Plumbers generally advise against using Drano and other chemical drain cleaners because they can cause more harm than good. Here are a few reasons why: Damage to pipes: Chemical drain cleaners are highly corrosive and can damage pipes over time. If used too frequently, they can weaken pipes and lead to leaks or even pipe failure. It may also melt the glue between PVC pipes, which leaves your plumbing system unuseable. Environmental concerns: Chemical drain cleaners contain harsh chemicals that can be harmful to the environment. When they're flushed down the drain, these chemicals can enter the water supply and cause pollution. Safety concerns: Chemical drain cleaners can be dangerous if not used properly. They can cause skin and eye irritation and release toxic fumes when mixed with other chemicals. If ingested, they can cause severe injury or even death. Ineffectiveness: In some cases, chemical drain cleaners may not even work to clear a clog. Instead of using chemical drain cleaners like Drano, plumbers often recommend using natural methods like a plunger, a drain snake, or a natural drain cleaner made from baking soda and vinegar. These methods are generally safer and more effective at clearing clogs without causing damage to pipes or harm to humans or the environment.