At what altitude is the use of the EMER DEPRESS switch prohibited to prevent crew and ear damage?

The use of the EMER DEPRESS switch is prohibited above 15,000 feet to prevent potential crew and ear damage. At altitudes higher than 15,000 feet, the cabin pressure differential increases significantly, which can lead to rapid decompression if the EMER DEPRESS switch is activated. This rapid change in pressure can be harmful to both crew and passengers, causing barotrauma or ear injuries due to the inability to equalize ear pressure quickly enough. The limits are implemented to ensure safety during operations, particularly in maintaining a controlled cabin environment for all occupants.