Aluminium metaphosphate

Endpoint summary

Description of key information

Oral: LD50(rat, f) > 2000 mg/kg bw (OECD 423, GLP)
Inhalation: LC50(rat, m/f) > 2.17 mg/L (max. achievable concentration, OECD 436, GLP)
Dermal: no study available

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 May - 21 Jun 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories
- Weight at study initiation: 190-250 g
- Fasting period before study: 3 h
- Housing: single-caged
- Diet: Common diet (pellets, ssniff Spezialdiäten GmbH, Germany), ad libitum
- Water: Tap water (drinking quality), ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-60
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Amount of vehicle (if gavage): 1 mL/100 g bw

MAXIMUM DOSE VOLUME APPLIED: 1 mL/100 g bw

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: A starting dose level of 300 mg/kg bw was used which is recommended in OECD 423 for animal welfare reasons when no toxicological information on the substance to be tested is available.

Doses:

300 and 2000 mg/kg bw

No. of animals per sex per dose:

control group: 3
test groups: 6

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The body weight of all animals was determined at test start, 1 week after test start and at test end. The animals were observed daily for clinical symptoms.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

Control group: no mortality occurred
300 mg/kg bw: 1/6 animals died on Day 2
2000 mg/kg bw: no mortality occurred

Clinical signs:

other: Control group: no clinical signs of toxicity were observed. 300 mg/kg bw: 1/6 animals showed left forelimb in relieving posture at 0-4 h post-treatment. The same animal showed intense swelling of the left forelimb prior to death on Day 2. 2000 mg/kg bw: n

Gross pathology:

Control group: there were no abnormal findings at gross necropsy.
300 mg/kg bw: macroscopic findings in the animal found death on Day 2 included: perforation of the oesophagus (ca. 4 mm); rectum faeces not formed; moderate congestion hyperaemia in the spleen, liver and kidneys; high-grade congestion hyperaemia in the heart; moderate congestion hyperaemia, different blood distribution and low-grade oedema and emphysema in the lung.
2000 mg/kg bw: there were no abnormal findings at gross necropsy.

Table 1. Summary of mortality and clinical signs.

Dose level (mg/kg bw)	Animal number	Observation period
		0-4 h		Day 1-14
		Mortality	Clinical signs	Mortality	Clinical signs
Control	1	no	NAD	no	NAD
	2	no	NAD	no	NAD
	3	no	NAD	no	NAD
300	1	no	NAD	no	NAD
	2	no	(1)	yes, Day 2	(2)
	3	no	NAD	no	NAD
	4	no	NAD	no	NAD
	5	no	NAD	no	NAD
	6	no	NAD	no	NAD
2000	1	no	NAD	no	NAD
	2	no	NAD	no	NAD
	3	no	NAD	no	NAD
	4	no	NAD	no	NAD
	5	no	NAD	no	NAD
	6	no	NAD	no	NAD

 

NAD: no abnormality detected

(1): left forelimb in relieving posture

(2): intense swelling of left forelimb

 

Table 2. Summary of body weight (gain).

Dose level (mg/kg bw)	Animal number	Body weight (gain) (g)
		Day 0	Day 7	Day 0-7	Day 14	Day 0-14
Control	1	197.7	214.5	16.8	206.3	8.6
	2	209.8	229.6	19.8	237.3	27.5
	3	201.6	221.2	19.6	235.7	34.1
300	1	195.5	218.8	23.3	225.8	30.3
	2	216.5	-	-	-	-
	3	219.2	242.3	23.1	255.4	36.2
	4	247.4	276.1	28.7	280.1	32.7
	5	201.7	220.3	18.6	226.2	24.5
	6	230.1	258.6	28.5	264.0	33.9
2000	1	187.3	211.8	24.5	227.7	40.4
	2	193.7	224.5	30.8	241.5	47.8
	3	192.7	229.0	36.3	243.9	51.2
	4	202.0	238.2	36.2	263.0	61.0
	5	194.4	220.6	26.6	236.4	42.0
	6	195.0	224.3	29.3	245.3	50.3

 

 

Table 3. Summary of necropsy findings.

Dose level (mg/kg bw)	Animal number	Necropsy findings
Control	1	NAD
	2	NAD
	3	NAD
300	1	NAD
	2	(1)
	3	NAD
	4	NAD
	5	NAD
	6	NAD
2000	1	NAD
	2	NAD
	3	NAD
	4	NAD
	5	NAD
	6	NAD

 

NAD: no abnormality detected

(1):

Oesophagus: perforation (ca. 4 mm)

Rectum: faeces not formed

Spleen: moderate congestion hyperaemia

Liver: moderate congestion hyperaemia

Lungs: moderate congestion hyperaemia, different blood distribution, low-grade oedem and emphysema

Heart: high-grade congestion hyperaemia

Kidneys: moderate congestion hyperaemia

Macroscopic suspected diagnosis: oesophagus perforation with food dislocation.

Interpretation of results:

not classified

Conclusions:

The oral LD50 of the test material in female rats was determined to be >2000 mg/kg bw. One animal given the test material at 300 mg/kg bw showed adverse clinical signs and died on Day 2 post-treatment. Necropsy findings led to the diagnosis "oesophagus perforation with food dislocation" and further to the conclusion that the animal died due to a treatment mistake and not caused by the test material. Except for this incident, there were no test material-related mortalities, clinical signs of systemic toxicity, adverse effects on body weight (gain) or abnormal necropsy findings. Therefore, the material does not fulfil the criteria for classification according to Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus considered to be not acutely toxic by the oral route.

CLP: not classified
GHS: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

The available data comprise one study conducted following an OECD Guideline and under GLP conditions, with no or no relevant deviations or deficiencies which may affect the validity and reliability of the study results. Therefore, the available data are sufficient to fulfil the endpoint specific standard information requirements of Regulation (EC) No 1907/2006 (REACH) and are likewise sufficient for the purpose of classification and labelling in accordance with Regulation (EC) 1272/2008 (CLP).

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 Mar - 07 Apr 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Documented deviations were considered to have no impact on the quality / integrity of the study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Deviations:

yes

Remarks:

see 'Remarks on results including tables and figures'

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Barcelona, Spain
- Age at study initiation: 8 weeks
- Weight at study initiation: 267-278 g (m) and 175-183 g (f)
- Housing: 4 animals per cage before distribution, 3 animals per cage after distribution
- Diet: Global Diet 2914 C (Harlan Teklad, UK), ad libitum, except when animals were restrained in the exposure tubes
- Water: Tap water, ad libitum, except when animals were restrained in the exposure tubes
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.9-23.2
- Humidity (%): 21-53
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

3.15 µm

Remark on MMAD/GSD:

(Mass median aerodynamic diameter) / GSD (Geometric st. dev.): Mean Mass Median Aerodynamic Diameter (MMAD) of particle size distribution during exposure was calculated from two gravimetric measurements PSD #1 and PSD #2. Mean MMAD during exposure was 3.15 μm. This value is within the respirable range (1-4 μm) and appropriate for acute inhalation toxicity testing. Geometric Standard Deviation (GSD) on PSD #2 was above the upper limit of 3 but considered acceptable as more than 55% of particles were below the upper limit of 4 μm (see Table 1).

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Exposure chambers type EC-FPC-232 (anodised aluminium), equipped with glass exposure tubes were used.
- Exposure chamber volume: approximately 3 L
- Method of holding animals in test chamber: The animals were confined separately in restraint tubes which were positioned radially around the exposure chamber.
- Source and rate of air: Filtered air from a compressor. The exposure airflow rate was adjusted as appropriate before the start of the exposure using the pressure difference over a Venturi tube. The actual airflow rate was monitored hourly in each group during each exposure. The target range was 0.5-1.0 L/min through each inhalation tube.
- System of generating particulates/aerosols: A dust aerosol was generated from the sieved test item using a Dust Generator SAG 410 (TOPAS GmbH, Germany). The dust was diluted with filtered air from a compressor and conveyed via glass tubing, from the generator to the exposure chamber. The flow rate through the exposure chamber was adjusted as necessary.
- Method of particle size determination: The particle size distribution was determined gravimetrically twice during exposure. The cumulative particle size distribution of the test aerosol was determined using a PIXE cascade impactor. The particle size distribution of the test item in the generated aerosol was measured by gravimetry analyzing the test item deposited on each stage of the cascade impactor.
The mass median aerodynamic diameter (MMAD) and the geometric standard deviation (GSD) were calculated on the basis of the results from the impactor, using Microsoft Excel® software (Microsoft Corporation, USA). The target ranges were 1 to 4 μm for the MMAD and 1.5 to 3 for the GSD.
- Temperature, humidity in air chamber: The temperature in the chamber was measured continuously during exposure using a thermohygrometer (Kimoth110, Kimo). The target range was 19-25°C. The results were reported approximately hourly from the start of the inhalation exposure.
The relative humidity in the chamber was measured continuously during exposure using a thermohygrometer (Kimoth110, Kimo). The target range was 30-70%. The results were reported approximately hourly from the start of the inhalation exposure.

TEST ATMOSPHERE
- Brief description of analytical method used: The test item usage was determined once per exposure by weighing the amount of the test item before and after exposure to determine the quantity of test item used. The weight used was then divided by the total air-flow volume to give the nominal concentration. These data were used for the purpose of monitoring the performance of the generation system.
Gravimetric determination of the aerosol concentration was performed at least once during each hour of exposure. Test aerosol samples were collected onto a Whatman filter (grade F319-04) using a filter sampling device. The sampling flow was similar to the air flow rate per exposure port. The duration of sampling was 5 minutes. The filters were weighed before and immediately after sampling using a calibrated balance. The gravimetric aerosol concentration was calculated from the amount of test item present on the filter and the sample volume.
- Samples taken from breathing zone: yes

TEST ATMOSPHERE

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: The starting dose (approximately 2 mg/L air, during 4 hours) was selected as no toxic effects were expected based on the available data. This concentration was found to be the highest technically achievable during technical trials (see 'Any other information on materials and methods incl. tables').

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Nominal concentration: 2 mg/L
Analytical concentration: 2.17 mg/L

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were examined daily for mortality and morbidity. Clinical observations in response to treatment were performed on all animals hourly during exposure (only grossly abnormal signs), immediately and 1h after exposure, and once daily thereafter until the end of the observation period. Any visible clinical signs and discomfort were recorded. All animals were weighed on the day of treatment, just before starting the inhalation period (Day 1 of study), on Day 2, 4, 8 and immediately before sacrifice on Day 15 of study.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

No statistical analysis was performed.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.17 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: maximum achievable concentration

Mortality:

All animals survived the scheduled observation period.

Clinical signs:

other: Dirty fur and chromorrhinorrhea were observed in all animals immediately after exposure with the exception of 1 male. Chromorrhinorrhea was still present 1 h after exposure in all animals previously recorded, while dirty fur was not longer present in any

Body weight:

A slight decrease in body weight (approximately 2-3% less than body weight at pre-treatment) was observed in all animals from Day 1 of study to Day 2 of study. Body weight higher than body weight at pre-treatment was observed in all animals at Day 4 of study. Thereafter, a normal body weight gain was observed in all animals.

Gross pathology:

No macroscopic findings were observed during necropsy.

Test atmosphere conditions

Temperature during exposure was considered to be satisfactory and within target range (19-25ºC). Relative humidity was below target range (30-70%). Data are presented in the following table:

Recording time (h:min from exposure start)	Temperature (ºC)	Relative Humidity (%)
0:16	19.7	27.6
1:07	19.8	27.2
2:09	19.8	26.4
3:04	19.8	26.1
Mean	19.8	26.8
SD	0.05	0.69
N	4	4

Mean oxygen and carbon dioxide concentrations were 20.9 % and 0.04% respectively. These values are considered satisfactory for inhalation studies and within target range (at least 19% and below 1% respectively). Data are presented in the following table:

Recording time (h:min from exposure start)	Oxygen (%)	Carbon dioxide (%)
0:16	20.9	0.04
1:07	20.9	0.04
2:09	20.9	0.04
3:04	20.9	0.04
Mean	20.9	0.04
SD	0	0
N	4	4

 

Aerosol concentrations

The mean of the gravimetric concentrations during exposure was 2.17 mg/L air, as targeted. Data on aerosol concentrations are presented in the following table:

Group A (2.17 mg/L air). Day 1 of study
Sampling starting time (h:min from exposure start)	Sampling volume (L)	Amount of test item on the filter (mg)	Gravimetric aerosol concentration (mg/L)
0:05	7.31	15.51	2.12
0:29	7.31	19.03	2.61
1:00	6.23	18.53	2.97
1:30	7.22	15.27	2.11
1:59	7.41	15.67	2.12
2:28	7.39	14.22	1.93
2:59	7.39	10.48	1.42
3:29	7.37	15.29	2.07
MEAN	7.20	15.50	2.17
SD	0.40	2.64	0.46
N	8	8	8

Table 2. Summary of mortality and clinical signs.

Concentration (mg/L)	Animal number (sex)	Mortality	Clinical signs	Time point/duration
2.17	1 (male)	no	Chromorrhinorrhea	Immediately post-exposure – 1 h post-exposure
			Dirty fur	2 h exposure – Immediately post-exposure
	2 (male)	no	Chromorrhinorrhea	Immediately post-exposure
			Chromodacryorrhea	Immediately post-exposure – 1 h post-exposure
			Dirty fur	Immediately post-exposure – 1 h post-exposure
	3 (male)	no	Dirty fur	Immediately post-exposure
	4 (female)	no	Hunched posture	1 h post-exposure
			Piloerection	1 h post-exposure
			Chromorrhinorrhea	Immediately post-exposure – 1 h post-exposure
			Dirty fur	2 h exposure – 1 h post-exposure
	5 (female)	no	Piloerection	1 h post-exposure
			Chromorrhinorrhea	Immediately post-exposure – 1 h post-exposure
			Dirty fur	1 h exposure – Immediately post-exposure
	6 (female)	no	Piloerection	1 h post-exposure
			Chromorrhinorrhea	Immediately post-exposure – 1 h post-exposure
			Dirty fur	1 h exposure – Immediately post-exposure

 

Table 3. Summary of body weight (gain).

Concentration (mg/L)	Animal number (sex)	Body weight (gain) (g)
		Day 1	Day 2	Day 4	Day 8	Day 15
2.17	1 (male)	267.23	260.17 (-7.06)	280.66 (20.49)	302.36 (21.70)	333.10 (30.74)
	2 (male)	277.95	269.62 (-8.33)	287.03 (17.41)	316.83 (29.80)	359.87 (43.04)
	3 (male)	277.87	267.64 (-10.23)	298.89 (31.25)	324.35 (25.46)	375.17 (50.82)
	4 (female)	175.40	173.75 (-1.65)	179.19 (5.44)	182.03 (2.84)	194.32 (12.29)
	5 (female)	182.75	177.25 (-5.50)	192.06 (14.81)	195.27 (3.21)	213.54 (18.27)
	6 (female)	180.99	176.60 (-4.39)	189.30 (12.70)	193.30 (4.00)	199.60 (6.30)

 

Interpretation of results:

not classified

Conclusions:

The LC50 of the test material in male and female rats was determined to be >2.17 mg/L, which was the maximum technically achievable concentration under the conditions of this study. There were no test material-related mortalities, clinical signs of systemic toxicity, adverse effects on body weight (gain) or abnormal necropsy findings.Therefore, the material does not fulfil the criteria for classification according to Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus considered to be not acutely toxic by the inhalation route.

CLP: not classified
GHS: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating conc.

Value:

2 170 mg/m³ air

Quality of whole database:

The available data comprise one study conducted following an OECD Guideline and under GLP conditions, with no or no relevant deviations or deficiencies which may affect the validity and reliability of the study results. Therefore, the available data are sufficient to fulfil the endpoint specific standard information requirements of Regulation (EC) No 1907/2006 (REACH) and are likewise sufficient for the purpose of classification and labelling in accordance with Regulation (EC) 1272/2008 (CLP).

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute oral toxicity

The acute oral toxicity of aluminium metaphosphate was tested in rats in a study following OECD Guideline 423 and under GLP conditions (Entzian, 2013). Groups of female Wistar rats (3 per testing step, i.e. 6 per dose level) were sequentially given the test substance (in water) at a single doses of 300 and 2000 mg/kg bw by oral gavage, respectively.

One animal of the 300 mg/kg bw group showed left forelimb in relieving posture at 0-4 h post-treatment. The same animal showed intense swelling of the left forelimb prior to death on Day 2. Macroscopic findings in this animal included: perforation of the oesophagus (ca. 4 mm); rectum faeces not formed; moderate congestion hyperaemia in the spleen, liver and kidneys; high-grade congestion hyperaemia in the heart; moderate congestion hyperaemia, different blood distribution and low-grade oedema and emphysema in the lung. The diagnosis "oesophagus perforation with food dislocation" based on the macroscopic pathologic findings leads to the conclusion that this animal died due to a treatment mistake and that the early death was not caused by the test material.

Except for this incident, no mortality occurred and no clinical signs of systemic toxicity or effects on body weight (gain) were observed during the 14-day observation period. Gross necropsy revealed no treatment-related findings. The oral LD50 of the test material in female rats was thus determined to be > 2000 mg/kg bw.

Therefore, the test material does not fulfil the criteria for classification according to Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus considered to be not acutely toxic by the oral route.

Acute inhalation toxicity

The acute inhalation toxicity of aluminium metaphosphate was evaluated in male and female Sprague Dawley rats by the acute toxic class (ATC) method according to OECD Guideline 436 and under GLP conditions (Veiga, 2015). A group of three male and three female rats was exposed by nose-only, flow-past inhalation to the test material at a mean concentration of 2.17 mg/L air during 4 hours. This concentration was found to be the highest technically achievable concentration. The mean Mass Median Aerodynamic Diameter (MMAD) during exposure was 3.15 µm. More than 55% of the particles were <4 µm, and more than 95% of the particles were <8 µm. The test material was therefore considered to be respirable to rats.

Ungroomed appearance was observed in all animals immediately after exposure and was still present 1 hour after exposure in 1 out of 3 males and in 1 out of 3 females. Chromorrhinorrhea was observed in 2 out of 3 males and in all females immediately after exposure. Chromodacryorrhea was observed only in 1 out of 3 males immediately and 1 hour after exposure. In addition, piloerection (3 out of 3 females) and hunched posture (1 out of 3 females) was only observed in females 1 hour after exposure. These clinical signs are frequently observed in inhalation studies at the day of treatment and are considered to be mainly related with the stress of the procedure. No clinical signs were recorded from Day of study 2 until the end of the observation period. A slight decrease in body weight was observed in all animals from Day 1 of study to Day 2 of study. This body weight loss was transient and body weight from all animals was higher at Day 4 of study than body weight at pre-treatment.

The LC50 of the test material in male and female rats was determined to be >2.17 mg/L, which was the maximum technically achievable concentration under the conditions of this study.

Therefore, the test material does not fulfil the criteria for classification according to Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus considered to be not acutely toxic by the inhalation route.

Acute dermal toxicity

This information is not available.

Justification for classification or non-classification

The available data indicate that the substance does not meet the classification criteria in accordance with Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).

CLP

Acute oral toxicity: not classified

Acute inhalation toxicity: not classified

Acute dermal toxicity: data lacking

GHS

Acute oral toxicity: not classified

Acute inhalation toxicity: not classified

Acute dermal toxicity: data lacking