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Bismuth Trioxide Toxicology

Introduction

Bismuth trioxide occurs in nature as the
mineral bismite.

I-Product Identification
:

Synonyms:

-Bismuth oxide;

-bismuth yellow;

-bismuthous oxide;

-dibismuth trioxide.

CAS No.: 1304-76-3

Molecular weight: 465.96

Chemical formula: Bi2O₃

II-Uses and sources of emission
:

It is used in

-disinfectants;

-magnets;

-glass;

-ceramics;

-rubber vulcanization;

-fireproofing of papers and
polymers;

-catalysts.

It is also an astringent.

Toxicology

I-General Information
:

Few environmental measurements of
bismuth have been reported, in general ambient concentration of
bismuth appears to be low; less than 1µg/m³ in rural air
and about 1 mg/kg in soil.

The daily intake of bismuth from food
and water was estimated to range from 5 to 20 µg.

Bismuth and its compounds are considered
to be the least toxic of the heavy metals but they are not without
important human toxicity.

Previously, salts of bismuth (e.g.
salicylate) were given parenterally to humans in an attempt to
treat syphilis; and more recently, bismuth compounds have been
used as an over-the-counter drug against certain gastrointestinal
symptoms and disorders.

Severe side effects, including
gingivostomatitis and toxicity to the liver, kidney, and the
central nervous system, have been recorded. Most severe is the
encephalopathy, which, during the 1970s in France and Australia,
was associated with long-term per os treatment with high daily
doses of bismuth subnitrate and subgallate; it is considered to be
totally reversible in almost all cases if exposure to bismuth
ceases.

If occupational toxicity has occurred,
reports are not found in the pertaining literature.

II-Bismuth Trioxide Toxicity
:

A-Inhalation :

Not expected to be a health hazard.

B-Ingestion :

Low toxicity. Bismuth salts are poorly
absorbed. Should absorption occur, symptoms may include loss of
appetite, headache, skin rashes, kidney damage, and rarely mild
jaundice.

C-Skin Contact :

Not expected to be a health hazard from
skin exposure.

D-Eye Contact :

Not expected to be a health hazard.

E-Chronic Exposure :

Repeated or prolonged ingestion may
cause a "bismuth line", black spots on the gums, foul breath, and
salivation.

F-Aggravation of Pre-existing
Conditions :

No information found.

Thermal
Decomposition

When heated to decomposition bismuth
oxide emits toxic vapors of Bi.

First Aid
Measures

I-Inhalation :

Remove to fresh air. Get medical
attention for any breathing difficulty.

II-Ingestion :

Give several glasses of water to drink
to dilute. If large amounts were swallowed, get medical advice.

III-Skin Contact
:

Remove any contaminated clothing. Wash
skin with soap or mild detergent and water for at least 15
minutes. Get medical attention if irritation develops or persists.

IV-Eye Contact :

In case of contact, immediately flush
eyes with plenty of water for at least 15 minutes, lifting upper
and lower eyelids occasionally. Call a physician if irritation
persists.

Fire Fighting
Measures

I-Fire :

Not considered to be a fire hazard.

II-Explosion :

Not considered to be an explosion
hazard.

III-Fire Extinguishing Media :

Use any means suitable for extinguishing
surrounding fire.

IV-Special Information :

Use protective clothing and breathing
equipment appropriate for the surrounding fire.

Accidental Release
Measures

Ventilate area of leak or spill. Wear
appropriate personal protective equipment.

Spills: Sweep up and containerize for
reclamation or disposal. Vacuuming or wet sweeping may be used to
avoid dust dispersal.

Handling and
Storage

Keep in a tightly closed container,
stored in a cool, dry, ventilated area. Protect against physical
damage. Containers of this material may be hazardous when empty
since they retain product residues (dust, solids); observe all
warnings and precautions listed for the product.

Exposure
Controls/Personal Protection

I-USA-Airborne Exposure Limits :

A- OSHA Permissible Exposure Limit
(PEL) :

15 mg/m3 total dust, 5 mg/m3 respirable
fraction for nuisance dusts.

B- ACGIH Threshold Limit Value (TLV)

for Particulates (insoluble or poorly
soluble) Not Otherwise Specified (PNOS) :

3 mg/m3 respirable particles and 10
mg/m3 inhalable particles.

II-Ventilation System :

A system of local and/or general exhaust
is recommended to keep employee exposures below the Airborne
Exposure Limits. Local exhaust ventilation is generally preferred
because it can control the emissions of the contaminant at its
source, preventing dispersion of it into the general work area.

Personal protection

I-Personal Respirators :

Wear an appropriate respirator according
to the severity of exposure.

II-Skin Protection :

Wear protective gloves and clean
body-covering clothing.

III-Eye Protection
:

Use chemical safety goggles. Maintain
eye wash fountain and quick-drench facilities in work area.

References :

1-Occupational Medicine,Carl Zenz,
last edition.

2-Clinical Environmental Health and
Toxic Exposures, Sullivan & Krieger; last edition.

3-Sax's Dangerous Properties of
Industrial Materials, Lewis C., last edition.

4-Toxicologie Industrielle et
Intoxications Professionnelles, Lauwerys R.R. last
edition.

5-Chemical Hazards of the Workplace,
Proctor & Hughes, 4th edition

6- Mallinckrodt Baker, MSDS, Bismuth
Trioxide, May 2003.

By Edouard Bastarache

Related Information

Links

Materials	Bismuth Subnitrate
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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