*Original information: OPI Nail Polish boasts about not having the toxic trio (toluene, formaldehyde, and DPB) but, it has other ingredients that aren't the greatest: camphor, which can cause nausea and dizziness if inhaled, and Benzophenone 1, which may negatively affect the endocrine system.

Make sure to seal the open edges with the base coat, or cap the free edge, as this process is called. Capping the free edge means to paint over the edge of your nail so that this protective layer gives your nail a chip-resistant finish.

While color separation is one sign of age, Wang says it's important to look for other changes in a nail polish's color and texture. If the hue has changed since you bought it or it looks thick and gloopy, it's likely past its prime. Another huge red flag is odor, adds Berry.

Officially described as a "deep-sea indigo," this is a very deep pthalo or ultramarine blue bearing abundant pearly microfine particulate shimmers in red and dark blue.