Something every makeup artist should know is how to PROPERLY sanitize their kit. There is a lot of misinformation out there and I'm going on a hunt for the truth in this post. I will share some links with you, from credible sources, before we move on to what I've discovered so you have a chance to inform yourself as well:
http://www.cdc.gov/hicpac/Disinfection_Sterilization/13_0Sterilization.html
http://www.journalofoptometry.org/en/epidemic-keratoconjunctivitis-a-review-of/articulo/90197282/
http://aem.asm.org/content/42/2/297.full.pdf (Makeup testers in stores)
http://www.accessdata.fda.gov/cms_ia/importalert_136.html
Please remember that bacteria is all around us, and always will be, you cannot avoid all bacterial organisms. Obsessing over germs is not what this post is about, it is about being logical and responsible as a professional artist.
Quickly, lets get the 70% vs 91% vs 99% alcohol controversy out of the way with some good ol' scientific knowledge:
Higher alcohol concentrations, like 91%-99%, coagulates protein on contact, creating a "shell" around the entire bacterial organism. After that shell is made, the alcohol CANNOT go through that shell to further coagulate the rest of the bacterial organism and its organelles. This will render the bacteria, not dead, but inactive. If given favorable conditions, it can start to function once more. Now if you use 70% alcohol (which has the highest osmotic pressure of alcohol/water mixtures), it will coagulate the protein but it will do so at a much slower rate, giving it the opportunity to penetrate fully. Since it does this slowly, nothing can coagulate in time to stop it which ends up leaving the bacterial organism dead.
From all I've read, learned in college, discussed with fellow artists and some scientists, here is what I've concluded:
Pressed Powders
The consensus of professionals, with clean, professional kits, say NO to spraying pressed powders with alcohol. Aside from the claim of pressed powder "not being able to harbor bacteria" it can ruin the composition of the product. Many suggest wiping off the top layer with a tissue, or using a UV light to disinfect the top layer. But using a tissue or cotton ball will press the bacteria present into the product and UV lights need proper upkeep of the bulbs to maintain proper wavelengths providing sanitization. This was discussed by people in the industry over 20 years, some scientists as well, and have never had an issue with cross contamination and infecting someone. They also stressed cleaning your brushes is a huge factor with powders being clean! One thing that does throw me off is that bacteria can remain dormant on any surface, and function when given the right conditions, but generally bacteria that grows on your skin will not usually grow on a powder surface. After all is said and done, it all comes down to making sure your brushes are CLEAN and SANITIZED!
Creams
This one is simple to remember. Creams harbor bacteria the moment you dip a used brush or your finger on contact! NEVER apply cream product directly to a person's face from the container. These products must be scraped from the container on to a clean surface for application, and used from said surface. Lipsticks, concealers, foundations, cream shadows, cream colors etc... all need to be scraped out onto a clean palette. If you do see professional artists (usually celebrity artists) applying directly from said containers, it is 99% likely that those products are designated for that one person, and no one else they work on. YOU CANNOT sanitize the surface of creams with alcohol of any concentration. Once it is touched by a double dipped brush or finger, the product has been contaminated and must be thrown away. Bacteria sinks in the product the moment on contact, there is no reversing this.
Liquids
Same goes for liquids as creams do, they cannot be sanitized when a brush or finger is dipped into the container. The liquid should always be placed on a clean palette before use, always dispense enough to be safe. For things like mascara, you can use disposable wands and make sure to not double-dip the wand or use a mascara fan by putting a decent sized amount onto a palette, dipping the brush in and applying to the lashes. Lipgloss has the same rules as well, use disposables without double-dipping or dispense on a clean palette for use with a brush.
Pencils
For wooden pencils that need to be sharpened, make sure you sanitize the sharpener before sharpening the pencil. After that is cleaned, wipe the pencil with alcohol, sharpen in the clean sharpener then wipe with alcohol once more. For automatic pencils, simply wipe with alcohol.
Makeup Brushes
It is very obvious that we have to keep our brushes clean to prevent the spread of infections as well as other things. There are many brush cleaners and soaps on the market, so we can all find something that works with us. Personally, I swear by Parian Spirit and Clean Apothecary Brush Soap. Deep cleaning can be defined as cleaning with soap and water. Sanitizing is using a "spot cleaning" kind of brush cleaner with disinfecting properties. When I'm on set, I make sure my brushes are deep cleaned prior to arriving, and I use Parian Spirit to clean in between models/clients. After the shoot is done, if time allows, I will use Parian Spirit to clean my brushes before I put them away so no residue from products sticks on longer than it needs to. Using straight alcohol can damage brushes with natural fibers, but it can be used as a cleaner if there is nothing else available.
Hair Brushes and Combs
We can't forget hair brushes and combs! The way suggested by most is to use a brush/comb cleaner like Ship-Shape powder prior to disinfectant use, such as Barbicide. If those are not available, you can wash with a mild shampoo and spray combs/brushes with 70% alcohol. It is very important to clean these tools after each use, just like makeup brushes. Ship-Shape is safe to use on natural bristle brushes, but always read the labels on the packaging before using them on your tools. When using Barbicide, remember to submerge the combs/shears/guards etc. for 10 minutes!
Miscellaneous
Clean & sanitize the outside of your kit bags/cases
Clean & sanitize palettes and containers to maintain a tidy kit
Stay organized