1. Bryan Seal, CIH, CSP Steve Delp, CAS
Crystalline Silica
Bryan Seal, CIH, CSP
Steve Delp, CAS

2. What is it? Silica is an oxide of Silicon (metal)
Specifically it is Silicon dioxide
It’s structure is crystalline
Very hard
Quartz
Plain old sand

3. Where do you find silica?
Foundries that use sand in mold and core-making processes
Steel and other metal processing – used in some refractories
Coal mining
Quarries and cement mills
Oil and gas well fracking operations
Construction – concrete cutting, demolition, removing old pointing

4. How are you exposed to silica?
Silica must be inhaled to be toxic
Dust particles must be small enough to enter the lungs – Respirable (<10 microns)
Any operations that create dust – falling sand, dry sweeping, cutting, grinding, blowing, shaking, dropping, chopping, shoveling and any other task that creates dust.

5. Health Effects - Silicosis
These small sharp crystalline particles collect in the lungs and over time continuously cut and irritate the lung tissue.
This causes scarring which decreases the oxygen transfer capability of the lung.
It also decreases the elasticity of the lungs which decreases flow of air into and out of lungs

7. Health Effects - Silicosis
Silicosis is progressive and can be fatal – 15 – 20 Years
Silica exposure has also been linked to lung cancer
Accelerated Silicosis – 5-10 Years
Acute Silicosis – A Few Months
200 Deaths Per Year

8. What must employers do? Know that there is silica in the workplace
Know what the silica exposure levels are
Provide training to employees
Control or eliminate silica exposures through engineering controls
Provide PPE

9. How workers can help? Recognize that silica may be present
Adopt work practices that minimize exposure
Wear PPE

10. What Is OSHA Doing? Standards (Prerule – OMB Fall 2009)
General Industry
, Ventilation
, Air contaminants
Table Z-1, Limits for air contaminants
Table Z-3, Mineral dusts Silica PEL mg/M3 - Respirable
Construction Industry
, Air contaminants
Ventilation

11. Guidance – General Industry
"Crystalline Silica Exposure" Health Hazard Information for General Industry Employees. OSHA Publication 3176, (2002). Discusses what silica is, what are its hazards, and what employers and employees can do to protect against exposures to silica.
Crystalline Silica Exposure Health Hazard Information OSHA Fact Sheet, (2002) Provides information regarding silicosis disease and exposures.
Crystalline Silica Exposure in General Industry. OSHA Health Hazard Information Card. Provides health hazard information and good work practices for workers.

12. Guidance – Construction Industry
Crystalline Silica Exposure Card for Construction. OSHA, (2002). Discusses what silica is, what are its hazards, and what employers and employees can do to protect against exposures to silica.
Crystalline Silica Exposure in the Construction Industry. OSHA.
"Crystalline Silica Exposure" Health Hazard Information for Construction Employees. OSHA Publication 3177, (2002). Discusses what silica is, what are its hazards, and what employers and employees can do to protect against exposures to silica.
Crystalline Silica Exposures in Construction. OSHA (Ellen I. Roznowski), (1997, July). Includes case studies and OSHA enforcement data.
Controlling Silica Exposures in Construction OSHA Publication , (2009). Provides information on the effectiveness of various engineering control approaches for several kinds of construction operations and equipment, and contains recommendations for work practices and respiratory protection.

13. Enforcement National Emphasis Program
National Emphasis Program – Crystalline Silica (CPL , 1/24/2008)
Local Emphasis Program – Concrete Block and Brick, Concrete Products and Ready-Mixed Concrete (CPL ) – Pittsburgh Area Office

14. Letters of Interpretation (LOIs)
02/11/
Label requirements for crystalline silica.
03/27/ &
Special emphasis program for silicosis.
05/12/ (a)(1) & (a)(2)
Respirators for silica dust must be selected based on exposure levels.
04/27/ Table Z-1; Table Z-3; ; (d); (g)
Requirements for maintaining Material Safety Data Sheets (MSDSs) for coal including coal dust, fly ash, and silica dust.

15. Wrap-up Identify, Quantify, Control Questions??
Thank you for your attention