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Sodium Azide Toxicology


There are potters who suggest the use of Sodium Azide as a biocide in slips and gums.
"Depending on time, temperature, pH, gum can be attacked by microbes or molds. If this happens store in a cooler place, make smaller batches, adjust the pH to make a less friendly environment, or add an antiseptic i.e. NaN3
I put sodium azide in my CMC solutions - just a tiny pinch, less than 0.5% stops bacteria cold turkey". (Clayart, 2004)
We disagree with the use of this chemical for the following reasons :

Sodium azide :

An azide is a compound of hydrogen or a metal ion and the monovalent -N3 radical.
Sodium azide is used in protection airbags of cars and this use has increased a lot its production. In small amounts it is used in biology labs as an antimicrobial in reagents.

I-Experimental Toxicology :

In animals it is a poison by ingestion, skin contact, intraperitoneal, intraveinous, and subcutaneous routes.

II-Human Toxicology :

The lowest toxic dose by ingestion is 5 mg.

A-Routes of Entry :


B-Ingestion :

1-Peripheral vasodilatation :

rapidly causing a drop in the blood pressure :
-a tendancy to loose consciousness,

2-Severe cases :

Cardiovascular collapsus.

3-Cardiac Ischaemic Symptoms :

If the amount ingested is large, cardiac ischaemic symptoms and signs may occur ( 80 mg).

4-Severe Acute Intoxication (Suicide) :

-coma (brain oedema),
-cardiac arythmias,
-metabolic acidosis,
-respiratory depression,
-pulmonary oedema.

Treatment :

There is no known treatment.

C-Inhalation :

In a study among workers exposed to airborne sodium azide, most suffered from :
-periods of hypotension

Two workers exposed to large amounts of this chemical suffered from :
- RADS, Reactive Airways Dysfonction Syndrome, an asthma-like condition (delayed reaction).

Mutagenesis :

Human mutation data reported.

Hazardous Reactions :

Reacts violently with many chemicals.
Reacts with heavy metals to form dangerously explosive heavy metal azides, a particular problem in laboratory equipment and drain traps Sodium azide " per se " can be an explosion danger, following a shock or when heated rapidly

Thermal Decomposition :

When heated to decomposition it emits very toxic fumes of NOx,
and Na2O.

Azides :

Variable Toxicity.
Many azides are poisonous, and cause a fall in blood pressure, and some inhibit enzyme action, thus resembling nitrites and cyanides.
All azide salts and the acid are unstable and some decompose explosively, altough lead azide, which is one of the most important azides, is not very sensitive.

Hazardous Decomposition :
When heated to decomposition they emit highly toxic fumes.

Explosiveness :
Schock and heat will explode them.
If exposed to CS2, they form violently explosive salts.

For more pertaining information on micro-organisms and ceramic material, go to :

1-Toxicologie Industrielle et Intoxications Professionnelles, Lawerys R.R.
2-Sax's Dangerous Properties of Industrial Materials, Lewis R.

By Edouard Bastarache

Related Information


Materials Tektamer 38 Biocide
Typecodes Article by Edouard Bastarache
Edouard Bastarache is a well known doctor that has written many articles on the subject of toxicity of ceramic materials and books on technical aspects of ceramics. He writes in both English and French.

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