Jake von Slatt has posted an update to his Gas Mask Respirator page at the Steampunk Workshop. He writes:

Sometimes when I’m working in the shop I just need to wear a respirator for a short period. For instance if I just need to walk into the paint area to shoot a second coat on a small part or make a quick cut on the table saw – read below to see why that’s an issue for me.

Doning the powered respirator for these tasks takes much longer then the task itself. It’s so much trouble that, more likely then not, I’ll just try to hold my breath. This doesn’t always work.

So I came up with this simple solution. I took a respirator cartidge and hot glued it to the mouthpiece of a diving snorkel. Now can pop this in my mouth and have both hands free for a quick operation, I just breath in through the cartridge and out through my nose.

Gas Mask Powered Respirator – Link