Respirators ANSI, standards

The level of protection that can be provided by a respirator is indicated by the respirator s protection factor (PF). This number, determined experimentally by measuring facepiece seal and exhalation valve leakage, indicates the relative difference in concentration of the concentrations of substances outside and inside the facepiece that can be maintained by the respirator. For example, a PF of 10 for a respirator means that a user could expect to inhale no more than one tenth of the airborne contaminant present. A source of protection factors for various types of atmosphere-supplying and air-purifying respirators can be found in the American National Standards Institute (ANSI) standard ANSI Z-88.2-1980. 

Under Occupational Safety and Health Administration (OSHA) regulations, only equipment listed and approved by the Mine Safety and Health Administration (MSHA) and the National Institute for Occupational Safety and Health (NIOSH) may be used for respiratory protection. Also under the regulations, each site on which respiratory protective equipment is used must implement a respirator program (including training and medical certification) in compliance with OSHA s Respiratory Protection Standard (29 CFR 1910.134) see also ANSI standard Z88.2-1992, Practices for Respiratory Protection. 

Face protection includes welding helmets and face shields with plastic or mesh windows, but note that many hard hats, non-rigid helmets, and respirators are designed with face protection built in. Regardless of the type, all face protectors must meet American National Standards Institute (ANSI ) standard Z87.1-1968, Practice for Occupational and Educational Eye and Face Protection. Look for the ANSI Z87.1 marking on your face protection. 

Clothing Wear appropriate protective clothing to prevent skin exposure. Respirators A respiratory protection program that meets OSHA s 29 CER 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator s use. 

Since a power-assisted air-purifying (PAAP) respirator is a positive-pressure system, i.e., the air within the facepiece is atahigherpressure than the outside air, this type of unit intrinsically provides more protection than the ordinary half-face respirator. If provision is made for an escape mode of operation, i.e., the wearer can continue to breathe through the filters should the pump fail, and escape from the contaminated atmosphere. The ANSI Z88.2 standard (AmericanNational Standard Institute) would permit the use ofthis type ofrespiratorin an IDLH atmosphere. Some ofthe early models of this type of unit had some problems with the seals on the pumps, but these problems have been corrected and they represent a desirable alternative if the wearer is to remain in a contaminated atmosphere for extended periods. There have been a few problems with the pumps overheating while being used at elevated temperatures. 

ANSI Z88.6, Respirator Use—Physical Qualifications for Personnel ANSI Z89, Safety Standard for Industrial Head Protection (DU)... 

Respirators selection should be made according to generally recognized standards (e.g., ANSI Z88.2, Practices forRespiratory Protection). Whenever respirators are used, a written program which addresses the selection and use ofrespirators should be in place and include the following... 

The electrical model of the respiration circuit of the Fig. 2 includes the defibrillator proteetion resistances (Rp) in each wire of the ECG cable and the electrode impedanee. The electrode impedance is modeled as a 51-kf2 resistor in parallel with a 47-nF capaeitor as specified in the ANSI/AAMI EC13 2002 standard. The total baseline impedance consists of the sum of Rp, Rb, and electrode impedance [9]. 

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