Crystalline silica is an important industrial material, and occupational exposure
occurs in a variety of workplace settings, including mining, manufacturing,
construction, maritime, and agriculture. Processes associated
historically with high rates of silicosis include sandblasting,
sand-casting foundry operations, mining, tunneling, cement cutting
and demolition, masonry work, and granite cutting. Appendix A
provides further information on silica, including sources, industrial
uses, and adverse health effects. Appendix B provides a list of
North American Industrial Classification System (NAICS) and Standard
Industrial Classification (SIC) codes for industries in which
silica exposure occurs frequently, based on a review of OSHA inspection
data for the period 1996 to 2007.
Reducing and ultimately eliminating the workplace incidence of silicosis has been a primary
goal of the Agency since its inception. In 1972, OSHA issued guidelines
for conducting inspections in workplaces with significant crystalline
silica exposure. In the early 1980s, the Agency placed a special
emphasis on the prevention of silicosis in foundry personnel,
and in 1996 OSHA implemented a Special Emphasis Program (SEP)
to reduce the workplace incidence of silicosis.
The 1994 Government Performance and Results Act (GPRA) mandates that federal agencies
improve performance and devise a system for measuring results.
To comply with the provisions of GPRA, OSHA developed a Strategic
Plan for improving the safety and health of all employees. In
1998 and again in 2003, under the Strategic Plan, OSHA identified
crystalline silica as one of the focused hazards.
This NEP is being implemented to direct OSHA's field staff inspection efforts to
address elevated silica exposures in the workplace, including
General Industry (1910) and Construction (1926). These efforts
meet the Strategic Plan goal of reducing silicosis, set forth
by the Agency.
MOSH Instruction 08-7
National Emphasis Program (NEP) - Crystalline Silica
I. National Emphasis Program Goals.
The purpose of this NEP is to significantly reduce/eliminate employee overexposures
to crystalline silica and, therefore, control the health hazards
associated with such exposures. This goal will be accomplished
by a combined effort of inspection targeting, outreach to employers,
and compliance assistance.
Inspections should be targeted to work sites that likely create high silica exposures.
In each Region, at least 2 percent of inspections every year should
be silica-related inspections. Additionally, the silica-related
inspections should be conducted at a range of facilities reasonably
representing the distribution of general industry and construction
work sites in that region.
To ensure abatement and measure the effectiveness of this NEP, follow-up site visits
often will be necessary as outlined in Section XI(D.) below.
II. Program Procedures.
A. NEP Inspections
under this NEP will focus on industries where employees are
potentially exposed to levels of crystalline silica in excess
of the permissible exposure limit (PEL). Appendix B, which was
developed from OSHA inspection data, lists industries with potential
silica exposure and provides an overview of the types of industries
in which silica exposures frequently occur.
1. Industry Selection
The Chief of Compliance, or designee, will identify the industry sectors
that are to be targeted by the Regional Offices and shall
then prepare a master list of NAICS codes from those listed
in Appendix B. The rationale for selecting each industry shall
be documented, and may include information such as, but not
a. History of overexposures, based on previous local inspection history
within a Regional Office's jurisdiction of industries listed
in Appendix B.
b. Limited or no local inspection history of an industry listed in Appendix B.
c. The Chief of Compliance, or designee, may establish knowledge of a
pattern of silicosis or overexposures to silica by reviewing
objective illness or exposure data from any and all sources
including, state workers' compensation records or public
health data from sources such as the National Institute
for Occupational Safety and Health (NIOSH).
that are not included in Appendix B, but are known by the
Chief of Compliance, Assistant Chief, or Regional Supervisor,
based on local knowledge (i.e. a documented history of referrals
from local agencies or healthcare providers, or previous
inspection histories, etc.), to have demonstrated a pattern
of silica overexposures or cases of silicosis.
2. Site Selection and Scheduling
a. General Industry
The Chief of Compliance, or designee, shall develop a list of general
industry establishments in Maryland that fall within the
NAICS codes listed in Appendix B. Establishment sources
1. The Harris Directory of Maryland Employers;
2. Commercial directories;
3. Telephone listings;
4. Knowledge of establishments.
the relevant general industry establishments, those establishments
shall be incorporated into Maryland's High Hazard Industries
LEP (MOSH Instruction 08-9) inspection list for each Region
using a random number table.
industry establishment that has a NAICS code that falls
outside of those industries identified in MOSH Instruction
08-9, Maryland's High Hazard Industries, will be place
on the inspection list, however the inspection will be
conducted focused on only the hazards related to silica.
inspection shall be scheduled from a list of work sites
rather than construction employers, in accordance with MOSH
Instruction 08-3, Inspection Scheduling Criteria for Construction.
If during the course of any construction inspection a Compliance
Safety & Health Officer (CSHO) encounters a site that
falls within any of the NAICS listed in Appendix B, that
inspection shall also focus on any activity(s) that potentially
exposes employees to silica.
Based on their
familiarity with local industries, Regional Supervisors
in conjunction with the Chief of Compliance, or designee,
shall delete from the master list any establishment known
to be out of business. The Regional Office will document
the basis for the determination.
supervisors in conjunction with the Chief of Compliance,
or designee, shall also delete any establishment that has
had an inspection where employee exposures to silica have
been evaluated within the previous three (3) years, provided
either that no serious violations related to silica exposures
were cited or that serious violations were cited but a follow-up
inspection documented effective abatement of the cited conditions.
office becomes aware of a previously unknown establishment
in one of the identified NAICSs, Regional Supervisors in
conjunction with the Chief of Compliance, or designee, shall
add that establishment to the appropriate High Hazard Industry
list for inclusion in the next inspection cycle.
3. Complaints and Referrals
regarding polices and procedures when conducting complaints
and referrals inspections is provided in MOSH Instruction
08-2, Complaint and Referrals.
that has requested an initial full-service comprehensive consultation
visit for safety or health from the MOSH Consultation Program,
and that visit has been scheduled by Consultation may be deferred
from the inspection for 90 calendar days from the date of
notification by MOSH Consultation Program to the Regional
Office. No extension of the deferral beyond the 90 calendar
is possible, unless the consultation visit is "in progress"
which begins at the opening conference of the consultation
visit. See 29 CFR 1907.7(b)(1) for a definition of "in
If an establishment
is in the process of applying for MOSH's Voluntary Protection
Program (VPP), the Chief of Compliance, upon receiving notification
from the VPP Manager that a VPP on-site review has been scheduled,
will defer any programmed inspection. The applicant workplace
will be deferred starting no more than 75 days prior to the
commencement of its scheduled pre-approval on-site review.
The applicant workplace will be removed from any programmed
inspection list for the duration of VPP participation, unless
the site chooses otherwise.
If an establishment
is in pre-Sharp status, that is in the process of meeting
the criteria of a MOSH Consultation Safety and Health Achievement
Recognition Program (SHARP), it may be deferred for up to
18 months, while the employer is working to achieve recognition
and exemption status. See 29 CFR 1908.7(b)(4)(i)(A).
If an establishment
is an approved participant in MOSH's Voluntary Protection
Program (VPP), in MOSH Consultation's Safety and Health Achievement
Program (SHARP), or Cooperative Compliance Partnership (CCP)
program it is to be deleted from the inspection list.
Scope of Inspection:
Safety and Health Officer (CSHO) may expand the scope of a
NEP inspection beyond the silica-related activities if other
hazards or violations are observed, following the guidelines
set forth in the FOM.
B. Inspection Procedures.
This section outlines
procedures for conducting inspections and preparing citations
for silica-related violations. For further guidance, the CSHO
should consult the OSHA directives, appendices, and other references
provided below. Appendix H contains a checklist that summarizes
the information to be documented during a silica-related inspection.
The checklist may be used by the CSHO to ensure proper coverage
of the essential elements of a silica-related inspection.
1. Employee Exposure Monitoring
monitoring to determine employee exposure to respirable
dust containing crystalline silica, in accordance with the
OSHA Technical Manual (OTM), Section II, Chapter 1 and OSHA
method ID-142. Appendix C contains guidelines on collecting
air samples and Appendix D summarizes procedures for performing
leak tests on cyclones.
bulk samples of settled dust from silica operations, in
accordance with the OTM, Section II, Chapters 1 and 4.
any existing employer's silica exposure monitoring records.
Guidance: When the PEL for respirable dust containing
silica is exceeded (regardless of the use of PPE), the CSHO
should cite 1910.1000(c) or 1926.55(a) for the relevant
industry in accordance with the Field Operations Manual
(FOM); Chapter IV, Section 5.
exposures are not based on the general industry PEL,
but are determined gravimetrically and converted to mppcf
and should therefore be cited as exceeding the construction
PEL in mppcf. Appendix C contains guidance on calculating
the general industry PEL, and Appendix E provides information
on calculating the construction and maritime industry PELs
for crystalline silica.
and Work Practice Controls
and evaluate any engineering and work practice controls
in place intended to reduce exposure to respirable crystalline
silica, such as:
of employee(s) with respect to dust generation source.
(e.g., control room, enclosures, or barriers).
exhaust ventilation (LEV) systems.
4. Wet methods
for cutting, chipping, drilling, sawing, grinding, etc.
5. Use of
HEPA-equipped vacuums or wet sweeping for cleaning.
should be advised not to use compressed air for cleaning
silica contaminated surfaces.
with non-crystalline silica material.
8. Use of
tools with dust collecting systems.
for abrasive blasting are addressed further in Section
II (B)(7), below.
for investigations of ventilation systems are contained
in the OTM, Section III Chapter 3.
Guidance: If an employer fails to implement feasible
engineering or work practice controls for reducing respirable
crystalline silica exposures to levels less than the PEL,
the CSHO should cite 1910.1000(e), 1926.55(b), or 1926.57(a)
and (b), as appropriate. Guidance on what constitutes feasible
administrative, work practice, and engineering controls
is provided in the MOSH Field Operations Manual (FOM); Chapter
III, Section E .6. Information is also available on the
citations may not be appropriate when all of the following
conditions have been met:
1. the employer
has fully implemented the feasible means of abatement
recommended in the previous citation;
2. the employer
has fully implemented a respiratory protection program;
engineering controls used to address the hazard have not
significantly advanced since the previous citation.
conditions, the Regional Office shall contact the Chief
of Compliance for guidance. (Note: This policy is limited
to situations where the employer has made good faith efforts
to comply with the silica exposure limit by implementing
engineering controls previously suggested by the MOSH
but which have not reduced exposures below the PEL. In
such situations requiring the employer to continue to
implement additional controls which may not reduce the
exposures below the PEL may be inappropriate.)
inspection and citation guidance related to respiratory
protection is contained in OSHA Instruction 02-00-120 (CPL
2-0.120) - Inspection Procedures for the Respiratory Protection
Respiratory Protection: When respirators are a permissible
means to address overexposure, the minimum respiratory protection
for employees exposed to crystalline silica during operations,
other than abrasive blasting, is the N95 NIOSH-approved
respirator for exposures that do not exceed the assigned
Evaluations for Respirator Use: Medical evaluations must
be given to all employees required to wear a respirator,
however, medical evaluations are not required for employees
who voluntarily use filtering face-piece respirators (dust
masks). Employees who refuse to be medically evaluated cannot
be assigned to work in areas where they are required to
wear a respirator.
inspection and citation guidance related to hazard communication
is contained in OSHA Instruction CPL 02-02-038 (CPL 2-2.38D)-Inspection
Procedures for the Hazard Communication Standard.
of Carcinogens: Information regarding evidence of carcinogenicity
must be included on container labels and Material Safety
Data Sheets (MSDSs) for crystalline silica, and for products
containing crystalline silica. Carcinogen warnings are required
on containers of materials containing more than 0.1 percent
crystalline silica by weight or volume, as determined by
analysis of a bulk sample of the original product. The CSHO
should collect bulk samples to determine silica content
if MSDSs appear inadequate or incomplete.
boards: Bricks, tiles and cement boards containing silica
fall under the requirements of the Hazard Communication
standard (HCS) due to the hazards associated with silica.
Under normal conditions of use, bricks, tiles and cement
boards are cut, sawed, or drilled, generating airborne levels
of crystalline silica that could result in elevated exposures
and are therefore not considered to be exempt under the
HCS as articles. Note: Bricks do not need to be individually
labeled. Bricks that are palletized and bound by metal bands
are considered to be containers and are to be tagged with
an appropriate label.
Stone: Vehicles hauling shipments of crushed stone shall
include hazard warnings concerning the carcinogenicity of
crystalline silica on their shipping papers or bills of
lading. CSHOs should initially determine whether the Mine
Safety and Health Administration (MSHA) or MOSH has jurisdiction
over the specific crushed stone operation.
and Hygiene Practices
whether the employer's housekeeping and hygiene practices
may contribute to overexposure. For example:
surfaces should be as free as practicable of silica-containing
dust (bulk samples of the dust may need to be collected).
surfaces should not be blown clean with compressed air
or other forced air (such as leaf blowers).
3. Wet sweeping
should be used to clean areas if possible.
4. If vacuuming
is used for cleaning, the exhaust air should be properly
filtered to prevent release of airborne silica back into
should be separate break areas for consuming food, beverages,
etc. that are kept free of silica.
contaminated with silica should not be blown or shaken
to remove dust.
b. Document poor housekeeping and hygiene practices.
Guidance: If employees are overexposed to crystalline
silica, and poor housekeeping practices are noted, the CSHO
should cite, as applicable, 1910.141, 1926.51(f), or 1926.51(g).
Exposure and Medical Records
employees to determine whether they understand their right
to review their medical and exposure records, as well as
their rights regarding the confidentiality of such records.
the employer's recordkeeping program to ensure that the
required information is being collected and reported.
the employer's method for ensuring the confidentiality of
employee medical records.
d. When it
is necessary to review employee medical records, ensure
that they are obtained and remain confidential in accordance
with 1913.10 and 1910.1020.
Guidance: If violations are found, CSHOs should
cite the applicable section of 1910.1020 or 1926.33. These
rules do not require creation of any records, only preservation
and access requirements.
to recordkeeping policies and procedures are described in
CPL 02-00-135, Recordkeeping Policies and Procedures Manual
In addition to
the program elements described above, the following procedures
apply specifically to abrasive blasting operations:
monitoring to determine employee exposure to metals, such
as: lead, arsenic, manganese, chromium, cadmium, copper,
and magnesium. (Abrasive blasters may be exposed to metals
either from the surface being blasted or from non-silica
b. The air
sampling device (cyclone) must be placed within the breathing
zone, outside of any protective equipment including the
abrasive blasting hood.
exposure monitoring of potentially exposed employees not
engaged in abrasive blasting but still working in the area.
noise exposure monitoring as appropriate.
whether the ventilation systems for abrasive blasting rooms
and containment structures prevent escape of dust and provide
prompt clearance of dust-laden air.
whether each blast cleaning nozzle is properly equipped
with an operating valve that must be held open manually.
g. For supplied-air
respirators, evaluate breathing air quality and use. For
oil-lubricated compressors, ensure that the compressor is
equipped with a high-temperature or carbon monoxide alarm,
or both, to ensure that carbon monoxide levels remain below
the PEL. [Note: Using an abrasive blasting hood while wearing
a filtering face piece respirator violates the NIOSH approval
for both respirators.]
h. When compressors
are used to supply air, ensure that in-line absorbent beds
are used and maintained.
i. Review electrical grounding.
j. Review pressure controls.
whether the abrasive blasters have adequate PPE, such as
canvas or leather gloves and aprons, to protect against
injury from material impact.
l. Where an
alternative abrasive material is being used such as glass
beads, steel grit and shot, sawdust and shells, ensure that
an appropriate evaluation of the hazards associated with
the material has been conducted.
Guidance: If overexposures to metals or noise are
found, the CSHO should cite the applicable standard.
If the ventilation system for a blast cleaning enclosure
is found to be inadequately designed or ineffective at controlling
dust, the CSHO should cite the applicable section of 1910.94(a).
If blast cleaning
nozzles are not properly equipped with operating valves
that must be held open manually, the CSHO should cite 1910.244(b)
related to respiratory protection for abrasive blasting
operations may be cited under 1910.94(a)(5). Guidance is
also contained in OSHA Directive CPL 02-00-120 (CPL 2-0.120),
Inspection Procedures for the Respiratory Protection Standard.
related to personal protective equipment should be cited
under 1910.94(a)(5), 1910.132, 1926.28, 1926.95, or 1926.100-103.
The OSHA Office
of Training and Education, in conjunction with the Directorate
of Enforcement Programs and the Office of Communications, will
develop crystalline silica-related information and training
materials. This information will be obtained from OSHA and made
available to the MOSH Compliance and Consultation Offices as
well as the public through seminars, booths, materials requests
forms and site visit resources. In addition we will continue
to hold seminars that address silica identification, dangers,
and solutions during our public seminars in related courses
such as Industrial Hygiene for Construction and basic General
1. Where citations
are issued for overexposure to crystalline silica, follow-up
site visits must be conducted to determine whether the company
is eliminating silica exposures or reducing exposures below
the PEL. Where exposures can not feasibly be reduced below
the PEL, engineering and administrative controls must be used
to reduce exposures to the extent feasible and employees protected
with the use of PPE.
2. For those
employers where follow-ups cannot be done, (i.e., construction
sites or temporary abrasive blasting operations) the Regional
Office should request that the employer provide written updates
documenting the progress of their abatement efforts per 1903.19.
E. IMIS Coding Instructions.
For each form that
has a Strategic Plan field, "SILICA" will be entered in that
field for all inspections.
which are conducted under this NEP, for each form that has an
NEP field, enter "SILICA" in the appropriate field (see below).
situations where crystalline silica is used as the abrasive
media when abrasive blasting, Optional Information "ABRASIVE"
will be entered on all forms (see below).