Crystalline Silica • SiO2 –silicon dioxide • Also known as “free silica” • Significantly more hazardous than amorphous silica • 3 mineralogical forms • Quartz—most common • Cristobalite • Tridymite
Application of the NEP • General Industry—1910 • Construction--1926
Features of NEP • Expands 1996 SEP memorandum • Provides updated research results on silica exposure hazards • Details inspection procedures, including follow-up inspections where overexposure found • Addresses targeting of worksites and provides updated NAICS codes for industries with worker exposure to crystalline silica • Explains calculation of PELS in General Industry, Construction, and Maritime • Establishes program evaluation procedures • Provides for Regional and Area Office outreach programs
Goals of NEP • Eliminate employee overexposure • Control health hazards associated with overexposure
Health Effects of Crystalline Silica • Silicosis • Chronic, accelerated, acute • A continuing problem • Lung cancer • Tuberculosis • Chronic obstructive pulmonary disorder • Other • Immunologic disorders and autoimmune diseases • Renal disease • Stomach and other cancers
Symptoms and Signs of Chronic Silicosis NOTE: There may be no symptoms in the early stages. • As the diseaseprogresses • Cough • Breathlessness • Weakness • Significant X-ray changes after 15-20 years of exposure
Symptoms of Related Illnesses (such as Tuberculosis) • Fever • Weight loss • Night sweats • Chest pains • Respiratory failure These symptoms can become worse over time, leading to death.
Exposure to Crystalline Silica • High historical exposures • Sandblasting • Mining (regulated by MSHA) • Tunneling • Granite cutting • Sand-casting foundry operations • Other exposures—see Appendix B, “Industries with Potential Overexposure to Silica”
Probable Use of Silica If you can answer YES to any of these, then it is likely that Silica is used at your work and that it is airborne. Identify factors that indicate probable use of crystalline silica Left column: Industries with exposure Middle column: Occupations with exposure Right column: Materials containing crystalline silica IndustryDo you work in any of these? OccupationsAre you one of these? MaterialsAre any of these involved? • Abrasive blasting • Asphalt pavement manufacturing • Blast furnaces • Cement manufacturing • Ceramics, clay, and pottery • Concrete mixing • Concrete tunneling • Construction (mainly cement, concrete work) • Demolition • Electronics industry • Foundry industry: grinding, molding, shakeout, core room (High Risk) • Hand molding, casting, and forming • Jack hammer operations • Manufacturing abrasives, paints, soaps, and glass • Mining • Repair or replacement of linings of rotary kilns and cupola furnaces • Rolling and finishing mills • Sandblasting (High Risk) • Setting, laying, and repairing railroad track • Steelwork • Stone, brick, and concrete block cutting, blasting, chipping, grinding, and sawing • Tunneling operations • Brickmason/stonemason • Construction laborer • Crane and tower operator • Crushing and grinding machine operator • Furnace, kiln, non-food oven operator • Grinding, abrading, buffing, and polishing machine operator • Hand molder/shaper (not jeweler) • Heavy-equipment mechanic • Janitor or cleaner • Machinist • Metals/plastics machine operator • Molding and casting machine operator • Mining machine operator • Miscellaneous material moving equipment operator • Millwright • Operating engineer • Painter who sandblasts (High Risk) • Production supervisor • Rock driller (High Risk) • Roof bolter (High Risk) • Sandblaster (High Risk) • Steelworker • Welder/cutter • See how the chance of death is increased according to occupation • Abrasives • Coal Dust • Concrete • Dirt • Filter Aids • Graphite, natural • Mica • Mineral Products • Paints • Pavement • Perlite • Plant Materials • Plastic Fillers • Polishing Compounds • Portland Cement • Sands • Silicates • Slag • Soapstone • Soil Source: OSHA’s Silica eTool
And One You May Not Usually Think of—Dental Laboratories! Source: What Dental Technicians Need to Know About Silicosis. NJDHSS.
PEL—General Industry • Quartz (respirable dust): 10 mg/m3 % respirable quartz + 2 • Cristobalite and Tridymite: use ½ of the value calculated from the formula for quartz
PEL—Construction and Maritime • Quartz (respirable dust): 250 mppcf % silica + 5 • OSHA-adopted conversion factor: 1 mppcf = 0.1 mg/m3 respirable dust
Crystalline Silica PELs: “Bottom Line” Message • Whatever the worksite: The more crystalline silica there is in the dust, the less of the dust may be breathed
Selection of Worksites for NEP • Focus: Worksites where workers are potentially exposed to levels of crystalline silica in excess of the PEL • Representative of the distribution of worksites in general industry and construction in each Region • At least 2 percent of inspections every year in each Region must be silica-related • Functionally, NEP will be a composite of LEPs
Sources for Selection • NAICS codes identified from OSHA inspection data (Appendix B) • Other sources • Workers’ comp claims data • Public health data from sources such as NIOSH • Referrals from • Local agencies • Healthcare providers • Previous inspection histories
Sources for Selection (cont’d) • Other sources (cont’d) • Dun & Bradstreet employer list • Commercial directories • Telephone listings • Local knowledge • Dodge reports for construction sites
Scope of Inspection Inspection may be expanded beyond silica-related activities if other hazards or violations are observed.
Inspection Procedures • Employee exposure monitoring, including the collection of bulk samples • Engineering and work practice controls • Respiratory protection • Hazard communication • Symptoms of silicosis in workplace • Housekeeping and hygiene • Employee exposure and medical records • Abrasive blasting
Follow-up and Evaluation • Mandatory follow-up inspections where citations for overexposure are issued • If follow-up not possible (operation concluded), written documentation of abatement efforts from employers • Where exposures cannot be reduced below the PEL • engineering and administrative controls to reduce exposures as low as possible • respiratory protection to supplement • Abatement verification data used by Office of Statistics
Follow-up and Evaluation (cont’d) • Each LEP will be evaluated for effectiveness 1 year after implementation.
Ways to Reduce Exposure • Substitute materials that have no crystalline silica • Locate employees as far as possible from dust-generation source • Isolate employees OR the source • Control rooms • Enclosures • Barriers
Moving Employees Farther from Point of Exposure Source: NIOSH Publication No. 1999-113: Control of Drywall Sanding Dust Exposures
Ways to Reduce Exposure (cont’d) • Use local exhaust ventilation (LEV systems) • Use tools with dust-collecting systems
Example of a Combination of Controls Source: What Dental Technicians Need to Know About Silicosis. NJDHSS.
Ways to Reduce Exposure (cont’d) • Use wet methods • Cutting • Chipping • Drilling • Sawing • Grinding • Clean surfaces with HEPA vacuums or wet sweeping—no compressed air!
Controls—Wet Methods Source: Dry Cutting and Grinding is RISKY BUSINESS. NJDHSS.
Ways to Reduce Exposure (cont’d) • And if other methods are not sufficient— Use Proper Respiratory Protection
Respiratory Protection Source: NIOSH Publication No. 2004-108: Silicosis: Learn the Facts!
Example of a Combination of Controls Source: NIOSH Publication No. 1999-113: Control of Drywall Sanding Dust Exposures
Outreach • Crystalline silica-related information and training materials will be available through the Regional Offices for distribution to the Area Offices and Consultation Program offices • Regions and Area Offices will develop outreach programs to support enforcement efforts
OSHA Internet Information • NEP for crystalline silica: • Go to www.osha.gov • Select Directives • Select 2008 • Look under January (1/24/08) • Other information on crystalline silica • Go to www.osha.gov • Select “S” from the alphabetical topic index • Select “Silica, Crystalline”
NIOSH Internet Information • National Institute for Occupational Safety and Health (NIOSH) website: • www.cdc.gov/niosh/topics/silica
Audience Suggestions? • Control methods for crystalline silica on your job or in your workplace? • Suggestions for “getting the word out”? • Other groups that might be interested in reducing exposure to crystalline silica?