Pressure units for US labeling (atm, psi, or in-Hg)

Wondering what the recommended pressure unit for US public is (specifically when labeling operational, transport and storage conditions)?

I've seen atm, psi, and in-Hg used in various US documents, but am not sure if one is more generally used/suitable for medical device labeling.

(We had originally used kilo-Pascals (kPa), but these units were rejected by the FDA)

Any advice much appreciated,
MM.

 

I don't know your context/application but I'd think that most Americans would have the best comprehension of psi from an understanding and frame of reference (tire pressure, etc). On the other hand, the default atmospheric pressure being shown to me by AccuWeather is in inches of mercury.

David