The main source of membranes is the world boss Dendilord level 78. He is located in an arena in the red zone in the north of the World Tree map. You can find this point under the name “Root Rotmist”, where a portal to enter the battle is located.

Dendilord belongs to dark and grass elements, so you will deal maximum damage using fire and dragon type pals. To capture the boss use Sun Spheres or Ancient Spheres to ensure a reasonable success chance. If you defeat the boss or the arena falls you will receive several toxin filtering membranes along with the rest of the loot.
How to craft this mask ?
The mask is considered just an accessory that completely blocks gas damage in the Rotmist location. This item can be crafted at the ancient workbench, for which you will need soralite, bio batteries and AI cores in advance.

Resource list to craft the item :
- 30 units of paloxite
- 10 toxin filtering membranes

Paloxite can be obtained from large purple crystals, they are located in the World Tree region. If touched or attacked without preparation, they will instantly disappear without dropping anything. To ensure easy resource gathering, the character needs to drink Holy Water of the World Tree, this consumable can be easily obtained by defeating any local pals.