# Presentation: 714925

## 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.

## Why Does OSHA Have a New National Emphasis Program?

- Silica-related illnesses and fatalities continue to occur
- The NEP is a written compliance directive incorporating updated information and policies and procedures adopted since 1996

**Notes:**
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.

--NIOSH estimates (Faye L. Rice, October 23, 2007, PCIH) about 2 million U.S. workers potentially exposed.  Approximately 200 deaths each year are silica-related.

--More than 100,000 U.S. workers are in high-risk occupations such as sandblasting.

The severity of overexposures (amount by which the OSHA PEL is exceeded) has started to increase, after a decline following the initiation of the 1996 SEP.

## Why a New NEP? (cont’d)

- 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 and 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.

## What Is 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.

Naturally occurring forms of amorphous silica include diatomaceous earth (the skeletal remains of marine organisms) and vitreous silica or volcanic glass.

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 in both 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.

## What Are the Health Effects of Crystalline Silica?

- Silicosis (pulmonary fibrosis)
- 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 particles (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 the exposure.

Silicosis exposure and resultant disease are a continuing problem.
--Silicosis was associated with more than 14,000 U.S. fatalities since 1968.  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

## What Are the 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.*

## Where Are There Workplace Exposures to Crystalline Silica?

- Solid dust particles generated from silica-containing materials by
- Handling
- Grinding
- Blasting
- Drilling
- Crushing
- High historical exposures
- Sandblasting
- Mining *(regulated by MSHA)*
- Tunneling
- Granite cutting
- Sand-casting foundry operations

**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 molds and cores, shakeout and knockout; finishing and grinding operations
--Manufacturing:  use of silica as a raw material to 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

## Crystalline Silica Exposures

**Crystalline Silica Exposures**

**Notes:**
If you work near dust clouds like the ones in these photos, you might be exposed to silica. You may be exposed even when dust is not visible.

## How Will Employees Know They May Exposed? 

- Identify factors that indicate probable use of silica
- Check product labels
- Check the Material Safety Data Sheets

- 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

- Check to see whether you
-  (a) Work in an industry in the left column;
- (b) Are in an occupation in the middle column; or
- (c) Work with materials listed in the right column

**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.

## Labels

- A product that contains ≥ 0.1%
-     crystalline silica (by weight or
-     volume) must say so
- The machines used in the operations may also have warning signs indicating that silica is being used
- Manufacturer’s responsibility:  attach a label to all products that contain ≥ 0.1% crystalline silica
- Employer’s responsibility:  ensure that the label is not removed or defaced

## Material Safety Data Sheets (MSDS)

- Contain data for materials
- 	or products containing hazardous
- 	chemicals
- If a material or product contains
- 	≥ 0.1% crystalline silica, there
- 	must be a MSDS
- Manufacturers and importers:
- 	obtain or develop a MSDS for each hazardous chemical they produce or import
- Employers:  ensure access to MSDSs for all hazardous chemicals at the workplace

## The National Emphasis Program

- Applies to General Industry
- 	and Construction worksites
- Goals
- Eliminate employee overexposure
- Control health hazards associated
- 	with overexposure
- Features
- OSHA procedures for inspections
- 2 percent of inspections
- Mandatory follow-up inspections if possible where overexposures occurred

## What Will OSHA Check for on an Inspection?

- Employee exposure monitoring, including collection of bulk samples
- Engineering and work practice	controls
- Respiratory protection
- Hazard communication

**Notes:**
--The OSHA inspector will ask employees to wear air sampling pumps to monitor for exposure to dust and silica.

--The inspector will look for engineering controls, such as using substitute abrasive materials for blasting and ventilation for powder filling operations or wet methods for grinding and drilling; the inspector will also look for work practice controls such as limiting the time that an employee spends at a job that has exposure to silica.

--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.
If employees are required to wear respirators, the employer must have a written respirator program.  Employees must receive medical evaluations and fit tests.

--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.)
Employees must be trained about hazards to which they are exposed.

## What is the OSHA PEL for 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 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.  It is a legal limit.

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.

## What is the OSHA PEL for Construction?

- 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

- Whether you work in General Industry or in Construction:  ***The more crystalline silica there is in the dust, the less of the dust you should breath***

## What Will OSHA Check for on an Inspection? (cont’d)

- Symptoms of silicosis in workplace
- Housekeeping and hygiene
- Employee exposure and medical records
- Abrasive blasting

**Notes:**
--The OSHA inspector will interview employees to see if they are experiencing any symptoms that might be related to silicosis.
--The inspector will determine whether the employer is aware of the silicosis risk and is referring possible cases to a physician.
--The inspector will determine whether the employer is maintaining exposure and medical records related to silica and if employees have access to these records.
--The inspector will determine if the employer is keeping surfaces as free from dust as practicable—without using compressed air to blow off the dust!  There should be separate break areas and contaminated clothes should not be blown off or shaken.
--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

## Scope of Inspection

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

## 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

**Notes:**
It may not be possible to carry out follow-up inspections of some employers, e.g., construction sites or temporary abrasive blasting operations.

## Follow-up and Evaluation (cont’d)

- Where exposures cannot be reduced below the PEL
- engineering and administrative controls must be used to reduce exposures as low as possible
- respiratory protection must be used to supplement other controls
- Abatement verification data used by Office of Statistics

**Notes:**
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.

## What Are Some Possible 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.

## What Are Some Possible 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.

## What Are Some Possible 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.

## What Are Some Possible 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. 2002-105:  Silicosis in Sandblasters:  A Case Study for Use in U.S. High Schools

**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. 

## What Can Workers Do to Protect Themselves and Their Families?

- Become informed
- Reduce their exposure to dust
- Use respirators when needed
- Participate in medical screening
- Practice good personal hygiene at the workplace
*It is the employer’s responsibility to provide a safe*
*workplace*
*It is your responsibility to use any controls*
*provided*

- Source:  CPWR.

**Notes:**
The worker pictured is using a cut-off saw with a vacuum and respiratory protection.

Go over the handout “What Can I Do to Protect Myself and My Family?”, which is adapted from NIOSH Publication No. 2004-108:  Silicosis:  Learn the Facts!

## What Information Does OSHA Have on the Internet?

- 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”

## Other 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?