Transcript NPCA Silica Awareness - National Precast Concrete

Silica
WHAT IS SILICA?
SILICA IS QUARTZ
Quartz (silica) is found
naturally in almost all rock,
sand and soil.
Silica is a principal
component of sand
It is found in all concrete
products
SILICA EXPOSURE IN INDUSTRY
Sandblasting
Foundry work
Concrete mixing
Concrete products
 Manufacturing
Glass manufacturing
Work with abrasives
SILICA EXPOSURE
Generates moderate
to heavy amounts of
dust
Generates
heavy amounts
of dust
SILICA EXPOSURE (cont)
DRILLING
CONCRETE
CONCRETE CUTTING
SILICA EXPOSURE (cont)
SILICA EXPOSURE (cont)
SWEEPING AND BLOWING WITH AIR
SILICA EXPOSURE (cont)
WHAT IS SILICOSIS?
Silicosis is one type of pneumoconiosis
the medical term for lung scarring from inhaled
dust.
Pneumoconiosis can occur from inhaled
asbestos, coal, beryllium, and other inhalable
dusts.
There is no effective treatment for any
pneumoconiosis, including silicosis
THREE ‘TYPES’ OF SILICOSIS
Simple chronic silicosis
From long-term exposure (10-20 years) to low
amounts of silica dust.
Accelerated silicosis
Occurs after exposure to larger amounts of
silica over a shorter period of time (5-10 years).
Acute silicosis
From short-term exposure to very large
amounts of silica dust.
SILICOSIS – ASSOCIATED RISKS
Increased risk of tuberculosis & lung
cancer.
Degree of increased risk
is highly variable
depends on several OTHER factors, including
immune system
exposure history (for TB),
amount of lung scarring
age
smoking history (for cancer).
SILICA EXPOSURE LIMITS
The safest amount of silica
in the air is zero.
This is the legal limit set
The legal limit is called
a “permissible exposure
limit” or “PEL”. This limit
is for respirable (fine)
dust.
In the air – 100
micrograms per
cubic meter
Rule-of–thumb: if dust containing
silica is visible in the air, it’s almost
certainly over the permissible limit.
SILICA EXPOSURE CONTROL
Silica dust exposure can be controlled by
use of water or exhaust ventilation to
reduce dust
Capture or dispose of controlled dust
Avoid dry sweeping and use of
compressed air on concrete
Respirators must be used if silica dust
can’t be controlled with water or ventilation
SILICA EXPOSURE CONTROL
HEPA vacuum cleaners can be used
instead of sweeping and air blowing.
Floors can be spray wet is sweeping is
done.
Exhaust systems must be inspected and
maintained
Areas with heavy traffic should be paved
Speed limits shall be posted
SILICA AND USE OF RESPIRATORS

When respirators are used, the employer
must establish a respiratory protection
program
outlined in the NIOSH Guide to Industrial
Respiratory Protection [NIOSH 1987a]
required in the OSHA respiratory protection
standard [29 CFR 1910.134 and 1926.103].
SILICA AND USE OF RESPIRATORS
 periodic environmental monitoring,
 regular training of personnel,
 selection of proper NIOSH-approved respirators,
 an evaluation of the worker's ability to perform
the work while wearing a respirator,
 respirator fit testing, and
 maintenance, inspection, cleaning, and storage
of respiratory protection equipment.
SILICA AND USE OF RESPIRATORS
One-piece dust masks can also be used,
but are not recommended because they
don’t always fit properly and can leak.
Respirators may still be needed even
when steps have been taken to reduce the
amount of dust in the air.
A supplied air respirator is required if the
amount of silica in the air is more than 10
times the permissible limit”
SILICA AND RESPIRATOR USE
Employees using respirators must be trained
Training is required for
anyone who wears a
respirator.
If you don’t know how to
use a respirator properly,
you may think your
respirator is providing
protection when it is not.
SILICA AND RESPIRATOR USE
Respirators must fit
properly to prevent leaks
around the edges.
Fit-testing must be done
before first wearing a
respirator.
Beards are not allowed
when wearing a respirator
SUMMARY
Remember silicosis can kill over time
There is no cure for silicosis
Keep dust down to a minimum
Use engineering methods or process
controls
Last recourse use respirators