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Chemical Sampling Information (CSI)
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General Description

Synonyms: Cristobalite; Cristobalite dust

OSHA IMIS Code Number: 9015

Chemical Abstracts Service (CAS) Registry Number: 14464-46-1

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: VV7330000

NIOSH Pocket Guide to Chemical Hazards - Silica, Crystalline, Respirable Dust: Chemical description, physical properties, potentially hazardous incompatibilities, and more





Exposure Limits and Health Effects

Exposure Limit

Limit Values

HE Code

Health Factors and Target Organs

OSHA Permissible Exposure Limit (PEL) - General Industry
See 29 CFR 1910.1000 Table Z-3

Use ½ the value calculated from the count or mass formulae for quartz

HE10

Silicosis

OSHA PEL - Construction Industry
See 29 CFR 1926.55 Appendix A

20 mppcf*

HE10

Silicosis

OSHA PEL - Shipyard Employment
See 29 CFR 1915.1000 Table Z-Shipyards

20 mppcf*

HE10

Silicosis

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL)
(Listed under Crystalline Silica)
See Appendix A

0.05 mg/m3
TWA

Ca

HE10

Silicosis

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) (2010)

0.025 mg/m3

A2

HE2

Lung cancer

HE10

Silicosis

CAL/OSHA PEL

0.05 mg/m3
TWA

 

 

*mppcf = Millions of particles per cubic foot of air

National Toxicology Program (NTP) carcinogenic classification: Known to be a human carcinogen [128 KB PDF, 3 pages]

International Agency for Research on Cancer (IARC) carcinogenic classification: Group 1 [71 KB PDF, 24 pages] (carcinogenic to humans); see also IARC Monograph 100C [980 KB PDF, 52 pages]

U.S. Environmental Protection Agency (EPA) carcinogenic classification: Not listed

EPA Inhalation Reference Concentration (RfC): Not established

Agency for Toxic Substances and Disease Registry (ATSDR) Inhalation Minimal Risk Level (MRL): Not established

NIOSH Immediately Dangerous to Life or Health (IDLH) concentration: 25 mg/m3

Notes on Other Potential Health Effects and Hazards

  1. Silicosis increases risk of tuberculosis and other respiratory diseases (American Thoracic Society 1997).
  2. Extrapulmonary silicosis has also been found, where lesions spread to the liver, spleen, kidneys, bone marrow, and extrathoracic lymph nodes (IARC 1997).

Date Last Revised: 9/6/2012

Literature Basis


Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):
  • sampling media: Tared Low Ash Polyvinyl Chloride (LAPVC) filter 5 microns preceded by 10 mm Nylon Cyclone
    maximum volume: 816 Liters
    maximum flow rate: 1.7 L/min
    current analytical method: X-ray Diffraction; XRD
    method reference: 2 (OSHA ID-142)
    method classification: Partially Validated
    note: Collect a sample of the bulk substance and send to the lab in a separate mailing container at the time the air samples are submitted. Indicate on the sample sheet that a bulk sample has been submitted. For SiO2, a high volume area or settled dust sample is preferred. Any sample weight between 0.10 mg and 5.0 mg is acceptable (0.5 to 3.0 mg is preferred). If they are present in the work environment, the following major interferences should be noted: aluminum phosphate, feldspars (microcline orthoclase, plagioclase), graphite, iron carbide, lead sulphate, micas (biotite, muscovite), montmorillonite, potash, sillimanite, silver chloride, talc and zircon (zirconium silicate). Quartz and cristobalite may be submitted on the same filter; otherwise, submit as a separate filter.

** All Trademarks are the property of their respective owners.


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