Calcium phosphinate

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

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

Adequacy of study:

key study

Study period:

2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study is conducted on a read across test material. The complete read across justification is attached in section 13. The reliability of the original study is 1.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Similar Substance 1

IUPAC Name:

Similar Substance 1

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: BIOAGRI's animal house
- Weight at study initiation: Average of 244.8 g (males) 169.0 g (females)
- Age at study initiation: 7-8 weeks
- Housing: Polypropylene cages 3-2 rats/sex/group
- Diet and water ad libitum, regularly assayed for centesimal composition as well as for chemical and microbiological contaminant
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±3 °C
- Humidity (%): 30-70 %
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 hrs

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: Rodent diet

Details on oral exposure:

DIET PREPARATION WITH Test Item
- Nuvilab CR-1 diet type for rodents supplied by Nuvital nutrientes rtda (Brazil)
- Rate of preparation of diet (frequency): 10 days
- Mixing appropriate amounts with autoclaved feed through premix
- Storage temperature of food: room temperature

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The concentration and homogeneity of the test substance in the diet were determined by HPLC.
Difference between nominal and measured concentration was always within ±20 % acceptability

Duration of treatment / exposure:

Test duration: 28 days (4 weeks)
Satellite group was taken 2 more weeks without treatment.

Frequency of treatment:

Dosing regime: 7 days/week

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 ppm

Remarks:

0 mg/kg bw/day

Doses / concentrations 2

Dose / conc.:

100 ppm

Remarks:

equal to 9.9 mg/kg bw/day for males and 11.4 mg/kg bw/day for females

Doses / concentrations 3

Dose / conc.:

300 ppm

Remarks:

equal to 27.8 mg/kg bw/day for males and 35.2 mg/kg bw/day for females

Doses / concentrations 4

Dose / conc.:

1 000 ppm

Remarks:

equal to 86.9 mg/kg bw/day for males and 121.2 mg/kg bw/day for females

No. of animals per sex per dose:

Male: 5 animals at 0 ppm (0 mg/kg bw/day)
Male: 5 animals at 100 ppm (9.9 mg/kg bw/day)
Male: 5 animals at 300 ppm (27.8 mg/kg bw/day)
Male: 5 animals at 1000 ppm (86.9 mg/kg bw/day)
Female: 5 animals at 0 ppm (0 mg/kg bw/day)
Female: 5 animals at 100 ppm (11.4 mg/kg bw/day)
Female: 5 animals at 300 ppm (35.2 mg/kg bw/day)
Female: 5 animals at 1000 ppm (121.2 mg/kg bw/day)
Additional satellite groups (5 animals/sex/group) of the control and highest dose (1000 ppm) were maintained for more 2 weeks after the end of the treatment period for observation of reversibility or persistence of toxic effects

Control animals:

yes

Details on study design:

- Post-exposure recovery period in satellite groups: 2 weeks

Positive control:

None

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice a day for mortality and morbidity (once a day on Saturday and public holidays, no observation on Sunday)

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Weekly

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly

FOOD CONSUMPTION AND COMPOUND INTAKE:
- 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

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

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the dosing regime
- Anaesthetic used for blood collection: Yes with CO2
- Animals fasted: Yes, overnight
- How many animals: all
- Parameters checked in table were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the end of the dosing regime
- Anaesthetic used for blood collection: Yes with CO2
- Animals fasted: Yes, overnight
- How many animals: all
- Parameters checked in table were examined.

URINALYSIS: No

OTHER: Organ weight and histopathology

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Statistics:

Parametric: ANOVA followed by Dunnett's test
Non parametric: Wilcoxon, Kruskal Wallis
Fischer exact test was applied for macroscopic and histopathologic lesions
The level of significance was set at p < 0.05.
Statistical Program: SAS software v.8

Results and discussion

Results of examinations

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):

effects observed, non-treatment-related

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

Clinical observations:
- There was no mortality during the study.
- No significant clinical signs or disturbances of the general behaviour were detected in males and females of all tested groups.
- No alterations of mean body weight during treatment period.
- Statistical differences on food consumption observed in males during recovery period not related to treatment. No statistical differences on food consumption was observed on females during treatment or recovery periods.

Laboratory findings:
- Statistically significant increase on mean corpuscular hemoglobin concentration (MCHC) and platelet count (PLT) were observed on group 4 (1,000 ppm) of females, during treatment period. Statistically significant decrease on hematocrit (HCT) was observed on group 4 (1,000 ppm). No alteration on clotting and hematology parameters of males were observed in all tested groups during treatment period.
- No alterations on clinical chemistry of males were observed in all tested groups during treatment period.

Effects in organs:
- There were no alterations that could be attributed to the likely toxicity of the test item.

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

ca. 35.2 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: 300 ppm, based on increased platelet count and mean corpuscolar haemoglobin concentration and a decrease of hematocrit. The results obtained for the satellite groups showed that these findings were fully reversible after recovery period.

2

Dose descriptor:

NOAEL

Effect level:

> 86.9 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: 1000 ppm. No substance related findings.

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Repeated oral administration through diet of Phoslite IP-A to Wistar Hannover rats at doses of 0, 100, 300 and 1000 ppm for 28 days produced no mortality and no clinical signs of toxicological relevance.
Statistically significant increase on mean corpuscular hemoglobin concentration and platelet count were observed on group 4 (1,000 ppm) of females, during treatment period. Statistically significant  decrease on hematocrit (HCT) was observed on group 4 (1,000 ppm). 

Creatinine (CRE) concentration of females on group 4 (1,000 ppm) was statistically significant increased when compared to the control group.

Based on these results, the no-observed-adverse-effect-level (NOAEL) of Phoslite IP-A resulted to be higher than 300 ppm test item in diet for females (35.2 mg/kg body weight/day) and greater than 1000 ppm for males (86.9 mg/kg body weight/day).

Applicant's summary and conclusion

Conclusions:

NOAEL females = 35.2 mg/kg bw/day.
NOAEL males > 86.9 mg/kg bw/day.
There were no alteration that can be attributed to the toxicity of the test item. Minor alterations were detected in the female group at the highest dose (1000 ppm). All effects disappeared in the satellite group at the end of the recovery period.

Executive summary:

The test item was administered to Wistar rats (5 animals/sex/group) in the diet for 4 weeks at doses of 0, 100, 300, 1000 ppm, equal to compound intake of 0, 9.9, 27.8 and 86.9 mg/kg/bw on males and 0, 11.4, 35.2 and 121.2 mg/kg/bw on females. Additional satellite groups (5 animals/sex/group) of the control and highest dose were maintained for more 2 weeks after the end of the treatment period for observation of reversibility or persistence of toxic effects. Body weight and food consumption were determined weekly. Animals were checked daily for mortality and morbidity (except on Sundays) and were subjected to a careful clinical examination once a week. At the end of the treatment or after recovery period, blood samples were collected for clinical chemistry, hematological and clotting analyses. During the necropsy, the animals were subjected to a gross examination and the appropriate organs and tissues were removed, weighed and submitted for histopathological examination. In general, no substance related findings were observed. In the female group treated at the highest dose, increased on PLT and MHCH and decrease on HCT were recorded after treatment. The effects were fully reversible after the recovery period.