If you look at the label on a bottle of Drano, you will notice a warning stating you should not pour the product down a toilet's drain. Some may be tempted to pour Drano into a clogged toilet since removing toilet clogs can be messy work, but doing so will not clear the clog and can put you in danger.
Mixing different cleaners, including clog removers such as Drano, can create a dangerous or even deadly mixture. Drano contains ammonia, and some toilet cleaners contain bleach, including toilet tank tablets. Mixing bleach and ammonia will produce toxic gasses called chloramines. Exposure to chloramines will cause a number of symptoms such as difficulty breathing, eye irritation, chest pain and even pneumonia.
Toilet Drain Design
Toilet drains have a different design than drains for sinks, bathtubs and showers, making Drano less effective at reaching clogs. Drano products will not sink down a toilet's drain as they will in other drains, meaning the Drano will never reach the clog. If you decide to use a plunger to remove the clog later, you could potentially splash yourself with the Drano in the water, which can irritate your skin or eyes. Drano's toilet cleaning solutions work only in toilets that have partial clogs since they cannot reach clogs once a toilet stops up completely.
The clogs in a toilet normally contain human waste and toilet paper, unless a foreign object is flushed down the toilet. Clogs in sinks, bathtubs and showers consist of hair, skin oils, soap scum, food scraps and makeup. Drano works to eat away at the types of clogs found in other drains, not in toilets. Drano does make cleaning solutions for toilets, which contain microorganisms that eat human waste to remove the clogs.
When your toilet stops up completely, Drano recommends using basic plumbing tools to remove the clog so you can continue using your toilet. Use a funnel-cup plunger first, since the rounded portion on the bottom of the cup will fit into the toilet's drain opening better than other plungers. After you use the plunger, move on to a toilet auger. Run the auger's flexible line down the drain as you spin its handle clockwise, and then turn the handle counterclockwise as you retract it from the drain. Drano recommends calling a plumber if using a plunger and auger does not clear the toilet's drain.