[Elle Bee]

I was told they're a little toxic ... and in my singular experience it seemed to give the lungs a healthy workout ... and I had a bit of a residual 'hangover' feeling afterward

.

[Travis McGee]

We used chemicals such as “Sodasorb” and “Baralyme” for the CO2 scrubber. If any water got into the dry cannister full of chemical powder, you could be slurping a “caustic coctail” into your lungs.

The system had to be 100% leak-tight, including the seal of your lips on the mouthpiece. This became tricky at times, such as during a long (multiple hours) cold water attack swim, when your lips might start twitching from cold. Or in the summer, when stinging sea nettles draped across your face.

Frogmen are not sissies, that is for sure.