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Talc Toxicology


Talc as a pure chemical compound is a hydrous magnesium silicate, [Mg6 (Si8O20) (OH4)], that exists in sheetlike crystalline forms or as fibers. The purity and physical form of any sample depends on the source of the talc and on the minerals found in the ore body from which it is refined. Talc can exist in many forms and depending on the ore source in can be found in a pure form or mixed with asbestos or silica. Talc used in industrial settings can contain mixtures of silica, amphibole asbestos, tremolite, actinolite, and anthophyllite. Exposure to low-grade talc may give rise to talcosilicosis or talcoasbestosis, in which cases the disease will exhibit the features of silicosis or asbestosis, respectively.

Inhalation talc exposure can result in

Talco-asbestosis closely resembles asbestosis and is produced by crystalline talc, generally inhaled with asbestos fibers. Pathologic and radiographic abnormalities are virtually identical with those of asbestosis, including calcifications and malignant tumor formation.

Talc containing more than 1% asbestos is considered a human carcinogen.


The first form, talco-silicosis, is caused by talc mined with high-silica-content mineral. Findings in this form are identical with those of silicosis.

Pure Talcosis

This type of talc is less fibrogenic than the others.
Pure talcosis results from the inhalation of pure talc without contamination from other mineral sources. It is found in occupational and non-occupational settings associated with cosmetic use of talcum powder.
Excessive use of talcum powder, as well as the accidental aspiration of talc by infants, has been associated with diffuse irregular opacities throughout the upper or lower lung fields, focal fibrosis of the small airways, bronchiolitis, and extensive fibrosis with granuloma formation.
On tissue examination, fibrosis, foreign body granulomas, and multinucleated giant cells are seen.
Radiologic abnormalities include round or irregular opacities.
Physiologic pulmonary testing reveals normal, restrictive, or mixed restrictive and obstructive abnormalities in pulmonary function.
In animals pure talc induces a cytogenic rather than fibrogenic effect on the lungs.

Intravenous Form

The fourth form, due to intravenous administration of talc, is usually associated with abuse of oral medications and production of vascular granulomas manifested by consolidations, large nodules, and masses. Talcosis may also present as a granulomatous pneumonitis and give rise to a radiological appearance of sarcoidosis or miliary tuberculosis. Such foreign body granulomas are seen especially (but not only) in intravenous drug addicts as result of the injection of crushed talc-containing tablets.

Here are a few toxicologic data sheets made available to us by The Répertoire Toxicologique de la Commission de la Santé et Sécurité du Travail du Québec :

Fibrous Talc


Main Synonyms

French names

Talc (fibreux)

English names

Talc, fibrous

Use and Sources of Emission

Manufacture of pharmaceutical products, pharmaceutical product.

Hygiene and safety


Solid fibrous, white-gray, odourless

II-Physical Properties

A- Physical State : Solid
B- Solubility in Water : 0.00 g/l at 20 °C
C- Melting Point : 0.00 °C
D- Boiling Point : 0.00 °C

III-Inflammability and Explosiveness


This product is non flammable.



This product is stable.


No known incompatibility.

C-Products of Decomposition

Information nonavailable


Avoid any contact with the skin. Wear suitable eye protection. In the case of insufficient ventilation, wear a suitable breathing apparatus.


Store in an airtight container.


Collect in a hermetic container duly identified by using a suitable technique in order to prevent the contamination of the environment.

V-Waste Disposal

Consult with the regional authority.



This product is absorbed by the respiratory tract.

II-Chronic Effects
Cancerogenic Effects

Cancerogenic to human beings.

First aid

In the event of inhalation of vapors or dust, bring the person into a ventilated place.

Quebec039;s Exposure Limit

I-Valeur d039;exposition moyenne pondérée (VEMP)

1 Fiber/cm³ (Respirable)


C1 : Cancerogenic effet demonstrated in human beings.

EM : The exposure to this substance must be reduced to a minimum.

Non Fibrous Talc (Pure)


CAS Number : 14807-96-6
Molecular Formula: H2Mg3O12Si4

Main Synonyms

French names
Talc (non fibreux)
Poudre de talc

English Names
Talc, not fibrous
Cosmetic talc.


This product can contain quartz (<1%)

Uses and Sources of Emission

Adsorption agent, manufacture of pharmaceutical products.

Hygiene and safety


Powdery, white, odourless.

II-Physical Properties

A- State : Solid
B- Molecular Mass : 379,3
C- Density : 2,7 g/ml at 20 °C
D- Solubility in Water : Insoluble
E- Fusion Point : 950 °C.

III-Inflammability and Explosiveness

Inflammability: This product is non flammable.



A. Stability

This product is stable.

B. Incompatibility

No known incompatibility for this product.

C. Decomposition Products

Information unavailable.


Wear ocular protection, and in the case of insufficient ventilation, a suitable breathing apparatus.


Preserve in an airtight container.
Preserve in a well ventilated place.


Collect wastes and put them in a dustbin.

V-Waste disposal

Put in a dustbin.


I-IDLH (Immediate danger to life and health)

1 000 mg/m³


This product is absorbed by the respiratory and digestive tracts.

III-Acute Effects
A-Possible irritation B-Digestive tract
IV-Chronic Effects
Effects on Development

Several studies in several animal species suggest the absence of effects on antenatal development.

Effects on Reproduction

No data concerning the effects on reproduction were found in the consulted documentary sources.

Data on Mother039;s Milk

There is no data concerning its excretion or detection in milk.

Cancerogenic Effects
I-Evaluation by the I.A.R.C.

It cannot be classified as for its cancerogenicity for man (group 3).

II-Evaluation by the A.C.G.I.H.

Substance not classifiable as cancerogenic for man (A4 group).

Mutagenic effects

Several studies in animal species suggest the absence of a mutagenic effect.

First aid

I-Ocular Contact

Rinse eyes with plenty of water and see a doctor. Wash skin with soap and water.


Provoke vomiting if the patient is conscious.


Bring the person into a ventilated place.

Quebec039;s exposure limit

Valeur d039;exposition moyenne pondérée (VEMP)
Respirable dust : 3 (mg/m³)

Massive Talc (Soapstone)


CAS Number : 14378-12-2

Molecular Formula : H2MG3O12SI4

Main Synonyms

French names

Pierre à savon

English names:

Massive talc

Uses and Sources of Emission

Soapstone is a steatite stone and its primary components are magnesite, dolomite, chlorite, and talc.
For thousands of years, soapstone has been used throughout the world for tools, karafes, vases, goblets, sculptures, fireplaces, etc.
In early American history, soapstone was used primarily for building blocks, sculpting and urns.
In early New England, Soapstone uses ranged fom fireplace hearths to countertops, sinks, and oven fireplace stoves.
Currently in the USA and in different parts of the world, soapstone is used for the largest variety of items ever yet - including balusters, stair treads, window sills and island tops.
For over one hundred years, soapstone sinks and tiles have been used in science class rooms and labs along with work tables and counter tops. Its longevity to long term - high traffic use is amazing!
Because of its truly remarkable and natural heat retention characteristics, soapstone is widely used for masonry heater fireplaces, wood stoves, fireplace liners and pizza ovens.
It is also used as a colourant.

Hygiene and safety

I- Appearance
Powdery, white, odourless.
II- Physical properties

A-Physical State : Solid
B-Molecular Mass : 379,2
C-Density : 2,75 g/ml at 20 °C
D-Solubility in Water : Insoluble.

III- Inflammability and Explosiveness

Inflammability : This product is non flammable.



This product is stable.

No known incompatibility for this product

C-Products of Decomposition
Information non available


Ventilate adequately if not wear a suitable breathing apparatus


Collect waste and put in a hermetic container.

IV-Waste disposal

Consult with the regional office of the Department of the Environment.


I- IDLH (Immediate Danger to Life and Health)

3 000 mg/m³

II- Absorption

This product is absorbed by the respiratory tract.

III- Chronic Effects
Fibrotic pneumoconiosis

First aid


Rinse eyes with plenty of water.


In the event of inhalation of vapors or dust, bring the person into a ventilated place.
If he does not breathe, give the artificial respiration.
Call a doctor.

Quebec039;s Exposure Limit

Valeur d039;Exposition Moyenne Pondérée (VEMP)

Respirable dust : 3 (mg/m³)

Total dust : 6 (mg/m³)

Note : The limit applies to dust not containing asbestos and in which the percentage of crystalline silica is lower than 1 %.

References :
  1. Occupational Medicine,Carl Zenz, last edition.
  2. Clinical Environmental Health and Toxic Exposures, Sullivan & Krieger; last edition.
  3. Sax039;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. CSST-Québec, Service du Répertoire Toxicologique, 2005

By Edouard Bastarache

Related Information


Hazards Asbestos: A Difficult-to-Repace Material
Hazards Talc Hazards Overview
Talc is invaluable in the ceramics industry, it is used as a glaze and body ingredient and as a parting a release agent in various processes. Is it safe?
Materials Talc
A source of MgO for ceramic glazes, a flux or thermal expansion additive in clay bodies, also used in the manufacture of cordierite.
Materials Pioneer 2661 Talc
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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