Not necessarily, but IP (Ingress Protection) ratings are a good indication that the keyboard will withstand the rigours which a medical keyboard is likely to encounter during washing, disinfection and daily use. IP65 being the most relevant showing that the device is tested to withstand water jets and dust.
There are some medical keyboard models which do not carry an IP rating. Often these are fully sealed across the top and sides where the user would touch them allowing for them to be wiped, but underneath may not be so well protected or sealed.
Some full travel switched keyboards look like a standard keyboard but achieve IP65 rating with the use of internal gaskets and O Rings such that the important internal electronics are protected while liquids can pass through the case itself.
A full explanation on IP ratings is available from the International Electrotechnical Commission
