Newbie question about Ego One Mega

I'm new to all of this, and I'm a little confused. I got a joyetech evic VTC mini and the ego tank along with some CLR atomizer heads. I read online that vaping on the wrong setting can release some nasty chemicals, and there is no indication of what mode to use with the CLR's. Anyone have a clue what metal is used in these coils and if I need to be using temp control mode? Thanks in advance!