Sodium metaphosphate

Acute Toxicity: other routes

Administrative data

Endpoint:

acute toxicity: other routes

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Documentation insufficient for assessment

Data source

Reference

Reference Type:

secondary source

Title:

The influence of chain length on the metabolic fate of condensed phosphates

Author:

Gosselin RE, Megirian R

Year:

1955

Bibliographic source:

J Pharmacol Exp Ther. 115(4):402-7; PMID: 13272192

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The respective LD50 values are cited from another publication, namely: Gosselin RE, Tidball CS, Megirian R, Maynard EA, Downs WL, Hodge HC, Metabolic acidosis and hypocalcemia as toxic manifestations of polymeric phosphates, J Pharmacol Exp Ther. 1953 ;108(1):117-27.

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium metaphosphate

EC Number:

233-343-1

EC Name:

Sodium metaphosphate

Cas Number:

10124-56-8

Molecular formula:

H6O18P6.6Na

IUPAC Name:

Sodium metaphosphate

Details on test material:

- Name of test material (as cited in study report): hexametaphosphate; NaMP-6

Test animals

Species:

rat

Strain:

not specified

Sex:

female

Details on test animals or test system and environmental conditions:

no data

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

not specified

Details on exposure:

single i.p. injections in rats weighing 200 to 300 grams.

Doses:

no data

No. of animals per sex per dose:

no data

Control animals:

not specified

Statistics:

All concentrations given were converted from grams phosphorus (as they were expressed in the article) to grams of the respective test compound.

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

632.11 mg/kg bw

Remarks on result:

other: Calculated from the given value (59 mg P/kg bw) using the molecular masses of phosphorus (90.97 g/mol) and sodium hexametaphosphate (611.77 g/mol).

Other findings:

The main cause for the observed mortalities seems to be severe metabolic acidosis due to hydrolytic release of phosphate / phosphoric acid.

Applicant's summary and conclusion

Conclusions:

This article cites a LD50 (i.p. rat) for sodium hexametaphosphate of 632.11 mg/kg bw, as calculated from the given value (192 mg/kg bw) which is expressed as amount of phosphorus. The main cause for the observed mortalities seems to be severe metabolic acidosis due to hydrolytic release of phosphate / phosphoric acid.

Executive summary:

This article gives information on the acute toxicity of sodium hexametaphosphate after single i.p. injection. The given value is based on an earlier publication of the same author (Gosselin RE, Tidball CS, Megirian R, Maynard EA, Downs WL, Hodge HC, Metabolic acidosis and hypocalcemia as toxic manifestations of polymeric phosphates, J Pharmacol Exp Ther. 1953 ;108(1):117-27) which can be assumed to give further details on the experimental procedure.

The cited value for the LD50 (i.p., rat) is 192 mg phosphorus per kg body weight which can be converted into 632.11 mg/kg bw sodium hexametaphosphate using their molecular masses of 30.97 and 611.77 mg/kg bw, respectively. The main cause for the observed mortalities seems to be severe metabolic acidosis due to hydrolytic release of phosphate / phosphoric acid.