At least 1.7 million U.S. workers are exposed to respirable crystalline silica in a variety of industries and occupations, including construction, sandblasting, and mining. Silicosis, an irreversible but preventable disease, is the illness most closely associated with occupational exposure to the material, which also is known as silica dust. Occupational exposures to respirable crystalline silica are associated with the development of silicosis, lung cancer, pulmonary tuberculosis, and airways diseases. These exposures may also be related to the development of autoimmune disorders, chronic renal disease, and other adverse health effects.
Please note: For information about health effects from dust particles in environments outside of the workplace, see websites of the United States Environmental Protection Agency "Particulate Matter" and the CDC "Air Pollution and Respiratory Health".
NIOSHTIC-2 search results on Silica
NIOSHTIC-2 is a searchable bibliographic database of occupational safety and health publications, documents, grant reports, and journal articles supported in whole or in part by NIOSH.
NIOSH Hazard Review: Health Effects of Occupational Exposure to Respirable Crystalline Silica
NIOSH Publication No. 2002-129 (April 2002)
This Hazard Review describes published studies and literature on the health effects of occupational exposure to respirable crystalline silica among workers in the U.S. and many other countries. Occupational exposures to respirable crystalline silica are associated with the development of silicosis, lung cancer, pulmonary tuberculosis, and airways diseases. These exposures may also be related to the development of autoimmune disorders, chronic renal disease, and other adverse health effects.
OSHA/NIOSH Hazard Alert: Worker Exposure to Silica during Countertop Manufacturing, Finishing and Installation
NIOSH Publication No. 2015-106 (2015)
The Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) have identified exposure to silica as a health hazard to workers involved in manufacturing, finishing and installing natural and manufactured stone countertop products, both in fabrication shops and during in-home finishing/installation. This hazard can be mitigated with simple and effective dust controls in most countertop operations.
Criteria for a Recommended Standard–Crystalline Silica
NIOSH Publication No. 75-120 (1974)
This report presents the criteria and recommended standards for preventing occupational diseases arising from exposure to crystalline variants of free silica. Criteria presented in this document do no pertain to amorphous, noncrystalline forms of silica.
Current Intelligence Bulletin No. 36: Silica Flour: Silicosis (Crystalline Silica)
NIOSH Publication No. 81-137 (1981)
This report warns producers and users of silica flour that the risk of developing silicosis may be very high for exposed workers.
Alert: Request for Assistance in Preventing Silicosis and Deaths from Sandblasting
NIOSH Publication No. 92-102 (1992)
This Alert describes 99 cases of silicosis from exposure to crystalline silica during sandblasting. Of the 99 workers reported, 14 have already died from the disease, and the remaining 85 may die eventually from silicosis or its complications.
Alert: Request in Preventing Silicosis and Deaths in Rock Drillers
NIOSH Publication No. 92-107 (1992)
This Alert describes 23 cases of silicosis from exposure to crystalline silica during rock drilling. Of the 23 workers reported, 2 workers have already died from the disease, and the remaining 21 may die eventually from silicosis or its complications.
NIOSH Alert: Request for Assistance in Preventing Silicosis and Deaths in Construction Workers
NIOSH Publication No. 96-112 (1996)
This Alert describes six case reports of construction workers who have died or are suffering from silicosis. In addition, the Alert cites examples of five construction operations that used poor dust controls and two operations that used good dust controls.
Occupational Health Guideline for Amorphous Silica [PDF - 199 KB]
This guideline is intended as a source of information for employees, employers, physicians, industrial hygienists and other occupational health professionals who may have a need for information on amorphous silica.
Occupational Health Guideline for Crystalline Silica [PDF - 232 KB]
This guideline is intended as a source of information for employees, employers, physicians, industrial hygienists and other occupational health professionals who may have a need for a need for information on crystalline silica.
OSHA NIOSH Hazard Alert: Worker Exposure to Silica During Hydraulic Fracturing [PDF - 2 MB]
DHHS (NIOSH) Publication No. 2012-166 (2012)
This Hazard Alert discusses the health hazards associated with hydraulic fracturing and focuses on worker exposures to silica in the air. It covers the health effects of breathing silica, recommends ways to protect workers, and describes how OSHA and NIOSH can help.
NIOSH B-Reader Program
NIOSH B Reader certification is granted to physicians who demonstrate proficiency in the classification of chest x-rays for the pneumoconioses using the International Labour Office (ILO) Classification System. The NIOSH Chest Radiography Topic Page has searchable databases of NIOSH B readers and successful international examinees.
Spirometry Monitoring Technology
NIOSH topic page with link to software for Spirometry Longitudinal Data Analysis (SPIROLA).
Spirometry Training Course
Information about training for those individuals who will be administering screening pulmonary function testing to employees who are exposed to cotton dust.
Respiratory Protection Recommendations for Airborne Exposures to Crystalline Silica
NIOSH Publication No. 2008-140 (July 2008)
NIOSH recommends the use of half-facepiece particulate respirators with N95 or better filters for airborne exposures to crystalline silica at concentrations less than or equal to 0.5 mg/m3.
NIOSH Respirators Topic Page
Provides information about respirators, including user notices, respirator selection, respirator certification processes, standards and rulemaking.
Certified Equipment List
Database of all certified respirators and coal mine dust personal sampler units.
NIOSH Training Videos
Some NIOSH video programs are available online in streaming and downloadable formats. All NIOSH video programs can be borrowed (and copied) free of charge.
A Guide To Working Safely With Silica: If It's Silica, It's Not Just Dust (1997)
This guide, a cooperative effort between the Department of Labor and NIOSH, explains how you can protect yourself and others if you work in one of the dozens of industries where dust containing silica is present.
Press Release on Joint Campaign on Silicosis Prevention
Reprint of original press release from the U.S. Department of Labor - Office of Public Affairs
NIOSH Manual of Analytical Methods (NMAM) (3rd Supplement)
NIOSH Publication No. 2003-154 (2003)
NMAM is a collection of methods for sampling and analysis of contaminants in workplace air, and in the blood and urine of workers who are occupationally exposed. These methods have been developed or adapted by NIOSH or its partners and have been evaluated according to established experimental protocols and performance criteria. NMAM also includes chapters on quality assurance, sampling, portable instrumentation, etc.
- NIOSH Method 7501 - Silica, Amorphous [PDF - 44 KB]
- NIOSH Method 7500 - Silica, Crystalline, by XRD [PDF - 50 KB]
- NIOSH Method 7601 - Silica, Crystalline [PDF - 97 KB]
NIOSH Method 7602 - Silica, Crystalline (IR) [PDF - 130 KB]
En Español [PDF - 231 KB]
- NIOSH Method 7603 - Silica in coal mine dust [PDF - 120 KB]
NIOSH Pocket Guide to Chemical Hazards
Exposure limits, Respirator Recommendations, First Aid, more...
The Pocket Guide is a source of general industrial hygiene information on several hundred chemicals/classes found in the work environment. Key data provided for each chemical/substance includes name (including synonyms/trade names), structure/formula, CAS/RTECS Numbers, DOT ID, conversion factors, exposure limits, IDLH, chemical and physical properties, measurement methods, personal protection, respirator recommendations, symptoms, and first aid.
Through the NIOSH Worker Notification Program , NIOSH notifies workers and other stakeholders about the findings of past research studies related to a wide variety of exposures. The links below present archival materials sent to participants in studies related to crystalline silica exposure.
Occupational Respiratory Disease Surveillance (ORDS)
NIOSH Topic Page about occupational respiratory disease medical screening and monitoring.
Atlas of Respiratory Disease Mortality, United States: 1982-1993
NIOSH Publication No. 98-157 (1998)
This report presents maps showing geographic distributions (by health service area) of mortality associated with selected respiratory conditions that together represent nearly all respiratory diseases. For categories of traditional occupational lung diseases mapped in this atlas (i.e., the pneumoconioses, including coal workers’ pneumoconiosis, asbestosis, silicosis, byssinosis, and other and unspecified pneumoconioses), nearly all cases are attributable to hazardous occupational exposure.
MMWR: Morbidity and Mortality Weekly Reports
The MMWR weekly contains data on specific diseases as reported by state and territorial health departments and reports on infectious and chronic diseases, environmental hazards, natural or human-generated disasters, occupational diseases and injuries, and intentional and unintentional injuries. Included here are a collection of articles related to occupational exposure to silica.
Update: Silicosis Mortality - United States, 1999-2013
Jacek M. Mazurek, MD; Patricia L. Schleiff, MS; John M. Wood, MS; et al.
Morbidity and Mortality Weekly Report: June 19, 2015 /23;64:653-4
Silicosis Mortality Trends and New Exposures to Respirable Crystalline Silica - United States, 2001-2010
Morbidity and Mortality Weekly Report: February 13, 2015 / 15;64:117-20
Notes from the Field: Silicosis in a Countertop Fabricator - Texas, 2014
Morbidity and Mortality Weekly Report: February 13, 2015 / 64:129-30
Coal Workers' Pneumoconiosis-Related Years of Potential Life Lost Before Age 65 Years --- United States, 1968–2006
Morbidity and Mortality Weekly Report: December 25, 2009 / 58(50);1412-1416.
Silicosis-Related Years of Potential Life Lost Before Age 65 Years --- United States, 1968--2005
Morbidity and Mortality Weekly Report: July 18, 2008 / 57(28);771-775.
Silicosis Deaths Among Young Adults -- United States, 1968-1994
Morbidity and Mortality Weekly Report: May 1, 1998 / 47(16);331-335.
Silicosis Mortality, Prevention, and Control --- United States, 1968--2002
Morbidity and Mortality Weekly Report: April 19, 2005 / 54(16);401-405.
Silicosis in Dental Laboratory Technicians --- Five States, 1994--2000
Morbidity and Mortality Weekly Report: March 12, 2004 / 53(09);195-197.
Fatal Illness [PDF - 1.7 MB]
NIOSH Publication No. 2002-118
Nonfatal Illness [PDF - 2.8 MB]
NIOSH Publication No. 2002-120
Focus on Mining [PDF - 1.4 MB]
NIOSH Publication No. 2002-121
Work-Related Lung Disease (eWoRLD) Surveillance System
The Work-Related Lung Disease (eWoRLD) Surveillance System, produced by the National Institute for Occupational Safety and Health (NIOSH), presents up-to-date summary tables, graphs, and figures of occupationally-related respiratory disease surveillance data on the pneumoconioses, occupational asthma and other airways diseases, and several other respiratory conditions. For many of these diseases, selected data on related exposures are also presented.
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