What prevents a padding standard to cause a data loss?
Padding is always added, even if the plaintext is a product of the block size. This way the algorithm look for the last byte(s) and can safely interpret it as padding data. In case of alignment to the block size, a full block is added just for padding purposes.

So if your example shows 8 bytes of data and you are using a 64-bit block cipher, a block of eight 08 would be added as padding.