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 hazards.
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 maintenance program.
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 health-and-safety professionals.
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 workplace;
* Medical evaluation, including how it should be done and by whom;
* Fit-testing requirements, including use of qualitative and/or quantitative fit-test procedures; fit testing must be performed annually;
* 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 respiratory protection);
* 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 performed annually;
* 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 overexposure.
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 fits.
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 protection.
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.