A chemical or enzymatic drain cleaner is often the first choice to remove blockages caused by hair, grease, soap, human waste or other foreign materials. It's easy and inexpensive to use, but can cause problems if you choose the wrong cleaner for the type of clogged drain you have, or if you use the product incorrectly. Damage to Pipes or Surrounding Surfaces Chemical drain cleaners react with the blockage material by creating heat that disintegrates it. Designed to be denser than water, they are more likely to splash and corrode surrounding surfaces. To reduce damage to surrounding areas like porcelain, stainless steel and aluminum faucets, pour the cleaner as close to the drain as possible and use only the minimum amount necessary. Most require that you either add water to the cleaner or add cleaner to the water. Do so carefully and slowly to reduce splashing. Avoid pouring the cleaner into a plastic or porcelain basin to reduce the chance of cracking it. Be aware of what type of piping you have. Chemical drain cleaners can soften soft plastic pipes (PVC). They can also cause additional damage to already old and corroded pipes. You may have to use an enzymatic drain cleaner to prevent damage to your pipes. They tend to be less corrosive, but they're also less effective at dissolving blockages. A manual drain cleaner like a drain snake is also an option.