# Presentation: 714910

## OSHA’s New National Emphasis Program:Crystalline Silica

**Notes:**
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.

## Crystalline Silica

- SiO2 –silicon dioxide
- Also known as “free silica”
- Significantly more hazardous than amorphous silica
- 3 mineralogical forms
- Quartz—most common
- Cristobalite
- Tridymite

**Notes:**
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.

## Application of the NEP

- General Industry—1910
- Construction--1926

**Notes:**
Current standards for exposure to crystalline silica are

General Industry:  29 CFR 1910.1000

Construction:  29 CFR 1926.55(a)

## 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

**Notes:**
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.

## Goals of NEP

- Eliminate employee overexposure
- Control health hazards associated with overexposure

**Notes:**
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.

## 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

**Notes:**
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 20-40 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 from1968-1990.  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 1985-1992

## 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 15-20 years of exposure

**Notes:**
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 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”

**Notes:**
From 1990-1999, the industries regulated by OSHA that were most frequently recorded on U.S. death certificates for silicosis-related deaths were
	Construction				13.4%
	Blast furnaces, steelworks, rolling and finishing
	mills				5.8%
	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

- 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

- 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](http://www.osha.gov/SLTC/etools/silica/determine_exposure/silicadeaths/silicadeaths.html)_

- 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

**Materials**Are any of these
- involved?

**Occupations**Are you one of these?

**Industry**Do you work in any of these?

- 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.

**Probable Use of Silica**

- Identify factors that indicate probable use of crystalline silica

- Source:  OSHA’s Silica eTool

- Left column: Industries with exposure
- Middle column:
- Occupations with exposure
- Right column:  Materials containing crystalline silica

**Notes:**
These industries, occupations, and materials are listed on OSHA’s Silica eTool.

## And One You May Not Usually Think of—Dental Laboratories!

**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 1⁄2 of the value calculated from the formula for quartz

**Notes:**
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 1910.1000.

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.

## PEL—Construction and Maritime

- Quartz (respirable dust):
- 				250 mppcf
- 				% silica + 5
- OSHA-adopted conversion factor:
- 	1 mppcf = 0.1 mg/m3 respirable dust

**Notes:**
What is an overexposure in Construction and Maritime?

The crystalline silica PELs for Construction and Maritime are found at 29 CFR 1926.55(a) and 1915.1000 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.

## 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

**Notes:**
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.

## 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

**Notes:**
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

## Sources for Selection (cont’d)

- Other sources (cont’d)
- Dun & Bradstreet employer list
- Commercial directories
- Telephone listings
- Local knowledge
- Dodge reports for
- 	construction sites

**Notes:**
A number of other possible sources for the identification of companies and worksites with potential silica exposure exist.

## 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

**Notes:**
--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

## 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

**Notes:**
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.

## Follow-up and Evaluation (cont’d)

- Each LEP will be evaluated for
- 	effectiveness 1 year after
- 	implementation.

**Notes:**
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.

## 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

**Notes:**
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.

## Moving Employees Farther from Point of Exposure

**Moving Employees Farther from Point of Exposure**

- Source:  NIOSH Publication No. 1999-113:  Control of Drywall Sanding Dust Exposures

**Notes:**
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.

## Ways to Reduce Exposure (cont’d)

- Use local exhaust ventilation (LEV systems)
- Use tools with dust-collecting
- 	systems

## Example of a Combination of Controls

**Example of a Combination of Controls**

- Source:  What Dental Technicians Need to Know About Silicosis.  NJDHSS.

**Notes:**
Enclosure of the process and local exhaust ventilation in a dental laboratory.

## 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

**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

**Respiratory Protection**

- Source:  NIOSH Publication No. 2004-108:  Silicosis:  Learn the Facts!

## Example of a Combination of Controls

**Example of a Combination of Controls**

- Source:  NIOSH Publication No. 1999-113:  Control of Drywall Sanding Dust Exposures

**Notes:**
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. 

## 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

**Notes:**
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.

## OSHA Internet Information

- NEP for crystalline silica:
- Go to _[www.osha.gov](http://www.osha.gov/)_
- Select _Directives_
- Select _2008_
- Look under January (1/24/08)
- Other information on crystalline silica
- Go to _[www.osha.gov](http://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](http://www.cdc.gov/niosh/topics/silica)_

## Questions?

**Notes:**
Do you have any questions about the information that has been presented?

## 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?

**Notes:**
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?