Reaction mass of [[(2-hydroxyethyl)imino]dimethylene]bisphosphonic acid, sodium salt and 4-(Phosphonomethyl)-2-hydroxy-2-oxo-1,4,2-oxazaphosphorinane, sodium salt

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 26 April 2012 and 22 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

tetrasodium 4-(hydrogen phosphonatomethyl)-2-oxo-1,4,2λ⁵-oxazaphosphinan-2-olate hydrogen {[(hydrogen phosphonatomethyl)(2-hydroxyethyl)amino]methyl}phosphonate

EC Number:

939-513-8

Molecular formula:

C4H12NNaO7P2, C4H11NNa2O7P2 and C4H10NNa3O7P2

IUPAC Name:

tetrasodium 4-(hydrogen phosphonatomethyl)-2-oxo-1,4,2λ⁵-oxazaphosphinan-2-olate hydrogen {[(hydrogen phosphonatomethyl)(2-hydroxyethyl)amino]methyl}phosphonate

Test material form:

other: white paste

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Female Wistar (RccHan:WIST) strain rats were supplied by Harlan Laboratories UK Ltd., Oxon, UK. On receipt the animals were randomly allocated to cages. The animals were nulliparous and non-pregnant. After an acclimatisation period of at least five days the animals were selected at random and given a number unique within the study by indelible ink marking on the tail and a number written on a cage card. At the start of the study the animals were eight to twelve weeks of age. The bodyweights fell within an interval of ±20% of the mean initial bodyweight of the first treated group.

The animals were housed in groups of three in suspended solid floor polypropylene cages furnished with woodflakes. With the exception of an overnight fast immediately before dosing and for approximately three to four hours after dosing, free access to mains drinking water and food (2014C Teklad Global Rodent diet) was allowed throughout the study. The diet, drinking water and bedding were routinely analysed and were considered not to contain any contaminants that would reasonably be expected to affect the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 19 to 25°C and 30 to 70% respectively. Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 224.6 mg/ml

MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg

DOSAGE PREPARATION (if unusual): The test item contains 10.95% water. For the purposes of the study the concentration was corrected for this. The test item was freshly prepared, as required, as a solution at the appropriate concentration in distilled water.

The test item was formulated within two hours of being applied to the test system. It is assumed that the formulation was stable for this duration.

All animals were dosed once only by gavage, using a metal cannula attached to a graduated syringe. The volume administered to each animal was calculated according to the fasted bodyweight at the time of dosing. Treatment of animals was sequential.
Sufficient time was allowed between each group to confirm the survival of the previously dosed animals.

Doses:

2246 mg/kg (Equivalent to 2000 mg active ingredient/kg bodyweight)

No. of animals per sex per dose:

6 females at dose level of 2246 mg/kg (2000 mg ai/kg)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: The animals were observed for deaths or overt signs of toxicity 1/2, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days.
Individual bodyweights were recorded prior to dosing and seven and fourteen days after treatment.

- Necropsy of survivors performed: yes
At the end of the observation period the animals were killed by cervical dislocation. All animals were subjected to gross pathological examination. This consisted of an external examination and opening of the abdominal and thoracic cavities for examination of major organs. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

>= 2 000 mg/kg bw

Based on:

act. ingr.

Remarks on result:

other: equivalent to 2000 mg active ingredient/kg bodyweight, equivalent to 1580 mg/kg bw active acid

Mortality:

Individual mortality data are given in Table 1.
There were no deaths.

Clinical signs:

other: Individual clinical observations are given in Table 1. No signs of systemic toxicity were noted.

Gross pathology:

Individual necropsy findings are given in Table 3.
No abnormalities were noted at necropsy.

Any other information on results incl. tables

Table 1              Individual Clinical Observations and Mortality Data

Dose Level mg/kg	Animal Number and Sex	Effects Noted After Dosing (Hours)				Effects Noted During Period After Dosing (Days)
		½	1	2	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
2246^Ä	2-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-1 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-2 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-1 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-2 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Ä=      Equivalent to 2000 mg active ingredient/kg bodyweight

0=     No signs of systemic toxicity

Table 2              Individual Bodyweights and Weekly Bodyweight Changes

Dose Level mg/kg	Animal Number and Sex	Bodyweight (g) at Day			Bodyweight Gain (g) During Week
		0	7	14	1	2
2246^Ä	2-0 Female	159	172	190	13	18
	2-1 Female	159	178	189	19	11
	2-2 Female	173	194	216	21	22
	3-0 Female	159	169	210	10	41
	3-1 Female	153	156	195	3	39
	3-2 Female	154	160	196	6	36

Ä=      Equivalent to 2000 mg active ingredient/kg bodyweight

Table 3              Individual Necropsy Findings

Dose Level mg/kg	Animal Number and Sex	Time of Death	Macroscopic Observations
2246^Ä	2-0 Female	Killed Day 14	No abnormalities detected
	2-1 Female	Killed Day 14	No abnormalities detected
	2-2 Female	Killed Day 14	No abnormalities detected
	3-0 Female	Killed Day 14	No abnormalities detected
	3-1 Female	Killed Day 14	No abnormalities detected
	3-2 Female	Killed Day 14	No abnormalities detected

Ä=      Equivalent to 2000 mg active ingredient/kg bodyweight

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 the female Wistar strain rat was estimated to be greater than 2246 mg/kg bodyweight (equivalent to 2000 mg active ingredient/kg bodyweight, equivalent to to 1580 mg/kg bw active acid)