All of the taps labeled NPCW or NP, or NPW.... are to be regarded as non-potable because they are in lab sinks (or were originally), but they are indeed on the potable water supply line.
At
right is another NON-violation (as long as water does not rise into
the vertical pipe to a height that comes over the delivery end of the
tap) However, it represents the type of situation that IS ALWAYS a
violation if a hose is used for the same purpose of preventing splashing
or simply directing water into the sink.
If a hose is used, whether it is stuffed down the drain, or hanging into the bottom of the sink, or hanging into a bucket or beaker ... there is the potential for a back-flow event -- a rare but real occurrence -- to cause contaminated water to be sucked backward in to the supply. (This is where some people, the ones who believe they know most everything and that these rules were simply made to inconvenience them, roll their eyes, sigh, and make faces.)
The PVC pipe solution is simple and functional. Cutting a couple of big notches in the bottom of the vertical pipe will help ensure that water doesn't build up. If it causes more splashing, try sitting the vertical pipe into shallow dish.
In particularly tight spaces it will help to use a combination of a hose and a standing pipe. The hose must not extend into the sink basin.