance-related clinical findings of impaired use of hindlimbs, cool body, and ataxia were noted for a single female (No. 4552) dosed at 2000 mg/kg at approximately 1 hour following dose administration on Study Day 0. Other clinical observations noted for females in the 2000 mg/kg consisted of clear ocular discharge, yellow material on the anogenital and/or urogenital areas, salivation, and/or red material around the nose at approximately 1, 2, and/or 4 hours following dose administration on Study Day 0; additionally, the yellow and/or red material findings were also noted during Study Days 1–4. All females in the 2000 mg/kg group appeared normal by Study Day 5.

Body weight:

- There were no remarkable body weight changes noted during the study.
- All animals surpassed their initial body weight by Study Day 14.

Gross pathology:

- There were no macroscopic findings at the scheduled necropsy.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The estimated LD50 of the test item was greater than 2000 mg/kg when administered once orally via gavage to fasted female albino rats.

Executive summary:

GUIDELINE

This study was conducted in general accordance with OECD Guidelines for Testing of Chemicals, Section 420 (2001): “Acute Oral Toxicity - Fixed Dose Procedure”.

 

METHODS

The acute oral toxicity of the test item was evaluated in a single-dose study in rats. The test substance was administered once orally via gavage to one fasted female albino rat at a dose level of 300 mg/kg. No mortality was observed, and another female rat was dosed at 2000 mg/kg (limit dose). No mortality was observed, and four additional female animals were dosed at 2000 mg/kg. Mortality, clinical observations, and body weight changes were evaluated over a 14-day observation period. All animals were subjected to a gross necropsy.

 

RESULTS

There were no deaths, remarkable body weight changes, or test substance-related gross necropsy findings. There were no clinical observations noted at 300 mg/kg. Test substance-related clinical findings of impaired use of hindlimbs, cool body, and ataxia were noted for one female dosed at 2000 mg/kg at approximately 1 hour following dose administration on Study Day 0. Other clinical observations noted in the 2000 mg/kg group consisted of clear ocular discharge, yellow material on the anogenital and/or urogenital areas, salivation, and/or red material around the nose; these observations were noted at approximately 1, 2, and/or 4 hours following dose administration on Study Day 0 and/or during Study Days 1–4. All females in the 2000 mg/kg group appeared normal by Study Day 5.

 

CONCLUSION

The estimated LD50 of the test item was greater than 2000 mg/kg when administered once orally via gavage to fasted female albino rats.