Monthly Tech-Tip from Tony Hansen SignUp

No tracking! No ads!

Alumina Toxicology | Ammonia and Latex Toxicity | Antimony Oxide | Are colored porcelains hazardous? | Arsenic Oxide | Asbestos: A Difficult-to-Repace Material | Ball Clay | BARIUM and COMPOUNDS / Toxicology | Barium Carbonate | Bentonite Toxicity | Beryllium Monoxide Toxicology | Bismuth Trioxide Toxicology | Boron Compounds and Their Toxicity | Brown Stain | Cadmium Toxicity | Calcium Carbonate Toxicology | Carbon Monoxide Toxicity | Cesium Toxicology | Chromium Compounds Toxicology | Clay Toxicity | Cobalt Oxide and Carbonate | Cobalt Toxicology | Copper Compounds Toxicology | Copper Oxide and Carbonate | Cristobalite Toxicity | Cryolite and Ceramics | Dealing With Dust in Ceramics | | Dioxins in Clays | Epsom Salts | Eye Injuries Due to Radiation | Feldspar | Fighting Micro-Organisms in Ceramics | Fluorine Gas | Fumes from gas kilns | Gallium Oxide Toxicology | Hafnium Oxide Toxicty | Hydrofluoric Acid Toxicity | Iron oxide and Hematite | Lead Chromate | Lead in Ceramic Glazes | Lead Toxicology | Lithium Carbonate Toxicity | Lithium Toxicology | Man-Made Vitreous Fibers (MMVF) Toxicology | Man-Made Vitreous Fibers Safety Update | Manganese and Parkinsons by Jane Watkins | Manganese in Clay Bodies | Manganese Inorganic Compounds Toxicology | Manganese Toxicity by Elke Blodgett | Manganese: Creativity and Illness by Dierdre O'Reilly | Molybdenum Compounds Toxicology | Nickel Compounds Toxicity | Niobium Oxide Toxicity | Occupational Dermatoses | Overview of Material Safety by Gavin Stairs | Paraffin Toxicology | Perlite Toxicity | Plant Ash Toxicity | Potassium Carbonate Toxicity | Pregnancy and Ceramics | Propane Toxicology | Quartz Toxicity | Quartz Toxicity on Clayart | Rare Earth Compounds Toxicity | Rubidium and Cesium Toxicology | Rutile Toxicology | Silicosis and Screening | Silver Compounds Toxicology | Sodium Azide Toxicology | Sodium Carbonate Toxicology | Sodium Silicate Powder Toxicology | Stannous Chloride Toxicity | Strontium Carbonate Toxicity Note | Sulfur Dioxide Toxicity | Talc Hazards Overview | Talc Toxicology | Thallium Oxide Toxicology | The Use of Barium in Clay Bodies | Thorium Dioxide Toxicity | Tin Inorganic Compounds | Titanium Dioxide Toxicology | Toxicological Assessment of Zeolites | Tungsten Compounds Toxicology | Understanding Acronyms on MSDS's | Uranium and Ceramics | Vanadium and Compounds Toxicology | Vermiculite | Zinc Compounds Toxicology | Zirconium Compounds Toxicity | Zirconium Encapsulated Stains Toxicity

Diatomaceous Earth Toxicology

Synonyms

Diatomite, diatomaceous silica, infusorial earth.

Uses

In the production of filters, polishes, absorbents, insulators.

Toxicity

Amorphous silica, natural diatomaceous earth, is usually considered to be of low toxicity; however, pure amorphous silica is rarely found. Depending on the source, it may contain a low percentage of contaminating quartz, rarely over 2%; characteristically, natural diatomite contains no measurable cristobalite.

Processing of amorphous silica by high-temperature calcining, with or without the concomitant use of fluxing agents, alters the silica from the benign amorphous to the pathogenic form (cristobalite), which causes lung fibrosis.

Non-flux-calcined diatomite may contain from 20% to 30% cristobalite, flux-calcined diatomite may contain as much as 60% cristobalite. Calcined diatomite can produce a severe and disabling pneumoconiose, which is attributed to its cristobalite content. Although a form of silicosis, it characteristically produces pathologic and radiographic changes, which are different from classical quartz silicosis. Diffuse rather than nodular changes are more common.

There is no evidence to associate any form of diatomaceous earth with human cancer.

The IARC concluded that evidence is inadequate to describe amorphous silica as carcinogenic in either experimental animals or humans. The IARC concluded that crystalline silica is a probable human carcinogen.

Quebec's exposure limit

VEMP (Valeur d'Exposition Moyenne Pondérée) =3D 6mg/m³ (Total dust), if the crystalline silica content is < 1%.

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.

By Edouard Bastarache

Related Information

Links

Materials Diatomaceous Earth
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.

Got a Question?

Buy me a coffee and we can talk

 


https://backup.digitalfire.com, All Rights Reserved
Privacy Policy