[Ilgaz]

You need to install it to OS X using keychain utility. OS X native apps ask the OS itself for certificates. I am not sure about firefox but can speak for icab/omniweb/safari. IE for Mac while being old and insecure asks same location and even installs own certs.
I'd recommend launching keychain access and reading its help. As SSL certs are critical; I can`t post step by step instructions. It is easy though.
Ask Clara guys if you need. They must have instructions or ready made knowledge base.