Mae'rcanllawiau'nnodi manylion ynghylch defnydd e-sigaréts ymhlith pobl ifanc yng Nghymru a chamau y gall ysgolion eu cymryd i fynd i'r afael â defnyddio e-sigaréts.
Theguidancesets out details of vaping use among young people in Wales and actions schools can take to address vaping.