Cleaning makeup brushes and sponges: how often, how, and when to replace them

Wash makeup brushes every 7 to 10 days, which is the American Academy of Dermatology’s (AAD) guidance, and wash brushes and sponges used with liquid or cream products more often than the ones that only touch powder. Every time a brush touches your face it picks up oil, dead skin and a little bacteria, and the makeup holds all of that in the bristles. This lesson covers the schedule, the washing method that keeps brushes in one piece, drying, when to throw a tool away, and why sharing makeup is a bigger risk than it looks.

Why dirty tools matter

A brush that has not been washed in weeks is a damp, oily mat of old product sitting on your face every morning. The AAD says dirty brushes can contribute to acne, rashes and infections. Cleveland Clinic adds skin infections such as staph and eye infections such as pink eye, especially if the skin has a small cut. Brushes kept in an open cup on the counter also collect dust and whatever is in the air of the bathroom.

Sponges are worse. In a 2019 study from Aston University, researchers tested makeup that people had donated after using it. Around 79-90% of the used products carried bacteria, and the sponges (beauty blenders) carried by far the most. 93% of the sponges had never been cleaned, and 64% had been dropped on the floor and used again. The reason is simple: a sponge is used damp and often put away damp, and damp is where bacteria and yeast grow.

A tool that stays damp grows germs. Washing matters, but drying it completely matters just as much.

How often, by tool

The AAD gives one figure for brushes in general: every 7 to 10 days. Cleveland Clinic splits it by what the brush touches.

Tool	How often to wash	Why
Foundation and concealer brushes (liquid, cream)	Once a week	Wet product holds moisture and oil
Eyeshadow and eyeliner brushes	Every 2 weeks	Close to the eyes
Powder and blush brushes	Once a month	Dry product, less build-up
Sponge used with liquid foundation	After every use is safest, at least weekly	Stays damp inside

If you only remember one rule, follow the AAD: every 7 to 10 days for all brushes, and do not let the sponge go longer than that either.

How to wash a brush without ruining it

This is the AAD method, step by step.

1. Rinse only the tips under lukewarm running water to loosen old makeup. Do not dunk the whole head, because water soaks into the glue that holds the bristles in the handle and dissolves it.
2. Fill a bowl with lukewarm water and add 1 tablespoon of gentle or clarifying shampoo. Plain bar soap can dry out the bristles.
3. Swirl each tip in the bowl. For more lather, massage the tip gently in your palm.
4. Rinse the tips under running water.
5. Repeat shampoo and rinse until the water runs clear.
6. Squeeze out the extra water with a clean, dry paper towel and reshape the head with your fingers.

A sponge is washed the same way, but you can squeeze it under water many times until no colour comes out. Squeeze, do not twist, or it tears.

Drying: flat, head over the edge

Lay brushes flat on a clean towel with the bristles hanging over the edge of the counter, and leave them overnight. Do not stand them upright in a cup while wet: water runs down into the handle, the glue loosens and the bristles start falling out. Just let them air dry.

A sponge needs air all around it. Put it on a clean, dry surface or a rack in a room with moving air, not in a closed bag or a damp bathroom cupboard. Only put it away when it is dry right through, including the middle.

Example: one month for a small kit

Say your kit has 2 foundation and concealer brushes, 3 eye brushes, 2 powder and blush brushes, and 1 sponge you use with liquid foundation every day. On the Cleveland Clinic schedule, over 4 weeks:

Group	Washes per brush	Number of brushes	Total washes
Liquid and cream	4 (weekly)	2	8
Eye	2 (every 2 weeks)	3	6
Powder	1 (monthly)	2	2
Brushes in total			16

That looks like a lot, but it fits into one wash session a week: every week wash the 2 liquid brushes, every second week add the 3 eye brushes, and once a month add the 2 powder brushes. One bowl with 1 tablespoon of shampoo is enough for a whole session. The sponge is separate: rinse it after each use, or at the very least wash it in that weekly session, and always let it dry overnight.

When to replace a brush or sponge

Cleveland Clinic says to replace a brush when the bristles fray, wear out or lose their shape. Also replace it when bristles keep falling out (usually the glue has gone) or when it still smells after washing.

For a sponge, there is no single proven lifespan, so go by what you see: tears, crumbling, stains that will not wash out, a smell, or it does not dry fully between uses. A sponge that has been dropped on a dirty floor is cheaper to replace than an infection.

Sharing makeup: the risk you cannot see

The US FDA’s first safety tips for cosmetics include one line: do not share makeup. When you share, you share the germs of the other person’s skin, lips and eyes too. Eye makeup is the clearest case: a mascara wand or eyeliner that touches one person’s eye can carry an infection to the next.

• Do not share brushes, sponges, mascara, eyeliner or lip products, even with family or close friends.
• If you try products in a store, use a fresh disposable applicator or the back of your hand, not the shared wand or brush.
• Do not add water or saliva to mascara to thin it. FDA warns you could add germs.
• If you get an eye infection, throw away the eye makeup you used. FDA says it may have become contaminated.

This works the same way as nail tools; see cleaning and disinfecting nail tools.

Common mistakes

Mistake	What happens	Do this instead
Dunking the whole brush head	Glue dissolves, bristles fall out	Wash and rinse the tips only
Drying upright in a cup	Water runs into the handle	Dry flat, head hanging over the edge
Putting the sponge away damp	Bacteria and yeast grow inside	Dry in moving air until the middle is dry
Only spraying with alcohol	Build-up stays in the bristles	Wash with shampoo on schedule
Washing with harsh soap every day	Bristles dry out and fray	Gentle shampoo, on the schedule above
Lending your mascara	Eye germs pass between people	Keep eye products for one person

When to see a doctor

If spots, a rash or itching get worse after using makeup, stop using it and talk to a pharmacist or dermatologist. See a doctor straight away for very red eyes, discharge from the eye, or eye pain after applying makeup.

Sources

• How to clean your makeup brushes — American Academy of Dermatology
• How often should you clean your makeup brushes? — Cleveland Clinic
• Using cosmetics safely — U.S. Food and Drug Administration
• Microbiological study of used cosmetic products (Bashir and Lambert, J Appl Microbiol 2020) — Aston University Research Portal