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Silicon																				Related Pages
Synonyms & Trade Names
			Elemental silicon
					[Note: Does not occur freely in nature, but is found in silicon dioxide (silica) and in various silicates.]
CAS No.
			7440-21-3
	RTECS No.
			VW0400000
	DOT ID & Guide
			1346 170(amorphous powder)

FormulaSi
	Conversion
	IDLH
			N.D.See: IDLH INDEX

Exposure Limits
			NIOSH RELTWA 10 mg/m3 (total) TWA 5 mg/m3 (resp)
					OSHA PEL TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp) See Appendix G
	Measurement Methods
			**NIOSH** 0500 , 0600
					
					See: NMAM or OSHA Methods
										
Physical Description
			Black to gray, lustrous, needle-like crystals.
					[Note: The amorphous form is a dark-brown powder.]													
										
Molecular Weight28.1	
	Boiling Point4271°F
	Melting Point2570°F
	SolubilityInsoluble
	Vapor Pressure0 mmHg (approx)
	Ionization PotentialNA											
Specific Gravity(77°F): 2.33	
	Flash PointNA
	Upper Explosive LimitNA
	Lower Explosive LimitNA
	
	Minimum Explosive Concentration160 g/m3
Combustible Solid in powder form.
Incompatibilities & Reactivities
			Chlorine, fluorine, oxidizers, calcium, cesium carbide, alkaline carbonates
Exposure Routes
			inhalation, ingestion, skin and/or eye contact
Symptoms
			irritation eyes, skin, upper respiratory system; cough
Target Organs
			Eyes, skin, respiratory system
										
Personal Protection/Sanitation
			(See protection codes) **Skin:**No recommendation
							**Eyes:**Prevent eye contact
							**Wash skin:**No recommendation
							**Remove:**No recommendation
							**Change:**No recommendation
	First Aid
			(See procedures)**Eye:**Irrigate immediately
							**Breathing:**Fresh air
							**Swallow:**Medical attention immediately
Respirator Recommendations
			Not available.
				Important additional information about respirator selection
See also
			INTRODUCTION
					  ICSC CARD: 1508

			
							

			Page last reviewed:  October 30, 2019						Content
							source: 	National Institute for Occupational Safety and Health NIOSH Pocket Guide to Chemical Hazards
Introduction
Search the Pocket Guide
Chemical Names, Synonyms and Trade Names
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C
D
E
F
G
H
I
J
K
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M
N
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P
Q
R
S
T
U
V
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CAS Numbers
RTECS Numbers
Appendices
A – NIOSH Potential Occupational Carcinogens
B – Thirteen OSHA-Regulated Carcinogens
C – Supplementary Exposure Limits
D – Substances with No Established RELs
E – OSHA Respirator Requirements for Selected Chemicals
F – Miscellaneous Notes
G – 1989 Air Contaminants Update Project: Exposure Limits NOT in Effect
Type C & CE – Definitions for Type C and Type CE Respirators
Personal Protection and Sanitation Codes
First Aid Procedures Follow NIOSH Facebook
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