(AP) — Union Pacific’s CEO says the railroad industry has agreed to begin treating crude oil like a toxic chemical and carefully plan out the safest routes possible.

UP’s Jack Koraleski said Thursday the railroad industry will start using existing rules for hazardous chemicals like anhydrous ammonia to determine the best route for crude oil shipments.

Railroads hauled more than 400,000 carloads of crude oil last year because production in North Dakota has outpaced pipeline capacity.

Several fiery accidents involving crude oil, including one that killed 47 in Canada last summer, have increased concerns about the shipments. Federal accident investigators recommended several new safety measures Thursday.

Koraleski says railroads are working hard to make crude oil shipments safer than they already are.