Drain cleaners come in four different varieties — acids, alkalis, oxidizers and enzymatics — and their job is to get rid of blockages in drains, most commonly in kitchens and bathrooms. Compared to mechanical drain cleaners, chemical and enzymatic cleaners are easy to use, but chemical cleaners have the potential to harm the user if instructions aren't followed exactly. Enzymatic cleaners have a slower, biological reaction and are thus safer to use than chemical cleaners.