What is the ruling on drinking chlorine-purified water that causes diseases like cancer? Is it considered suicide? And is it obligatory to use mineral water?

Chlorine is added to water to sterilize it. If the amount is small, such that it achieves sterilization without causing harm, then there is no objection. However, if it is excessive and causes harm to the body, then drinking it is forbidden, due to the Almighty's saying: "And do not kill yourselves. Indeed, Allah is to you ever Merciful." In such a case, one must use bottled water or sterilize the water using a method that does not cause harm. Whoever drinks chlorinated water, being certain that it will lead to their death, is committing suicide, according to the Prophet's (PBUH) saying: "And whoever drinks poison, killing himself with it, his poison will be in his hand, which he will drink in the fire of Hell, abiding therein eternally forever." And whoever drinks it knowing of its harm, but not to the extent of death, is sinful. However, whoever drinks it unknowingly of its harm bears no sin.