Sounds like tear gas. I’m inclined to side with the Kurds, but it wouldn’t surprise me if they concocted a few fairy tales to get Uncle Sam to jump in with both feet on their behalf.
This is not the first such incident. They suspected Chlorine gas the prior times. And Syrian government has been accused of many attacks with chemical weapons.
It is altogether possible it happened. Turkey employees the FSA which includes stragglers from ISIS and some units of al Qaeda (Nusra).
It is possible that the Kurds could fake it? I doubt it. I know they want U.S. to step in and remove this threat. But I find their stats of war totally credible and all others are really out there. Turkey clams killing a thousand Kurds. The actual deaths were reported recently by the SDF as 98 of YPG/YPJ (on Feb 12). Syrian civilian dead were at 168 on same day. So almost 2X the Syrian civilian deaths as those killed in battle.
Kurds claimed on Feb 12 that there had been 862 FSA (Jihadi’s) and Turk soldiers killed.