SIX days before last week’s deadly Amtrak derailment, a train carrying crude oil went off the tracks in rural North Dakota and burst into flames. Thankfully, no one was killed. But it should not take a deadly disaster — like the one that took 47 lives in the town of Lac-Mégantic, Quebec, in July 2013 — for us to grasp the risk from oil trains, which pass through many densely populated parts of the United States.

The Obama administration recently issued new safety rules for oil trains, to take effect in October. But it didn’t do the one thing many independent petroleum engineers say could immediately reduce the risk of a deadly disaster: require energy producers to remove more of the volatile gases that the oil contains when it comes out of the ground, before they load the crude into rail tankers.

This can be done easily at most wells. North Dakota recently required producers to extract some of these gases, which include propane and butane. The state is the epicenter of the new oil boom and was the departure point for most of the more than 400,000 oil tank cars that rolled across the United States in 2013.

But the North Dakota rule is still too lax, and instead of toughening it, the new federal rules focus on strengthening the tankers that carry the oil. That is a long overdue step that will take five years to complete. And already, the oil industry, which owns many of the tankers and will bear much of the cost of upgrading them, has sued to extend the deadline.