2. OSHA’s New National Emphasis Program: Crystalline Silica
Effective January 24, 2008,the Occupational Safety and Health Administration (OSHA) is implementing a National Emphasis Program (NEP) to identify, reduce, and eliminate the health hazards associated with occupational exposure to crystalline silica.

3. Crystalline Silica SiO2 –silicon dioxide Also known as “free silica”
Significantly more hazardous than amorphous silica
3 mineralogical forms
Quartz—most common
Cristobalite
Tridymite
Silica is a naturally-occurring mineral compound that occurs as both crystalline and non-crystalline (or amorphous) forms.
Crystalline silica is significantly more hazardous to workers.
Of the 3 crystalline forms, quartz is the most stable and is much more common. It is a major component of soils and is readily found inboth sedimentary and igneous rocks.
--Granite is about 30% quartz.
--Shales contain about 20% quartz.
--Beach sand or sandstone may be nearly pure quartz.
Some volcanic rock contains cristobalite and tridymite. Heating (calcining) of diatomaceous earth (amorphous silica) converts it to a product containing up to 75% cristobalite. Cristobalite is also found in superficial layers of refractory brick subjected to contact with molten metal.

4. Application of the NEP General Industry—1910 Construction--1926
Current standards for exposure to crystalline silica are
General Industry: 29 CFR
Construction: 29 CFR (a)

5. 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
In 1996, OSHA established a Special Emphasis Program (SEP) for Silicosis, which provided guidance for targeting inspections of worksites with employees at risk of developing silicosis. The SEP was a memorandum.
This National Emphasis Program (NEP) is a compliance directive that builds upon and expands the 1996 SEP by including updated information and policies and procedures adopted since 1996.
The NEP addresses targeting of worksites with elevated exposure to crystalline silica, as well as silica-related inspection procedures. NAICS = North American Industrial Classification System.
The NEP provides information based on current research regarding silica exposure hazards.
The NEP Instruction provides guidance on calculating the permissible exposure limits (PELs) for dust containing respirable crystalline silica in General Industry, Construction and Maritime industries, using the OSHA-adopted conversion factor of 0.1 milligrams per cubic meter (mg/m3) per 1 million particles per cubic foot (mppcf), described in Appendix E.
Procedures are established to evaluate the NEP.
The NEP provides for the development of outreach programs by each Region and Area Office, emphasizing the formation of voluntary partnerships to share information on effective methods for reducing or eliminating employee exposure to crystalline silica.

6. Goals of NEP Eliminate employee overexposure
Control health hazards associated with overexposure
An important feature of the NEP is the establishment of evaluation procedures to track the achievement of the Program’s goals.
These procedures are designed to ensure that the goals are measured as accurately as possible.

7. 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
Silicosis is one of the oldest known occupational diseases, identified as far back as ancient Greece. Silicosis is a disabling, nonreversible and sometimes fatal lung disease caused by breathing in a large amount of crystalline silica.
Chronic or “classical” silicosis is the most common type. It typically appears years after exposure and progresses even if exposure ceases.
Accelerated silicosis may occur 5-15 years after exposure that is more intense. It progresses more rapidly than classic chronic silicosis. It is considered a variant of chronic silicosis.
Acute silicosis results form an overwhelming exposure to crystalline silica and may occur within weeks of the exposure. An immune mechanism may be involved.
The development of silicosis is dependent on the size of the crystalline silica dust particle (with respirable particles smaller than 5 micrometers being the most hazardous), the percentage of crystalline silica in the dust in the air, the dust concentration that is breathed, and the duration of exposure.
Silicosis exposure and resultant disease are a continuing problem.
--Silicosis was associated with 13,744 U.S. fatalities from Still about 200 silicosis deaths in U.S. every year
--Silicosis was the underlying cause of death of 868 men and 46 women in non-mining occupations from

8. Symptoms and Signs of Chronic Silicosis
NOTE: There may be no symptoms in the early stages.
As the disease progresses
Cough
Breathlessness
Weakness
Significant X-ray changes
after years of exposure
Cough
Initial stages: Dry or non-productive cough when exposed to the irritant
Advanced stages: Cough that is prolonged and distressing, with sputum production
Breathlessness
Initially only while exercising
Later shortness of breath during normal activity
Wheezing if chronic obstructive bronchitis or asthma are also present
Pneumothorax and respiratory failure in advanced states
Significant X-ray changes after years of exposure

9. 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.

10. 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”
From , the industries regulated by OSHA that were most frequently recorded on U.S. death certificates for silicosis-related deaths were
Construction %
Blast furnaces, steelworks, rolling and finishing
mills %
Iron and steel foundries 5.5%
Jobs in construction with high silica exposures are
Tunnel and road construction
Excavation and earth moving
Masonry and concrete work
Demolition
Sandblasting
Exposures in general industry include
--Foundries: production of sand-based moles and cores, shakeout and knockout; finishing and grinding operations
--Manufacturing: use of silica as a raw material t produce concrete, brick, tile, porcelain, pottery, glass, abrasives, paints, and plastics
--Electronics industry: use of rock quartz
--Agricultural services sector: sorting, grading, and washing areas of food processing operations for crops such as potatoes and beans
--Food & beverage processing: use of calcined diatomaceous earth (containing cristobalite) as a filter
--Maintenance and repair of refractory brick linings of rotary kilns and cupola
--Metal refinishing: sandblasting

11. Identify factors that indicate probable use of crystalline 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
Industry Do you work in any of these?  
Occupations Are you one of these?
Materials Are 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
These industries, occupations, and materials are listed on OSHA’s Silica eTool.
Source: OSHA’s Silica eTool

12. And One You May Not Usually Think of—Dental Laboratories!
Source: What Dental Technicians Need to Know About Silicosis. NJDHSS.

13. 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
What is an overexposure in General Industry?
OSHA’s Permissible Exposure Limit (PEL) for General Industry was adopted in 1971 (from 1968 ACGIH TLVs) and represents the maximum amount of respirable dust containing crystalline silica (as quartz) that is permitted in the work environment. The standard is codified at 29 CFR
As shown by this formula the PEL, expressed as milligrams of respirable dust in a cubic meter of air, decreases as the percentage of the dust that is crystalline silica increases.
In other words, the more crystalline silica there is in the dust, the less dust you are allowed to breathe into your lungs!
Sample results are obtained by a gravimetric method.

14. PEL—Construction and Maritime
Quartz (respirable dust):
250 mppcf
% silica + 5
OSHA-adopted conversion factor:
1 mppcf = 0.1 mg/m3 respirable dust
What is an overexposure in Construction and Maritime?
The crystalline silica PELs for Construction and Maritime are found at 29 CFR (a) and respectively. These PELs are expressed in terms of millions of particles per cubic foot (mppcf) and are based on a particle count method that is obsolete.
OSHA consulted with NIOSH for help in converting sampling results obtained by the contemporary gravimetric method, to mppcf. NIOSH recommended a conversion factor of
1 mppcf – 0.1 mg/m3 respirable dust.
A detailed discussion of the use of this conversion factor can be found in Appendix E of the NEP Instruction.

15. 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

16. 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
Inspections conducted under this NEP must focus on industries and particular establishments where workers are potentially exposed to levels of crystalline silica in excess of the PEL. Additionally, the silica-related inspections must be conducted at a range of facilities representing the distribution of general industry and construction worksites in that OSHA Region.
At least 2 percent of inspections every year in each Region must be silica-related.
Each Area Office of Regional office that does not already have a Local Emphasis Program for crystalline silica, will develop and implement a LEP for crystalline silica based on one or more of the industries in Appendix B.

17. 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
The primary source for targeting inspections under the LEPs is the NAICS codes for industries with potential silica exposure, listed in Appendix B of the Instruction. This list, which was developed using OSHA inspection data from January 1996 through March 2007, provides an overview of the types of industries in which silica exposure frequently occurs. Within each region there may be specialized industries with silica exposure that are not included on the list. Likewise, silica exposure may not occur in all industries within a given SIC.
Information sources for General Industry site selection include
Workers’ Compensation claims data, especially data that have trigger entries such as silicosis, pulmonary fibrosis, nonmalignant respiratory disease, congenital heart failure, or scarring of the lung.
Public health data from NIOSH, including the state silicosis surveillance systems (SENSOR) in Ohio, New Jersey, and Michigan
Referrals from local public and environmental health agencies and healthcare providers
Previous inspection histories for companies within the office’s jurisdiction

18. Sources for Selection (cont’d)
Other sources (cont’d)
Dun & Bradstreet employer list
Commercial directories
Telephone listings
Local knowledge
Dodge reports for
construction sites
A number of other possible sources for the identification of companies and worksites with potential silica exposure exist.

19. Scope of Inspection Inspection may be expanded beyond silica-related
activities if other
hazards or violations
are observed.

20. 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
--The minimum respiratory protection for workers exposed to crystalline silica during operations other than abrasive blasting is an N95 NIOSH-approved respirator for exposures that do not exceed the assigned protection factor.
--Information regarding carcinogenicity must be included on labels and MSDSs
--Bricks and crushed stone are covered by the Hazard Communication Standard (NOTE: some crushed stone operations fall under MSHA rather than OSHA.)
--Other inspection issues for abrasive blasting operations include:
Heavy metal exposure (lead, chromium, others)
Exposure of other employees working in area
Noise
Adequacy of ventilation systems
Manual operation of blast cleaning nozzles
Breathing air quality and use
Electrical grounding
Pressure controls
Other adequate PPE
Hazards of alternative abrasive materials

21. 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
It may not be possible to carry out follow-up inspections of some employers, e.g., construction sites or temporary abrasive blasting operations.
Once the Office of Statistics has received a reasonable number of case files and follow-up site visit reports, the data will be evaluated to determine the impact of OSHA inspections on the reduction of crystalline silica exposures at each worksite.

22. Follow-up and Evaluation (cont’d)
Each LEP will be evaluated for
effectiveness 1 year after
implementation.
If the LEP is determined to be effective AND there are still enough employers to be inspected under the procedures of the NEP, the LEP may be renewed.
If the LEP is determined to be ineffective, OR If the LEP is determined to be effective BUT there are too few employers remaining, different industries from Appendix B will be selected and a new LEP developed and implemented.

23. 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
Although there are many possible substitutes for silica sand in sandblasting, many of them can create serious exposures to heavy metals and other contaminants. Use of substitutes in sandblasting needs to be carefully evaluated.
It is important to keep employees who are not actively involved in sandblasting as far from the work as possible.

24. Moving Employees Farther from Point of Exposure
NIOSH study results suggest that the dust exposures of construction workers doing drywall sanding might be cut simply by changing from hand-sanding to pole sanding. This change is even more important when working overhead. The pole increases the space between the worker and the sanding surface, which in turn reduces the amount of dust close to the worker’s nose and mouth.
The pole sander shown in this photo is also equipped with a vacuum, which helps to collect the dust before it enters the breathing zone of the employee.
Source: NIOSH Publication No : Control of Drywall Sanding Dust Exposures

25. Ways to Reduce Exposure (cont’d)
Use local exhaust ventilation (LEV systems)
Use tools with dust-collecting
systems

26. Example of a Combination of Controls
Enclosure of the process and local exhaust ventilation in a dental laboratory.
Source: What Dental Technicians Need to Know About Silicosis. NJDHSS.

27. 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!

28. Controls—Wet Methods
Source: Dry Cutting and Grinding is RISKY BUSINESS. NJDHSS.

29. Ways to Reduce Exposure (cont’d)
And if other methods are not sufficient—
Use Proper Respiratory Protection

30. Respiratory Protection
Source: NIOSH Publication No : Silicosis: Learn the Facts!

31. Example of a Combination of Controls
Sandblaster using proper respiratory protection inside a ventilated booth. Note that the worker is supplied with two separate air lines - one to supply fresh air for the worker to breathe and the other to supply air for sandblasting.
Source: NIOSH Publication No : Control of Drywall Sanding Dust Exposures

32. 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
Outreach products and activities may include letters and news releases, seminars on silica-related topics, and Partnerships and Alliances to share successes and technical information.
Audiences for outreach may include local employers engaged in silica-related work; local employer and professional associations; local trade unions and apprenticeship programs; independent contractors and self-employed workers; local hospitals and occupational health clinics; temporary employment agencies; local building permitting authorities; local media outlets; local government agencies; and local materials suppliers.

33. OSHA Internet Information
NEP for crystalline silica:
Go to
Select Directives
Select 2008
Look under January (1/24/08)
Other information on crystalline silica
Select “S” from the alphabetical topic index
Select “Silica, Crystalline”

34. NIOSH Internet Information
National Institute for Occupational Safety and Health (NIOSH) website:

35. Questions?
Do you have any questions about the information that has been presented?

36. 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?
1. Do you have experience with any type of control methods for crystalline silica on your job or in your workplace?
2. What suggestions do you have for getting the word out about the dangers of exposure to crystalline silica?
3. Do you know any other groups that we should approach that might be interested in partnering with OSHA to reduce exposure to crystalline silica?