Pentacalcium hydroxide tris(orthophosphate)

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02/02/1982 to 29-05-1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Non GLP, carried out according to recognised (older) guideline, results fully documented. Considered appropriate for use based on data available and animal welfare concerns.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: RTL-A-12: EPA US Guidelines; Hazard Evaluation: Humans and Domestic animals, Fed. Reg. 43:163, 37336-37402 (1978)

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

1981

Deviations:

yes

Remarks:

test on abraded skin and occlusive dressing

GLP compliance:

no

Remarks:

This study was conducted in compliance with RTL Quality Assurance Practices, RTL Standard Operating Procedures, and Good Laboratory Practices.

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Pentacalcium hydroxide tris(orthophosphate)

EC Number:

235-330-6

EC Name:

Pentacalcium hydroxide tris(orthophosphate)

Cas Number:

12167-74-7

Molecular formula:

Ca5HO13P3

IUPAC Name:

Calcium hydroxycalcium(1+) phosphate (4:1:3)

Constituent 2

Reference substance name:

tricalcium phosphate

IUPAC Name:

tricalcium phosphate

Test animals

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, CA.
- Age at study initiation: no data
- Weight at study initiation: 1.647 to 2.352 kg
- Fasting period before study: yes, overnight.
- Housing: Temperature controlled rooms, two to a cage in suspended steel cages (24" x 16.5" x 14").
- Diet: 'Special mixture, Gunter Bros., Morgan Hill, CA' provided ad libitum
- Water: ad libitum
- Acclimation period: no data


ENVIRONMENTAL CONDITIONS
- Temperature: 65-70°F (18.3 - 21.1°C)
- no other data on conditions.

Administration / exposure

Type of coverage:

occlusive

Vehicle:

other: the test material was moistened with physiological saline.

Details on dermal exposure:

The test material was applied to closely clipped abdominal skin beneath a protective binder. The skin was abraded on half of the animals and left intact on the others. The abrasions will be sufficiently deep to penetrate the stratum corneum, but not the dermis. A single application of the compound will be applied to the dose site.
After a 24-hour period, the binder material and test material were removed. The dose site will be wiped (not washed) to remove any remaining substance. The skin was then rewrapped in a guaze binder, three days later the binder was removed.

Duration of exposure:

24 hour

Doses:

2000 mg/kg

No. of animals per sex per dose:

4 animals/sex/dose of the test material
2 animals/sex/control

Control animals:

yes

Details on study design:

- Duration of observation period following administration: At least 14 days
- Frequency of observations and weighing: Rabbits will be weighed on days 0 (prior to treatment), 7, 14 or at death.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs and mortality will be recorded frequently the first day, and early morning and later afternoon thereafter. These animals will be observed once a day during weekends and holidays. All clinical signs will be recorded as for their onset, duration and severity.

Statistics:

not applicable

Results and discussion

Preliminary study:

no data

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no mortalities.

Clinical signs:

other: All rabbits appeared normal throughout the 14 day test. There were no apparent local dermal effects following a 24 hour exposure.

Gross pathology:

All animals appeared normal at autopsy

Other findings:

not applicable

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The dermal toxicity LD50 was > 2000mg/kg bw. No adverse effects were observed throughout the study period. In accordance with Regulation (EC) No. 1282/2008 (EU CLP) pentacalcium hydroxide tris(orthophosphate) has not to be classified for acute toxicity via the dermal route.