Long a staple of industrial food processors, partially hydrogenated oils are widely known to have health-ruining effects.

After decades of looking the other way as study after study emerged documenting this phenomenon, the FDA is finally making moves to at least encourage consumers to avoid them. The industry is already retrenching, removing the vile stuff from popular junk-food products, often heralded by a “0 Grams Trans Fat” label on the package.

Restaurant chains such as McDonalds’ own Chipotle Grill have followed suit. Archer-Daniels Midland and Monsanto have even forged an evil alliance to market a genetically altered, trans-fat-free soybean oil that mimics some of the properties manufacturers have come to love about partially hydrogenated oil.

Yet does any of this mean anything at all?

I ask because many potato/corn chip labels I’ve seen declare “trans fat free” in one place and then casually list partially hydrogenated oil on their ingredient lists. Don’t believe me? Check this out.

From what I can tell, when a fat has undergone partial hydrogenation — making it solid at higher temperatures, mimicking that grand and blameless ingredient, butter — it becomes a trans fat. For practical purposes, trans fat and partially hydrogenated oil are synonymous.

How do they get away with it?