Calcium bis(dihydrogenorthophosphate)

Endpoint summary

Description of key information

Oral (similar to OECD 401, RL2), rat: LD50 > 3968 mg/kg bw for females, LD 50 > 5000 mg/kg bw for males

Dermal (similar to OECD 402, RL2), rabbit: LD50 > 2000 mg/kg bw (limit test)

Inhalation (OECD 403, RL1), rat: LC50 > 2.6 mg/L air (limit test)

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:

20/8/1984 to 7/11/1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

details on bodyweight observations during and at the end of the test period were not reported

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Principles of method if other than guideline:

Study states protocols were consitent with or exceeded the requirements of EPA and OECD guidelines at the time of the study.

GLP compliance:

not specified

Test type:

standard acute method

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Portage, Michigan
- Age at study initiation: no data
- Weight at study initiation: Male: 202-250 g
Female: 153-226 g
- Fasting period before study: 16-18 hours prior to treatment
- Housing: no data


ENVIRONMENTAL CONDITIONS: no data

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED:
dose volume to body weight ratio (mL/kg): 10

Doses:

Male: single dose of 5000 mg/kg bw
Female: 5000, 4467, 3981, 3162 mg/kg bw

No. of animals per sex per dose:

10 males / females per dose group.
40 females in control group.

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: no data
- Necropsy of survivors performed: yes (dead animals were also subject to necropsy)
- Other examinations performed: clinical signs

Sex:

male

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Sex:

female

Dose descriptor:

LD50

Effect level:

3 986 mg/kg bw

Based on:

test mat.

95% CL:

> 3 341 - < 4 757

Mortality:

Male:
At a dose level of 5000 mg/kg bw 3 out of 10 rats died within the first 24 hours (1 rat died before the first observation).
In the vehicle control group no rats died.

Female:
At a dose level of 5000 mg/kg 7 rats died within 24 hours.
At a dose level of 4467 mg/kg 7 rats died within 24 hours.
At a dose level of 3981 mg/kg 3 rats died within 24 hours.
At a dose level of 3162 mg/kg 3 rats died within 24 hours.
No rats died in the control group.

Clinical signs:

other: Male: Dose level: 5000 mg/kg. The following adverse clinical signs were noted; mild to moderate depression (9 rats), diahorrea (1 rat) and piloerection (8 rats). The survivors appeared normal within 24 hours. Dose level: 0 mg/kg. All rats appeared norma

Gross pathology:

See below for details of necropsy.

NECROPSY:

Male; dose level 5000 mg/kg.10 rats were necropsied. Observations for the rats that died during the test included evidence of salivation (1 rat); clear discharge from the nostrils (2 rats); pale lungs (1 rat), reddened lungs (1 rat), a purple-spotted thymus (1 rat), a pale liver (1 rat), darkened spleens (2 rats); test material-like fluid in the gastrointestinal tract (1 rat); a distended stomach filled with clear fluid (1 rat); reddened stomach mucosa (1 rat); pale intestines (1 rat); pale kidneys (1 rat); and gelatinous appearing intestines (1 rat). The survivors were necropsied following termination on day 14. Observations for 1 rat included pale lungs, a pale liver, a darkened spleen, test material-like fluid in the stomach and dark gelatinous-like material lining the stomach.

Male, dose level 0 mg/kg.10 rats were necropsied following termination on day 14 and appeared normal.

Female, dose level 5000 mg/kg.10 rats were necropsied. Observations for the rats that died included evidence of lacrimation (3 rats); reddish stains at the nostrils (1 rat), mottled lungs (4 rats); clear fluid in the thoraic cavity (2 rats); greenish lungs (2 rats); purple-spotted thymus (2 rats); pale livers (6 rats); darkened or dark-tipped spleens (7 rats); test material-like fluid in the gastrointestinal tract (1 rat); distended stomachs filled with clear fluid (4 rats); pale kidneys (5 rats); pale intestines (3 rats); and pale uterine horns (6 rats). The survivors were necropsied following termination on day 14 and appeared normal.

Female, dose level 4467 mg/kg. 9 rats were necropsied (1 rat was cannibalised and therefore not necropsied). Observations for the remaining rats that died during the test included yellowish anogenital stains (2 rats); evidence of lacrimation (1 rat); pale lungs (1 rat); discoloured lungs (1 rat); mottled livers (1 rat); pale kidneys (2 rats); a darkened spleen (1 rat); reddened intestines (1 rat) and gelatinous appearing intestines ( 1rat). The survivors were necropsied following termination on day 14 and appeared normal.

Female, dose level 3981 mg/kg.10 rats were necropsied. Observations for the rats that died included cannabalised facial areas (2 rats); pale lungs (3 rats); pale kidneys (4 rats); reddish-yellow gelatinous fluid in the intestines (4 rats), darkened spleens (2 rats); and a pale spleen (1 rat). The survivors were necropsied following termination on day 14 and appeared normal.

Female, dose level 3162 mg/kg.10 rats were necropsied. Observations for the rats that died included a purple-spotted thymus (1 rat); reddened lungs (3 rats); pale, dark-edged livers (3 rats); darkened spleens (2 rats); and pale kidneys ( 2 rats). The survivors were necropsied following termination on day 14 and appeared normal.

Female, dose level 0 mg/kg. 40 rats were necropsied following termination on day 14 and appeared normal.

Interpretation of results:

GHS criteria not met

Conclusions:

The LD50 of calcium bis(dihydrogenorthophosphate) in the male rat was calculated to be >5,000 mg/kg bw and the LD50 in female rats was calculated to be 3986 mg/kg bw.
This study has been selected as the key study because the results are sufficient in order to derive a reliable conclusion on classification and labelling in accordance with Regulation EC (No.) 1272/2008 (EU CLP). Calcium bis(dihydrogenorthophosphate) is not considered to be classified according to Regulation (EC) No. 1272/2008 (EU CLP).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

3 986 mg/kg bw

Quality of whole database:

The available information comprises an adequate and reliable study, and is thus sufficient to fulfill the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No. 1907/2006.

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:

26th July 2010 - 30 August 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Values for relative humidity above the range occasionally occurred, usually following room cleaning, and were considered not to have any influence on the study.

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

yes

Remarks:

Values for relative humidity above the range occasionally occurred, usually following room cleaning, and were considered not to have any influence on the study.

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS

- Source:
Harlan Laboratories B.V., Kreuzelweg 53, 5961 NM Horst / Netherlands

- Age at study initiation:
Males: 11 weeks, Females: 11 weeks

- Weight at study initiation:
Males: 300.6 to 318.0 g, Females: 189.6 to 217.6 g

- Fasting period before study:
Not applicable

- Housing:
Animals were housed in groups of 5 of the same sex in Makrolon® type-IV cages with wire mesh tops and standard softwood bedding ("Lignocel" J. Rettenmaier & Söhne GmbH & Co KG, 73494 Rosenberg / Germany, imported by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) including paper enrichment (Enviro-dri from Lillico, Biotechnology, Surrey, UK).

- Diet (e.g. ad libitum):
Animals had ad libitum access to a pelleted standard Harlan Teklad 2914C rat maintenance diet (Provimi Kliba AG, 4303 Kaiseraugst, Switzerland) batch no. 20/10 except during the period when the animals were restrained in exposure tubes. Results of the analyses for contaminants and their limits of acceptability are archived at Harlan Laboratories Ltd.

- Water (e.g. ad libitum):
Community tap water from Füllinsdorf ad libitum in water bottles, except during the period when they were restrained in exposure tubes. Results of representative analyses for contaminants are archived at Harlan Laboratories Ltd.

- Acclimation period:
Performed under Harlan Laboratories Study B68308 for eighteen days under laboratory conditions, after a clinical health examination. Only animals without any visible signs of illness were used for the study. A further observation of clinical signs was performed on the day of exposure, before exposure start.


ENVIRONMENTAL CONDITIONS
Optimal Hygienic Conditions (OHC) inside a barrier system. Air-conditioned with 10 - 15 air changes per hour, continuously monitored environment with a temperature range of 22 ± 3 °C, a relative humidity range of 30 - 70% and a 12 hour fluorescent light / 12 hour dark cycle. Values for relative humidity above the range occasionally occurred, usually following room cleaning, and were considered not to have any influence on the study. These data are not reported but retained at Harlan Laboratories Ltd. A radio program was played during most of the light period.

IN-LIFE DATES: From: Day 1 To: Day 14

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Remarks:

flow-past

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

>= 2.95 - <= 3.03 µm

Geometric standard deviation (GSD):

>= 2.97 - <= 3.06

Remark on MMAD/GSD:

Mean Mass Median Aerodynamic Diameter (µm) 3.03, 2.95 and 3.03
Geometric Standard Deviation 3.06, 2.97 and 3.04

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:
A CR3020 rotating brush aerosol generator connected to a micronizing jet mill. The aerosol generated was then discharged into the exposure chamber through a 63Ni charge neutralizer.

- Exposure chamber volume:
Not applicable (nose-only, flow-past inhalation exposure chamber)

- Method of holding animals in test chamber:
The animals were confined separately in restraint tubes which were positioned radially around the flow-past, nose-only exposure chamber. Only the nose of each animal was exposed to the test atmosphere.

- Source of air:
Compressed air was supplied by means of an oil free compressor and passed respiratory quality filters before it was introduced into the exposure system.

- Method of conditioning air:
Respiratory quality filters

- System of generating particulates/aerosols:
A dust aerosol was generated from the test item using a CR3020 rotating brush aerosol generator connected to a micronizing jet mill. The aerosol generated was then discharged into the exposure chamber through a 63Ni charge neutralizer.

- Method of particle size determination:
Mercer Impactor (Model 02-130, In-Tox. Products Inc., Albuquerque, New Mexico, U.S.A.).

- Treatment of exhaust air:
Filtered

- Temperature, humidity, pressure in air chamber:
The oxygen concentration, temperature and relative humidity of the test atmosphere were measured continuously during the exposure on test aerosol samples taken at a representative exposure port using a calibrated device. The results were recorded manually and are reported at 30 minute intervals from the start of exposure.

TEST ATMOSPHERE
- Brief description of analytical method used:
Gravimetric determinations of aerosol concentration were performed four times during exposure. The samples were collected on a Millipore®durapore filter, Type HVLP loaded in a 47 mm in-line stainless steel filter sampling device. The filters were weighed before and immediately after sampling using a calibrated balance. The test aerosol concentration was calculated from the amount of test item present on the filter and the sample volume.

- Samples taken from breathing zone:
yes

VEHICLE
No vehicle used.

Analytical verification of test atmosphere concentrations:

no

Remarks:

Gravimetric only

Duration of exposure:

4 h

Concentrations:

Mean Achieved (mg/L) 2.6
The nominal aerosol concentration was 7.5 mg/L air.
Mean Mass Median Aerodynamic Diameter (µm) 3.03, 2.95 and 3.03
Inhalable Fraction (% <4 µm) 59.8% , 61.8 and 59.9%
Geometric Standard Deviation 3.06, 2.97 and 3.04

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration:
14 days

- Frequency of observations and weighing:
All animals were observed for clinical signs at hourly intervals during exposure, immediately on removal from the restraining tubes at the end of exposure, one hour after termination of exposure and subsequently once daily for fourteen days. Individual bodyweights were recorded prior to treatment on the day of exposure (day 1) and on Days 2, 4, 8 and 15 or at death.

- Necropsy of survivors performed:
yes

- Other examinations performed:
None

Statistics:

No statistical analysis was performed as only one group was allocated to the study.

Preliminary study:

Not applicable

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2.6 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

All animals survived the scheduled observation period.

Clinical signs:

other: Slight to moderate ruffled fur was noted in all animals on test day 1, one hour after the end of the exposure and persisted slightly until test day 2 in nine animals. From test day 3 onwards, all animals were free from clinical signs until their scheduled

Body weight:

From test day 1 to test day 2, marginal to slight body weight loss was noted in all animals. Thereafter all animals gained weight until scheduled necropsy.

Gross pathology:

There were no macroscopic findings.

Other findings:

Not applicable.

The nominal aerosol concentration was 7.5 mg/L air.

Interpretation of results:

GHS criteria not met

Conclusions:

The LC50 of Calcium bis(dihydrogenorthophosphate) obtained in this study was estimated to be greater than 2.6 mg/L air (gravimetrically determined mean aerosol concentration). This was the highest technically achievable test concentration. There was no indication of relevant sex-related differences in toxicity of the test item.

In accordance with Regulation (EC) No. 1272/2008 (EU CLP) calcium bis(orthophosphate) is not considered to be classified as acutely toxic via the inhalation route.

Executive summary:

A group of five male and five female albino rats [RccHan^TM:WIST(SPF)] was exposed by nose-only, flow-past inhalation for four hours to the test item at agravimetricallydetermined mean concentration of 2.6 mg/L air.All animals were observed for clinical signs and mortality during the inhalation exposure and the subsequent 14-dayobservation period. Body weights were recorded prior to exposure on test day 1, and during the observation period on test days 2, 4, 8 and 15 before necropsy. On test day 15 all animals were sacrificed and necropsied.

The ranges of aerosol concentration, temperature, relative humidity, oxygen content and airflow rate measured during the exposure were considered to be satisfactory for a study of this type. In addition, the test item was considered to be respirable to rats.

 

All animals survived the scheduled observation period.

 

Slight to moderate ruffled fur was noted in all animals after the end of the exposure and was still present in most animals up to test day 2. Thereafter, all animals were free from clinical signs.

 

Transient body weight loss was noted in all animals from test day 1 to test day 2. Normal body weight development was observed thereafter.

 

No macroscopical findings were present at necropsy.

 

In conclusion, the LC₅₀of Calcium bis(dihydrogenorthophosphate) obtained in this study was estimated to be greater than 2.6 mg/L air (gravimetrically determined mean aerosol concentration). There was no indication of relevant sex-related differences in toxicity of the test item.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

2 600 mg/m³ air

Quality of whole database:

The available information comprises an adequate and reliable study, and is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No. 1907/2006.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20/8/1984 - 7/11/1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

details on bodyweight observations during and at the end of the test period were not reported

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

1987

Deviations:

yes

Remarks:

occlusive dressing was used, skin was abraded, exposure duration 72 hours

Principles of method if other than guideline:

Study states protocols were consitent with or exceeded the requirements of EPA and OECD guidelines at the time of the study.

GLP compliance:

not specified

Test type:

fixed dose procedure

Limit test:

yes

Species:

rabbit

Strain:

other: Stauffland albino

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Phillips Rabbitry, Soquel, California
- Weight at study initiation: 1.642 - 2.146 kg

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: abdominal skin
- % coverage: no data
- Type of wrap if used: gauze binder

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg
- For solids, paste formed: no

Duration of exposure:

72 hr

Doses:

0, 2000 mg/kg bw

No. of animals per sex per dose:

5 male and 5 female

Control animals:

other: sham-treated

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: :no data
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs

Statistics:

no data

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

A single dermal dose of 2000 mg/kg bw produced no mortalities in a mixed group of albino rabbits (5 male and 5 female).

Clinical signs:

other: All rabbits in the test group and the sham-exposed control group appeared normal throughout the 14-day test.

Gross pathology:

10 rabbits from the test material exposed group and 4 rabbits from the sham-exposed group were necropsied on day 14 and appeared normal.

Other findings:

- Other observations: local effects: Local dermal effects in the test material group included darkened dose sites, severe erythema, mild edema and the skin at the abrasion marks was separated and filled with reddish fluid and pus-like material. There were no apparent local dermal effects following a 24 hour sham-treatment.

Interpretation of results:

GHS criteria not met

Conclusions:

Calcium bis(dihydrogenorthophosphate) was found to have a dermal LD50 of >2000 mg/kg bw, therefore, calcium bis(dihydrogenorthophosphate) is not considered to be classified according to Regulation (EC) No. 1272/2008 (EU CLP).
This study has been selected as the key study because the results are sufficient in order to derive a reliable conclusion on classification and labelling in accordance with Regulation EC (No.) 1272/2008 (EU CLP).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The available information comprises an adequate and reliable study, and is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No. 1907/2006.

Additional information

Oral:

In an acute oral toxicity study (similar to OECD 401, 1985), groups of fasted young Sprague Dawley rats (10/sex and group) were given up to 5000 mg/kg bw of the test substance in water by gavage and were observed for 14 days. Males were tested only at 5000 mg/kg bw and females were tested with 5000, 4467, 3981 and 3162 mg/kg bw. At a dose level of 5000 mg/kg bw 3 out of 10 male rats and 7 out of 10 female rats died within the first 24 hours. At a dose level of 4467 mg/kg 7/10, at 3981 mg/kg bw 3/10 and at 3162 mg/kg bw 3/10 female rats died within the first 24 hours. The following clinical sings were observed: depression, piloerection, diahorrea, ptosis, prostration and ataxia. The survivors appeared normal on day 2 after treatment. At necropsy of dead rats changes in lungs, thymus, liver, spleen, stomach, intestines kidneys and uterine horns were observed. Test material-like fluid in gastrointestinal tract, a distended stomach filled with clear fluid, clear fluid in the thoracic cavity were also found in rats found dead after treatment. Rats which survived until the 14-day observation period appeared normal at necropsy.

The following LD50 after oral administration of calcium bis(dihydrohenorthophosphate) were determined: LD50 (males) > 5000 mg/kg bw; LD 50 (females) = 3986 mg/kg bw (95% CL 3341 – 4757).

 

Inhalation:

In an inhalation toxicity study (according to OECD 403), groups of 11 week old Wistar rats (5/sex) were exposed by inhalation route (nose only) to the test substance as a dust and observed for 14 days. The maximal achievable dose was 2.6 mg/L. The rats were exposed for 4 hours. The ranges of aerosol concentration, temperature, relative humidity, oxygen content and airflow rate measured during the exposure were considered to be satisfactory for a study of this type. In addition, the test item was considered to be respirable to rats. All animals survived the scheduled observation period. Slight to moderate ruffled fur was noted in all animals after the end of the exposure and was still present in most animals up to test day 2. Thereafter, all animals were free from clinical signs. Transient body weight loss was noted in all animals from test day 1 to test day 2. Normal body weight development was observed thereafter. No macroscopical findings were present at necropsy.

In conclusion, the LC50 of calcium bis(dihydrogenorthophosphate) obtained in this study was estimated to be > 2.6 mg/L air (gravimetrically determined mean aerosol concentration). There was no indication of relevant sex-related differences in toxicity of the test item.

 

Dermal:

In an acute dermal toxicity study (similar to OECD 402, 1985), groups of fasted young Stauffland albino rabbits (5/sex) were dermally exposed to the undiluted test substance for 72 hours at 2000 mg/kg bw. and observed for 14 days. The skin was abraded before treatment and test substance was hold in place by an occlusive dressing. This procedure represents a worst case scenario since the exposure duration was 72 hours instead of 24 hours and occlusive dressing and abrasion of the skin was performed. No mortality or unusual clinical signs occurred during this study. At autopsy, no abnormalities were observed. Local dermal effects in the test material group included darkened dose sites, severe erythema, mild edema and the skin at the abrasion marks was separated and filled with reddish fluid and pus-like material. Under the conditions of this study, the LD50 was considered to be > 2000 mg/kg bw.

Justification for classification or non-classification

The available data on acute oral toxicity with calcium bis(dihydrogenorthophosphate) (CAS 7758 -23 -8) do not meet the criteria for classification according to Regulation (EC) No. 1272/2008, and are therefore conclusive but not sufficient for classification.

The available data on acute inhalation toxicity with calcium bis(dihydrogenorthophosphate) (CAS 7758 -23 -8) do not meet the criteria for classification according to Regulation (EC) No. 1272/2008, and are therefore conclusive but not sufficient for classification.

The available data on acute dermal toxicity with calcium bis(dihydrogenorthophosphate) (CAS 7758 -23 -8) do not meet the criteria for classification according to Regulation (EC) No. 1272/2008, and are therefore conclusive but not sufficient for classification.