Workers in heavy construction are exposed to a variety of
air contaminants that may be generated by the work they are doing or the vehicular
traffic that surrounds them. These contaminants may be gases, vapors, dusts,
fumes, smoke or mist. Despite these health hazards, only about four in 10
workers in heavy construction use respiratory protection when needed, according
to recent surveys, leaving hundreds of thousands exposed to respiratory
While a great deal of recent attention has focused on gas
masks for combat and homeland defense, it is clear that respiratory protection
is every bit as important for workers in heavy construction. After engineering
controls have removed respiratory hazards where possible, two key steps are
required to ensure that your workers' respiratory systems are protected.
First, establish a respiratory protection program that
accounts for the unique aspects of your construction workplace and that builds
understanding among your employees about the importance of wearing respiratory
protection when needed. Then, choose the right respirators for various hazards
to which workers are exposed.
Turn on the program
(This section offers the perspectives of Jeffrey S. Birkner,
M.S., CIH, vice president of technical services for respiratory protection
manufacturer Moldex-Metric Inc., Culver City, Calif. This information appeared
first in the January 2003 issue of Plant Safety & Maintenance magazine and
is used with permission of that publication.)
Becoming familiar with the U.S. Occupational Safety and
Health Administration (OSHA) Standard 29 CFR1910.134 represents a good first
step toward an effective respiratory protection program. This standard outlines
minimum elements required for an acceptable comprehensive program. It explains
how the respirator should be used, the training and record keeping required,
the type of medical surveillance that must be done and the extent of the
Depending on the nature of the hazard, it may be prudent to
put in place a program that exceeds OSHA's minimums. Respiratory manufacturers
can provide assistance and recommend other sources of information. In addition,
you may wish to consider obtaining help from an industrial hygienist or other
After becoming familiar with OSHA's regulation, the next
step is to determine what respiratory hazards exist in your workplaces, their
concentrations and potential health effects, including whether they may be
immediately dangerous to life and health or present a chronic hazard.
Assembling this information also helps determine whether the substances present
other hazards--being absorbed through the skin or the eyes, for example--that
require additional protection.
The detail required for the program is driven mainly by the
toxicity of the hazards in the workplace and site-specific concerns including
operations that create the hazards, the temperature, humidity and work rates.
Employers also need to consider how to handle emergency situations. Finally, a
suitably trained individual must administer the program. At a minimum, the
program should include sections that address each of the following elements:
* Procedures for selecting respirators for use in the
* Medical evaluation, including how it should be done and by
* Fit-testing requirements, including use of qualitative
and/or quantitative fit-test procedures; fit testing must be performed
* Respirator use, including the employer's responsibilities;
* Respirator maintenance and care, including acknowledgment
that the employer must provide for cleaning and disinfecting, storage,
inspection and repairs;
* Breathing air quality and use, including requirements for
supplied air and SCBA respirators (not all programs will use this level of
* Identification of filters, cartridges and canisters, which
indicates that all of these components must be properly color-coded with a
legible NIOSH approval label;
* Training requirements, including that retraining must be
* Program evaluation and measurement; items that should be
examined include fit, exposures, employee use and maintenance; and
* Record keeping.
Naturally, each program must be developed based on employee
needs and the level of respiratory protection required. Selection of
respiratory protection is more complex than any other type of personal
protective equipment. In selecting the proper equipment, the chemical and
physical properties of the contaminant, the toxicity and concentration of the
hazardous material and the amount of oxygen present in the work environment are
among numerous items that must be considered.
The process of selecting the right equipment should begin as
soon as the hazard or hazards are identified and evaluated. Material Safety
Data Sheets (MSDSs) on the material hazards to which workers may be exposed
often provide guidance on the levels of protection needed.
On one end of the spectrum, if the potential hazard is a
dust with relatively low toxicity, the workers may need only disposable
filtering face pieces as part of a relatively elemental respiratory protection
program. On the other hand, workers potentially exposed to highly toxic
chemical vapors in high concentrations are likely to need supplied-air
respirators as part of a much more detailed program.
Heavy construction, itself, presents unique respiratory
protection challenges. The work zone, as well as personnel, may be mobile.
Worker turnover rates may be higher than in some other trades, requiring more
frequent training. Getting male workers to wear respirators may even require
overcoming cultural resistance to seeming less than "manly." These nuances
all must be considered in developing a respirator program for your operations.
(This section offers the perspectives of George Blank,
respiratory product manager for manufacturer Draeger Safety, Pittsburgh, Pa.)
Each heavy construction work zone poses its own set of
respiratory hazards and each should be evaluated to determine the right
respiratory protection equipment as part of a comprehensive program. Even so,
nine out of 10 respiratory hazards in heavy construction can be addressed with
the disposable particle mask, also known as the filtering face mask.
Fine aerosols or respirable dusts may be released by
grinding, drilling, milling and painting and cleaning processes. These
substances may cause respiratory tract and lung irritation and diseases
including cancer, asbestosis and silicosis. Individual respirators should only
be used when such hazards cannot be eliminated by engineering methods.
Respiratory protection users must be trained in respirator
donning/doffing and such things as recognizing possible symptoms of
Following manufactures' recommendations for donning
respirators is very important because improper donning can cause a poor fit and
subject the user to high levels of contaminants. Workers also may be required
to have a medical checkup to ensure they can wear a respirator. They must be
clean-shaven and have been fit tested with the appropriate respirator within
the last 12 months.
There are two basic fit-testing methods--qualitative and
quantitative. Qualitative methods
include smoke, Bitrex, saccharin and isoamyl acetate. This method can be
considered a go no-go type of test. The user must not detect any of the test
media in order to pass the test. If the media are detected by taste or smell,
the fit test has failed. The quantitative test method has two approved testers:
the Fit Test 3000 by OHD and the Portacount by TSI. These testers are very
sophisticated and provide an actual number that signifies how well the mask
If a test from either the quantitative or qualitative method
has failed, the wearer should re-don the same mask, select a different size, or
try a different brand until a successful test has been achieved. Whichever
method is chosen, every user who falls under a respiratory protection program
must be fit tested annually.
Particles may result from grinding, crushing, milling,
mixing, combustion, reactions, heating metal, sweeping debris or demolition and
renovation work. Particles with a size of less than 5 microns are referred to
as respirable substances or fine dusts.
Fine dusts are invisible and may penetrate the respiratory
tract as far down as the alveoli.
The first thing to remember when choosing a disposable
particle mask is to consider only those that have been approved by the National
Institute for Occupational Safety and Health (NIOSH). NIOSH tests and evaluates
respirators for performance; those approved bear the NIOSH logo.
All disposable particle masks fit into one of the nine
NIOSH-assigned filter-media categories. Filter media remove contaminants by
mechanical or electrostatic means, or a combination of the two methods.
The three NIOSH-assigned filter media categories are
"N" for "not oil resistant," "R" for "oil
resistant" and "P" for "oil proof." Each filter media
category has three levels of filtering efficiency--95%, 99% and 99.97% (100). A
respirator designated N95 affords the lowest level of NIOSH-approved
protection, while one designated P100 provides the greatest level of
Filtering face masks are available in shapes that include
preformed-three-dimensional, accordion-flat-fold, fold-in-half and combinations
of these designs. Masks that are individually packaged can be kept clean when
taken to the workplace in pockets or tool boxes. The mask's elastic head straps
should stretch to adjust to any size head without having to be tied in a knot
to shorten them. The mask should provide a good fit and be comfortable to wear
for long periods.
Because different manufacturers use different materials, the
filter capacity of the masks can vary widely. As a rule of thumb, a layered
filter material should provide longer service life than a single-ply material.
Worker acceptance is important because no respirator can
protect if it is not worn. Lack of comfort is a key reason why workers object
to wearing filtering face masks. To enhance comfort, equip workers with masks
that are designed to minimize breathing resistance and that have exhalation
valves. Both features minimize heat generated within the mask.
Numerous other mask qualities affect user acceptance,
including ease of donning and doffing, individual packaging and sizing,
adjustable nose bridge, sealing surfaces (elastomeric or cloth), strap comfort,
durability and interface with additional protective accessories such as
goggles, hearing protection or a safety helmet.
Remember, the respirator chosen must not only meet the
safety requirements for respiratory protection, but also should be easy to use
and comfortable to wear.