DCHAS-L Discussion List Archive

>I recently learned that organic vapor respirator cartridges do not 
>adequately filter out methanol. Can someone explain why? Are there 
>other common solvents that these cartridges are inadequate for?
>
>Thanks,
>
>Susan Hadden
>Senior Occupational Safety Specialist
>J&J PRD Environmental, Health & Safety
>1000 Rt 202, PO Box 300
>Raritan, NJ 08869
>908-704-4295 (ph), 908-707-9211 (fax)

As far as the "why" question goes, it is the chemical nature of 
methanol.  Methanol can be thought of as water in which one H has 
been replaced by a methyl group.   Methanol is a very polar, 
hydrogen-bonding solvent that has behavior very untypical of a more 
"common" organic solvent such as benzene.  It does not bond well to 
the materials used in organic cartridges (activated carbon, for 
example).

As far as other solvents go, it is easier to use a cartridge 
selection guide than to make a comprehensive list.  You can download 
one from Bullard here:

	http://www.bullard.com/downloads/pdf_files2/cartridgeselectorguide.pdf

Notice that for methanol, it suggests a supplied air respirator (SAR) 
rather than an air-purifying filter/cartridge.  On page 3, there is 
contact information for chemicals that are not listed in their guide.

Standard disclaimer: my company is a Bullard distributor.

Best regards,

Rob Toreki
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