Suicide
The act of ending someone's life by themselves, most of the time without external "help" is called suicide.
Prevent people from killing themselves
How not to commit suicide
If you want to kill yourself, you should refrain from using these methods. They usually inflict a lot of pain and suffering. Like all suicide methods, these will not reliably kill you.
Drinking Bleach
further information
How to commit suicide
Keep in mind that even the most lethal methods are not 100% guaranteed to kill you.