Gas mask

The gas mask reduces the effect of respiratory-based gases on its user.

Mechanically, the does all of the following:
 * Effectively reduces gas density by 40 prior to calculating gas effects on its wearer.
 * Provides a saving throw bonus of +8 against inhaled gas effects, and prevents critical failure when rolling a 1 on the saving throw.
 * Reduces gas-based damage by 8%

This item's effects stack if you wear multiple.