Um, about that. ABS (aka Acrylonitrile Butadiene Styrene). Styrene is known to cause cancer. That said, so long as its not ingested you should be fine.
As mentioned above wearing PPE (N95 or higher respirators) when working with fine particles should protect you.
Lastly, when softening or shaping with heat (like a heat gun), carcinogens are released. In this case wearing a 1/2 faced respirator and gloves is advised.