Fiberglass is
one of the most useful manufactured products in industry,
with numerous commercial applications. It is a man-made
fiber used primarily in the production of insulating
materials and for reinforcing plastics and composites.
Various products ranging from home insulation materials to
boats are composed of fiberglass. Its physical properties
make it ideal for structural building materials because it
is inert, lightweight, heat resistant and a very strong
fiber. These same properties are also responsible for some
of the hazards encountered in the workplace.
Depending on
the size and dimensions of the fibers measured in the
workplace, you will find different biological effects on
humans. Smaller fibers, generally less than 3.5 microns in
length, can be inhaled and deposited in the lung where
they can accumulate and cause fibrotic changes, while
larger fibers cause skin irritation due to mechanical
action. It is both the inhalation and dermal hazards that
give fiberglass a greater hazard potential than nuisance
dust and require appropriate protective equipment to
minimize exposure. The purpose of this paper is to review
the potential hazards of working with fiberglass, assess
the risk and provide a recommended best practice.
Hazards
Since there
are numerous uses for fiberglass, one needs to identify
the other hazards associated with the production of
fiberglass products in order to determine and control the
greater hazard. Generally, the principles involved are
similar for most hazardous substances and basically
involve following good industrial hygiene practices.
Various trade organizations have developed and published
their own specific guides and work practices and should be
consulted for reference. For the purpose of this paper,
fiberglass will be considered the primary hazard and the
best practices will be limited to general principles.
As was
mentioned before, small fiberglass fibers can be inhaled
and therefore are an inhalation hazard, but the primary
hazard associated with fiberglass is skin irritation.
Respiratory protection devices are not needed for
fiberglass exposures below the recommended environmental
limit (ACGIH TWA 10mg/m3), but for situations where
airborne concentrations may exceed the limits recommended,
respirators approved by NIOSH may be used, but not as a
substitute for feasible engineering controls.
The primary
health effect and hazard associated with larger fiberglass
fibers involve skin and eye irritation. Most skin problems
arise from direct contact with fiberglass through handling
rather than from airborne fibers or dust. Decisions on
whether to wear gloves or other protective clothing will
depend on the nature of the work as well as the nature of
the materials involved. In general, wearing gloves and
other items of protective clothing such as booties will
prevent fiberglass from contacting exposed skin surfaces
and street clothes worn underneath. Fiberglass can and
does adhere to street clothes and shoes where it is
retained in fabrics and bonded to shoes if adhesives are
used in production processes to make fiberglass
composites. If these street clothes and shoes are not
removed and laundered at work, they are brought home
contaminated with fiberglass which in turn will
contaminate household family laundry.
Eye
irritation is another hazard associated with working with
fiberglass, particularly when installing fiberglass
insulation materials overhead. Safety glasses or goggles
will prevent contact with the eye and alleviate potential
eye injuries. It should also be noted that in many
applications and processes fiberglass is bound with
adhesives and in plasticizers where it becomes rigid and
sharp.
These sharp
glass fibers then can act like a razor blade, causing cuts
and lacerations, particularly when cutting fiberglass
products or when removing them from molds.
Because of
the diverse use of fiberglass in manufacturing operations,
there is no one main occupational disease associated with
working with fiberglass. Epidemiological studies have not
determined that there is a substantial risk of lung injury
resulting from the inhalation of small fiberglass fibers,
even though fibrotic changes in lung tissue have been
observed in some occupations working exclusively with the
production of fiberglass. However, large fiberglass fibers
can and do cause irritation to the skin and eye. The
irritation is primarily due to the mechanical abrasion of
fiberglass on wet sweaty exposed skin. Repeated exposures
to the skin cause additional irritation, redness and
itchiness. In some cases individuals develop tough skin as
a result of continued exposure and become immune to
irritation. Individuals who work intermittently with
fiberglass tend to develop irritation repeatedly after
each exposure. Therefore, these acute exposures that
repeatedly cause irritation tend to be the major risk
involved with handling fiberglass.
Standard
Practices
The best
practice to follow when working with fiberglass is to
prevent and avoid skin contact. Inhalation of small
fiberglass fibers is not a major concern if airborne fiber
concentrations are below recommended environmental limits.
Respirators should be worn if concentrations exceed this
limit and if other airborne contaminants produced in the
process exceed recommended exposure limits.
Protection
from skin exposure is best achieved by wearing appropriate
protective equipment such as gloves, suits and boots if
necessary. A hazard assessment should be made in
accordance with OSHA's personal protective equipment
standard to determine the appropriate protective clothing
and procedures to be followed. This would include wearing
gloves, suits and booties that prevent skin exposure.
These items of clothing should be worn over regular street
clothes and disposed of or removed at the end of the work
day to be laundered if they are going to be worn again the
next day. Workers should have access to lockers and a
shower and wash basin where they wash away fibers from
contaminated body surfaces.
In general
good industrial hygiene practices should be followed, such
as utilizing engineering controls to reduce airborne
exposures and good housekeeping to keep fiberglass
contained in work areas. A separate lunchroom or area
should be designated for eating and drinking. Eye glasses
or goggles should be worn to prevent eye exposures, and an
eye wash and safety shower should be readily accessible.
Since cuts can occur from handling bonded fiberglass,
first aid kits should also be readily available. Finally,
waste bins or cans should be located in work areas to
dispose of excess unused fiberglass.
LINTING CHARACTERISTICS OF Tyvek® vs. COTTON vs. PAPER
DISPOSABLES
Test
Procedure
Samples were
precleaned, enclosed in a polyethylene envelope and flexed
500 cycles in a stress-flex tester. After flexing,
materials were vacuumed and loose material was collected
on a filter and counted.
|
Test Results |
Tyvek® |
Cotton |
Scrim Reinforced
Paper Disposable |
|
Fibers per sq. in. |
0.7
|
29
|
9
|
|
Particles per sq. in. |
3.9
|
280
|
115
|
Conclusions
Tyvek®
reduces particle generation vs. paper disposables 96% and
vs. cotton: 99%
Tyvek®
reduces fiber generation vs. paper disposables 92% and vs.
cotton: 98%
DuPont Tyvek® Type 1422 provides excellent barrier to
particulates.
Tyvek®
proprietary nonwoven is a unique DuPont material that
offers high strength and provides excellent barrier to
many dry particulates including asbestos, lead dust, and
radioactive dusts down to sub-micron size. Laboratory
tests have shown Tyvek® to hold out >99 % of asbestos
fibers.
|
PARTICULATE HAZARD |
AVERAGE %
PENETRATION |
|
Dust particles (0.2-6 µ) |
<
0.6 |
|
Asbestos (<1 µ) |
0.9
|
|
Co
60 Colloid |
ND
|
|
Radioactive dust particles (0-80 µ) |
ND
|
ND = none
detected < = less than
DON'T SETTLE
FOR A SUBSTITUTE. SPECIFY GARMENTS OF DUPONT Tyvek.
We believe
this information is the best currently available. It is
subject to revision as additional knowledge and experience
are gained. DuPont makes no guarantee of results and
assumes no obligation or liability in connection with this
information. It is the user's responsibility to determine
the level of toxicity and the proper personal protective
equipment needed. The information set forth herein
reflects laboratory performance of fabrics, not complete
garments, under controlled conditions. It is intended for
informational use by persons having the technical skill
for evaluation under their specific end-use conditions at
their own discretion and risk. Anyone intending to use
this information should first verify that the garment
selected is suitable for the intended use. Since
conditions of use are outside our control, we make no
warranties, express or implied, and assume no liability in
connection with any use of this information. This
information is not intended as a license to operate under
or a recommendation to infringe any patent or technical
information of DuPont or others covering any material or
its use.
WARNINGS:
(1) Garments
of Tyvek® spunbonded olefin are not flame resistant and
should not be used around heat, flame, sparks, or in
potentially flammable or explosive environments.
(2) Garments
of Tyvek® spunbonded olefin should have slip resistant or
antislip materials on the outer surface of boots,
shoecovers, or other garment surfaces where slipping could
occur.