Who finishes nail polish? Seriously I've never been able to do it. It's either clumpy, I'm over it or it would just be impossible unless I lived until 160 and painted my nails every day.
Whatever the reason, we shouldn't just hold onto old polishes forever. However, some formulas contain toxins like formaldehyde, toluene, and DBP—which is why we recommend looking for safer "three-free" lacquers. If nail polishes aren't properly disposed of, these dangerous ingredients can seep into the soil and water supply.
Whatever you do, don't throw polish into the trash or down the drain. (It is paint, after all.) Your city's hazardous-waste collection is the answer. Search the web to get the scoop on the details of your local centre. And since it's Earth Month, be sure to check out what other beauty items can and can't be recycled, too.