Dear Recyclebank: What are magic erasers? Is the manufacturing process bad for the environment? They disappear while scrubbing, so in theory there is no waste, so long as we recycle the cardboard box packaging. –E. M.

Dear E.M.: Mr. Clean Magic Erasers, Scotch-Brite Easy Erasers, and off-brand eraser pads are sponge-like products that remove stains as if by magic. But are they too good to be true? Yes, and no. The Magic Eraser has been making waves since it came out in 2003 for its ability to remove tough stains (such as crayon marks) with ease. Unlike other cleaning products, Magic Erasers contain no harsh soaps or cleaning agents. Rather, it is the sponge’s physical structure that gets the job done, which is pretty amazing.

Eraser pads are made of a plastic product known as melamine foam (formaldehyde-melamine-sodium bisulfite copolymers to be exact), which was —and continues to be — in use for many years in industry before it was discovered to have cleaning properties. Melamine foam is sound absorbent and flame resistant — two reasons it has been used as insulation in buildings, trains, and aircraft for decades. The plastic foam cleans by scraping stains off surfaces, acting as “extremely fine sandpaper,“ and trapping the loose particles of dirt inside its structure.

Unfortunately, the manufacturing process for melamine foam is considered a trade secret, so the environmental impact of its production cannot be accurately estimated. We do know production begins with melamine-formaldehyde resin, a synthetic polymer that is foamed through a tunnel with the use of a blowing agent. The melamine resin is cured into foam sheets, and then shipped from manufacturing plants to processing plants.

Both Mr. Clean and Scotch-Brite erasers are manufactured in Germany, however they are sold around the world. One obvious environmental impact is the exhaust produced, and the energy consumed, by worldwide shipping. Though the sponges are lightweight, the quantity required to regularly clean your home with them is quite high. The amount of time an eraser pad will last depends on a number of factors including the roughness of the surface you are cleaning, and the type of stain you are trying to remove; on average they last for only 4 to 5 uses. That’s a lot of trips across the sea, burning fossil fuels for just a few cleaning uses per item.

And though melamine foam erasers seem to disappear after use, that’s not really the case. They compress, pill, and breakdown with use, leaving tiny particles of super-abrasive plastic on the surfaces cleaned. For this reason, you should avoid using them in the bath or sink, where plastic particles will end up down the drain and in our water supply. Even though melamine foam is not toxic, don’t clean your dishware with them: Otherwise you could potentially be consuming tiny plastic particles with your food.

We recommend using green-cleaning tools first, and reserving melamine foam for only those stains, such as crayon marks, that seem to require its unique properties.

If you can’t live without your eraser pads, you can still reduce waste and get more use out of them by cutting the sponges into quarters before use. To keep your erasers working for you longer, be sure to squeeze out excess water between uses — do not ring out the pad by twisting it. When the pad becomes unusable make sure to throw out any remaining product. And whenever possible, choose good old-fashioned elbow grease with a more sustainable cleaning tool such as a recycled-content rag or a natural abrasive sponge.

SOURCES: 3M, BASF, Encyclopædia Britannica, P&G, The Chemical Company, The Collapsed Wave Function, Wired