Starting your Mozilla application with a specified profile
From MozillaZine Knowledge Base
This article explains how you can start with a specific profile when you have multiple profiles for your Mozilla application.
Profiles listed in the Profile Manager
When multiple profiles are listed in the Profile Manager, the last selected profile is automatically used, unless you uncheck the "Don't ask at startup" option. If you don't wish to always see the Profile Manager at startup, you can use the -P "<profile name>" command line argument, either directly or from a desktop shortcut, to start your Mozilla application with a specific profile. See Shortcut to a specific profile for details.
Bypassing the Profile Manager
You can use the