Silicon carbide

Agent Name
Silicon carbide
CAS Number
409-21-2
Formula
C-Si
Major Category
Mineral Dusts
Synonyms
Carbon silicide; Carborundum; Silicon monocarbide; [NIOSH] Crystolon; Carbonite; Electroln; [ACGIH]
Category
Other Mineral Dusts
Description
Yellow to green to bluish-black, iridescent crystals; [NIOSH]
Sources/Uses
Used as an abrasive and refractory material; Produced in furnaces containing petroleum coke and crystalline silica at a temperature of >2200 degrees C for 36 hours; [ACGIH]
Comments
Production workers loading and unloading furnaces are exposed to carbon monoxide, sulfur dioxide, crystalline silica, and fibrous and nonfibrous silicon carbide particles. [Rom, p. 534-5] Workers in production and manufacturing, e.g., abrasive products industry, are exposed to varying quantities of fibers (or "whiskers") that have dimensions similar to amphibole asbestos fibers. Nonfibrous particles have low to very low toxic effects on lung tissue. Silicon carbide fibers, on the other hand, can cause lung fibrosis, lung cancer, and possibly mesothelioma. Silicon carbide fibers should be counted and controlled in the same manner as asbestos fibers. [ACGIH] "Occupational exposures associated with the Acheson process are carcinogenic to humans (Group 1). Fibrous silicon carbide is possibly carcinogenic to humans (Group 2B). Silicon carbide whiskers are probably carcinogenic to humans (Group 2A)." [IARC Vol. 111] See the agent, "Acheson process, occupational exposure."
Biomedical References

Exposure Assessment

Skin Designation (ACGIH)
Insufficient data
Bioaccumulates
Yes
TLV (ACGIH)
10 mg/m3, (inhalable particulate matter), 3 mg/m3 (respirable fraction) [nonfibrous forms], 0.1 respirable fibers/cc [fibrous forms]
PEL (OSHA)
15 mg/m3(total dust), 5 mg/m3(respirable fraction) [fibrous dust]
Explanatory Notes
mp = 2700 degrees C (sublimes and then decomposes); [ACGIH]

Adverse Effects

Fibrogenic
Yes
IARC Carcinogen
Probable (2a)
ACGIH Carcinogen
Suspected Human

Diseases, Processes, and Activities Linked to This Agent

Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: