In past years, MSA offered escape only hydrogen sulfide air-purifying approvals for use in atmospheres with concentrations exceeding occupational exposure limits. However, testing has shown that MSA APR cartridges are effective against H2S, resulting in NIOSH approval to remove the escape only designation from a selection of MSA cartridges. 

Users may now use MSA APR products in atmospheres containing up to 100 ppm (NIOSH IDLH) H2S concentration when following a cartridge change-out schedule.

Users can calculate cartridge service time by visiting http://webapps.msanet.com/responseguide.

Please contact MSA Customer Service at 1-800-672-2222 for additional information.

The following MSA cartridges will have the escape only for H2S designation removed: 

This approval extension only applies to MSA cartridges with date codes of 1812 and beyond. Cartridges with date codes 1712 or earlier can only be used within parameters of prior approval as escape only from H₂S.  

MSA uses a four-digit date code on its respirator cartridges to indicate date of manufacture. The cartridge label is stamped with four characters XXYY, in which XX is the week of the year and YY is the year. A cartridge stamped 1812 would have been manufactured the eighteenth week of 2012.