This is not technically true (but often true). Water vapor is a gas and is much smaller than the "leaks" of particles. A perfectly sealed filter (like an elast

This is not technically true (but often true). Water vapor is a gas and is much smaller than the "leaks" of particles. A perfectly sealed filter (like an elastomeric mask with high fit factor) will still release a ton of H20. EVIDENCE: The exhaust from PAPRS and viralhelmets.com has a ton of moisture.