Effective Nov. 22, 2006, OSHA made some changes to its Respiratory Protection Standard. The standard revision includes a table giving the Assigned Protection Factors (APFs) for all types of respirators (see Table 1). This is a good time to review your respirator program (or determine if you need one) to be sure you are adequately protecting your employees.
There are two types of respirators: Air purifying respirators filter the air from the immediate work area before it enters your lungs; supplied air respirators provide you with clean air from an airline or tank. Each of these types has various models, including those that cover half your face (mouth and nose area), all of your face (referred to as a full face piece) or a helmet or hood. Respirator selection becomes particularly important with air purifying or filtering respirators because you are cleaning the air rather than supplying fresh air.
How Do Respirator Filters Work?
Air purifying respirators work by filtering the air before it reaches the lungs. For dust or particles, the pores of the filter are small enough to screen out the particulate. For chemical fumes or gases, the filter contains absorbents like charcoal that capture the chemicals before they reach the lungs. Some work situations require both dust and chemical removal.
How Do You Know Which Respirator To Use?
To determine what respirator to use and how long it lasts, OSHA and the National Institute for Occupational Safety and Health (NIOSH) have developed a rating system for respirators, the APF. Another new term, Maximum Use Concentration (MUC), has also been incorporated into the revised OSHA Standard.
What Are APFs?
APFs are numbers that indicate the level of workplace respiratory protection that a respirator, or class of respirators, is expected to provide to the user. APFs are used to select the appropriate type of respirator based upon the permissible exposure limit (PEL) of a contaminant and the level of the contaminant in the workplace. The APF is the percentage of the contaminant that will be filtered out of the surrounding air.
What Are MUCs?
The respirator you select must keep the employee's exposure at or below the PEL. For each specific respirator, the MUC is the largest concentration of an airborne contaminant that that the respirator can handle. The exposure level must be measured using OSHA protocol and compared to the MUC for the respirator you have selected. If the workplace exposure exceeds the respirator's MUC, the employer must choose a respirator with a higher APF.
What Does This Mean To Business Owners In The Surface Fabrication Industry?
Surface fabricators may be required to use respirators to protect themselves from inhaling grit and dust, exposure that occurs when dry-cutting masonry or stone that contains silica, and exposure to chemicals released when sawing, routing, drilling or sanding synthetic sheet goods. These chemicals may include methyl methacrylate, butyl acrylate, alumina trihydrate, carbon black and ferric oxide among others. Additionally, it is likely that your adhesives produce hazardous fumes. You must determine what your employee exposure is for each chemical produced or used in the workplace, and ensure that your respirator's protection level is adequate for that exposure level.
What Constitutes An Effective Respirator Program?
First determine what airborne hazards exist in your workplace. You must be familiar with the PELs of airborne contaminants and physical agents used.