Silicic acid, sodium salt

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

other: Case study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Health, safety and environmental aspects of soluble silicates.

Author:

Schleyer WL and Blumberg JG (1982).

Year:

1982

Bibliographic source:

In Soluble Silicates, Falcone JS (ed). ACS Symposium Series 194, Chapter 4, 49-69.

Reference 2

Reference Type:

publication

Title:

Tod durch perorale Aufnahme von Wasserglas (Natriumsilikat).

Author:

Sigrist Th and Flury K

Year:

1985

Bibliographic source:

Z. Rechtsmed. 94, 245-250.

Reference 3

Reference Type:

review article or handbook

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Study type:

poisoning incident

Endpoint addressed:

acute toxicity: oral

Principles of method if other than guideline:

Case study

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, sodium salt

EC Number:

215-687-4

EC Name:

Silicic acid, sodium salt

Cas Number:

1344-09-8

Molecular formula:

Na2O x (SiO2)n with Molar Ratio (MR) (SiO2/Na2O): 1.5 – 4

IUPAC Name:

sodium hydroxy(oxo)silanolate

Details on test material:

Although the authors state that sodium metasilicate was used (in form of an egg preserving solution from a local drug store), the relatively low pH of 12.5 makes it more likely that a silicate solution of a molar ratio of greater than 1.0 was ingested. Moreover, egg preservatives typically contain 5-36% of 3.2 SiO2/Na2O silicate (Schleyer & Blumberg, 1982).

Method

Type of population:

general

Subjects:

68-year old women

Ethical approval:

not applicable

Route of exposure:

oral

Reason of exposure:

intentional

Exposure assessment:

not specified

Details on exposure:

Ingestion of 500 ml of an egg-preserving solution.

Results and discussion

Clinical signs:

Ingestion of 500 ml of an egg-preserving solution containing sodium  silicate in suicidal intention led to death of a 68 year old woman within 1 hour by suffocation. Aspiration of the vomited silicate solution caused obstruction of the lungs by precipitation of amorphous silica. The transformation of sodium silicate from liquid to solid occured in the lungs by means of the carbonic acid of expiration air.