Assigned protection factors

Table 13.9 Assigned Protection Factors for Respirators and Breathing Apparatus ...

Assigned protection factor This was not included in the standard. However, the latest documentation indicates that OSHA will eventually add APFs into the standard. For now, employers should rely on the best available information when selecting the appropriate respirator. 

Assigned protection factor (APF) The minimum level of respiratory protection that a respirator can be expected to provide, assuming it is properly fitted, worn, and functioning. APFs are assigned by NIOSH. 

Maximum use concentration (MUC) The maximum atmospheric concentration of contaminants in which a respirator cartridge or filter is recommended for use. Can be approximated by multiplying the PEL for the contaminant of concern by the assigned protection factor. 

Each subsequent line lists a maximum use concentration (MUC) followed by the classes of respirators that are acceptable for use up to the MUC. Codes for the various categories of respirators, and Assigned Protection Factors (APFs) for these respirators, are listed in Table 3 (page xx). Individual respirator classes are separated by diagonal lines (/). More protective respirators may be worn. The symbol is followed by the classes of respirators that are acceptable for emergency or planned entry into unknown concentrations or entry into IDLH conditions. Escape indicates that the respirators are to be used only... 

The choice of facepiece depends on the level of protection needed - that is, the assigned protection factor (APF) needed. See Table 3 (page xx) for APFs of respirator classes, and see Reconunendations for Respirator Selection (page xiv) for more information. 

When employee exposure is identified, the employer can consider the respirators Assigned Protection Factors (APFs). The APFs are used to select equipment that will meet or exceed the required level of filter to protect the employee from the hazardous contaminant. 

Assigned protection factor—A rating assigned to a respirator style by OSHA or NIOSH this rating indicates the level of protection most workers can expect from the properly worn, maintained, and fitted respirator used under actual workplace conditions. 

Respiratory Protection Assigned Protection Factors for the Revised Respiratory Protection Standard (OSHA 3352—2009). 

Overview of Assigned Protection Factors, and when fit testing is necessary... 

Assigned protection factor (APF) means the workplace level of respiratory protection that a respirator or class of respirators is expected to provide to employees when the employer implements a continuing, effective respiratory protection program as specified by this section. 

Maximum use concentration (MUC) means the maximum atmospheric concentration of a hazardous substance from which an employee can be expected to be protected when wearing a respirator, and is determined by the assigned protection factor of the respirator or class of respirators and the exposure limit of the hazardous substance. The MUC can be determined mathematically by multiplying the assigned protection factor specified for a respirator by the required QSHA permissible exposure limit, short-term exposure limit, or ceiling limit. When no QSHA exposure limit is available for a hazardous substance, an employer must determine an MUC on the basis of relevant available information and informed professional judgement. 

A) Assigned Protection Factors (APFs) Employers must use the assigned protection factors listed in Table 1 to select a respirator that meets or exceeds the required level of employee protection. When using a combination respirator (e.g., airline respirators with an air-purifying filter), employers must ensure that the assigned protection factor is appropriate to the mode of operation in which the respirator is being used. 

Because each worker s environment is different, and the amount of occupational exposure to crystalline silica dust varies, an occupational exposure determination should be completed before selecting an appropriate respirator. The minimum respiratory protection for a worker who is working with crystalline silica dust, but is not doing abrasive-blasting, may be an N95 NIOSH-approved respirator. However, the exposure to crystalline silica must not exceed the assigned protection factor of the respirator. 

Assigned Protection Factor—Used in the context of respiratory protection. 

There are several important technical standards which must be considered during the selection process. Respiratory protection equipment must either be CE marked or HSE approved (HSE approval ceased on 30 June 1995 but such approved equipment may still be used). Other standards include the minimum protection required (MPR) and the assigned protection factor (APF). The CE mark does not indicate that the equipment is suitable for a particular hazard. The following information will be needed before a selection can be made ... 

The MPR values can then be compared with the Assigned Protection Factors (APFs) listed in the standard . The APFs are intended to be used as a guide and these protection levels may not be achieved where the... 

RSL is a decision-making tool developed by NIOSH to help employers choose the right kind of respirators for their workplaces by taking them through a series of questions on how and in what environments the respirator will be used, and with what types of contaminants. The RSL takes into account the Assigned Protection Factors (APF) developed by OSHA to indicate the level of protection that a respirator or a class of respirators is expected to provide. 

Several types of respiratory protective equipment may have the necessary ratio of assigned protection factor to nominal protection factor when predictions and/or measurements have been made of the physical form and concentration of contamination in the workplace. The choice could include all types of respiratory... 

---