How can food products claim ';o grams transfat'; and yet list ';hydrogenated vegetable oil'; as an ingredient?

Sometimes if the amount of something is very low, they can claim it contains a ';negligible'; amount of it.How can food products claim ';o grams transfat'; and yet list ';hydrogenated vegetable oil'; as an ingredient?
Because they lie, and the FDA is now an arm of big business due to the Republicans.