DIY Beauty: 6 Rules For Avoiding Contamination And Other Disgustingness

Certain organisms are healthy to some degree, but when given the chance to multiply, they can cause illness. Here are some basic tips to keep things fresh.
Publish date:
January 27, 2014
DIY, bacteria, preservatives, contamination, essential oils

DIY beauty products are a really fun rabbit hole to wander down. You can make almost anything once you nail down some basics. But there are always more lessons to learn, and sometimes, gettin’ turn’t is not a good thing.

I had the brilliant idea last year to take a sprig of rosemary and stick it in a jar of argan and olive oil, thinking it was going to make me have shiny, beautiful hair. Imagine my surprise when, in less than two days, there was a branch of mold growing in tandem to the rosemary. Lesson learned. Yuck.

Without access to the things that a professional manufacturer or chemist has--a sterile work environment, a range of commercial preservative ingredients--lab testing to ensure a safe formulation, etc.--we are at risk for potential contamination. Instead of a lab, we have dogs and cats and babies and roommates and birds and moms and dads and germs.

Some of the things to remember about your DIY products can also apply to commercially made products, as I have encountered my share of moldy drugstore, professional, and luxury-grade products. There are SO many factors, but if you take some basic knowledge along with you to the store and in the kitchen, you can protect yourself better.

Mold, bacteria, yeast, and other organisms are present and even healthy to some degree, but when given the chance to multiply, they can cause illness. Here are some basic tips to avoid contamination.


Water-based products are one of the main culprits. Tap water contains trace amounts of things that can grow when given the right environment.

Always use filtered, then boiled or distilled water in your formulations. Use purified flower waters or other hydrosols from organic plants to substitute water if you wish--these can also provide further theraputic benefits!


We can’t all be like Martha Stewart, who is so clean that she doesn’t even have to clean. She sits with oils on her face at her vanity while someone scrubs her kitchen. But you can take basic precautions before a project, such as cleaning your work surface, boiling all tools and containers intended for use; and when you can’t boil use rubbing alcohol.

Wear gloves and use disposable sticks and/or pipettes to dispense product or ingredients. Keep the pets and children away from projects for safety and cleanliness, too.


Many at-home formulations--especially water-based or water and oil emulsions--require refrigeration to prevent the growth of organisms. It might seem like a pain, but consider the environment of a bathroom: hot, moist, and potentially smelly, AKA a perfect place for bacteria to find it’s way in and to grow.


Even with commercial preparations, there is a shelf life. No visible presence of mold, bacteria, or yeast does not mean that there is none present.

A good guideline is to use the shelf life of the least stable ingredient as a date. Water would be somewhere around two or three weeks with refrigeration.


When allowed in a formulation, it can be helpful to use known antibacterial, anti-fungal, and yeast-inhibiting ingredients. Some may not smell pleasant, and others can be irritating, so do a little reading first.

Essential oils of rosemary, cinnamon and grapefruit seed oil are good for this, as well as neem oil, vegetable glycerin, vodka or another clear, high-proof liquor, and vinegar.


Last but not least, one of the most simple ways to make sure your products get used before they spoil is to MAKE THEM LITTLE!

Using small glass bottles instead of recycling plastic ones is helpful, as well as small mason jars. It may seem easier to make large amounts, but when you are tossing $5 worth of coconut oil and who knows how much in argan on a spoiled product in a big jar, you are wasting money.

Another benefit to having to re-make something every few weeks is that you can always improve on your formulas! I always buy more ingredients to have on hand when I have some extra money; that way, I have the freedom to experiment more even when I don’t have extra money.

Don’t be discouraged by the idea that there could be mold, yeast, and bacteria all up in your shizz. To be honest, it is everywhere. As we have learned through the use of probiotics and the lessening of antibacterial wash and cleanser use, bacteria can be good as well as bad, and needs to be balanced, not eradicated.

I am a mold-o-phobe, so if something is past it’s due date, it’s gone. When in doubt, throw it out!