Glen H. Hetzel
Virginia Cooperative Extension
Table
of Contents
Introduction
Choosing the Proper Equipment
Hazardous Sources and Their Contaminants
Places Where You Can Buy Respiratory Equipment
Respiratory Equipment Safety
In Case of Emergency
Introduction
Who Needs Respiratory Protection?
- THOSE working in dusty fields and buildings
- THOSE handling moldy hay
- THOSE working in silos
- THOSE feeding or working with feedstuffs
- THOSE working in corn silage
- THOSE uncapping silos
- THOSE cleaning grain bins
- THOSE exposed to bird droppings or dust from animal hair or fur
- THOSE exposed to fish meal
- THOSE applying agricultural chemicals (e.g. fertilizers and pesticides)
- THOSE working with toxic paints or solvents
If you work in any one of these situations and do not wear some form of respiratory protection, then you are placing yourself at risk for serious lung diseases or even death.
You may encounter a range of health problems from minor, temporary discomfort caused by allergic reactions to fatal asphyxiation depending upon the work environment and the hazards presented.
In each of these cases, however, proper respiratory equipment can protect you. Using such equipment is not the only means of protection in all of these cases, but it is a practical solution to safeguard and even improve your health.
Choosing the Proper EquipmentIt is important to wear respiratory equipment when working in a hazardous environment, BUT IT MUST BE THE PROPER EQUIPMENT FOR THE SPECIFIC TASK. Here are some things to keep in mind when deciding which equipment to choose:
- Make a list of operations and work sites where there is any kind of contamination.
- List any type of job where a lack of oxygen is a problem.
- List the specific contaminants that correspond to the work site and its jobs.
- List how harmful the contaminants are - both potentially and/or actually.
- List the form of the contaminant material: dust, mist, spray, gas, vapor, fume or some combination of these.
- Give the concentrations of each contaminant.
- READ ALL LABELS.
There are several types of protective equipment available for all tasks. They are broken down into two categories:
-
1. Air
Purifying. This type removes contaminants from the air. It
is only to be used where there is a sufficient oxygen supply.
This category includes: mechanical filter, chemical cartridge
and canister gas mask respirators.
2. Oxygen Providing. This type provides oxygen for the user in oxygen-deficient atmospheres. This category includes: supplied-air respirators and Self-Contained Breathing Apparatus (SCBA).
Air
Purifying Respiratory Protection
Mechanical
filter respiratory protection devices are commonly known as
dust masks. These simple filters commonly consist of a molded
filter designed to cover the nose and mouth. The filter is held
in place by one or two elastic straps that are stretched over
the head. Some of these type masks have a valve made into the
filtering substance to allow easier breathing. When the filter
becomes clogged, the complete unit is discarded. Units having
two straps fit better.
Dust masks provide protection against airborne dust particles (chemical, mineral, field or barn, chaff, pollen) and non-toxic paint spray dusts. Sufficient levels of oxygen must be present in the air to be filtered.
Chemical
Cartridge Respirators
Chemical cartridge respirators provide a higher level of protection
than dust masks. A soft rubber-like face piece (silicone) covers
the nose and mouth and contains valves to control
air movement
through the device. A full face respirator also contains a lens
to cover the eyes. Replaceable cartridges containing activated
carbon are used to filter the incoming air. Prefilters are usually
installed on the outside of the cartridges. Elastic straps or
harness are used to hold the respirator snugly against the user's
face. A half mask covers only the nose and mouth of the user.
A full face respirator also includes an eye shield and covers
the entire face and eyes.
The user must anticipate the type of hazard to be protected against and purchase the correct cartridges. Most cartridges are designed to provide protection for a specific type of chemical hazard such as pesticides, ammonia, anhydrous ammonia, etc. Sufficient levels of oxygen must be present in the air to be filtered.
Gas
Masks
Gas
masks have full face coverage. The filtering cartridge or canister
has a larger capacity than a cartridge type respirator. The
cartridge may be mounted on the face piece or at the end of
a flexible hose to allow mounting at the user's belt. Sufficient
levels of oxygen must be present in the air where gas masks
are used.
Gas masks provide protection against pesticides, and often toxic airborne materials. The greater capacity of gas mask cartridges (canisters) allows longer working times in high levels of contaminants than typical respirators.
Supplied-Air Respiratory Protection Supplied-air respirators provide fresh air from a remote source or from pressurized tanks. The face pieces are similar to cartridge type respirators or gas masks. The air may be supplied by a portable air compressor or pressure tanks located up to 300 feet from the user. Compressors must be located in a clean air area.
Supplied-air respirators can be used in confined spaces where
there is likely to be an inadequate level of oxygen.
SELF-CONTAINED BREATHING APPARATUS (SCBA) is a type of respirator that has full face coverage and an oxygen supply contained in a compressed air tank carried on the users back. It can be used in oxygen deficient areas and in hazardous atmospheres.
A self-contained breathing apparatus can be used where ever the user must work, such as in silos, manure pits, grain storage and fumigation of structures.
Hazardous
Sources and Their Contaminants
The
table below identifies some common hazardous sources and their
potential contaminants. It briefly summarizes situations where
you should use protective equipment to guard against dangerous
elements that may be present in the listed work environments--YOUR
work environment.
| SILAGE | MANURE PITS | CONFINED POULTRY HOUSING | CONFINED HOG HOUSING | PESTICIDES |
|---|---|---|---|---|
| CO2
nitrogen oxides mold spores |
ammonia methane CO2 hydrogen sulfide |
DUSTS: feathers and feather particles dried skin material dried fecal material dried feed products
GASES: |
DUSTS: hair and skin particles dried feed products dried fecal particles
GASES: |
TOXIC: fumes gases mists dusts |
If you are not sure which type of protective equipment is best for the work you do, then ask the professionals who sell the various products.
Places
Where You Can Buy Respiratory Equipment
You
can probably find most types of equipment at a safety supply
store, but farm supply stores and agricultural chemical suppliers
are also good sources. If any of these suppliers do not have
the equipment you need, they can likely order it for you or
tell you how you can order it yourself. Places that test-fit
the respiratory device to ensure a proper fit are the best places
to purchase your equipment.
For information concerning the selection and use of respiratory equipment, contact local agricultural stores, safety supply stores, pesticide sales outlets, or the Virginia Cooperative Extension.
Respiratory
Equipment Safety
Respiratory
equipment can safeguard your health and save your life in any
hazardous air condition you may encounter. However, without
proper care and precautions when using such equipment, the device
you rely on could be ineffective. Here is a list of guidelines
and precautions every worker should follow when using protective
equipment.
- Individuals should be completely familiar with equipment use. replacement. care. cleaning and storage. Individuals should be properly trained (SCBA requires special training for use).
- Individuals
should test equipment before every use. Follow the manufacturer's
instructions for properly testing equipment. If you are
using a respirator that has cartridges, you can use one
of two methods of testing:
-
1)
Positive Fit Check. Exhale while you cover the exhalation
valve with the palm of your hand -- if you feel air against
the skin of your face, there is a leak in the seal.
2) Negative Fit Check. Cover the cartridge(s) with your hands and inhale -- if the mask is drawn tightly to your face, there is no leakage.
- Make sure the equipment properly fits you. Leakage defeats the effectiveness of even the best respirator for the situation. Testing the equipment will assure a proper fit.
- Individuals should regularly clean and repair equipment.
- Individuals should regularly change filter cartridges and pre-filters.
If you are using a pre-filter for more than five or six hours a day, then you should change the filter daily. It is important to change filter cartridges before breathing becomes difficult.
- Individuals should store protective equipment in a clean, dry place AWAY from work and chemical storage areas. Self-sealing plastic bags are ideal for storing clean respirators.
- Individuals must be fully capable of wearing protective equipment. If you are not sure or do not know how a condition you may have could affect proper use of equipment, check with your physician. Some conditions which could cause problems are: asthma, allergies, emphysema, high blood pressure, heart disorder, claustrophobia or minor facial abnormalities.
- Buy only certified respirators. Look for labels approved by NIOSH or MSA that show an approval number.
- If it is practical, assign respirators to individuals.
Caution: Often, it is necessary to use other protective equipment and clothing when using respiratory protective equipment, such as special gloves, eye protection, and long sleeve shirts.
| In Case
of Emergency If you suddenly feel SICK, DIZZY or CANNOT BREATHE properly, leave the hazardous area immediately. If someone else is overcome by toxic gases:
2. Remove the victim to fresh air. |
Glen H. Hetzel, Extension Agricultural Engineer Virginia Tech
Disclaimer and Reproduction Information: Information in NASD does not represent NIOSH policy. Information included in NASD appears by permission of the author and/or copyright holder. More
Reviewed for NASD: 04/2002

