Establish a comprehensive respiratory protection program.  Key elements of such a program are:

• Knowing what exposures require respiratory protection
• Reducing or eliminating exposures 
• Periodically monitoring environmental conditions
• Regular training of personnel
• Selecting proper NIOSH-approved respirators
• Evaluating the worker's ability to perform the work while wearing a respirator
• Conducting respirator fit testing
• Maintaining, inspecting, cleaning and storing of respiratory protection equipment
• Regular evaluation of the respiratory protection program

Under OSHA’s 1910.134 respirator standard, the employer must do the following:

• Obtain and use Safety Data Sheets (SDSs) for all hazardous products used by a contractor.  Sample SDSs for portland cement, a sealant, a solvent containing paint and a surface coating containing an engineered nanomaterial illustrate the kind of information provided, including general respirator recommendations and allowable exposure levels.
• Reduce or eliminate exposures by using engineering controls such as ventilated tools or wet work methods before requiring respirators. Ventilated tools can reduce exposures by a factor of 10 or more. Feasible exposure reduction is required even if respirators will still be needed. 
• Determine whether exposures at your jobs exceed allowable limits.  Exposure assessment must be done by a qualified person.  You may be able to obtain assistance in measuring exposures from your State OSHA consultation service or from your contractor association. Air sampling has shown that levels of silica, respirable dust, or engineered nanomaterials when disturbing nano-enabled construction products can exceed allowable limits. Silica can even exceed those limits when ventilation is used.
• If respirators are needed, establish, update and follow a written, worksite-specific respiratory protection program. The program must be administered by a person with the appropriate training or experience and must specify how respirators will be selected, how workers will be medically evaluated, fit-tested and trained, and how the program will be regularly evaluated. For vapors and gases, a qualified person must establish a cartridge change schedule based upon the workplace contaminants and exposure levels. Some cartridge manufacturers provide an on-line calculator that estimates service life based upon workplace conditions.
• Ensure workers are medically qualified to wear a respirator.  Determination of qualification must be made by a physician or other licensed health care provider (PLHCP). Medical qualification can be done through a local occupational medicine clinic. 3M offers an on-line medical qualification service.
• Select the correct respirator and filter type for the task performed. Filters for air purifying respirators designed to capture airborne particulates are available in three levels based on resistance to oils and three levels of  particle filtration efficiency.  The classification N means the filter is not resistant to oil; R means the filter resists oil; P means the filter is oil proof. A "P" or "R" filter must be used when oil mists are present, a situation more common in factories than construction sites.  Filters are rated at 95%, 99% or 99.97%  particle filtration efficiency.  99.97% efficiency filters are labeled as 100. An N95 filter (commonly used in general construction) is acceptable if you only need to remove 95% of particles in an oil-free environment.  Higher rated filters are needed in more extreme situations.  Filter efficiency must also be factored in when calculating the maximum use level of a respirator.  For a half-face respirator with N95 filters the total leakage is calculated as 10% (around the facepiece) + 5% (through the filter).
• For workers exposed to engineered nanomaterials, NIOSH has concluded that N95 and P100 particulate filters provide the expected filtration efficiency according to their efficiency ratings (Rengasamy, et al., 2009). However, both OSHA and NIOSH recommend that N100 or P100 filters be used when workers are exposed to high levels of airborne engineered nanomaterials (OSHA Fact Sheet FS-3634;  NIOSH blog post December 7, 2011). Surveys have shown that the most common respirators that are in use against engineered nanomaterials are P100 filters on elastomeric half mask or filtering facepiece respirators (Conti, et al 2008).

Routine construction site exposures to construction dust, not including cutting, grinding or tuck pointing, may be controlled by an N95 filtering facepiece respirator if good work practices are followed. OSHA also specifically excludes filtering facepieces from use in asbestos control work. Many safety and health professionals assign filtering facepieces a protection factor of only 5 because they can not be as reliably fitted and checked as elastomeric half-face respirators. Surgical type masks are not designed for protection from workplace exposures and are not permitted by OSHA to be used in a construction respiratory protection program.  More intense dust exposures such as those resulting from tuck pointing, cement grinding or cutting, and extensive brick or block cutting is likely to require specific engineering controls and/or higher level respiratory protection.

For chemical cartridges, a qualified person must select the cartridge to use and establish a cartridge change schedule. To do this it is essential to know the nature and level of all contaminants that will or may be in the workplace air.  Work level, humidity and altitude will affect respirator selection and performance.  For painting tasks, a combination filter and organic vapor cartridge may be required, and a prefilter may also be used to limit filter overloading. Respirator manufacturers and suppliers can provide you with guidance on how to select the right respirator.

Workers must be fit tested for the respirators assigned to them. Qualitative fit testing is the easiest to perform but is only allowed for exposures up to 10 times the permissible exposure limit (PEL). The contractor may obtain fitting assistance from a local safety supply company or may conduct the tests in-house using standard testing materials.

Workers must be trained in the use and limitations of respirators and on how to properly don, doff and wear them. The worker must be informed about how the respirator will be stored and maintained.

Respirators that are used repeatedly must be properly stored and maintained.  Single use respirators, such as filtering facepieces, do not require maintenance.

The respiratory protection program must be supervised by a person having the appropriate experience or training.  Persons with a beard or other feature that interferes with a good fit may not be allowed to perform work requiring the wearing of a tight fitting respirator.  The contractor must document the periodic auditing of the program and must confer with respirator users about the program's effectiveness.

The contractor must maintain employee-specific records of medical evaluation, fit testing and training.  The written respiratory protection program must be maintained and available for inspection by OSHA.

Note on the voluntary use of respirators.  Workers who are not overexposed may be allowed to wear a filtering facepiece with no additional control by the contractor. Voluntary use of any other type of respirator requires the contractor to institute those parts of a respiratory protection program necessary to determine the workers' medical ability to wear a respirator and to ensure that the respirator is properly cleaned, stored and maintained. The wearer must also be provided with a copy of Appendix D of 29 CFR 1910.134.

Respirators may slow the work process and reduce productivity.  Compared to the use of respirators without an effective program, a well-managed program can minimize the negative impact of respirators on productivity.  Engineering controls that eliminate the need for PPE with the associated tasks generally improve productivity.