Introduction:
Although Mac has been changed a lot since the days of Free-BSD it is still Unix and has lots of commands that are very compatible with the ones of its brother Linux. So here are the commands done in the Mac terminal which creates a bootable USB drive using an ISO file as the source.
Important Note: The result will NOT be bootable on Mac since OS X does have some extra quirks that prevents this. In order to make an USB stick bootable on MAC use another article in this site which does exactly that.
Steps:
Plug you destination USB drive into Mac USB port and run the following command to find out which drive this is:
diskutil list
The result might look like this:
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS MAC13 676.2 GB disk0s2
3: Microsoft Basic Data LINUX 60.1 GB disk0s3
4: Microsoft Basic Data Linux Mint 60.1 GB disk0s4
5: Microsoft Basic Data 4.1 GB disk0s5
6: Microsoft Basic Data COMMON 199.3 GB disk0s6
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
..............
/dev/disk4
#: TYPE NAME SIZE IDENTIFIER
0: Apple_partition_scheme *104.9 MB disk4
1: Apple_partition_map 32.3 KB disk4s1
2: Apple_HFS 7zX 104.9 MB disk4s2
/dev/disk5
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *67.0 GB disk5
1: EFI EFI 209.7 MB disk5s1
2: Apple_HFS 64GB-OSX 66.7 GB disk5s2
In this case here the last device /dev/disk5s2 is the one in question.
We need now to unmount this device using the command:
diskutil unmount /dev/disk5s2
Then use the following command to create the bootable USB drive using the iso file:
dd if=/Volumes/DATA/ISO/debian-8.6.0-amd64-netinst.iso of=/dev/disk5s2 bs=1m
You can afterwards pull out the USB drive and use it to boot on a PC.