Masks are not created equal, nor
are the definitions of masks quite the same. A
dust mask may not have the same interpretation
from one individual to the next, and manufacturers do
not always use the same definitions. A dust mask
typically has one supporting strap, is not governed by
federal or state regulations, and is not given a
National Institute for Occupational Safety and Health
(NIOSH)
rating. Dust masks are not intended to
be used while applying or working around toxic chemicals
or aerosols.
A respirator, on the
other hand, is a device to protect you from inhaling
dangerous substances such as chemicals and infectious
particles. There are several different types of
respirators, as described below.
Escape respirators are
designed to be used only in an emergency, and
only to escape from a dangerous area to a safe area.
There are several escape respirators on the market.
Many of them have a hood with a neck seal instead of a
face piece. The escape respirators are typically
designed for a one-time use and for only a short
period of time, typically from 15 minutes to 1 hour.
Particulate respirator is
the simplest, least expensive, and least protective of
the respirator types available. These respirators
only protect against particles. They do not protect
against chemicals, gases, or vapors, and are intended
for low hazard levels.
Chemical Cartridge/Gas Mask
respirators are also known as “air-purifying
respirators” because they filter or clean chemical
gases and possible particles out of the air as you
breathe. This type of respirator includes a full face
or half face mask, and a filter/cartridge (if the filter
is in a metal shell it is called a “canister”). Straps
secure the face piece to your head. These cartridges
may have a filter (to remove particles), charcoal (to
remove certain chemicals), both of these components,
and/or other parts. When you inhale, air is pulled in
through the filter/cartridge and is purified as you
breathe.
Gas Masks are effective only
if the correct filter and/or cartridge (these terms are
often used interchangeably) is used for a particular
biological or chemical substance. You need to know what
hazards you will face in order to be certain you are
choosing the right filters. Particulate respirators,
filters, and pre-filters all work in the same way: by
trapping solid and liquid particulates such as dusts,
mists, and fumes. They may be found in the form of a
disposable particulate respirator or in the form of a
pre-filter (half-mask and full-face respirators), which
may be used in conjunction with a disposable chemical
cartridge. These filters should be worn and changed
in accordance with manufacturer’s instructions.
Selecting the proper filter or cartridge can become a
complicated process. Fortunately all manufacturers use
the same chemical cartridge color coding system.
- Acid Gas - White
- Organic Vapors - Black
- Ammonia Gas-Green
- Acid Gas and Organic Vapor - Yellow
- Multi-gas (protects against numerous gases and
vapors) – Olive
- HEPA (P100) – A Particulate filter. (All others
are for gases and/or vapors) – Magenta
Powered Air-Purifying Respirator (PAPR) Powered
air-purifying respirators use a fan to blow air through
the filter to the user. They are easier to breathe
through, and they need a fully charged battery to work
properly. They use the same filters as gas masks,
so you need to know what the hazard is, and how much of
it is in the air.
Self-Contained Breathing
Apparatus (SCBA) is the respirator commonly used by
firefighters. These use their own air tank to
supply clean air, so you don't need to worry about
filters. They also protect against higher concentrations
of dangerous chemicals. However, they are very heavy (30
pounds or more) and require very special training to use
and to maintain them. Also, the air tanks typically
last an hour or less depending upon their rating and
how hard you are breathing.
There are filters and cartridges
that protect against more than one hazard, but there is
no “all-in-one” filter that offers protection against
all substances. You may start by asking yourself
the following questions:
1.)
Which respirator do I choose if I’m working
around dusts, mists, fumes, or agricultural molds?
You can wear an N95 in almost any dust situation.
Exceptions: If you are welding exotic metals (for
example- magnesium or titanium) which give off toxic
fumes and gases, you’ll need protection from an N100
or P100 HEPA type filter. OSHA also requires
HEPA respirator protection when coming in contact or in
environments which can contain lead or asbestos.
2.)
What do 95 and 100 refer to in the
N95 and P100 designations for disposable
and non-disposable particulate respirators? The
numbers refer to the efficiency of the filter. A 95
rating specifies a 95% filtration efficiency or
better for particles larger than .03 microns. A 100
rating specifies at least a 99.7% filtration efficiency.
N filters are "Not Resistant" to oil. R
filters are "Resistant to Oil" and can be used
for eight hours with chemicals and pesticides that
contain oil. P filters are "Oil Proof" and
can be used with oil and non-oil hazards; may be able to
use longer than eight hours. As an example: a P100
filter would be strongly resistant to particulates which
may contain oil and would have a filtering efficiency of
at least 99.7%.
3.)
What is the difference between a particulate
filter and a chemical cartridge? Particulate
respirators, filters, and pre-filters trap solid and
liquid particles such as dusts, mists, and fumes. They
can be purchased in the form of a disposable respirator,
a single use disposable particulate respirator, or in
the form of a pre-filter, which may be used in
conjunction with a chemical cartridge. The filters must
be used and changed in accordance with the
manufacturer's instructions or when you first experience
breathing resistance.
Chemical Cartridges-(gas and/or vapor removing
cartridge type respirators) are filled with specially
treated activated carbon which absorbs certain gases
and/or vapors. If you experience an odd taste or smell
something different, or if your eyes, your throat, or
your lungs feel irritated, it is time to change the
chemical cartridge. It is recommended that you schedule
regular cartridge changes/replacements before you
experience any symptoms to avoid being exposed to
contamination.
In accordance with OSHA standards, all
respirators that rely on a mask-to-face seal need to be
annually checked with either qualitative or quantitative
methods to determine whether the mask provides an
acceptable fit to the wearer. The relative workplace
exposure levels determine what constitutes an acceptable
fit and which fit test procedure is required.
We strongly urge you to check each manufacturer’s
website for more detailed information and detailed
explanations of each item you wish to purchase.
