Most legal practices would shred a cd (in a cd shredder) a disk in little pieces cannot be read - the data cannot be recovered.
with the right software, data CAN be recovered from a disk that has been quick formatted (any disk) - this is NOT sufficient for disposing of sensitive data.
a quick format does not erase the data. it just clears the information that keeps track of the files.
"Are you saying quick format is not available?" i didn't, but you are correct, you cannot quick format a CD or DVD