I tend to do ESPs personally but thought I'd try my hand at using RobCo Patcher (since it looks like a lovely way to offload some of the conflicts such patches can create ~~even if it only takes minutes to resolve such)~~. Patches add the gasmask keyword from Advanced Needs 76 to gasmask gear, requiring both AN76 and any mod patched (and said patches should obviously load after masters).  If you don't use a patch for your (modded) gasmask and haven't patched it yourself, odds are it's not working with AN76's particulate system.

If you don't use RobCo Patcher or want a version not dependent on it, I maintain such here. 

Currently Patched:* 4estGimp - Raider Overhaul ONE

• ~~Automatron Helmet - Visots and Headlamps~~*
• BoS Medic Battle Suit
• CROSS Brotherhood Recon
• CROSS Coursers Strigidae
• CROSS Institute Expeditionary Suit
• CROSS Institute Tech Mask
• CROSS Mojave Manhunter
• CROSS Vertibird Flightsuit
• Cyber Rebreather
• Dead Money Hazmat Suit with CBBE conversion! I use CBBE so that's what I patched for.
• Grease Rat Garbs
• ~~Gunner Armor Expansion~~*
• Gunner Operator
• Gunner Outfit Pack
• The Headpiece Dispatcher: Mod has a few ITMs so might not be a bad idea to clean it. I tend to manually clean ITMs but QAC should work just as well. 
• Heavy BoS Armor
• Heavy Institute Armor Corpus Praesidium
• Hornet Helmet
• Institute Exo Suit
• Just Another Gasmask mod or Not
• MW Kruegar
• Panzer Riot Armor
• Rainbow Six Siege Armor Depository
• RDA Mask
• Secret Service Armor
• Soviet Gasmask
• Steampunk Headgear
• Vault Tec Mask
• VTAW Wardrobe 5

*Patch tweaks OMODs to add the keyword when gasmasks are crafted since they're workbench addons for the helmets, not individual armor pieces.I dunno how to do so via RobCo so use the ESP versions for these.