Dirty makeup brushes can be covered in some really crazy types of bacteria. I recently watched a Buzzfeed video in which a few of the staff sent in the contents of their makeup pouches to be tested for bacteria.

The results included staph as well as bacteria linked to gastrointestinal problems, diarrhea, strep throat, UTI infections and meningitis – and all that in a tiny pouch of makeup. 

Unlike most makeup that needs to be thrown away within two years because of bacteria buildup or ingredient degradation, brushes can be cleaned quite thoroughly to remove bacteria, which allows them to last a lot longer.

That said, there are a number of other reasons you should be getting rid of them when they reach the end of their shelf life.

Here are some signs that it’s time to replace your makeup brushes:

1. When it’s bent too out of shape

The function of a makeup brush is primarily dependent on the shape of the bristles and the brush head.

Brushes are carefully tapered, rounded, flattened or angled a certain way to denote their specific use, and while many brushes can get a little misshapen, that can usually be fixed with a good wash and drying it right.

However, if your brush has gotten so old that it no longer holds the shape it used to even after a wash and dry, it’s time to let it go. The brush no longer serves its purpose and keeping it around just for the sake of it is only going to generate clutter and gather bacteria. 

2. When it doesn’t deposit product evenly

Sometimes it’s hard to tell that a brush doesn’t work the way it should just by looking at it. It could be that some bristles within the brush have broken off, and while the outer shape is still there, the brush just doesn’t work right.

This is especially obvious with foundation and eyeshadow brushes. If you begin to notice a rather patchy application when applying your makeup, it could be that the brush is too damaged to be of good use.

Of course, it could also be product build-up causing the brush to perform badly, so always give it a good wash before deciding if it’s no longer applying your makeup well.

3. When lots of bristles are falling out

Shape is one of the things that determines the function of a brush; the other is density. One of the distinguishing characteristics that sets quality brushes apart from crappy ones is how much they shed. Shedding occurs when the bristles fall out during use or while you’re cleaning them.

Higher quality brushes tend to be a lot more resistant to shedding, and will last longer as a result.

This can also be largely due to how the brush is constructed, as well as the quality of the glue that holds the bristles together.

If your brush has lost a lot of its bristles, chances are it no longer does what it needs to and should be thrown out.

To make sure you don’t accelerate the shedding process, always wash gently and dry them flat or bristle-side down to make sure the water doesn’t seep into the neck or ferrule of the brush.

This article was first published in Her World Online.