No, Israel did not start using laughing gas.
These Palestinian women laugh because they get paid to riot on the border with Israel.
Hamas sends them in order to create provocations and damage Israel’s image.
As you can see in the video below during the riots on the Gaza-Israel border the Muslims shouted an Arabic verse from the Quran to remind the Jews of Muhammad and his army’s slaughter and mass beheading of the Jews of Khaibar, after they had surrendered.
“Khaibar Khaibar ya yahud, jaish Muhammed sa-ya’ud” (In Arabic).
They were literally warning the Jews that their day to be beheaded by Muslims is coming, Like the Jews of Khaybar.