MSA makes choosing the right respirator and cartridge as easy as wearing it.

 
     
     
    The United States Federal OSHA regulations stipulate that respirator cartridges must be replaced at pre-determined intervals, based on worksite-specific usage conditions. Please find below the related text and some links to documents you may wish to review.    
     
     
   

From the Federal Register, p. 1272, col.1 OSHA 1910.134(d)(3)(iii)

   
     
     
    (iii) For protection against gases and vapors, the employer shall provide:

(A) An atmosphere-supplying respirator, or
(B) An air-purifying respirator, provided that:
(1) The respirator is equipped with an end-of-service indicator (ESLI) certified by NIOSH for the contaminant; or
(2) If there is no ESLI appropriate for conditions in the employer's workplace, the employer implements a change schedule for canisters and cartridges that is based on objective information or data that will ensure that canisters and cartridges are changed before the end of their service life. The employer shall describe in the respirator program the information and data relied upon and the basis for the canister and cartridge change schedule and the basis for reliance on the data. 		   
     
     
     
   

Links to Related Documents:

   
     
     
    1910.134 OSHA's new Respiratory Protection Standard

OSHA Directive CPL 2-0.120,
"Inspection procedures for the Respirator Protection Standard" (Sept. 25, 1998 )
http://www.osha.gov

Document from Director John B. Miles, Jr., to OSHA Regional Administrators, entitled
"Questions and Answers about the Respiratory Protection Standard" (August 3, 1998)
http://www.osha.gov/qna.pdf

   
     
     
   

MSA makes choosing the right respirator cartridge - and estimating its length-of-use time - a whole lot easier, with this Cartridge Life Expectancy Calculator.

   
     
    The service life calculations for organic vapor cartridges are based on a model presented by Wood (Wood, G. 1994. Estimating Service Lives of Organic Vapor Cartridges. American Industrial Hygiene Association Journal 55(1):11-15 ). The model was modified and some of the experimentally determined values were refined for the characteristics of MSA organic vapor cartridges.

The service time calculations for acid and basic gas calculations are based on a descriptive model by Yoon and Nelson (1. Yoon, Y. H., and J. H. Nelson. 1984. Application of Gas Adsorption Kinetics I. A Theoretical Model for Respirator Cartridge Service Life. American Industrial Hygiene Association Journal 45(8):509-516. 2. Yoon, Y. H., and J. H. Nelson. 1984. Application of Gas Adsorption Kinetics II. A Theoretical Model for Respirator Cartridge Service Life and Its Practical Applications. American Industrial Hygiene Association Journal 45(8):517-524.). The parameters are derived from experimental data collected on each adsorbate-adsorbent system of interest; in other words, each combination of challenge gas and chemical cartridge must be tested.

Mixtures of two or more chemicals can be entered directly into the calculator, even if the chemicals are from different categories. The calculator determines the time to breakthrough for mixtures in accordance with OSHA Directive CPL 2-0.120 "Inspection Procedures for the Respiratory Protection Standard". In all cases, the service life estimates are based on properties of the carbon used in MSA cartridges and can only be used for MSA cartridges.

By entering key environmental and usage factors on the calculator form, MSA can provide guidance as to how long a specific cartridge should be used before it needs to be replaced. The determination is called the "Time to Breakthrough," meaning the point at which a hazardous chemical will begin to break through the cartridge's protective filter. You will be given a series of choices and asked for information to complete the calculation. Select the choices that best describe your workplace and the worst-case working conditions as they pertain to the following:

  1. Chemical hazard.
  2. Temperature. Raising temperature decreases service time..
  3. Relative humidity. Raising relative humidity decreases the service time for organic vapors, but does not affect the service time for other chemicals.
  4. Atmospheric pressure (elevation above sea level).
  5. Current use of either a full-face or half-mask respirator and cartridge type.
  6. Type of work and average breathing rate (light, moderate or heavy). Raising flow rate decreases service time.
  7. Use concentration in ppm (parts per million) or mg/m3 (milligrams per cubic meter). Raising use concentration decreases service time.
  8. Breakthrough concentration preference.
  9. Safety factor.
Ready?

NOTE: The MSA Cartridge Life Expectancy Calculator utilizes JavaScript. If your browser does not support JavaScript, the calculator will not function properly.

   
     
   
     
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