Reaction mass of cerium phosphate and lanthanum phosphate and terbium phosphate

Endpoint summary

Description of key information

The No Observed Adverse Effect Level (NOAEL) of the test item for systemic toxicity is 1000 mg/kg bw/day (highest dose level tested) for both male and female rats (oral gavage, up to 39 days in males and up to 55 days in females).

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 26-NOV-2012 to 28-MAY-2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: the study was performed according to OECD guideline and GLP.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Italia, Calco, Italy
- Age at study initiation: on the first day of treatment, the males were approximately 10 weeks old and the females were approximately 9 weeks old
- Weight at study initiation: on the first day of treatment, the males had a mean body weight of 387 g (range: 328 g to 436 g) and the females had a mean body weight of 222 g (range: 192 g to 249 g)
- Fasting period before study: no
- Housing: the females were individually housed, except during mating and lactation, in polycarbonate cages (Tecniplast 2154, 940 cm²) with stainless steel lids and containing autoclaved sawdust (SICSA, Alfortville, France). The males were individually housed, except during mating, in wire-mesh cages (43.0 x 21.5 x 18.0 cm). A metal tray containing autoclaved sawdust (SICSA, Alfortville, France) was placed under each cage. Toward the end of gestation and during lactation, autoclaved wood shavings (SICSA, Alfortville, France) were provided to females and their litter as nesting material.
- Diet: free access to SSNIFF R/M-H pelleted maintenance diet, batch Nos. 2537604 and 8788036 (SSNIFF Spezialdiäten GmbH, Soest, Germany), distributed weekly
- Water: free access to bottles containing tap water (filtered with a 0.22 µm filter)
- Acclimation period: the animals were acclimated to the study conditions for a period of 7 days before the beginning of the treatment period

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 2°C
- Humidity: 50 ± 20%,
- Air changes: about 12 cycles/hour of filtered, non-recycled air
- Photoperiod: 12 hrs dark / 12 hrs light

IN-LIFE DATES: from 27 November 2012 (day of arrival of the animals) to 27 January 2013 (necropsy of last females)

Route of administration:

oral: gavage

Vehicle:

other: 0.5% (w/v) methylcellulose aqueous solution

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was administered as a suspension in the vehicle. The test item was ground to a fine powder, using a mortar and pestle, and then mixed with the required quantity of vehicle.
The test item dose formulations were prepared on a daily basis and delivered to the study room at room temperature.

VEHICLE
- Justification for use and choice of vehicle (if other than water): a stable suspension was obtained in this aqueous vehicle
- Concentration in vehicle: 20, 60 and 200 mg/mL, respectively for the dose levels of 100, 300 and 1000 mg/kg bw/day
- Amount of vehicle: a constant dosage-volume of 5 mL/kg/day was used
- Lot/batch no. (if required): the vehicle was prepared using: drinking water treated by reverse osmosis using ELIX 5 (Millipore SA) and methylcellulose (batch No. 079K0054)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Concentrations of the test item in the dose formulations were quantified by ICP-MS, a validated analytical method. It consisted of sampling accurate volume of dose formulations, mineralized the sample using acid and micro wave, and diluting it appropriately with diluent to reach the nominal concentration of measurement.
Before the start of treatment, the suitability of the dose formulation process was confirmed. The homogeneity was determined on a range of dose formulations prepared at levels which covered the lowest and highest concentrations proposed for use in this study.
The concentration of the test item in samples of each control and test item dose formulation used in weeks 1, 3 and 6 was determined.

Duration of treatment / exposure:

- in the males: 2 weeks before mating, during the mating period, and until sacrifice (at least 5 weeks in total)
- in the females: 2 weeks before mating, during the mating period, during gestation, during lactation until day 5 p.p. inclusive

Frequency of treatment:

Once a day, at approximately the same time.

Remarks:

Doses / Concentrations:
0, 100, 300 and 1000 mg/kg bw/day
Basis:
other: nominal

No. of animals per sex per dose:

10 males and 10 females per dose-level group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: following the results of a previous 2-week toxicity study (CiToxLAB France/Study No. 39259 TSR) in which no obvious test item-related effects occurred during the study up to higher dose tested (1000 mg/kd bw/day).
- Post-exposure recovery period in satellite groups: not applicable

Positive control:

not applicable (not required)

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: each animal was checked for mortality and morbidity once a day before the treatment period and at least twice a day during the treatment period. Each animal was observed once a day, at approximately the same time, for the recording of clinical signs.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once before the beginning of the treatment period and then once a week until the end of the study.
Observations included (but were not limited to) changes in the skin, fur, eyes, mucous membranes, occurrence of secretions and excretions and autonomic activity (e.g. lachrymation, piloerection, pupil size, unusual respiratory pattern). Changes in gait, posture and response to handling as well as the presence of clonic or tonic movements, stereotypes (e.g. excessive grooming, repetitive circling) or bizarre behavior (e.g. self-mutilation, walking backwards) were also recorded.

BODY WEIGHT: Yes
- Time schedule for examinations: the body weight of each male was recorded on the first day of treatment (day 1), then once a week until sacrifice. The body weight of each female was recorded on the first day of treatment (day 1), then once a week until mated, on days 0, 7, 14 and 20 post-coitum (p.c.) and days 1 and 5 p.p..

FOOD CONSUMPTION:
The quantity of food consumed by each male was measured once a week, over a 7-day period, from the first day of treatment until the start of the mating period. The quantity of food consumed by each female was measured once a week, over a 7-day period, from the first day of treatment until the start of the mating period, during gestation for the intervals days 0-7, 7-14 and 14-20 p.c. and during lactation for the interval days 1-5 p.p..
During the mating period, food consumption was not measured for males or females.

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: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: on day 6 p.p. from each group on the day of sacrifice
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes (deprived of food for an overnight period of at least 14 hours)
- How many animals: the first five surviving males and the first five females to be sacrificed on day 6 p.p. from each group on the day of sacrifice
- Parameters checked: Erythrocytes (RBC), Mean cell volume (MCV), Packed cell volume (PCV), Hemoglobin (HB), Mean cell haemoglobin concentration (MCH), Mean cell hemoglobin (MCH), Thrombocytes (PLT), Leucocytes (WBC), Differential white cell count with cell morphology (neutrophils (N), eosinophils (E), basophils (B), lymphocytes and large unstained cells (L+LUC), monocytes (M)), Reticulocytes (RTC), Prothrombin time (PT), Fibrinogen (FIB), Activated partial thromboplastin time (APTT)

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: on day 6 p.p. from each group on the day of sacrifice
- Animals fasted: Yes (deprived of food for an overnight period of at least 14 hours)
- How many animals: from the first five surviving males and the first five females to be sacrificed on day 6 p.p. from each group on the day of sacrifice
- Parameters checked: Sodium (Na+), Potassium (K+), Chloride (Cl-), Calcium (Ca++), Inorganic phosphorus (I.PHOS), Glucose (GLUC), Urea (UREA), Creatinine (CREAT), Total bilirubin (TOT.BIL.), Total cholesterol (CHOL), Triglycerides (TRIG), Alkaline phosphatase (ALP), Alanine aminotransferase (ALAT), Aspartate aminotransferase (ASAT), Total proteins (PROT), Albumin (ALB), Albumin/globulin ratio (A/G), Bile acids (BIL.AC)

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: once at the end of the treatment period
- Dose groups that were examined: the first five surviving males and the first five females to be sacrificed on day 6 p.p. from each group were evaluated with a functional observation battery
- Battery of functions tested:
>> Detailed clinical examination - The following parameters were assessed and graded:
* in the cage: "touch escape" or ease of removal from the cage,
* in the hand: fur appearance, salivation, lachrymation, piloerection, exophthalmos, reactivity to handling, pupil size (presence of myosis or mydriasis),
* in the standard arena (2-minute recording): grooming, palpebral closure, defecation, urination, tremors, twitches, tonic and clonic convulsions, gait, arousal (hypo- and hyper-activity), posture, stereotypy, behavior, breathing, ataxia and hypotonia.
>> Reactivity to manipulation and different stimuli - The following measurements, reflexes and responses were recorded:
* touch response, forelimb grip strength, pupillary reflex, visual stimulus response, auditory startle reflex, tail pinch response, righting reflex, landing foot splay, at the end of observation: rectal temperature.
>> Motor activity was measured once by automated infra-red sensor equipment over a 60 minute period.

Sacrifice and pathology:

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

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

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:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
One male given 1000 mg/kg/day was found dead on day 22. The death was considered to be related to the gavage procedure and thus not test item-related. No other animals died during the study.
There were no test item-related clinical signs in males and females from all groups.

BODY WEIGHT AND WEIGHT GAIN (see table 1)
There were no statistically significant effects of treatment with the test item on mean body weight and mean body weight gain in males and females from all groups.

FOOD CONSUMPTION
There were no effects of treatment with the test item on mean food consumption in males and females from all groups.

HAEMATOLOGY
There were no effects of the treatment with the test item on mean hematology data in males and females from all groups.

CLINICAL CHEMISTRY
There were no effects of the treatment with the test item on mean blood biochemistry data in males and females from all groups.

NEUROBEHAVIOUR
There were no toxicologically relevant effects on FOB and motor activity in treated groups as compared to control groups.

ORGAN WEIGHTS
There were no test item-related organ weight differences.
When compared with controls, there were not statistically significant increases in mean absolute and relative-to-body spleen weights in test item-treated males. In the absence of microscopic correlates, these poorly dose-related differences were considered not to be related to test item treatment.
The other mean organ weight differences were considered not to be test item treatment-related in the absence of dose-relationships and microscopic correlates and because of the low magnitude in these differences.

GROSS PATHOLOGY
There were no macroscopic test item-related findings in males and females.
The few macroscopic findings were considered as not test item effects because they were consistent with spontaneously occurring findings described in the literature or their appearance was similar to findings found in controls.

HISTOPATHOLOGY: NON-NEOPLASTIC
There were no microscopic test item-related findings in any males or females as compared to control animals.
The microscopic findings were considered not as related to the test item because they were consistent with spontaneously occurring findings described in the literature, the findings were distributed randomly among groups, or their appearance was similar to findings found in controls.

HISTORICAL CONTROL DATA (if applicable)

OTHER FINDINGS

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No relevant effects up to highest dose tested

Critical effects observed:

not specified

Table 1: Mean body weights and mean body weight changes (g)

Sex	Male				Female
Dose level (mg/kg/day)	0	100	300	1000		0	100	300	1000
Pre-mating
Day 1	383	387 (+1)	390 (+2)	389 (+2)		222	222 (0)	223 (0)	222 (0)
Day 15	437	446 (+2)	454 (+4)	456 (+4)		242	244 (+1)	246 (+2)	246 (+2)
Day 36	464	493 (+6)	494 (+6)	499 (+8)		/	/	/	/
Days 1 - 15	+54	+59	+64	+67		+20	+22	+24	+24
Days 15 - 36	+27	+47	+40	+38		/	/	/	/
Days 1 - 36	+81	+106 (+31)	+104 (+28)	+107 (+32)		/	/	/	/
Gestation
Day 0p.c.	/	/	/	/		252	250	248	256
Day 20p.c.	/	/	/	/		421	415	403	416
Days 0 - 20p.c.	/	/	/	/		+169	+165	+155	+160
Lactation
Day 1p.p.	/	/	/	/		316	313	305	321
Day 5p.p.	/	/	/	/		333	321	319	333
Days 1 - 5p.p.	/	/	/	/		+17	+7	+14	+12

Conclusions:

The No Observed Adverse Effect Level (NOAEL) of the test item is 1000 mg/kg/day for both male and female rats.

Executive summary:

In a combined repeated dose toxicity study with the reproduction/developmental toxicity screening test scored as validity 1 according to Klimisch criteria (OECD guideline 422, GLP, CitoxLab report No.39260 RSR, 2013) Reaction mass of Lanthanum Phosphate and Cerium Phosphate and Terbium Phosphate was administered to 10 Sprague-Dawley rats/sex/dose by gavage,following daily oral administration (gavage) from before mating, through mating and, for females, through gestation until day 5 post-partum (p.p.).

The test item was administered as a suspension in the vehicle,0.5% methylcellulose aqueous solution, at dose-levels of 0 (vehicle), 100, 300 or 1000 mg/kg/day.

The concentration of the dose formulation was checked in study weeks 1, 3 and 6.

 

The animals were checked at least twice daily during the dosing period for mortality and morbidity and at least once daily for clinical signs. Body weight and food consumption were recorded once a week. Detailed clinical observation was performed once a week, and a functional observation battery was performed at the end of the treatment period.

Hematological investigations and blood chemistry analyses were performed in the first five surviving males and the first five females to be sacrificed on day 6p.p.from each group on the day of sacrifice. Final body weights and selected organs weights (adrenals, brain, epididymes, heart, kidneys, liver, spleen, testes and thymus) were recorded and a complete macroscopic post-mortem examination was performed, with particular attention paid to the reproductive organs. A microscopic examination was performed on selected organs from the first five males and females to deliver in the control and high-dose groups, on the found dead male, and on all macroscopic lesions.

 

No treatment-related death or clinical signs occurred during the study. There were no effects on body weight, body weight gain or food consumption at any dose level. The Functional Observational Battery assessment, haematology and blood chemistry parameters revealed no treatment-related effects. Macroscopic and microscopic examinations at necropsy did not reveal any treatment-related findings and there were no treatment-related changes in organ weights.

 

 The No Observed Adverse Effect Level (NOAEL) for systemic toxicity was therefore considered to be 1000 mg/kg bw/d for both male and females rats.

No classification for repeat-dose toxicity is warranted based on the absence of relevant effects in this study, according to the criteria of Annex VI Directive 67/548/EEC or UN/EU GHS.

 

This study is classified as acceptable. It satisfies the OECD 422 guideline requirements on repeated dose toxicity testing.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Key study quoted as reliability 1 according to Klimisch criteria (performed according to OECD guidelines and in accordance with GLP)

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

A combined repeated dose toxicity study with the reproduction/developmental toxicity screening test is available on Reaction Mass of Lanthanum Phosphate and Cerium Phosphate and Terbium Phosphate. This study was performed according to OECD guideline n° 422 and in accordance with GLP. This study was thus scored as validity 1 according to Klimisch criteria and then was selected as the Key study.

In a combined repeated dose toxicity study with the reproduction/developmental toxicity screening test scored as validity 1 according to Klimisch criteria (OECD guideline 422, GLP, Citox report No.39260 RSR, 2013) Reaction mass of Lanthanum Phosphate and Cerium Phosphate and Terbium Phosphate was administered to 10 Sprague-Dawley rats/sex/dose by gavage,following daily oral administration (gavage) from before mating, through mating and, for females, through gestation until day 5 post-partum (p.p.).

The test item was administered as a suspension in the vehicle,0.5% methylcellulose aqueous solution, at dose-levels of 0 (vehicle), 100, 300 or 1000 mg/kg/day.

The concentration of the dose formulation was checked in study weeks 1, 3 and 6.

 

The animals were checked at least twice daily during the dosing period for mortality and morbidity and at least once daily for clinical signs. Body weight and food consumption were recordedonce a week. Detailed clinical observation was performed once a week, and a functional observation battery was performed at the end of the treatment period.

Hematological investigations and blood chemistry analyses were performed inthe first five surviving males and the first five females tobe sacrificed on day 6p.p.from each group on the day of sacrifice. Final body weights and selected organs weights (adrenals, brain, epididymes, heart, kidneys, liver, spleen, testes and thymus) were recorded and a complete macroscopicpost-mortemexamination was performed, with particular attention paid to the reproductive organs. A microscopic examination was performed on selected organs from the first five males and females to deliver in the control and high-dose groups, on the found dead male, and on all macroscopic lesions.

 

No treatment-related death or clinical signs occurred during the study. There were no effects on body weight, body weight gain or food consumption at any dose level. The Functional Observational Battery assessment, haematology and blood chemistry parameters revealed no treatment-related effects. Macroscopic and microscopic examinations at necropsy did not reveal any treatment-related findings and there were no treatment-related changes in organ weights.

 

 The No Observed Adverse Effect Level (NOAEL) was therefore considered to be 1000 mg/kg bw/d for both male and females rats.

No classification for repeat-dose toxicity is warranted based on the absence of relevant effects in this study, according to the criteria of Annex VI Directive 67/548/EEC or UN/EU GHS.

The realisation of a suchronic toxicity study appears not justified based on:

- The lack of adverse effects observed in the experimental toxicology data available (acute/repeated exposure by oral route, acute exposure by dermal route or by inhalation, skin and eye irritation, genotoxicity and screening for reproductive/developmental toxicity) and the really low water solubility confirm that the substance has a low absorption rate or is devoid of toxicity.

-The lack of adverse effects in all physico-chemical, toxicological and environmental studies allowing to conclude that the substance can be considered as unreactive.

- The low expected exposure at the production and use of the substance.

Therefore, and in accordance with REACH legislation (Annex IX, section 8.6.2, column 2), and for animal welfare reason, It is concluded that further testing is scientifically unjustified.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
This study is the longest one (up to 39 days for males and up to 55 days for females) and the only one by repeated exposure (according to OECD 422 guideline).

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:
No data are available by inhalation (repeated exposure). However a data by oral route (OECD guideline 422) is available and it is a route of administration which is recommended by the Regulatory Authorities for this type of study. As only one route of exposure is required, no additional test is necessary. Furthermore, according to the process of production and uses at industrial sites, the risk of inhalation exposure is very low (packaging and final use under controlled conditions)

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:
No data are available by inhalation (repeated exposure). However a data by oral route (OECD guideline 422) is available and it is a route of administration which is recommended by the Regulatory Authorities for this type of study. As only one route of exposure is required, no additional test is necessary. Furthermore, according to the process of production and uses at industrial sites, the risk of inhalation exposure is very low (packaging and final use under controlled conditions).

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:
No data are available by dermal route (repeated exposure). However a data by oral route (OECD guideline 422) is available and it is a route of administration which is recommended by the Regulatory Authorities for this type of study. As only one route of exposure is required, no additional test is necessary. Furthermore the very low water solubility of the substance indicates that skin absorption will be negligible (probably lower than absorption by oral route), and thus a test by dermal route is not appropriate.

Justification for selection of repeated dose toxicity dermal - local effects endpoint:
No data are available by dermal route (repeated exposure). However a data by oral route (OECD guideline 422) is available and it is a route of administration which is recommended by the Regulatory Authorities for this type of study. As only one route of exposure is required, no additional test is necessary.
Furthermore no systemic and local effects were observed in an acute dermal toxicity study up to 2000 mg/kg bw. no skin irritation was observed in an in vivo skin irritation study as well as no irritation of gastro intestinal tract was observed after repeated (up to 55 days) exposure in an OECD 422 study. These data support the fact that no additional information is necessary as no effect is expected.

Justification for classification or non-classification

Based on the classification criteria of Annex VI Directive 67/548/EEC or UN/EU GHS, and given the absence of signs of toxicity up to the highest dose of 1000 mg/kg bw/d administered in rats by gavage in a test performed according to OECD 422, no classification for repeat-dose toxicity is warranted according to the criteria of Annex VI Directive 67/548/EEC or UN/EU GHS.