Etymology: from Canada Oil Low Acid, developed in the 1970s.
Erucic acid has been linked to cardiac muscle damage, but rapeseed oil (not canola oil) is used as a cooking oil in some countries. Rapeseed oil is also used as an industrial lubricant. Although the original canola plant may have been created using traditional plant-breeding techniques, there are now genetically modified versions (such as Roundup Ready). Canola oil is currently one of the most widely-used cooking oils.
There's an email rumor floating around that lists the dangers of canola oil...both Mayo Clinic and snopes.com disagree with the claims made in the email. Among other inaccuracies, the chemical warfare agent mustard gas is not derived from rapeseed or any other member of the mustard family; it's called "mustard gas" because of a similarity in odor.
For the record, the official definition of canola is "Seeds of the genus Brassica (Brassica napus, Brassica rapa or Brassica juncea) from which the oil shall contain less than 2% erucic acid in its fatty acid profile and the solid component shall contain contain less than 30 micromoles of any one or any mixture of 3-butenyl glucosinolate, 4-pentenyl glucosinolate, 2-hydroxy-3 butenyl glucosinolate, and 2-hydroxy-4-pentenyl glucosinolate per gram of air-dry, oil-free solid."