[nitrilotris(methylene)]trisphosphonic acid, sodium salt

Repeated dose toxicity: oral

Administrative data

Endpoint:

chronic toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

04.12.1975 to 03.12.1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to a test protocol that is comparable to the appropriate OECD test guideline. It was not compliant with GLP. The study is read across from ATMP (CAS 6419-19-8).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Version / remarks:

Test conducted prior to adoption of OECD test guideline.

Deviations:

yes

Remarks:

No satellite group, and reduced haematology, clinical chemistry and urinalysis parameters examined.

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Nitrilotrimethylenetris(phosphonic acid)

EC Number:

229-146-5

EC Name:

Nitrilotrimethylenetris(phosphonic acid)

Cas Number:

6419-19-8

Molecular formula:

C3H12NO9P3

IUPAC Name:

[nitrilotris(methylene)]tris(phosphonic acid)

Details on test material:

- Name of test material (as cited in study report): CP42902
- Substance type: Phosphonic acid
- Physical state: white powder
- Analytical purity: No data
- Impurities (identity and concentrations): No data
- Purity test date: No data
- Lot/batch No.: 222638 and 1059624
- Expiration date of the lot/batch: No data
- Stability under test conditions: No data
- Storage condition of test material: Room temperature in locked storage cabinet.

Test animals

Species:

rat

Strain:

Long-Evans

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Blue Spruce Farms, Altamont, New York.
- Age at study initiation: 6-7 weeks
- Weight at study initiation: mean 212.6g (males) and 149.0g (females)
- Fasting period before study:
- Housing: Individually in elevated stainless steel cages.
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: 18 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): Monitored but no data
- Humidity (%): No data
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 17.11.1976 To: 30.11.1978

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): Weekly
- Mixing appropriate amounts with (Type of food): Standard laboratory diet.
- Storage temperature of food: No data

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

50 g samples of the control feed and each dietary level were taken weekly and shipped to the sponsor. No further details.

Duration of treatment / exposure:

24 months

Frequency of treatment:

continuous

Doses / concentrations

Remarks:

Doses / Concentrations:
50, 150, 500 mg/kg
Basis:
actual ingested

No. of animals per sex per dose:

70

Control animals:

yes, plain diet

Details on study design:

Post-exposure period: None
Satellite group: None

Positive control:

None

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily for the first two months and then twice daily until termination.
- Cage side observations: mortality, gross signs of toxicology or pharmacologic effects.

Interim necropsies were performed on 10/sex/group after 6 and 12 months, then on all surviving animals after 24 months. Animals that died spontaneously or were killed in a moribund condition were also examined.
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Weekly, for signs of local or systemic toxicity, pharmacologic effects and palpation for tissue masses.


BODY WEIGHT: Yes
- Time schedule for examinations: Twice pre-test, weekly through to week 13 of treatment, every two weeks for weeks 14 to 26, then monthly, and finally at termination.


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): pretest, weekly up to week 13, every other week for weeks 14 to 26 and then monthly.
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes


FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No


OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: Pretest, then 3, 6, 12, 18 and 24 months.
- Dose groups that were examined: No data


HAEMATOLOGY: Yes
- Time schedule for collection of blood: At 3, 6, 12, 18 and 24 months.
- Anaesthetic used for blood collection: Yes, ether.
- Animals fasted: Yes, overnight.
- How many animals: 6/sex from control and high dose groups.
- Parameters checked in table [No.1] were examined.


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At 3, 6, 12, 18 and 24 months.
- Animals fasted: Yes, overnight
- How many animals: 6/sex from control and high dose groups.
- Parameters checked in table [No.1] were examined.


URINALYSIS: Yes
- Time schedule for collection of urine: 6, 12 and 24 months all groups 6/sex; 3 months: 6/group (males) and 6/control and high dose groups (females); 18 months: 6/sex for control and high dose groups.
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data
- Parameters checked in table [No.1] were examined.


NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (see table 2)
HISTOPATHOLOGY: Yes (see table 2)

Other examinations:

None

Statistics:

Body weight, food consumption, haematology and clinical chemistry parameters, organ weights, organ/body weight ratios and organ/brain weight ratios were analysed. Mean values of all dose groups were compared to control at each time interval. Haematology and clinical chemistry: intergroup comparison v control by F-test and Student's t-test (using t-test modification if variances differed). Body weight, food consumption, organ weights and ratios by Dunnett's t-test.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY: No treatment effects. Males (per 70) 18 (controls), 22 (low), 21 (medium) and 18 (high) died. Females (per 70), 23 (controls), 24 (low), 19 (medium) and 19 (high) died during study. No treatment-related clinical signs of toxicity.


BODY WEIGHT AND WEIGHT GAIN: High dose males slightly reduced (5-10%) from week 16-87, resulting in slight reduction in terminal body weight (controls - 522.2+/-61.3; low dose - 520.5+/-72.5; medium dose - 508.2 +/-75.6 and high - 510.1 +/-52.2 g) which was not statistically significant. Other groups comparable to controls.


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Mean food consumption for high dose males was greater than control group by 3-17%.  Other groups comparable to controls.


OPHTHALMOSCOPIC EXAMINATION: No treatment-related effects.


HAEMATOLOGY: No statistically significant differences in any of the parameters measured for any group.


CLINICAL CHEMISTRY: No statistically significant differences for any of the parameters measured at any time point for any group. 


URINALYSIS: No treatment-related effects.


ORGAN WEIGHTS (statistically significant changes only): Changes were observed in the highest dose group only.  No other groups were affected at any sample time. Males: 15% reduction in absolute spleen weight at 24 months; 14% reduction in absolute and relative liver weight at 24 months; 23% increase in relative testes weight at 12 months, 14% increase in relative kidney weight at 12 months, 14% decrease in absolute liver weight at 6 months. Females: 13% decrease in absolute kidney weight at 12 months; 8% decrease in relative liver weight at 6 months.These changes were no considered adverse.


GROSS PATHOLOGY: No treatment-related findings.


HISTOPATHOLOGY: NON-NEOPLASTIC: No treatment-related findings. The following were found equally in control and treated groups: cortical vacuolation and hematocysts in adrenal glands, pituitary tumours, pulmonary lesions (varying degrees of severity of chronic murine pneumonia complex, lymphoid proliferations, abscesses and pneumonitis), chronic pleuritis, often with adhesions to the heart, varying degrees of chronic nephritis commonly observed, hepatic lesions in many; also bile duct hyperplasia, testicular atrophy, mammary galactocele in both sexes, possibly related to prolactin secreting pituitary tumours.


HISTOPATHOLOGY: NEOPLASTIC (if applicable): No treatment-related findings (see Section 7.7).

Effect levels

Dose descriptor:

NOAEL

Effect level:

> 500 other: mg/kg

Sex:

male/female

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

In a well conducted, pre-GLP chronic toxicity and carcinogenicity study (reliability score 2), CP42902 (nitrilotrimethylenetris(phosphonic acid), did not cause any toxological effects of concern, and the NOAEL was greater than the highest dose tested 500 mg/kg bw/day. The result is read across from ATMP (CAS 6419-19-8).

Executive summary:

In a well conducted, pre-GLP chronic toxicity and carcinogenicity study (reliability score 2), CP42902 (ATMP) was administered via the diet to Long-Evans rats (70/sex/dose) at dose levels of 50, 150 or 500 mg/kg bw/day (groups II to IV) for 24 months. Control animals received untreated diet (Group I). Animals were regularly observed for clinical signs of toxicity, and body weights and food consumption were measured. Interim necropsies were performed at six and 12 months (10/sex/dose). Ophthalmoscopic examination, haematology, clinical chemistry and urinalysis were performed at 3, 6, 12, 18 and 24 months. Histopathological examinations were conducted on all animals that died or had to be killed in extremis, and also for 10 animals/sex for groups I and IV at six months and for all survivors in Groups I and IV at 24 months. Mean body weight values for the high dose males were slightly reduced (5-10%) from week 16 to 87. Mean food consumption values for the high dose males were generally comparable to or greater than those of the control group (3-17%) during most weeks. In the high dose group there were statistically significant changes to organ weights (adrenal glands, spleen, liver, pituitary). There were no treatment-related gross lesions or histopathological findings in any of the groups. The NOAEL for carcinogenicity and general toxicity was greater than the highest dose tested (500 mg/kg bw/day).