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How do you estimate the service life of a respirator?
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How do you estimate the service life of a respirator?

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After choosing the right respiratory protection, the frequently asked question – to which there is no easy answer - is: what is the service life of our respiratory protective equipment (RPE) cartridge?

Check out the PREMEDIA software application, an electronic calculation tool based on an empirical model using the Wheeler-Jonas equation and a series of tests performed on test benches that simulate a polluted atmosphere.

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1/ What is PREMEDIA?

PREMEDIA is a software application developed by INRS for predicting the service life of respiratory protective equipment (RPE) cartridges. It is not an RPE user and selection guide. If that’s what you’re looking for, please read our article: How to select the right type of respiratory protection

The calculation algorithm is based on the Wheeler-Jonas empirical model, backed up by tests performed in the INRS laboratory. The method developed is described in full in INRS documentary memo ND 2342: Outil d'estimation de la durée de vie d'adsorbants (Tool for predicting the service life of adsorbents).

PREMEDIA only calculates the service life of a new cartridge used continuously in the specific conditions encountered by the user. Users must have defined the following points beforehand:

  •     Identification of the contaminant(s) (three maximum)
  •     Contaminant atmospheric concentrations (measured or estimated)
  •     Ambient temperature and relative humidity
  •     Estimated work rate (low, average, high)
  •     RPE and cartridge characteristics (manufacturer, model)

PREMEDIA: limits and cautions

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PREMEDIA: limits and cautions
PREMEDIA: limits and cautions

PREMEDIA is a predictive calculation tool for estimating the service life of respiratory protective equipment but it has certain limits, described below:

  •     The currently available version is limited to calculating the service life for Type A and ABEK cartridges, which are recommended for exposure to gases and organic vapours with boiling points higher than 65°C.
  •     Under no circumstances may the results provided be extrapolated to other cartridge models or chemical pollutants not covered by the application.
  •     The tool only calculates the service life for a new cartridge subject to continuous use.

Precaution to be taken into account: the calculation algorithm excludes the effects of storing the cartridge after initial usage and its re-usage.

Before using the software, INRS draws attention to several factors, including unsuitable storage conditions or partially or wrongly characterised exposure, which can have an impact on the actual service life of cartridges.

As a result, the recommendations derived from the PREMEDIA tool should be considered with caution. The PREMEDIA user is solely responsible for the ultimate use of the results provided by the calculation.

How to get access to PREMEDIA software

To get access to the software:

  1.     Go to the INRS website: https://premedia.inrs.fr/Premedia/jsp/Accueil.jsp?langue=EN
  2.     Carefully read through the cautions
  3.     Agree to the conditions of use to get access to the PREMEDIA software application
  4.     Enter the information about exposure, the workstation and protection used
  5.     Click "Predict the service life" to obtain a result. You can export the results in PDF format.

 

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How to get access to PREMEDIA software

Exposure: identified and quantified beforehand by samples taken from the atmosphere and gas detectors or analysers.

This prior identification is essential for estimating the service life of the cartridge; any inaccuracy with regard to the identification and/or quantification of the pollutants present will lead to a significant error in the final result.

Workstation: users specify the work conditions, such as temperature (°C), relative humidity (%) and pressure (mbar) of the atmosphere, as well as work rate (used to determine the respiratory flow).

Protection: type of respiratory protective equipment (respirator and cartridge)

Source: INRS