Siliciumcarbid

3.23 (NIOSH, 2024) - Denser than water; will sink

3.23

3.2 g/cm³

3.23

3.16 @25 °C

3.23

EXCEEDINGLY HARD, GREEN TO BLUISH-BLACK, IRIDESCENT, SHARP CRYSTALS

HEXAGONAL OR CUBIC

Yellow to green to bluish black, iridescent crystals.

Insoluble (NIOSH, 2024)

INSOL IN COLD WATER, HOT WATER, & ACID; SOL IN FUSED POTASSIUM HYDROXIDE

INSOL IN ALCOHOL; SOL IN MOLTEN IRON

Solubility in water: none

Insoluble

Sublimes (NIOSH, 2024)

sublimes

Sublimes

4892 °F (Sublimes) (NIOSH, 2024)

2600 °C

4892 °F (sublimes)

2830 °C

4892 °F (Sublimes)

0 mmHg (approx) (NIOSH, 2024)

0 mmHg (approx)

0 mmHg (approx)

9.30 eV

9.30 eV

Silicon carbide appears as yellow to green to bluish-black, iridescent crystals. Sublimes with decomposition at 2700 °C. Density 3.21 g cm-3. Insoluble in water. Soluble in molten alkalis (NaOH, KOH) and molten iron.

Dry Powder; Wet Solid; CBI; Large Crystals; Other Solid; Dry Powder; Liquid

Yellow to green to bluish-black, iridescent crystals; [NIOSH]

YELLOW-TO-GREEN-TO-BLUE-TO-BLACK CRYSTALS, DEPENDING ON PURITY.

Yellow to green to bluish-black, iridescent crystals.

Yellow to green to bluish-black, iridescent crystals.

DIELECTRIC CONSTANT: 7.0; HARDNESS: 9.5; ELECTRON MOBILITY: GREATER THAN 100 SQ CM/VOLT-SEC; HOLE MOBILITY: GREATER THAN 20 SQ CM/VOLT-SEC; BAND GAP ENERGY: 2.8 ELECTRON-VOLTS

SUBLIMES WITH DECOMPOSITION AT 2700 °C

EXCELLENT THERMAL CONDUCTIVITY; ELECTRICALLY CONDUCTIVE; RESISTS OXIDATION AT HIGHER TEMPERATURES

Danger

H350i: May cause cancer by inhalation [Danger Carcinogenicity]

P203, P280, P318, P405, and P501 (click each P-code to see the statement)

This chemical does not meet GHS hazard criteria for 70.3% (740 of 1053) of all reports.

Danger

H350i (16.6%): May cause cancer by inhalation [Danger Carcinogenicity]

Chemical: Silicon carbide (SiC)

Hazard Traits - Carcinogenicity

Hazard Traits - Carcinogenicity

Silicon carbide (SiC) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Silicon carbide (SiC) are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 08-05-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/15540

Silicon carbide: Does not have an individual approval but may be used under an appropriate group standard

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.

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 15 mg/cu m. /Total dust/

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 5 mg/cu m. /Respirable fraction/

Vacated 1989 OSHA PEL TWA 10 mg/cu m is still enforced in some states. /Total/

Vacated 1989 OSHA PEL TWA 5 mg/cu m is still enforced in some states. /Resp/

Fresh air, rest.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Excerpt from NIOSH Pocket Guide for Silicon carbide:

(General first aid procedures)

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

10.0 [mg/m3], (inhalable particulate matter), 3 mg/m3 (respirable fraction) [nonfibrous forms], 0.1 respirable fibers/cc [fibrous forms]

8 hr Time Weighted Avg (TWA): 10 mg/cu m. /Nonfibrous silicon carbide; inhalable fraction; particulate matter containing no asbestos & <1% crystalline silica/

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded. /Nonfibrous and fibrous (incl whiskers) forms of silicon carbide/

8 hr Time Weighted Avg (TWA): 3 mg/cu m. /Nonfibrous silicon carbide; respirable fraction; particulate matter containing no asbestos & <1% crystalline silica/

8 hr Time Weighted Avg (TWA): 0.1 fibers/cc. /Respirable fibers: length > 5 um; aspect ratio greater than or equal to 3:1, as determined by the membrane filter method at 400-450X magnification (4-mm objective), using phase-contrast illumination; fibrous forms of silicon carbide (incl whiskers)/

A2; Suspected human carcinogen. /fibrous forms of silicon carbide (incl whiskers)/

Cough.

Redness. Pain.

irritation eyes, skin, upper respiratory system; cough

SLIGHT RADIOGRAPHIC CHANGES /OCCURRED/ IN 10 OF 32 WORKERS EXPOSED ... TO SILICON CARBIDE. MOST ... HAD WORKED FOR 15 YR OR MORE IN DUSTY ATMOSPHERES WITH AVG DUST COUNT OF 1200 PARTICLES/CC (34 MPPCF) & AVG PARTICLE DIAMETER OF 1 MICRON. ALL CASES WERE TUBERCULIN POS. THOSE PRESENTING PULMONARY CHANGES HAD ... SLIGHT RESP SYMPTOMS.

ACUTE LOCAL: INHALATION 1; IRRITANT 1. CHRONIC LOCAL: INHALATION 1. 1= SLIGHT: CAUSES READILY REVERSIBLE CHANGES WHICH DISAPPEAR AFTER END OF EXPOSURE.

Nuisance particulate (accumulation in lungs).

Silicon carbide can alter the course of inhalation tuberculosis leading to extensive fibrosis and progressive disease.

For more Human Toxicity Excerpts (Complete) data for SILICON CARBIDE (6 total), please visit the HSDB record page.

Silicon carbide whiskers

Group 2A: Probably carcinogenic to humans

Volume 111: (2017) Some Nanomaterials and Some Fibres

2017

2014

SILICON CARBIDE PRODUCED NO FIBROSIS OF LUNGS IN NORMAL EXPERIMENTAL ANIMALS, BUT PROFOUNDLY ALTERED THE COURSE OF INHALATION TUBERCULOSIS, LEADING TO EXTENSIVE FIBROSIS & PROGRESSIVE DISEASE. ... INERT REACTION RESULTED WHEN SILICON CARBIDE WAS INJECTED IP IN GUINEA PIGS.

WOUNDING MOUSE SKIN BY STRIPPING WITH SILICON CARBIDE PAPER LED TO MARKED INDUCTION OF ORNITHINE DECARBOXYLASE ACTIVITY. ACTIVITY WAS MAX BETWEEN 20 & 26 HR AFTER WOUNDING, WITH SECONDARY RISE @ 72 HR.

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]

Abrasive Blasting [Category: Clean]

Polishing glass, granite; smoothing bisque ware; in sharpening stones; abrasive;manufacture /of/ porcelain, "emery" paper and wheels, shoe soles, refractory brick, furnace linings; antiskid pavements; in semiconductor technology.

COMPONENT OF TREADS & BRAKE LININGS; COMPONENT OF HEATING ELEMENTS FOR ELECTRICAL FURNACES; FIBERS IN MATERIALS TO RESIST HIGH RE-ENTRY TEMPS & ROCKET NOZZLE COMPOSITES; COMPONENT OF THERMISTORS & VARISTORS; STRUCTURAL COMPONENTS IN NUCLEAR REACTORS; DEOXIDANT IN FERROUS METALLURGY.

Abrasive for cutting and grinding metals, grinding wheels, refractory in non-ferrous metallurgy, ceramic industry and boiler furnaces, composite tubes for steam reforming operations. Fibrous form used in filament-wound structures and heat-resistant, high-strength composites.

(1972) 4.5X10+9 GRAMS

(1975) 5.79X10+8 GRAMS

(1972) 9.7X10+10 GRAMS (CRUDE & REFINED)

(1975) 7.73X10+10 GRAMS (CRUDE)

2023: 5,000,000,000 - <10,000,000,000 lb

(1972) 1.49X10+11 GRAMS (CRUDE)

(1975) 1.22X10+11 GRAMS (CRUDE)

REACTION OF SILICA SAND AND COKE OR ANTHRACITE COAL AT HIGH TEMPERATURES.

MADE BY HEATING COKE & SAND (& SALT AS FLUX) IN ELECTRIC FURNACE.

EPA Safer Chemical Functional Use Classes -> Processing Aids and Additives

Safer Chemical Classes -> Green circle - The chemical has been verified to be of low concern

Non-metallic Mineral Product Manufacturing (includes clay, glass, cement, concrete, lime, gypsum, and other non-metallic mineral product manufacturing)

Silicon carbide (SiC): ACTIVE

AVAILABLE FORMS: POWDER; FILAMENT; WHISKERS (3 MILLION PSI); SINGLE CRYSTALS.

LIQ WASTE OF NUCLEAR FUEL REPROCESSING CALCINED, PARTICLES OVERCOATED BY ALPHA-SILICON CARBIDE, GRAPHITE & FORMALDEHYDE-PHENOL RESIN, PRESSED, CARBONIZED & SINTERED FORMING BETA-SILICON CARBIDE MATRIX ENCLOSING WASTE.