Polyphosphoric acids

Endpoint summary

Description of key information

A 90-day oral administration of sodium aluminium phosphate to purebred beagle dogs at dietary levels of 0.3, 1.0 and 3.0% revealed in three Groups animals renal concretions which were unusually large and more numerous than those normally observed in untreated dogs. The NOAEL was established to 1% corresponding to 322 mg/kg bw/day.
The Joint FAO/WHO Expert Committee on Food has estimated on the basis of the available toxicity data an estimate of the maximum tolerable daily intake (MTDI) for phosphoric acid in man of  70 mg/kg bw of phosphorus. Specific occupational risks from phosphoric acid are as a result of inhalation due to the corrosive nature of the material and as such occupational OELs are available to adequately protect against this risk. The values are as follows: 
- Acute, inhalation: 15 min STEL: 2 mg/m3 
- Chronic, inhalation: 8 hr TWG OEL: 1mg/m3 

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

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

Adequacy of study:

key study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Meets generally accepted scientific standards with acceptable restrictions: The test substance identity has not been clarified in the study report, however composition of the test material is known and the study is considered to be reliable for use as a key study. The reliability has been amended in accordance with 'practical guide 6: How to report read-across and categories' which states that the maximum reliability for a read-across study is 2. The study is considered to be adequate and reliable for the purpose of registration under REACH (Regulation (EC) No. 1907/2006). JUSTIFICATION FOR READ-ACROSS AND CHOICE OF DATA (applicable to worker and general population DNELs): A Maximum tolerable daily intake (MTDI) value of 70 mg/kg bw /day of phosphorus as calculated by the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) is available. This can be applied to all the substances discussed as any toxicity effects noted via the oral route are not attributable to the cation but are as a result of high doses of phosphates. This value was based on data generated on a large number of different inorganic phosphates. On this basis a number of sodium, sodium aluminium, potassium, calcium and magnesium orthophosphates (those used as food additives and their analogues) are considered as suitable for read-across for the repeated-dose toxicity endpoint for the following reasons: - All substances are similar inorganic ionic compounds. In aqueous solutions they will dissociate to their cationic and anionic forms and therefore these can be viewed as separate moieties with regards to toxicity. - The Na+, K+, Ca2+and Mg2+cations are naturally occurring essential minerals that are highly regulated by homeostatic mechanisms. As such recommended intake values for all exist and are about the key NOAEL taken from the data and therefore no further assessment of their contribution to the toxicity of the materials is necessary. - The Al3+is present in the substance tested in the studies from which the values for risk assessment are derived and therefore no further consideration of the toxicity of the aluminium cation is required as this is already taken into account. - The phosphate moiety is not considered to differ to that from any other inorganic orthophosphate from a toxicological point of view for the purpose of risk assessment and the derivation of appropriate DNELs it is considered to be appropriate to use the most reliable data available for orthophosphates (see endpoint records and summary) and no further data was generated on calcium or magnesium orthophosphates - The main toxicological finding in repeated dose studies with most inorganic phosphates is nephrocalcinosis (calcification of the kidneys). It is noted by JEFCA that rats are particularly susceptible to these effects and these effects were taken into account when deriving the MTDI value. Please see the endpoint summary provided under ‘Toxicological Information’ for a full detailed justification.

Qualifier:

no guideline followed

Deviations:

not applicable

Principles of method if other than guideline:

A 90 day oral toxicity study was conducted with purebred beagle dogs fed KASAL at dietary levels of 0.3, 1.0 and 3.0%.

GLP compliance:

no

Remarks:

Study predates GLP

Limit test:

no

Species:

dog

Strain:

Beagle

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Laboratory's own IBTL colony
- Age at study initiation: See Table 1
- Weight at study initiation: See Table 1
- Fasting period before study: No data
- Housing: Animals were housed in kennels equipped with outside runs. Four dogs of the same sex and group were accommodated in a single kennel.
- Diet (e.g. ad libitum): Stock diet (Golden Choice Meals, Adolph Coors Company, Denver, Colorado) available ad libitum
- Water: available ad libitum
- Acclimation period: The dogs were observed for two weeks prior to the start of the investigation during which time they were reimmunised against rabies, distemper, infectious canine hepatitis and leptospirosis and rendered clinically free of any existing parasitic infestation.


ENVIRONMENTAL CONDITIONS
No data


IN-LIFE DATES: No data

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: No data


DIET PREPARATION
- Rate of preparation of diet (frequency): At the beginning of each week
- Mixing appropriate amounts with (Type of food): The appropriate dietary constituents for each group were thoroughly blended in a Hobart mixer. Preweighed amounts were distributed into self-feeding units and maintained in excess of the animals' consumption. One such unit was available to the dogs in each kennel on an ad libitum basis 24 hours per day.
- Storage temperature of food: No data


VEHICLE
Not applicable

Analytical verification of doses or concentrations:

no

Details on analytical verification of doses or concentrations:

Not applicable

Duration of treatment / exposure:

90 days

Frequency of treatment:

Continuous exposure in feed

Remarks:

Doses / Concentrations:
0.3, 1.0 and 3.0%
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
Male: 94.23, 322.88 and 1107.12 mg/kg bw/day Female: 129.31, 492.77 and 1433.56 mg/kg bw/day
Basis:
other: Calculated using the mean of the weekly body weight and food consumption (Week 5 has been discounted from the 492.77 mg/kg bw/day femal group due to illegible figures in the report)

No. of animals per sex per dose:

4 animals/sex/dose

Control animals:

yes, plain diet

Details on study design:

No data

Positive control:

Not used

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Daily


BODY WEIGHT: Yes
- Time schedule for examinations: The body weight of each dog in every group was determined and recorded at the start of the study and weekly thereafter.


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): At the end of each 7 day period, all unconsumed food was collected and weighed. Food consumption was calculated and recorded.


FOOD EFFICIENCY: No


OPHTHALMOSCOPIC EXAMINATION: No


HAEMATOLOGY: Yes
- Time schedule for collection of blood: Prior to inception of the study and after 42 and 84 days of testing
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: all animals
- Parameters: Total leukocyte count, erythrocyte count, haemoglobin, haematocrit, differential leukocyte count


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: Prior to inception of the study and after 42 and 84 days of testing
- Animals fasted: No data
- How many animals: all animals
- Parameters: Blood urea nitrogen, serum glucose, serum alkaline phosphatase, serum glutamic-oxalacetic transaminase, serum glutamic-pyruvic transaminase


URINALYSIS: Yes
- Time schedule for collection of urine: Prior to inception of the study and after 42 and 84 days of testing
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data
- Parameters: Albumin, glucose, pH, microscopic elements (leukocytes, erythrocytes, crystals)


NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
All major tissues and organs were examined grossly. The weights of the following organs were obtained: liver, kidneys, heart, brain, spleen, gonads, adrenal glands, thyroid gland and pituitary gland.

HISTOPATHOLOGY: Yes (see table)

Other examinations:

None

Statistics:

No data

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:

no effects observed

Behaviour (functional findings):

not examined

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: No untoward behavioural reactions were recorded during the investigation and no fatalities occurred.


BODY WEIGHT AND WEIGHT GAIN: No significant deviations from normally expected body weight gains for dogs of this age were noted (see Table 1).


FOOD CONSUMPTION AND COMPOUND INTAKE : There is no significant difference between the untreated control group and the three test groups (see Table 2).


HAEMATOLOGY: No significant abnormalities were noted at any level tested (see attached Tables 3-11).


CLINICAL CHEMISTRY: There is no significant difference between the untreated control group and the three test groups (see attached Tables 12-16).


URINALYSIS: Urinalysis revealed no significant abnormalities at any of the levels tested (see attached Tables 17-23).


ORGAN WEIGHTS: No significant abnormalities were noted among any levels tested (see attached Tables 24-32).


GROSS PATHOLOGY and HISTOPATHOLOGY: NON-NEOPLASTIC: There are no changes that can be attributed to the test material or the test procedure. All of the findings noted are attributed to spontaneous disease. (see Tables 33-36). All tissues and organs not mentioned were normal.

Dose descriptor:

NOAEL

Effect level:

322.88 mg/kg bw/day (nominal)

Based on:

other: test material, calculated based on food consumption

Sex:

male

Basis for effect level:

other: histopathology; specific to kidneys

Dose descriptor:

NOAEL

Effect level:

492.77 mg/kg bw/day (nominal)

Based on:

other: test material, calculated based on food consumption

Sex:

female

Basis for effect level:

other: histopathology; specific to kidneys

Critical effects observed:

not specified

Table 1: Mean body weight data and age for males and females

Group	Dietary level (%)	Males			Females
		Mean age at inception of test (months)	Mean body weight at week 0 (kg)	Overall weight gain (kg)	Mean age at inception of test (months)	Mean body weight at week 0 (kg)	Overall weight gain (kg)
UC	None	5.9	9.5	1.9	6.0	7.3	1.7
T-I	0.3%	5.9	8.2	1.8	5.6	7.6	1.4
T-II	1.0%	5.9	9.2	2.1	5.6	5.5	1.4
T-III	3.0%	6.0	7.6	2.0	5.5	7.1	1.4

 

Table 2: Mean food consumption data

Week	-	Mean food consumed during week indicated (g/day)
	Sex:	Males				Females
	Group:	UC	T-I	T-II	T-III	UC	T-I	T-II	T-III
	Dietary level (%):	None	0.3	1.0	3.0	None	0.3	1.0	3.0
1	-	352	375	388	401	380	451	436	385
2	-	361	381	385	430	417	407	458	418
3	-	366	362	359	392	397	378	410	386
4	-	338	371	353	342	366	382	407	375
5	-	356	358	336	363	399	359	391	369
6	-	348	335	332	366	375	352	394	351
7	-	319	347	328	364	343	369	398	352
8	-	285	305	277	323	323	331	358	346
9	-	315	335	268	325	321	361	377	363
10	-	333	303	274	328	362	370	361	356
11	-	300	336	321	317	341	332	334	330
12	-	286	268	261	287	298	302	279	288
13	-	281	338	304	346	285	344	423	350
Mean	-	326	340	322	353	354	364	387	359

 

Table 33: Gross and histological findings – Untreated control group

Dog number and sex	Organ	Gross	Grade	Histologic	Grade
1-M	Liver	-	-	Focal lymphoid infiltration	+
	Lungs	-	-	Focal interstitial pneumonia	++
	Prostate	-	-	Chronic focalprostatitis	++
	Spleen	-	-	Haemosiderosis	+
2-M	Lungs	-	-	Chronic interstitial pneumonia	++
3-M	Heart	-	-	Congestion	+
	Liver	-	-	Focal lymphoid infiltration	+
	Lungs	-	-	Focal interstitial pneumonia	++
4-M	Liver	-	-	Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia	++
	Spleen	-	-	Haemosiderosis	+
5-F	Liver	-	-	Congestion	++
				Focal lymphoid infiltration	+
	Lungs	-	-	Chronic interstitial pneumonia	+
		-	-	Hyperemia	+
6-F	Liver			Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia	+
	Uterus	-	-	In estrus	-
7-F	Ovaries	-	-	Proestrus	-
	Liver	-	-	Congestion	++
8-F	Lungs	-	-	Chronic interstitial pneumonia	+

 

Table 34: Gross and histological findings – Test group I: 0.3 percent

Dog number and sex	Organ	Gross	Grade	Histologic	Grade
9-M	Liver	-	-	Congestion	+
	Lungs	-	-	Hyperemia	+
10-M	Liver	-	-	Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia	+
11-M	Kidneys	-	-	Focal lymphoid infiltration	+
	Lungs	-	-	Congestion Focal lymphoid infiltration	+ +
12 -M	Liver	-	-	Congestion	+
	Lung	-	-	Chronic interstitial pneumonia	++
13-F	Liver	-	-	Focal lymphoid infiltration	+
	Lungs	-	-	Chronic interstitial pneumonia	+
14-F	Liver	-	-	Congestion	++
	Lungs	-	-	Bronchopneumonia	++
15-F	Liver	-	-	Focal lymphoid infiltration	+
	Lungs	-	-	Chronic interstitial pneumonia	++
16 -F	Liver	-	-	Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia	++

 

Table 35: Gross and histological findings – Test group II: 1.0 percent

Dog number and sex	Organ	Gross	Grade	Histologic	Grade
17-M	Lungs	-	-	Hyperemia Chronic interstitial pneumonia	+ ++
18-M	Liver	-	-	Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia	+
19 -M	-	-	-	-	-
20 -M	Lungs	-	-	Chronic interstitial pneumonia	+
21 -F	Liver	-	-	-Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia Bronchopneumonia	++ ++
22-F	Liver	-	-	Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia	+
23 -F	Liver	-	-	Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia	+
	Mesenteric lymph node	-	-	Hyperemia	+
	Pancreas	-	-	Hyperemia	+
24 -F	Lungs	-	-	Chronic interstitial pneumonia	+

 

Table 36: Gross and histological findings – Test group III: 3.0 percent

Dog number and sex	Organ	Gross	Grade	Histologic	Grade
25-M	Liver	-	-	Congestion	+
	Kidney	-	-	Tubular concretions	+++
26-M	Liver	-	-	Congestion	+
	Kidney	-	-	Tubular concretions	+++
27-M	Liver	-	-	Congestion	++
	Lung	-	-	Chronic interstitial pneumonia	+
	Prostate	-	-	Chronic focal prostatitis	+
28 -M	Kidneys	-	-	Focal lymphoid infiltration	+
	Lungs	-	-	Chronic interstitial pneumonia	++
29 -F	Liver	-	-	Congestion	++
	Lungs	-	-	Chronic interstitial pneumonia	++
30 -F	Liver	-	-	Congestion	+
	Lungs	-	-	Chronic interstitial pneumonia	+
31-F	Liver	-	-	Congestion	+
32 -F	Gonads	-	-	Calcified follicle	+
	Kidneys	-	-	Tubular concretions	+++
	Liver	-	-	Focal lymphoid infiltration	+
	Spinal cord	-	-	Calcified debris in central canal	+

 Grading system:

+ = minimal or slight

++ = mild

+++ = moderate

++++ = severe

Conclusions:

The 90-day oral administration of KASAL to purebred beagle dogs at dietary levels of 0.3, 1.0 and 3.0% revealed in three of the Group T-III animals renal concretions which were unusually large and more numerous than those normally observed in untreated dogs. The few other calcified microconcretions present in the lumen of renal tubules located at the corticomedullary junction and/or medulla of the kidney were attributed to normally occurring disease.
No significant other changes were noted. Thus the dietary level of 1% can be considered as NOAEL (this is equivalent to 322.88 mg/kg bw/day).

This study is considered to satisfy the guideline requirements for this endpoint and also be adequate for the purposes of risk assessment. Therefore, the study is submitted as a key study and the NOAEL reported in this study is used to derive the inhalation and dermal DNELs. On consideration of all the available data, the ratio of sodium, aluminium and phosphate in the test material is not considered to be of key relevance in determining the derived no effect levels.

Read-across from sodium aluminium phosphate to the substance to be registered is justified on the following basis: Sodium aluminium phosphate is essentially a sodium orthophosphate that also contains an aluminium ion. A Maximum tolerable daily intake (MTDI) value of 70 mg/kg bw /day of phosphorus as calculated by the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) is available. This can be applied to all the substances discussed as any toxicity effects noted via the oral route are not attributable to the cation but are as a result of high doses of phosphates. This value was based on data generated on a large number of different inorganic phosphates.
On this basis a number of sodium, sodium aluminium, potassium, calcium and magnesium orthophosphates (those used as food additives and their analogues) are considered as suitable for read-across for the repeated-dose toxicity endpoint for the following reasons:
- All substances are similar inorganic ionic compounds. In aqueous solutions they will dissociate to their cationic and anionic forms and therefore these can be viewed as separate moieties with regards to toxicity.
- The Na+, K+, Ca2+and Mg2+cations are naturally occurring essential minerals that are highly regulated by homeostatic mechanisms. As such recommended intake values for all exist and are about the key NOAEL taken from the data and therefore no further assessment of their contribution to the toxicity of the materials is necessary.
- The Al3+is present in the substance tested in the studies from which the values for risk assessment are derived and therefore no further consideration of the toxicity of the aluminium cation is required as this is already taken into account.
- The phosphate moiety is not considered to differ to that from any other inorganic orthophosphate from a toxicological point of view for the purpose of risk assessment and the derivation of appropriate DNELs it is considered to be appropriate to use the most reliable data available for orthophosphates (see endpoint records and summary) and no further data was generated on calcium or magnesium orthophosphates
- The main toxicological finding in repeated dose studies with most inorganic phosphates is nephrocalcinosis (calcification of the kidneys). It is noted by JEFCA that rats are particularly susceptible to these effects and these effects were taken into account when deriving the MTDIvalue.

Please see the endpoint summary provided under ‘Toxicological Information’ for a full detailed justification.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

322 mg/kg bw/day

Study duration:

subchronic

Species:

dog

Quality of whole database:

The safety evaluation of inorganic phosphates as a class, including the various ionic forms, has been thoroughly completed by the use of animal studies and regulatory reviews.

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

Quality of whole database:

The substance is classified corrosive to the skin and is not expected to easily pass the skin. The skin is therefore not a preferred route of dosing when studying repeated dose systemic toxicity.

Additional information

Polyphosphoric acid is a mixture of the corresponding acids to phosphate anion and its condensed phosphates as follows:

- orthophosphoric acid or phosphoric acid (17 -76%),

- pyrophosphoric acid (23 -50%),

- triphosphoric acid (1.5 -25%),

- tetraphosphoric acid (0 -12%)

- and pentaphosphoric acid (0 -7%).

 

A condensed phosphate anion M(n+2)PnO(3n+1)has one or several P-O-P bonds and has been obtained by heating (dehydration). When the substance polyphosphoric acid is in contact of excess of water, a rapid hydrolysis is observed with the longer chains (tri, tetra or penta) while a very slow hydrolysis is observed for the dimer form to ortho phosphate. The pyrophosphate ion is the simplest form of a condensed phosphate group. As the group contains only two phosphate groups, both of the phosphorus ions are classified as “terminal phosphorus”. The pyrophosphate can undergo ionisation with loss of H+ from each of the two –OH groups on each P and therefore can occur in the -1, -2 -3 or -4 state. The degree of ionisation is dependant upon the associated cations (if there are) and the ambient pH (if in solution).

No partition coefficient value was determined for these substances as they are inorganic phosphates that are highly ionic (depending on ambient pH). Because of this ionic nature the passive passage across biological membranes will be negligible. Pyrophosphate is an anion that occurs in all living cells and is formed mainly by the synthesis of DNA from Nucleotide triphosphates (DNAn + Deoxyribonucleotide triphosphate → DNAn+1 + pyrophosphate). Usually it is cleaved rapidly into two orthophosphate molecules by one of the different members of the alkaline phosphatase family which are present in all tissues. Pyrophosphate nevertheless is generally relatively stable against uncatalyzed hydrolysis (half life = 10 d in autoclaved Flat branch sediment (Blanchar RW and Riego DC, 1975, Tripolyphosphate and pyrophosphate hydrolysis in sediments, Soil sci. soc.Am. J 40: 225-229)).

Oral repeated dose toxicity study

The 90-day oral administration of KASAL (sodium aluminium phosphate) to purebred beagle dogs at dietary levels of 0.3, 1.0 and 3.0% revealed in three of the Group T-III animals renal concretions which were unusually large and more numerous than those normally observed in untreated dogs. The few other calcified microconcretions present in the lumen of renal tubules located at the corticomedullary junction and/or medulla of the kidney were attributed to normally occurring disease.

No significant other changes were noted. Thus the dietary level of 1% can be considered as NOAEL (this is equivalent to 322.88 mg/kg bw/day).

This study is considered to satisfy the guideline requirements for this endpoint and also be adequate for the purposes of risk assessment. Therefore, the study is submitted as a key study and the NOAEL reported in this study is used to derive the inhalation and dermal DNELs. On consideration of all the available data, the ratio of sodium, aluminium and phosphate in the test material is not considered to be of key relevance in determining the derived no effect levels.

Read-across from sodium aluminium phosphate to the substance to be registered is justified on the following basis: Sodium aluminium phosphate is essentially a sodium orthophosphate that also contains an aluminium ion. A Maximum tolerable daily intake (MTDI) value of 70 mg/kg bw /day of phosphorus as calculated by the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) is available. This can be applied to all the substances discussed as any toxicity effects noted via the oral route are not attributable to the cation but are as a result of high doses of phosphates. This value was based on data generated on a large number of different inorganic phosphates.

On this basis a number of sodium, sodium aluminium, potassium, calcium and magnesium orthophosphates (those used as food additives and their analogues) are considered as suitable for read-across for the repeated-dose toxicity endpoint for the following reasons:

- All substances are similar inorganic ionic compounds. In aqueous solutions they will dissociate to their cationic and anionic forms and therefore these can be viewed as separate moieties with regards to toxicity.

- The Na+, K+, Ca2+and Mg2+cations are naturally occurring essential minerals that are highly regulated by homeostatic mechanisms. As such recommended intake values for all exist and are about the key NOAEL taken from the data and therefore no further assessment of their contribution to the toxicity of the materials is necessary.

- The Al3+is present in the substance tested in the studies from which the values for risk assessment are derived and therefore no further consideration of the toxicity of the aluminium cation is required as this is already taken into account.

- The phosphate moiety is not considered to differ to that from any other inorganic orthophosphate from a toxicological point of view for the purpose of risk assessment and the derivation of appropriate DNELs it is considered to be appropriate to use the most reliable data available for orthophosphates (see endpoint records and summary) and no further data was generated on calcium or magnesium orthophosphates

- The main toxicological finding in repeated dose studies with most inorganic phosphates is nephrocalcinosis (calcification of the kidneys). It is noted by JEFCA that rats are particularly susceptible to these effects and these effects were taken into account when deriving the MTDIvalue.

Please see the endpoint summary provided under ‘Toxicological Information’ for a full detailed justification.

Repeated dose toxicity: inhalation

No reliable data were available for the inhalation route of exposure. Therefore, testing for this exposure route is waived based on column 1, annex VIII, section 8.6.1. In addition, Specific occupational risks from phosphoric acid are as a result of inhalation due to the corrosive nature of the material and as such occupational OELs are available to adequately protect against this risk. The values are as follows (1):

- Acute, inhalation: 15 min STEL: 2 mg/m3

- Chronic, inhalation: 8 hr TWG OEL: 1mg/m3

In a risk assessment scenario is it considered appropriate to use these values and as such no testing for the inhalation route would be considered necessary.

 

Repeated dose toxicity: dermal

No reliable studies were available for the dermal route of exposure. Therefore, testing via this exposure route is waived according to column 1, annex VIII, section 8.6.1. In addition, due to the corrosive nature of the substance, dermal route is not considered an appropriate route.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
See discussion below.

Repeated dose toxicity: via oral route - systemic effects (target organ) urogenital: kidneys

Justification for classification or non-classification

Evaluation for classification is based on the available data issued from inorganic phosphates where the cation is not considered to contribute to the overall toxicity of the material. As such a number of sub acute and sub chronic studies conducted on the food additive sodium aluminium phosphate and other inorganic phosphates. A MTDI of 70 mg/kg bw of phosphorus has been established by the joint FAO/WHO Expert Committee on Food for phosphoric acid and phosphates salts. The toxicological effects noted in these studies showed nephrocalcinosis occuring when high doses of phosphate are administered due to the precipitation of the phosphate moiety as insoluble calcium phosphates in the kidneys. these effects occur at dose levels well above the cut off for classification via the oral route in accordance with Regulation (EC) No. 1272/2008 (EU CLP) and therefore no classification is proposed.