2-Propenoic acid, 2-hydroxyethyl ester, reaction products with O,O-bis(dialkyalkyl) hydrogen phosphorodithioate and dimethyl phosphonate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 August 2019 to 12 September 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

17 December 2001

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Version / remarks:

30 May 2008

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

2002

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries, Test Data for Registration of Agricultural Chemicals, Acute oral toxicity (2-1-1), 12 Nousan No 8147, Agricultural Production Bureau

Version / remarks:

24 November 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid

Details on test material:

- Appearance/physical state: Light yellow liquid
- Storage conditions: Ambient temperature

Test animals

Species:

rat

Strain:

Wistar

Remarks:

RccHan WIST albino

Sex:

female

Details on test animals or test system and environmental conditions:

ANIMAL INFORMATION
- Healthy nulliparous and non-pregnant female RccHan:WIST albino rats were obtained from Envigo RMS (UK) Ltd.
- The animals were allocated without conscious bias to cages within the treatment groups. They were housed in groups of one or four rats of the same sex.
- Each animal was identified uniquely within the study by tail marking. Each cage label was colour-coded and was identified uniquely with the study number, dose level and animal mark.
- The animals were allowed to acclimatise to the conditions described below for at least five days before treatment. For those animals selected for the study, body weights were in the range 161 to 170 g and they were approximately eight to twelve weeks of age prior to dosing (Day 1). The body weight variation did not exceed ± 20 % of the mean body weight of any previously treated animals.

ANIMAL CARE AND HUSBANDRY
- Animals were housed inside a limited access rodent facility (Building F21, Room 044/045). The facility was designed and operated to minimize the entry of external biological and chemical agents and to minimize the transference of such agents between rooms.
- The animal room was kept at positive pressure with respect to the outside by its own supply of filtered fresh air, which was passed to atmosphere and not re-circulated. The temperature and relative humidity controls were set to maintain the range of 20 to 24 °C and 40 to 70 % respectively. Any minor deviations from these ranges would not have had an adverse effect on the animals and would not affect the integrity or validity of the study. Artificial lighting was controlled to give a cycle of 12 hours continuous light and 12 hours continuous dark per 24 hours. Environmental parameters are archived with the departmental raw data.
- Periodic checks were made on the number of air changes in the animal rooms. Temperature and humidity were monitored daily.
- Alarms were activated if there was any failure of the ventilation system, or temperature limits were exceeded. A stand-by electricity supply was available to be automatically brought into operation should the public supply fail.
- The cages were solid bottomed polycarbonate cages with a stainless steel mesh lid. Each cage contained a quantity of autoclaved softwood bark-free fiber bedding. Cages, food hoppers, water bottles and bedding were changed at appropriate intervals.
- The animals were allowed free access to a standard rodent diet (Teklad 2014C Diet), except for overnight prior to and approximately four hours after dosing. This diet contained no added antibiotic or other chemotherapeutic or prophylactic agent.
- Potable water taken from the public supply was freely available via polycarbonate bottles fitted with sipper tubes.
- Each cage of animals was provided with Aspen chew blocks or balls for environmental enrichment. Chew blocks or balls were provided throughout the study and were replaced when necessary. Each cage of animals was provided with a plastic shelter for environmental enrichment, which was replaced at the same time as the cages.
- Each batch of diet was analysed routinely by the supplier for various nutritional components and chemical and microbiological contaminants. Supplier’s analytical certificates were scrutinized and approved before any batch of diet was released for use. The quality of the water supply is governed by regulations published by the Department for Environment, Food and Rural Affairs. Certificates of analysis were received routinely from the water supplier. Certificates of analysis were received routinely from the supplier of the chew blocks or balls. Since the results of these various analyses did not provide evidence of contamination that might have prejudiced the study, they were not presented.
- No other specific contaminants that were likely to have been present in the diet or water were analysed, as none that may have interfered with or prejudiced the outcome of the study was known.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

FORMULATION
- The test item was formulated at concentrations of 30 and 200 mg/mL in the vehicle and administered at a volume of 10 mL/kg body weight.
- The absorption of the test item was not determined.
- Determination of the homogeneity, stability and purity of the test item or test item formulations were not undertaken as part of this study.
- Detailed records of test item usage were maintained. The amount of test item necessary to prepare the formulations and the amount actually used were determined on each occasion.
- The difference between these amounts was checked before the formulations were dispensed.

DOSE ADMINISTRATION
- The appropriate dose volume of the test item was administered to each rat by oral gavage using a plastic syringe and plastic catheter.
- A record of the weight of each formulation dispensed and the amount remaining after dosing was made. The balance of these two weights was compared with the predicted usage as a check that the doses had been administered correctly.
- Formulations were stirred before and throughout the dosing procedure.

Doses:

300mg/kg bw or 2000 mg/kg bw

No. of animals per sex per dose:

- One female dosed at 300 mg/kg bw
- Five females dosed at 2000 mg/kg bw

Control animals:

no

Details on study design:

- In the absence of data regarding the toxicity of the test item, 300 mg/kg was chosen as the starting dose.
- A single female animal was treated at a dose level of 300 mg/kg (concentration 30 mg/mL; dose volume 10 mL/kg).
- A single female animal was treated at a dose level of 2000 mg/kg (concentration 200 mg/mL; dose volume 10 mL/kg).
- In the absence of mortality or toxicity at a dose level of 2000 mg/kg, an additional four animals were treated at a dose level of 2000 mg/kg (concentration 200 mg/mL; dose volume 10 mL/kg).

Statistics:

- Using the mortality data obtained, an estimate of the acute oral median lethal dose (LD50) of the test item was made.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

- There were no deaths during the study.

Clinical signs:

- Individual clinical observations are presented in Appendix 1 (attached).
- Clinical signs observed were piloerection, seen in four females dosed at 2000 mg/kg bw, first noted approximately three hours after dosing. Additionally, hunched posture was noted in two females dosed at 2000 mg/kg bw approximately six hours after dosing. Recovery of animals, as judged by external appearance and behaviour, was complete by Day 2. No clinical signs were seen in the animal dosed at 300 mg/kg bw or the remaining animal dosed at 2000 mg/kg bw.

Body weight:

- Individual body weight and body weight changes are given in Appendices 2 and 3 (attached).
- All animals were considered to have achieved satisfactory body weight gains throughout the study.

Gross pathology:

- Individual necropsy findings are given in Appendix 4 (attached).
- No abnormalities were noted in any animal at the macroscopic examination at study termination on Day 15.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The acute oral median lethal dose (LD50) of the test item in female rats was demonstrated to be > 2000 mg/kg bw.

Executive summary:

GUIDELINE

The investigation was conducted in compliance with the OECD Guideline for Testing of Chemicals No 420 “Acute Oral Toxicity – Fixed Dose Method” (17 December 2001), Method B.1 bis Acute Toxicity: fixed dose procedure (30 May 2008), EPA Health Effects Test Guidelines OPPTS 870.1100 Acute Oral Toxicity EPA 712-C-02-190 (2002) and Japanese Ministry of Agriculture, Forestry and Fisheries, Test Data for Registration of Agricultural Chemicals, Acute oral toxicity (2-1-1), 12 Nousan No 8147, Agricultural Production Bureau (November 24, 2000).

 

METHODS

The purpose of the study was to assess the toxic potential of the test item following a single oral dose in the rat. Fasted female rats received a single oral gavage dose of the test item, formulated in corn oil,

at dose levels of 300 and 2000 mg/kg bw during sighting investigations). Based on the results of the sighting investigations a further four fasted females were similarly dosed at 2000 mg/kg bw. During the study, clinical condition, body weight and macropathology investigations were undertaken.

 

RESULTS

No unscheduled animal deaths took place during the study. Clinical signs observed were piloerection, seen in four females dosed at 2000 mg/kg bw, additionally hunched posture was noted in two females dosed at 2000 mg/kg bw. Recovery of animals, as judged by external appearance and behaviour, was complete by Day 2. No clinical signs were seen in any animal dosed at 300 mg/kg or the remaining animal dosed at 2000 mg/kg bw. All animals were considered to have achieved satisfactory body weight gains throughout the study. No abnormalities were noted in any animal at the macroscopic examination at study termination on Day 15.

 

CONCLUSION

The acute oral median lethal dose (LD50) of the test item in female rats was demonstrated to be > 2000 mg/kg bw.