Should I flush it? Most often, the answer is no
It might seem harmless at first: a thread of dental floss tossed in the toilet, a contact lens swirling down the drain of the bathroom sink. But even the tiniest items can contaminate waterways.
The small fragments of plastic contact lenses are believed to be contributing to the growing problem of microplastic pollution. Pharmaceuticals, which are also frequently flushed down the drain, have been found in our drinking water, and the consequences are not fully known.
Larger products like wipes and tampons are also clogging sewer systems, resulting in billions of dollars in maintenance and repair costs.
Wondering what is safe to flush or wash down the drain? We spoke with several waste water management experts who explained why many frequently disposed items belong in a garbage can, not the toilet.
Disposable wipes Many wipes claim on their packaging to be “flushable,” but almost all of them contain rayon or viscose, said Rob Villée, executive director of the Plainfield Area Regional Sewerage Authority in Middlesex, New Jersey.
“Unfortunately, the natural water bod- ies these get into do not have the heat or micro-organism levels to effectively degrade these,” he added. “That is why we see rayon accumulating in the oceans.”
Dental floss Dental floss, which is usually made of nylon or Teflon, should also stay out of the toilet.
“It seems like, ‘Oh, it’s just a little string,’ but it tends to wrap things up,” Villée said. “It’ll collect other things and make kind of a big wad of stuff. It’s in- credibly strong.”
Contact lenses When contact lenses are flushed down the toilet or washed down the sink, they do not biodegrade easily. As a result, they may make their way into surface water, causing environmental damage, new research has shown.
The lenses are also impervious to the bacteria that break down biological waste at treatment plants. When researchers at Arizona State University submerged contacts in chambers with the bacteria, they found that the lenses appeared intact seven days later.
Medications Waste water treatment plants are not designed to filter out pharmaceuticals, so drugs that are disposed of in the toilet or the sink drain end up entering streams, rivers and lakes.
The first major study to document this, conducted by the U.S. Geological Survey, found low levels of organic waste water compounds, including prescription and non-prescription drugs and hormones, in 139 streams across the United States during 1999 and 2000. One or more of these chemicals were found in 80 per cent of the streams sampled.
A more recent study, which sampled water from 25 drinking-water treatment plants in the United States, found that some pharmaceuticals persisted despite water treatment processes.
Facial tissues and paper towels Facial tissues might seem safe to flush because they look so much like toilet paper. But unlike toilet paper, facial tissues have been treated with a chemical binder that takes time to release and break apart when flushed.
When in doubt, throw it out (in a trash can).
When asked what is safe to dispose of down your toilet, experts say “not much.”