-
8/3/2019 Silica Training 2012
1/12
Respirable Silica Training
January 2012
-
8/3/2019 Silica Training 2012
2/12
OBJECTIVES
Definition of respirable silica
Respiratory system
Exposure to silica Health effects of silica
Silicosis
Control measures
Q&A
2
-
8/3/2019 Silica Training 2012
3/12
What is silica?
It is a very hard mineral found in
almost every rock.
It is the main part of sand,
sandstone, granite, quartzite,etc.
It naturally occurs in three forms.
Only the crystalline form is a
health hazard.
Respirable dust particles.
Small enough to breathe in, but big
enough to get caught in the lungs.
3
-
8/3/2019 Silica Training 2012
4/12
4
-
8/3/2019 Silica Training 2012
5/12
Silica Exposure in the Workplace
Risk of exposure occurs when crystalline
silica becomes airborne.
Airborne silica is produced by:
Sandblasting to remove paint and rust from
stone and metal structures and other
surfaces.
Jack hammering and drilling concrete.Concrete mixing, cutting,
and sawing.
Other activities not associated with this
project.5
-
8/3/2019 Silica Training 2012
6/12
Exposure Limits
TLV: 0.1 mg/m3 TWA of
respirable silica
PEL: (10 mg/m3
) (% respirable silica + 2) Exposure determined through
air sampling
Personal air sampling for ~ 4hours by industrial hygienist
Laboratory analysis of sample
6
-
8/3/2019 Silica Training 2012
7/12
Health Effects of Silica Exposure
Acute Intense crystalline silica
exposure.
Acute silicosis Inflammation in the gas
exchange area of the
lung
Fibrosis
Accelerated More intense exposure
over5 to 15 years
Silicosis Smaller fibrotic nodules
Massive fibrosis in the
mid-zones of the lungs
Shortness of breath Fever
Bluish skin at ear lobes or
lips
7
-
8/3/2019 Silica Training 2012
8/12
Health Effects of Silica Exposure
Chronic
20 to 45 years prolonged exposure to crystalline silica
Silicosis
Nodular lesions in the upper lobes
Shortness of breath with exertion
Cough and expectoration
Fatigue
Loss of appetite
Chest pain (airway obstruction)
8
-
8/3/2019 Silica Training 2012
9/12
Silicosis
Definition
Formation of nodules and
fibrous scar tissue in the
lungs.
Cause by over-exposure
to respirable silica.
Three types. See Health
Effects. Acute
Accelerated
Chronic
Complications
Lung Cancer
Tuberculosis
Connective Tissue
Disease
Rheumatoid Arthritis
Sclerodoma
Lupus
Respiratory Failure
9
-
8/3/2019 Silica Training 2012
10/12
Control Measures
Engineering
Substitution (NA)
Wet cutting (NA)
Dust collectionsystems
HEPA exhaust
Dust suppression
skirts
Administrative
Training
Warning signs
Medical surveillance
Scheduling
Work rotations
Housekeeping
Activity restrictions
No eating/drinking in
work areas
10
-
8/3/2019 Silica Training 2012
11/12
Control Measures
Personal Protective Equipment (PPE)Protective clothing and
shoes
Eye protection
Respirators Minimum N95, based on level of respirable silica
in
air sample and engineering controls in place
Half-face or Full-face
Follow IH guidelines Medical clearance and fit-testing
required
Clean off dust BEFORE removing PPE and
leaving work area.11
-
8/3/2019 Silica Training 2012
12/12
NEVER USE AIR HO
SE TO
CLEAN DUST OFF YOU,
YOUR COWORKER, OR THE
WORK AREA!
ALWAYS WASH BEFORE
EATING, DRINKING, SMOKING,OR OTHER ACTIVITY!
12
