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

Endpoint summary

Description of key information

In the key acute oral toxicity study for HEBMP-xNa, conducted according to OECD Test Guideline 423 and in compliance with GLP, the LD50 value was concluded to be greater than 2246 mg/kg body weight (equivalent to 2000 mg active salt/kg body weight, equivalent to 1580 mg/kg body weight active acid, see Note 1) (Harlan Laboratories, 2012a).

In the acute dermal toxicity study for HEBMP-xNa, conducted according to OECD Test Guideline 402 and in compliance with GLP, the LD50 value was concluded to be greater than 2246 mg/kg bodyweight (equivalent to 2000 mg active salt/kg bodyweight, equivalent to 1580 mg/kg bw active acid, see Note 1) (Harlan Laboratories, 2012b).

In accordance with Column 2 of REACH Annex VIII, the acute toxicity study via the inhalation route (required in Section 8.5.2) does not need to be conducted as reliable data via the oral and dermal routes are available.

Note 1: the calculation of results in terms of active acid equivalent was done as follows: LD50 >2246 mg/kg body weight is equivalent to 2000 mg/active ingredient/kg body weight due to the presence of 11% water, which was corrected by the performing laboratory. Assuming the study was conducted at neutral pH, this would be equivalent to a predominance of HEBMP-3Na based on pKa values. The result has been corrected to the equivalent dose of active acid using a using molecular weight conversions:

MW HEBMP acid (249.1 g/mol) / MW HEBMP-3Na (315.04 g/mol) = 0.79

[when taking the average of the Molecular Weights for the cyclic and linear forms of the substances]

Therefore 2000 mg HEBMP-3Na/kg * 0.79 = 1580 mg HEBMP acid/kg body weight

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:

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

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

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.

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.

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.

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

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)

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

other justification

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 16 May 2012 and 30 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (MAFF), Testing Guidelines for Toxicology Studies, 12 NohSan No. 8147, amended 26 June 2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Health and Welfare, 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Five male and five 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 females 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 weighed at least 200 g, and were eight to twelve weeks of age. The weight variation did not exceed ±20% of the mean weight for each sex.

The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24 Hour exposure period and in groups of five, by sex, for the remainder of the study. 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 could 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.

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

PREPARATION OF TEST ITEM:
The test item contains 10.95% water. For the purposes of the study the test item concentration was corrected for this. The test item was weighed out according to each animal's individual bodyweight and moistened with distilled water prior to application.
The absorption of the test item was not determined.

TEST SITE
On the day before treatment the back and flanks of each animal were clipped free of hair.

Using available information on the toxicity of the test item, a group of five male and five female rats was treated with the test item at a dose level of 2246 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight).

The appropriate amount of test item, moistened with distilled water, was applied as evenly as possible to an area of shorn skin (approximately 10% of the total body surface area). A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage. The animals were caged individually for the 24-Hour exposure period. Shortly after dosing the dressings were examined to ensure that they were
securely in place.

REMOVAL OF TEST SUBSTANCE:
After the 24-Hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with distilled water to remove any residual test item. The animals were returned to group housing for the remainder of the study period.

Duration of exposure:

24 hours

Doses:

2246 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight).

No. of animals per sex per dose:

5 male and 5 female at 2246 mg/kg (2000 mg ai/kg bodyweight).

Control animals:

not required

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 ½, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days.

After removal of the dressings and subsequently once daily for fourteen days, the test sites were examined for evidence of primary irritation and scored according to the Draize scale (see evaluation of skin reactions).

Any other skin reactions, if present were also recorded.

Individual bodyweights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.

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

Sex:

male/female

Dose descriptor:

LD50

Effect level:

>= 2 000 mg/kg bw

Based on:

act. ingr.

Remarks on result:

other: Equivalent to >1580 mg/kg bw active acid

Mortality:

Individual mortality data are given in Table 1 (see attached background material).
There were no deaths.

Clinical signs:

other: Individual clinical observations are given in Table 1 (see attached background material). There were no signs of systemic toxicity.

Gross pathology:

Individual necropsy findings are given in Table 5 (see attached background material).
No abnormalities were noted at necropsy.

Other findings:

Dermal Reactions:
Individual dermal reactions are given in Table 2 and Table 3 (see attached background material).
There were no signs of dermal irritation.

Interpretation of results:

GHS criteria not met

Conclusions:

The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found 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).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

In the key acute oral toxicity study for HEBMP-xNa, conducted according to OECD Test Guideline 423 and in compliance with GLP, the LD50 value was concluded to be greater than 2246 mg/kg body weight (equivalent to 2000 mg active salt/kg body weight, equivalent to 1580 mg/kg body weight active acid) (Harlan Laboratories, 2012a).

In the study, a group of three fasted females was treated with the test item at a dose level of 2246 mg/kg bodyweight (equivalent to 2000 mg active ingredient/kg bodyweight). This was followed by a further group of three fasted females at the same dose level. The test item was administered orally as a solution in distilled water. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy. There were no deaths during the 14-day study period. There were no signs of systemic toxicity. All animals showed expected gains in bodyweight over the study period. No abnormalities were noted at necropsy.

A supporting acute oral toxicity study was read-across from HEBMP-H (CAS 5995-42-6), conducted according to OECD Test Guideline 423 and in compliance with GLP, in which an LD50 of 500-1000 mg/kg bw (equivalent to 250-500 mg/kg bw pure substance) was concluded (SafePharm, 2003). Two animals treated at a dose level of 2000 mg/kg bw were found dead or killed in extremis two hours or one day after dosing. There were no deaths at a dose level of 300 mg/kg bw. Signs of toxicity noted at a dose level of 2000 mg/kg bw were hunched posture, ataxia, decreased respiratory rate, gasping, laboured and noisy respiration, loss of righting reflex, piloerection, ptosis, pallor of the extremities and red/brown staining around the eyes. One animal treated at a dose level of 2000 mg/kg bw was comatose one hour after dosing. There were no signs of toxicity at a dose level of 300 mg/kg bw. The surviving animals showed expected gains in body weight over the study period. Abnormalities noted at necropsy of the animal that was found dead two hours after dosing were haemorrhagic lungs, dark liver, dark kidneys, haemorrhage of the non-glandular region of the stomach and severe haemorrhage of the gastric mucosa and small and large intestines. Abnormalities noted at necropsy of the animal that was killed in extremis one day after dosing were haemorrhage of the gastric mucosa and gaseous stomach and small and large intestines. The effects noted during the study and at necropsy were considered to be secondary to local effects of the substance based on the known pH (<2). No abnormalities were noted at necropsy of animals that were killed at the end of the study.

In the acute dermal toxicity study for HEBMP-xNa, conducted according to OECD Test Guideline 402 and in compliance with GLP, the LD50 value was concluded to be greater than 2246 mg/kg bodyweight (equivalent to 2000 mg active salt/kg bodyweight, equivalent to 1580 mg/kg bw active acid, see Note 1 above) (Harlan Laboratories, 2012b). A group of ten animals (five males and five females) was given a single, 24-hour, semi‑occluded dermal application of the test item to intact skin at a dose level of 2246 mg/kg bodyweight (equivalent to 2000 mg active ingredient/kg bodyweight). Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy. There were no deaths. There were no signs of systemic toxicity. There were no signs of dermal irritation. Animals showed expected gains in bodyweight, except for one female which showed no gain in bodyweight during the first week but expected gain in bodyweight during the second week. No abnormalities were noted at necropsy.

Justification for classification or non-classification

Based on the available information, no classification is required for the sodium salt of HEBMP for acute oral, dermal or inhalation toxicity according to Regulation (EC) No 1272/2008.