Is there any chance we could get a new particle damage type relating to CS gas and whatnot?
For example, in particle config, we have:

damageType = "Fire";

Which can be used for modding White Phosphorus or other fire damage, but if there were another one called "gas" or something, that only damages the player if they're wearing an item that has some sort of config flag in its CfgWeapons entry, it would be beneficial for modders since the best way to mod chemical weapons is to use event handlers.
The entry could be something like

protectsAgainst[] = {"gas",1,"fire",0.5};

as an entry for CfgGlasses and CfgWeapons. It would be similar to the subItems entry for integrated night vision on helmets.
The string in the array represents the particle damageType, the number represents the amount of mitigation. So 1 would protect fully, and 0.5 would protect half, which would also be useful for fire retardant gear or having two different gear options that when worn together, protect fully.

As far as I understand, with event handlers you can't really get the particles themselves to do damage. If you had a gas grenade go off, but wind blows away the gas particles, the event handler will still do damage at the source depending on how you use the event handler, and the particles will simply have no effect.

Basically, a new particle damage type, and a way to negate particle damage somehow, would be really nice for modding.
There's lots of different gas masks and chemical weapons across many different mods and they don't line up correctly a lot of the time. So without additional work, a gas mask from one mod might not protect against a gas grenade from another mod. Or, a gas grenade from one mod might do damage in a different way than another mod's gas grenade. With this suggestion, it would be a way for modders to very simply have their modded gas grenades and masks to work with another mod's content without any specific compatibility work, since the game would handle it universally.