Canada's transport investigator says an oil train derailment in Ontario this month suggests new safety requirements for tank cars carrying flammable liquids are inadequate.

The Transportation Safety Board said Monday the Class 111 tank cars involved in the Feb. 14 CN train derailment met the upgraded standards for new tank cars carrying crude and other flammable liquids.

But it says the cars still "performed similarly" to those involved in the derailment in Lac-Megantic, Quebec that killed 47 people two years ago. That accident predated the changes.

In both cases, the tank cars ruptured and released crude oil, which fed the flames.

The agency says this month's incident "demonstrates the inadequacy" of the new standards and is urging Canada's regulator to quickly introduce enhanced protection standards.