The definition and abbreviation for Potentially Hazardous Food (Time/Temperature Control for Safety Food) or PHF/TCS should be modified to drop the reference to potentially hazardous food and PHF.
Yes, as a treat apples are fine for chickens. Some will say it is best not to feed them too many apples as the seed of an apple has a small amount of arsenic in it. I have an orchard on my property and in the fall, the chickens run there first thing in the morning. Never had a chicken drop dead under an apple tree.
Also, try cutting up the veggies or fruits into dices, long slices, or thin little strips. You can feed apple whole as long as you skin it. My birds love to shred apple! You can also feed them *plain* apple sauce! Also, make sure you remove the roots, pits, and seeds of the food you give them.