[nitrilotris(methylene)]trisphosphonic acid, sodium salt

Endpoint summary

Description of key information

In the key acute oral limit study, conducted according to the now-deleted OECD Test Guideline 401 and in compliance with GLP, the LD50 for ATMP-xNa (CAS 20592-85-2; EC 243-900-0; aqueous solution containing 41% w/w active salt) was concluded to be ≥10 ml/kg (equivalent to 5740 mg active salt/kg bw and 4437 mg active acid/kg bw) in rats (SafePharm Laboratories, 1982a, Reliability 1).

In the key acute dermal toxicity study, conducted according to a protocol similar to OECD Test Guideline 402 and in compliance with GLP, the LD50 for ATMP-xNa (aqueous solution containing 41% w/w active salt) was concluded to be >10 ml/kg (equivalent to 5740 mg active salt/kg bw and 4437 mg active acid/kg bw) in rats (SafePharm Laboratories, 1982c, Reliability 1).

Key acute toxicity studies on ATMP-H are included in support of read-across of the reproductive toxicity study on DTPMP (5-7Na) only.

Key acute toxicity studies on DTPMP acid and sodium salts are included in support of read-across of the reproductive toxicity study on DTPMP (5-7Na) only.

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:

20.08.1982 to 03.09.1982

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Principles of method if other than guideline:

Method: SafePharm protocol (number GM 11/80/21A), broadly comparable with now-deleted OECD 401 at limit dose.

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: A. Tuck & Sons Limited, Battlesbridge, Essex.
- Age at study initiation: 4-6 weeks
- Weight at study initiation: Males: 92-110 g; Females: 103-115 g
- Fasting period before study: Yes, overnight
- Housing: Groups of five in polypropylene cages
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: Minimum five days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2 °C
- Humidity (%): 65-72 %
- Air changes (per hr): approximately 15 per hour
- Photoperiod (hrs dark / hrs light): 12 hours dark / 12 hours light


IN-LIFE DATES: From: 20.08.1982 to 03.09.1982

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg

Doses:

10 mL/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed 0.5, 1, 2, 3, 4 and 5 hours following dosing. On subsequent days the animals were observed at least once. Body weights were recorded on days 0, 7 and 14.
- Necropsy of survivors performed: Yes
- Other examinations performed: None

Statistics:

None required

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

>= 10 mL/kg bw

Based on:

test mat.

Remarks on result:

other: equivalent to 5740 mg active salt/kg bw and 4437 mg active acid/kg bw

Mortality:

Two females died within 3-4 hours of dosing. No other deaths occurred.

Clinical signs:

other: Pilo-erection, abnormal body carriage (hunched posture), lethargy and decreased respiratory rate. These signs were accompanied by ptosis in two males and one female and pallor of the extremities in one female. Recovery of survivors occurred by Day 2.

Gross pathology:

Congestion of the lungs in both animals that died and haemorrhage of the small intestine in one. There were no abnormal findings in surviving animals.

Other findings:

None

Interpretation of results:

GHS criteria not met

Conclusions:

In the acute oral limit study, conducted according to the now-deleted OECD Test Guideline 401 and in compliance with GLP (Reliability 1), the LD50 for ATMP-xNa (aqueous solution containing 41% w/w active salt) was concluded to be ≥10 mL/kg (equivalent to 5740 mg active salt/kg bw and 4437 mg active acid/kg bw) in rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

4 437 mg/kg bw

Acute toxicity: via inhalation route

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:

03.08.1982 to 17.08.1982

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

Method: SafePharm protocol (number GM 08/82/53A)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: A. Tuck & Sons Limited, Essex, UK.
- Age at study initiation: 6-8 weeks
- Weight at study initiation: Males: 219-242 g: Females: 210-232 g.
- Fasting period before study: None
- Housing: Five per polypropylene cage
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: Minimum five days.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 65-75 %
- Air changes (per hr): approximately 15 per hour
- Photoperiod (hrs dark / hrs light): 12 hours dark / 12 hours light


IN-LIFE DATES: From: 03.08.1982 to 17.08.1982

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: Dorsal, lateral and ventral.
- % coverage: No data
- Type of wrap if used: The trunks of the rats were encircled with a strip of elastic adhesive bandage, backed with aluminium foil. The bandage was tightened sufficiently to prevent the animal from wriggling free and wrapped round to form a double layer.


REMOVAL OF TEST SUBSTANCE
- Washing: Yes
- Time after start of exposure: 24 hours


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 10 mL/kg
- Constant volume or concentration used: Yes

Duration of exposure:

24 hours

Doses:

10 ml/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed 0.5, 1, 2, 3, 4 and 5 hours following dosing. On subsequent days the animals were observed at least once. Body weights were recorded on days 0, 7 and 14.
- Necropsy of survivors performed: Yes
- Other examinations performed: None

Statistics:

None required.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 10 mL/kg bw

Based on:

test mat.

Remarks on result:

other: equivalent to >5740 mg active salt/kg bw and >4437 mg active acid/kg bw

Mortality:

No animals died.

Clinical signs:

other: Lethargy and increased red coloured lacrimation in one rat on the day of dosing.

Gross pathology:

No abnormal findings.

Other findings:

None

Interpretation of results:

GHS criteria not met

Conclusions:

In the acute dermal toxicity study, conducted according to a protocol similar to OECD Test Guideline 402 and in compliance with GLP (Reliability 1), the LD50 for ATMP-xNa (aqueous solution containing 41% w/w active salt) was concluded to be >10 mL/kg (equivalent to 5740 mg active salt/kg bw and 4437 mg active acid/kg bw) in rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

4 437 mg/kg bw

Additional information

The key studies were conducted using aqueous solutions of ATMP-xNa and LD50 values are reported on the basis of test material as well as the equivalent doses expressed as active acid and active salt.

The result has been corrected to the equivalent dose of active acid using a molecular weight conversion:

MW ATMP-H (299.05 g/mol) / MW ATMP-xNa (presumed to be ATMP-4Na) (386.974 g/mol) = 0.773.

Therefore, 5740 mg active salt/kg bw*0.773 = 4437 mg active acid/kg bw/day.

For studies where ATMP-5Na was tested the result has been corrected to the equivalent dose of active acid using a molecular weight conversions:

MW ATMP-H (299.05 g/mol) / MW ATMP-5Na (408.955 g/mol) = 0.731.

In the key acute oral limit study, conducted according to the now-deleted OECD Test Guideline 401 and in compliance with GLP, 5 male and 5 female rats were subject to a single oral gavage administration of 10 ml/kg ATMP-xNa (aqueous solution containing 41% w/w active salt) (SafePharm Laboratories, 1982a, Reliability 1). The animals were observed for 14 days following dosing. Body weights were recorded on days 0, 7 and 14. Necropsy was performed at the end of the study period. Two females died within 3-4 hours of dosing. No other deaths occurred. Pilo-erection, abnormal body carriage (hunched posture), lethargy and decreased respiratory rate were seen in the animals. These signs were accompanied by ptosis in two males and one female and pallor of the extremities in one female. Recovery of survivors occurred by Day 2. At necropsy, congestion of the lungs in both animals that died and haemorrhage of the small intestine in one animal were observed. There were no abnormal findings in surviving animals. The LD50 for ATMP-xNa was concluded to be ≥10 ml/kg (equivalent to 5740 mg active salt/kg bw and 4437 mg active acid/kg bw) in rats.

In a supporting acute oral toxicity study conducted according to a protocol similar to the now-deleted OECD Test Guideline 401 and in compliance with GLP, the LD50 for ATMP-xNa was approximately 15 ml/kg (calculated to be equivalent to 6654 mg active acid/kg bw) in rats (SafePharm Laboratories, 1982b, Reliability 1).

In another supporting acute oral toxicity study, conducted prior to OECD test guidelines and GLP, the LD50 value for ATMP-xNa (active acid content not specified) was concluded to be 7130 mg/kg (Younger Laboratories, 1971, Reliability 2).  

In a third supporting acute oral study toxicity study, conducted prior to OECD test guidelines and GLP but according to a protocol similar to the now-deleted OECD Test Guideline 401, aqueous solution of ATMP-5Na (40 % w/w active salt content) was administered to Sprague-Dawley rats (two or three per sex depending on dose; five in total) as aqueous solutions at doses of 12600, 15800, 20000 and 25100 mg/kg bw (equivalent to 5040, 6320, 8000 and 10040 mg active salt/kg respectively). Observations were made for clinical signs and the viscera of the animals that died were examined macroscopically. There were 0, 1, 4 and 5 deaths at 12600, 15800, 20000, 25100 mg/kg bw, respectively. Survival time was several hours to three days with most deaths occurring overnight. Toxic symptoms included severe diarrhoea, loss of appetite, lethargy, and increasing weakness. At macroscopic examination, there were renal, liver and pulmonary hyperaemia. the LD50 for ATMP-xNa was concluded to be 17800 mg/kg bw in rats (presumed equivalent to 7120 mg active salt/kg bw and 5204 mg active acid/kg bw) (Younger Laboratories, 1962, Reliability 2).

In the key acute dermal toxicity study, conducted according to a protocol similar to OECD Test Guideline 402 and in compliance with GLP, 5 male and 5 female rats were subject to a single 24-hour dermal occlusive application of 10 ml/kg ATMP-xNa (aqueous solution containing 41% w/w active salt) (SafePharm Laboratories, 1982c, Reliability 1). The animals were observed for 14 days following dosing. Body weights were recorded on days 0, 7 and 14. Necropsy was performed at the end of the 14-day observation period. No animals died during the 14-day study period. Lethargy and increased red coloured lacrimation were seen in one rat on the day of dosing. No abnormal findings were observed at necropsy. The LD50 for ATMP-xNa was concluded to be >10 ml/kg (equivalent to 5740 mg active salt/kg bw and 4437 mg active acid/kg bw) in rats.

In the supporting acute dermal toxicity study, conducted prior to OECD test guideline and GLP, the LD50 value for ATMP-xNa (active acid content not specified) was concluded to be greater than 7940 mg/kg bw (Younger Laboratories, 1971, Reliability 2).

In another acute dermal toxicity study conducted prior to the adoption of OECD Test Guidelines and GLP, aqueous solution of ATMP-5Na (40 % w/w active salt) was applied to the clipped, intact skin of albino rabbits (one female per dose) under occlusive dressing for 24 hours. The doses used were 1580, 2510, 3980, 6310, 10000 and 15800 mg/kg bw (equivalent to 632, 1004, 1592, 2524, 4000 and 6320 mg active salt/kg, respectively). Animals were then observed for clinical signs of toxicity and mortality (duration not specified). No deaths and no clinical signs were observed. The LD50 was therefore concluded to be greater than the highest dose tested, 15800 mg/kg bw (equivalent to 6320 mg active salt/kg and 4620 mg active acid/kg bw) (Younger Laboratories, 1962, Reliability 2).

Discussion of classification conclusion 

CLASSIFICATION: The classification decision is based on data for the substance itself ATMP-xNa. In the absence of detailed information of the impurities in the test material used in the key data, these are considered separately for completeness. The known impurity ammonium chloride is present at concentrations above 1% in the registered substance and has a classification listed in Annex VI of Regulation (EC) No 1272/2008. (Hydroxymethyl)phosphonate monosodium salt, [No CAS or EC Number], disodium phosphonate [CAS 13708-85-5, EC No: 237-249-1], disodium hydrogen phosphate [CAS 7558-79-4,EC 231-448-7], sodium chloride [CAS 7647-14-5, EC No.: 231-598-3] are also present at above 1% concentration but are not listed in Annex VI of Regulation (EC) No 1272/2008. Therefore, they have not been considered in this assessment.

 

REGISTERED SUBSTANCE: Not on the market as a solid product. The registered substance is typically manufactured as aqueous solutions containing about 50% w/w solids hence about 50% w/w water. However, in accordance with the definition in REACH of a substance, water (as a solvent that may be separated) is not considered to be a constituent. The SIP concentration ranges are based on the substance as registered (without water); therefore, concentration ranges in the substance as sold are approximately half of the values quoted here.

 

IMPURITIES: Only one impurity has a classification for acute toxicity according to Annex VI of CLP Regulation (EC) No 1272/2008. This impurity does not contribute to the acute toxicity of the substance and does not affect the classification conclusion for ATMP-xNa based on the additivity approach. Overall, the impurities present in ATMP-xNa do not affect the classification conclusion for the substance.

 

Ammonium chloride [CAS 12125-02-9, EC No. 235-186-4] is present at the concentration range of 0-3 % w/w (equivalent to 0-1.5% of a 50% aqueous solution). It is classified for acute oral toxicity Category 4 according to Annex VI of CLP Regulation (EC) No 1272/2008.

Justification for classification or non-classification

Based on the available data, no classification for acute toxicity is required for acute toxicity for ATMP-xNa according to Regulation (EC) No 1272/2008.