Sodium metaphosphate

Toxicity to reproduction

Administrative data

Endpoint:

three-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1960

Report date:

1960

Reference 2

Reference Type:

publication

Title:

Summaries of toxicological data

Author:

Summaries published by BIBRA

Year:

1964

Bibliographic source:

Fd Cosmet. Toxicol. Vol. 2 pp. 147-154. Pergamon Press 1964.

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

A reproduction study spanning 3 generations of rats reared and maintained on diets containing 0.0% and 0.5% HMP (Hexametaphosphate). Per generation two different litters were produced; one was sacrificed and the other was bred to produce the next generation. Matings were carried out between 16 females and 8 males in each group when the rats were 100 days old. Observations were limited to: the numbers of pups born, pup mortality up to 21 days, organ weights and histological changes of tissues and organs.

GLP compliance:

no

Remarks:

study predates GLP

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium metaphosphate

EC Number:

233-343-1

EC Name:

Sodium metaphosphate

Cas Number:

10124-56-8

Molecular formula:

H6O18P6.6Na

IUPAC Name:

Sodium metaphosphate

Details on test material:

- Name of test material (as cited in study report): Sodium hexametaphosphate
- Substance type: granular
- Physical state: solid
- Analytical purity: no data
- Lot/batch No.: #195001-8
- Stability under test conditions: Test material is considered stable at room temperature
- Specification: Calgon, Inc.

Test animals

Species:

rat

Strain:

other: Rochester (Ex-Wistar 1923)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: The original groups of rats were mated at 100 days
- Weight at study initiation: Bodyweight was approximately 70 grams for males and females at the start of the 100 day exposure.
- Fasting period before study:
- Housing: cages
- Diet (e.g. ad libitum): ad libitum,
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
no data

IN-LIFE DATES: From: *** To: ***

Administration / exposure

Route of administration:

oral: feed

Type of inhalation exposure (if applicable):

other: not applicable

Vehicle:

unchanged (no vehicle)

Details on exposure:

DIET PREPARATION

Diet mixtures were prepared using a basal ration of Purina Fox Chow Meal into which the appropriate amounts of sodium hexametaphosphate were mixed by a mechanical mixer. At weekly intervals. Diets were stored during the week in galvanized iron pails with covers.

Details on mating procedure:

- M/F ratio per cage: 1male: 2 female
- Length of cohabitation: 7 days
- Proof of pregnancy: no data
- Unsuccessful pairing replacement of first male by another male with proven fertility?: no.
- Further matings after two unsuccessful attempts: no data
- After successful mating each pregnant female was caged (how): no data
- other: males were rotated so that at each mating a different male would be placed in the cage with the female.

Details on mating schedules are tabulated below. - Table 1.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

not applicable

Duration of treatment / exposure:

Exposure took place for 100 days prior to mating, 21 days of gestation and during lactation for the P1, F1b, F2b. The F3b were exposed for their first 21days after which time they were sacrificed. Litters were culled to ten pups with approximately 5/sex/group on postnatal day 5.
For the F1, F2, F3-generations, offspring were weaned and exposed during an interim period of 10 days and then during a mating period of 7 days. Dams were exposed continually during gestation and lactation. Offspring of the second litter were again mated for 7 days after a 10 day interim period following weaning. The first litters (F1a, F2a, F3a) were sacrificed at 30 days of age. The F1c and F3b litters were sacrificed after 21 days.

Frequency of treatment:

daily in feed

Details on study schedule:

- F1 parental animals were mated at 100 days of age in order to produce the sacrificial group F2a, and at 151 days F1 animals were mated to produce the next parental generation for F2b.
- Per female the litters were culled to ten pups with approximately 5/sex/group. There are no details on the selection of parental animals.
- Age at mating of the mated animals in the study: 100 days to produce the sacrifical litter and at 151 days to produce the next parental generation.

More details on protocol are tabulated below. - Table 1.

Doses / concentrations

Remarks:

Doses / Concentrations:
0.0% and 0.5%
Basis:
nominal in diet

No. of animals per sex per dose:

16 females and 8 males were used to produce the subsequent generation. P1 , F1b , F2b , F3b.

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: Two doses were considered; 0.05% and 0.5%. After 100 days on these diets the 0.5% group exhibited no depression of body weight and was selected for use in this study.
- Other: The first litters born per generation were sacrificed, the F1a, F2a, F3a. The second litters born in a generation, the F1b, F2b, were mated to produce the next generation. The F1c was an additional litter produced and treated the same as the F1a.

Positive control:

no data

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: No

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule for examinations: Body weights were measured weekly during the 100 day pre-mating exposure for each generation.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Not measured

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Not measured

Oestrous cyclicity (parental animals):

not evaluated

Sperm parameters (parental animals):

not evaluated

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 5 postpartum: yes
- excess pups were sacrificed to leave 10 per litter.

PARAMETERS EXAMINED
The following parameters were examined in [F1 / F2 / F3] offspring:
[number of pups, pups/litter, pup mortality up to 21 days of age, weight gain per litter]

GROSS EXAMINATION OF DEAD PUPS: No

Postmortem examinations (parental animals):

SACRIFICE
- The first litters prodced per generation, the F1a, the F2a and the F3a were sacrificed at 30 days of birth.
- There is no data on the fate of the parents after they were mated to produce each generation.

GROSS NECROPSY
no data

HISTOPATHOLOGY
No histopathological examinations were performed for parental rats.

ORGAN WEIGHTS
No organ weight analyses were performed for parental rats.

Postmortem examinations (offspring):

SACRIFICE
- The non-parental litters, F1a , F1c, F2a , F3a , and F3b were sacrificed after 21 days.
- Observations amongst these litters were limited to litter weights on the 21st day. In the F3b histopathological and organ weight examinations were performed.

GROSS NECROPSY
F3b examined only.

HISTOPATHOLOGY / ORGAN WEIGTHS
The ten males and ten females from final litter, the F3b litter, were evaluated for body weight, histopathology (liver, kidneys, gonads, lungs, brain, stomach, heart, spleen, adrenal, stomach, large and small intestines, bladder, lymph nodes, gut, marrow, pancreas) and organ weights (liver, kidneys, testes, lungs, brain, stomach, heart, spleen).

Statistics:

no data

Reproductive indices:

no data

Offspring viability indices:

no data

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

not specified

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P0)

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)

In Table 2. a summary is presented of the reproductive performance.
Number of females mated: In all cases 15 or 16 females were mated after a 7-day cohabitation with one male (1 male caged with 2 females).
Number of pregnancies: Most of the pregnancies were successful. For the control rats there were 10 to 15 pregnancies per litter and for the rats maintained on the diet containing 0.5% HMP there were 10 to 13 in each mating.
Number of rats born: Comparable between the control and 0.5% group, the average number of pups ranged from 8-10 in both the controls and 0.5% group.

Effect levels (P0)

1

Key result

Dose descriptor:

NOAEL

Effect level:

0.5 other: %

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed

2

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 250 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed

Results: F1 generation

General toxicity (F1)

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not examined

Details on results (F1)

VIABILITY (OFFSPRING)
The number of pups surviving at 21 days was 65-122 in the control groups and 69-111 in the 0.5% HMP group.
The average weight of the pups at 21 days was 41.8 - 48.7 g in the control groups and 40.9 - 45.4g in the 0.5% HMP group.

BODYWEIGHT (OFFSPRING)
After 21 days the newly born rats surviving to 21 days were weighed per litter, differences between the control and HMP-fed rats were not considered to be significant. See Table 2.

F1a - The average bodyweight of rats on the HMP diet was less than that of the control group.
F1b - The average bodyweight of rats on the HMP diet was less than that of the control group.
F1c - The average bodyweight of rats on the HMP diet was greater than that of the control group - based on this the authors considered the decreased average litter weights of the F1a and F1b to be mere coincidental variations.

F2a - The average bodyweight of rats on the HMP diet was less than that of the control group.
F2b - There was a small difference, less than a gram, in the average weight of the control and HMP-fed rats. There was a peculiar delay of the HMP-fed rats within the first week on the diet, but growth was rapidly recovered and surpassed that of the control group.

F3a - The average weight of the HMP-fed and control rats was almost identical at 42.5 and 42.4 gram respectively
F3b - The average weight of the MHP-fed rats was greater than that of the controls.

ORGAN WEIGHTS (OFFSPRING)
When the F3b rats were at weaning age they were sacrificed. The author described the organ weights and organ weight body weight ratios as, being within normal ranges. See Table 3

HISTOPATHOLOGY (OFFSPRING)
No histological changes were found that were attributed to the presence of HMP in the diet. No tumours were present and only normal tissues were found.

Effect levels (F1)

1

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

ca. 250 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed

2

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

0.5 other: % w/w

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects noted

Target system / organ toxicity (F1)

Key result

Critical effects observed:

no

Results: F2 generation

General toxicity (F2)

Mortality / viability:

no mortality observed

Body weight and weight changes:

effects observed, non-treatment-related

Food efficiency:

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Developmental neurotoxicity (F2)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F2)

Developmental immunotoxicity:

not examined

Details on results (F2)

F2a - The average bodyweight of rats on the HMP diet was less than that of the control group.
F2b - There was a small difference, less than a gram, in the average weight of the control and HMP-fed rats. There was a peculiar delay of the HMP-fed rats within the first week on the diet, but growth was rapidly recovered and surpassed that of the control group.

Effect levels (F2)

Key result

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

0.5 other: %w/w

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects noted

Target system / organ toxicity (F2)

Key result

Critical effects observed:

no

Overall reproductive toxicity

Key result

Reproductive effects observed:

no

Any other information on results incl. tables

Table 2. Reproductive performance

Generation & Litter	F1a	F1b	F1c	F2a	F2b	F3a	F3b
Controls
Females	16	15	15	16	15	16	16
Pregnancies	14	10	10	11	10	15	11
Total pups	107	95	77	94	93	145	115
Avg. pups/litter	7.6	9.5	9.6	8.5	9.3	9.7	10.4
Mortality (days 0-5)	0	1	3	0	10	8	10
Mortality (days 6-21)	0	1	5	3	4	9	6
Total rats surviving to day 21	107	84	65	87	77	122	90
Avg. weight of surviving rats	48.7	45.2	42.0	44.9	41.8	42.4	42.9
0.5% Hexametaphosphate group
Females	16	15	15	16	16	16	16
Pregnancies	11	10	13	13	10	12	10
Total pups	83	100	126	118	89	119	97
Avg. pups/litter	8.3	10.0	9.7	9.1	8.9	9.9	9.7
Mortality (days 0-5)	6	15	3	11	2	1	3
Mortality (days 6-21)	5	1	0	9	11	3	0
Total rats surviving to day 21	69	77	111	95	73	108	87
Avg. weight of surviving rats	43.1	43.5	44.7	44.3	40.9	42.5	45.4

Table 3 - Organ Weights

Group	No. of Rats	Body Wt.	Liver	Kidneys	Testes	Lungs	Brain	Stomach	Heart	Spleen
Control Males	10	111	4.84	1.28	1.20	0.80	1.59	1.04	0.55	0.59
0.5%HMP-fed males	10	102	4.74	1.16	1.04	0.82	1.49	1.07	0.56	0.37
Control Females	10	96	4.03	1.06	n/a	0.69	1.43	1.02	0.53	0.64
0.5%HMP-fed females	10	90	3.71	1.03	n/a	0.67	1.54	1.09	0.47	0.36

Applicant's summary and conclusion

Conclusions:

Three generations of rats reared and maintained on diets containing 0.5% HMP showed no adverse effects to the test material - Control and test data were comparable across the range of observations made. Observations were limited to reproductive performance, pup mortality, organ weights and tissue and organ histopathology. Based on this evidence sodium metaphosphate is not considered to be classified as a reproductive toxicant according to Regulation (EC) 1272/2008 (EU CLP).

Although this study is limited and deficient by modern standards, it is still possible to make some valid scientific conclusions from the data. Adequate data are reported to show no effects on fertility or reproductive performance or on offspring growth and development over three generations with two litters per generation. Thus, the study should be considered acceptable for the dose level tested, 0.5% test material in the diet.