Sodium metaphosphate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

One study is available. This study was performed prior to the introduction of GLP.

Link to relevant study records

Reference

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

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

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: ***

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.

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

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

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: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

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.

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

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

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

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

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.

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

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

Key result

Critical effects observed:

no

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

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

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.

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

Key result

Critical effects observed:

no

Key result

Reproductive effects observed:

no

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

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.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

250 mg/kg bw/day

Species:

rat

Quality of whole database:

The dataset has been reviewed by an external assessor (M Weiner, TOXpertise, LLC) and it is concluded that the data is adequate and reliable for use as a key study under REACH. Please see expert report attached in endpoint under 'background information'.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

No adverse effects were noted at the highest concentration tested in the study.

The Hodge reproduction study (1960) was conducted prior to the institution of good laboratory practice guidelines and to the current OECD Guideline 416. Therefore, the study has deficiencies when examined according to today’s standards. The study is considered a Klimisch Code 2, reliable with restrictions. The conclusions regarding the hazard identification of sodium metaphospahte are supported by data on sodium tripolyphosphate / pentasodium triphosphate (STPP) and sodium trimetaphosphate (STMP), both of which are structurally similar to sodium metaphosphate. All three inorganic phosphate salts had no adverse effects on reproduction and fertility when tested in rats over three generations (Hodge 1959, 1960).

 

In theManual for Investigation of HPV Chemicals,Chapter 3: Data Evaluation (2005), Section 3.1.6 Weight-of-the-Evidence Analysis, requires the use of a weight-of-the-evidence analysis during the assessment of data quality and adequacy.  The guidance permits the pooling of several studies, one or more of which may be inadequate, to satisfy a specific SIDS element. In the current case, available data exist on two other sodium inorganic phosphate salts which are similar in structure to sodium metaphosphate (all are polyphosphates that have been shown to breakdown, via similar mechanisms, to orthophosphate in aqueous solutions).  Three generation reproduction studies have been conducted on pentasodium triphosphate and sodium trimetaphosphate which are similar to the one on sodium metaphospahte in that they were conducted prior to good laboratory practice guidelines and the existence of OECD Guideline 416; nevertheless, they provide additional support for the hazard assessment of sodium metaphosphate (The IUCLID Robust Study Summary have been included as supplemental information). All three sodium phosphates showed no effects on reproductive performance. The dose levels used in these studies were viewed as appropriate based on the results of the chronic toxicity/ carcinogenicity studies for each salt.

Based on this evidence sodium metaphosphate is not considered to be classified as a reproductive toxicant according to Regulation (EC) 1272/2008 (EU CLP).

Effects on developmental toxicity

Description of key information

 There is one key study (conducted by Bailey, 1974 and split into two parts according to species tested) to assess the potential for developmental toxicity in rats and in mice. The administration of up to 240 mg/kg bw of the test material to pregnant rats for 10 consecutive days had no clearly discernible effect on nidation or on maternal or foetal survival. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls. The NOAEL for both maternal and developmental is considered to be > 240 mg/kg bw. The administration of up to 370 mg/kg bw for 10 consecutive days showed no maternal or developmental toxicity. The NOAEL for both maternal and developmental is considered to be > 370 mg/kg bw. The results provide support for the argument that there is no concern with regard to effects of sodium metaphosphate on reproduction.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19/7/74 - 23/08/74

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Meets generally accepted scientific standards with acceptable restrictions. Noted deficiencies include; Food consumption not reported, Uterine weights not determined, One third used for visceral examination; should be 50%, Test substance identification (Batch etc) missing, No details on housing conditions/source of animals, administration of the test material was only during periods of organogenesis and not until day before pregnancy

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: no data

Deviations:

not specified

Principles of method if other than guideline:

Adult female albino CD-1 mice were mated with young adult males. Observation of a vaginal sperm plug was considered as Day 0 of gestation. Dosing by oral intubation with a control (Vehicle at level equivalent to group receiving the highest dose or aspirin at 150 mg/kg) or test article in a water suspension (10 mL/kg bw) at 3.7, 17.2, 79.7 and 370.0 mg/kg was carried out daily on Days 6 to 15 of gestation. Observations of body weight, appearence, behaviour, and food consumption were performed. On Day 17 of gestation all dams underwent Caesarean section. Sex, numbers or corpora lutea, implantation sites, resorption sites and live/dead foetuses recorded. Body weights of live pups recorded. Urogenital tract of each dam examined for anatomical normality. All foetuses examined grossly for presence of external congenital abnormalities. One third foetuses of each litter underwent detailed visceral examination and the remaining two thirds were cleared in potassium hydroxide, stained with alizarin red S dye and examined for skeletal defects.

GLP compliance:

no

Remarks:

Study predates GLP

Limit test:

no

Species:

mouse

Strain:

other: albino CD-1

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Outbred
- Age at study initiation: No data
- Weight at study initiation: 31 - 34 g
- Fasting period before study: No data
- Housing: Gang housing in disposable plastic cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: No data


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 - 26.7
- Humidity (%): 65 - 78

IN-LIFE DATES: 19/7/74 - 23/08/74

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
VEHICLE: Water
- Amount of vehicle (if gavage): 10 mL/kg bodyweight

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: cohoused
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy

Duration of treatment / exposure:

10 days (Day 6 to Day 15 of gestation)

Frequency of treatment:

Daily

Duration of test:

17 days

No. of animals per sex per dose:

Table 1 Number of animals dosed
Material Dose (mg/kg) Total
Mated Pregnant
Sham 0.0 24 21
Aspirin 150.0 29 19
FDA 73-3 3.7 23 20
17.2 29 20
79.7 30 20
370.0 31 21

Control animals:

yes, sham-exposed

other: positive control: 150 mg/kg aspirin

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Appearence, behaviour, food consumption and weight observed daily.
DETAILED CLINICAL OBSERVATIONS: No
BODY WEIGHT: Yes
- Time schedule for examinations: Body weights recorded on days 0, 6, 11, 15 and 17.
POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 17
- Organs examined: uterus and urogenital tract

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of resorptions: Yes

Fetal examinations:

- External examinations: Yes: one third per litter
- Soft tissue examinations: Yes: one third per litter
- Skeletal examinations: Yes: two thirds per litter
- Head examinations: Yes: two thirds per litter

Statistics:

No data

Indices:

No data

Historical control data:

No

Details on maternal toxic effects:

Maternal toxic effects:no effects

Dose descriptor:

NOAEL

Effect level:

> 370 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: no effects observed

Abnormalities:

no effects observed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Key result

Dose descriptor:

NOAEL

Effect level:

> 370 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Table 2 - Reproduction data

Dose (mg/kg)	Sham	Aspirin	3.7	17.2	79.7	370.0
Pregnancies
Total No.	21	19	20	20	20	21
Died or aborted (before Day 17)	0	0	0	0	0	1
To term (on Day 17)	21	19	20	20	20	20
Corpora Lutea
Total no.	244	246	257	260	245	249
Average/dam mated	11.1	8.79	11.2	8.97	8.17	8.30
Live litters
Total No.*	21	19	19	20	20	20
Implant Sites
Total No.	226	227	239	245	229	232
Average/dam*	10.8	12.0	12.0	12.3	11.5	11.6
Resorptions
Total No*	10	7	26	10	5	4
Dams with 1 or more sites resorbed	6	6	9	8	3	4
Dams with all sites resorbed	--	--	1	--	--	--
Per cent partial resorptions	28.6	31.6	45.0	40.0	15.0	20.0
Per cent complete resorptions	--	--	5.00	--	--	--
Live foetuses
Total No	215	219	211	232	221	224
Average/dam*	10.2	11.6	10.6	11.6	11.1	11.2
Sex ratio (M/F)	1.11	1.28	1.34	0.99	1.18	0.87
Dead Foetuses
Total No.*	1	1	2	3	3	4
Dams with 1 or more dead	1	1	2	2	3	4
Dams with all dead	--	--	--	--	--	--
Per cent partial dead	4.76	5.26	10.0	10.0	15.0	20.0
Per cent all dead	--	--	--	--	--	--
Average foetus weight (g)	0.88	0.90	0.91	0.89	0.94	0.88

* Includes only those dams examined at term

** Positive control: 150 mg/kg

 

Table 3 - Summary of skeletal findings

Findings	Dose (mg/kg)
	Sham	Aspirin	3.7	17.2	79.7	370.0
Live foetuses examined (at term)	151/21	151/19	146/19	161/20	151/20	157/20
Sternebrae
Incomplete oss.	59/18	24/13	56/16	72/18	19/7	28/9
Scrambled
Bipartite		3/2	2/2		3/3	5/5
Fused
Extra				2/1
Missing	15/10	15/6	15/10	31/12	14/6	15/8
Other
Ribs
Incomplete oss.
Fused/split
Wavy						1/1
Less than 12
More than 13	33/17	37/16	25/13	34/12	28/11	34/14
Other
Vertebrae
Incomplete oss.	2/2	3/2	2/2	3/2	9/3	6/5
Scrambled
Fused
Extra ctrs. oss.
Scoliosis
Tail defects
Other
Skull
Incomplete closure
Missing
Craniostosis
Other
Extremities
Incomplete oss.	3/3	2/2	5/5	4/3	6/2	1/1
Missing
Extra
Miscellaneous
Hyoid; missing	32/12	23/13	31/14	34/12	32/12	25/12
Hyoid; reduced	19/14	26/13	16/11	23/12	12/8	32/15

* Numerator = Number of foetuses affected; Denominator = Number of litters affected

** Positive control: 150 mg/kg

 

Table 4 - Summary of soft tissue abnormalities

Material	Dose level (mg/kg)	Dam	Number of pups	Description
FD 73-3	3.7	23073	1	Encephalomeningocele
FD 73-3	370	23178	1	Encephalomeningocele

Conclusions:

Under the conditions of the study, the test material administered to pregnant mice for 10 days up to a dose level of 370 mg/kg bw showed no maternal or developmental toxicity. The NOAEL for both maternal and fetoxicity is > 370 mg/kg bw. Based on this evidence sodium metaphosphate is not considered to be classified as a developmental toxicant according to Regulation (EC) 1272/2008 (EU CLP).

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23/7/74 - 27/8/74

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Meets generally accepted scientific standards with acceptable restrictions. Noted deficiencies include; Food consumption not reported, Uterine weights not determined, One third used for visceral examination; should be 50%, Test substance identification (Batch etc) missing, No details on housing conditions/source of animals, administration of the test material was only during periods of organogenesis and not until day before pregnancy

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: no data

Deviations:

not specified

Principles of method if other than guideline:

Adult female albino (Wistar derived stock) rats were mated with young adult males. Observation of a vaginal sperm plug was considered as Day 0 of gestation. Dosing by oral intubation with a control (Vehicle at level equivalent to group receiving the highest dose or aspirin at 250 mg/kg) or test article in a water suspension at 2.4, 11.1, 51.7 and 240.0 mg/kg was carried out daily on Days 6 to 15 of gestation. Observations of body weight, appearence, behaviour, and food consumption were performed. Daily room temperature was recorded. On Day 20 of gestation all dams underwent Caesarean section. Sex, number of corpora lutea, implantation sites, resorption sites and live/dead foetuses recorded. Body weights of live pups recorded. Urogenital tract of each dam examined for anatomical normality. All foetuses examined grossly for presence of external congenital abnormalities. One third foetuses of each litter underwent detailed visceral examination and the remaining two thirds were cleared in potassium hydroxide, stained with alizarin red S dye and examined for skeletal defects.

GLP compliance:

no

Remarks:

Study predates GLP

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Outbred
- Age at study initiation: No data
- Weight at study initiation: 223 - 231 g
- Fasting period before study: No data
- Housing: Individual housing in mesh bottom cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: No data


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 - 26.7
- Humidity (%): 64 - 78

IN-LIFE DATES: 23/7/74 - 27/8/74

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
VEHICLE: Water
- Amount of vehicle (if gavage): 1 mL/kg bw at doses equal to or below 250 mg/kg bw and 2 mL/kg at doses up to 500 mg/kg bw

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: No data
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy

Duration of treatment / exposure:

10 days (Day 6 to Day 15 of gestation)

Frequency of treatment:

Daily

Duration of test:

20 days

No. of animals per sex per dose:

Table 1 Number of animals dosed

Material Dose (mg/kg) Total
Mated Pregnant
Sham 0.0 25 20
Aspirin 250.0 21 21
FDA 73-3 2.4 25 20
11.1 22 20
51.7 20 20
240.0 22 20

Control animals:

yes, sham-exposed

other: positive control: 250 mg/kg aspirin

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Appearence, behaviour, food consumption and weight observed daily.
DETAILED CLINICAL OBSERVATIONS: No
BODY WEIGHT: Yes
- Time schedule for examinations: Body weights recorded on days 0, 6, 11, 15 and 20.
POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: uterus and urogenital tract

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of resorptions: Yes

Fetal examinations:

- External examinations: Yes: one third per litter
- Soft tissue examinations: Yes: one third per litter
- Skeletal examinations: Yes: two thirds per litter
- Head examinations: Yes: two thirds per litter

Statistics:

No data

Indices:

No data

Historical control data:

No

Details on maternal toxic effects:

Maternal toxic effects:no effects

Key result

Dose descriptor:

NOAEL

Effect level:

> 240 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: no effects observed

Key result

Abnormalities:

no effects observed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Dose descriptor:

NOAEL

Effect level:

> 240 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed

Abnormalities:

no effects observed

Developmental effects observed:

no

Table 2 - Reproduction data

Dose (mg/kg)	Sham	Aspirin	2.4	11.1	51.7	240.0
Pregnancies
Total No.	20	21	20	20	20	20
Died or aborted (before Day 20)	0	1	0	0	0	0
To term (on Day 20)	20	20	20	20	20	20
Corpora Lutea
Total no.	255	267	247	258	243	245
Average/dam mated	10.2	13.4	9.88	11.7	12.2	11.1
Live litters
Total No.*	20	18	20	20	20	20
Implant Sites
Total No.	243	234	226	229	214	228
Average/dam*	12.2	11.7	11.3	11.5	10.7	11.4
Resorptions
Total No*	2	75	3	13	6	1
Dams with 1 or more sites resorbed	2	13	3	5	3	1
Dams with all sites resorbed	--	2	--	--	--	--
Per cent partial resorptions	10.0	65.0	15.0	25.0	15.0	5.00
Per cent complete resorptions	--	10.0	--	--	--	--
Live foetuses
Total No	241	159	223	216	208	227
Average/dam*	12.1	7.95	11.2	10.8	10.4	11.4
Sex ratio (M/F)	1.04	1.04	1.23	1.43	1.29	0.99
Dead Foetuses
Total No.*	--	--	--	--	--	--
Dams with 1 or more dead	--	--	--	--	--	--
Dams with all dead	--	--	--	--	--	--
Per cent partial dead	--	--	--	--	--	--
Per cent all dead	--	--	--	--	--	--
Average foetus weight (g)	3.76	2.45	4.07	3.91	3.96	3.89

* Includes only those dams examined at term

** Positive control: 250 mg/kg

 

Table 3 - Summary of skeletal findings

Findings	Dose (mg/kg)
	Sham	Aspirin	2.4	11.1	51.7	240.0
Live foetuses examined (at term)	168/20	112/18	160/20	149/20	142/20	158/20
Sternebrae
Incomplete oss.	70/19	84/15	45/16	44/15	43/15	50/17
Scrambled
Bipartite		10/7		1/1		1/1
Fused
Extra
Missing	26/8	107/18	14/6	16/6	10/6	11/7
Other
Ribs
Incomplete oss.
Fused/split		4/3
Wavy	17/8	49/14	15/10	38/12	23/9	26/10
Less than 12
More than 13	1/1	102/17	1/1	1/1
Other
Vertebrae
Incomplete oss.	12/6	80/17	7/5	12/5	3/3	7/3
Scrambled
Fused
Extra ctrs. oss.
Scoliosis
Tail defects
Other
Skull
Incomplete closure	34/13	53/15	22/11	34/11	20/9	24/8
Missing		4/2
Craniostosis
Other
Extremities
Incomplete oss.		14/7
Missing
Extra
Miscellaneous
Hyoid; missing	12/4	49/17	13/7	9/5	9/6	6/4
Hyoid; reduced	44/17	12/6	32/12	42/14	19/8	40/12

* Numerator = Number of foetuses affected; Denominator = Number of litters affected

** Positive control: 250 mg/kg

 

Table 4 - Summary of soft tissue abnormalities

Material	Dose level (mg/kg)	Dam	Number of pups	Description
Sham	0	43004	1	Gastroschisis
		43011	1	Gastroschisis
Aspirin	250.0	43033	3	Encephalomyelocele
		43036	1	Hydrocephalus; Encephalomyelocele
		43038	1	Encephalomyelocele; anopia
			1	Encephalomeningocele;
		43039	1	Encephalomeningocele; Exophthalmos Encephalomyelocele
FDA 73-3		43043	1	Hydrocephalus; Gastroschisis
			2	Encephalomeningocele;
		43085	1	Gastroschisis
		43132	1	Gastroschisis
		43151	1	Gastroschisis

Conclusions:

Under the conditions of the study, the test material administered to pregnant rats for 10 days up to a dose level of 240 mg/kg bw showed no maternal or developmental toxicity. The NOAEL for both maternal and fetoxicity is > 240 mg/kg bw. Based on this evidence sodium metaphosphate is not considered to be classified as a developmental toxicant according to Regulation (EC) 1272/2008 (EU CLP).

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

240 mg/kg bw/day

Study duration:

chronic

Species:

rat

Quality of whole database:

One study available. Klimish reliability 2: Meets generally accepted scientific standards with acceptable restrictions. Noted deficiencies include; Food consumption not reported, Uterine weights not determined, One third used for visceral examination; should be 50%, Test substance identification (Batch etc) missing, No details on housing conditions/source of animals, administration of the test material was only during periods of organogenesis and not until day before pregnancy

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

The reported NOAEL is based on the highest concentration tested in the study by Bailey et al 1974 where rats were tested, as this gives a worst case value for use in risk assessment.

Observations were limited to:

- External examinations: Yes: one third per litter

- Soft tissue examinations: Yes: one third per litter

- Skeletal examinations: Yes: two thirds per litter

- Head examinations: Yes: two thirds per litter

In the prenatal developmental toxicity studies, pregnant females received sodium metaphosphate during gestation period by oral intubation. Sham-treated control groups were used for comparisons. At the end of gestation period, all dams were subjected to caesarean section and the number of implantation sites, resorption sites, as well as live and dead foetuses were recorded. The body weights of the live pups were taken. The urogenital tract level of dams was examined for abdominal abnormalities. All foetuses were examined for the presence of external congenital abnormalities. One-third of the foetuses were examined for visceral abnormalities and the remaining two-third were examined for skeletal abnormalities. No maternal toxicity or teratogenic effects were observed at up to the maximum dose levels tested in each species.

Summary of results in mice and rats.

animal / group	Dose Delivery/ vehicle	Treatment period	End of gestation	Result	(NOEL)
Mouse	Intubation/ water	Daily from day 6 to 15 of the gestation	Caesarean at day 17	Day 17	370 mg/kg Highest test concentration
Rat	Intubation/ water	Daily from day 6 to 15 of the gestation	Caesarean at day 20	Day 20	240 mg/kg Highest test concentration

 

Justification for classification or non-classification

The NOAELs recorded in the developmental and reproductive toxicity endpoints are for the highest doses tested and are above the limits for classification according to Regulation (EC) 1272/2008 (EU CLP) and therefore sodium metaphoshpate is not considered classified.