Unpreserved in-shower anhydrous products. Is it possible?
Updated: Oct 28, 2021
Waterless products are a big trend right now, combining the convenience of usage, environmental protection, and irresistibly gorgeous appearance of the products. There is practically no skincare product that can't be sold in a waterless form and some of the anhydrous products are already substituting mainstream cosmetics.
Skincare is evolving and formulators all over the world are stepping up their game to enter the industry with innovative, environmentally-friendly, water-free products.
WHEN AND WHY DOES AN ANHYDROUS PRODUCT NEED A PRESERVATIVE?
Let's start with two simple questions:
Does a water-containing product need a preservative? Yes. (almost always)
Does an anhydrous product need a preservative? No. (almost never – read on to find out about the exceptions)
Over time, every anhydrous product can become exposed to air, light, and moisture that can play around with the product's stability and safety. Generally speaking, anhydrous products are far more stable and present a lower microbial growth risk than water-based products, but it is still important to investigate all key factors that may mess up your waterless products.
Although anhydrous products have a lower chance to get contaminated, they are prone to rancidity and oxidation, which is why including an antioxidant is a smart move (vitamin E or rosemary co2 extract are a good option).
How about if an anhydrous product is exposed to water? A shampoo bar that is used under the shower? A butter scrub that the consumer dips wet fingers in it? Or powdered clay mask that is normally used in a steamy, humid bathroom?
If your product is unpreserved this can create a party-like environment for bacteria and mold.
So general recommendations "no need for a preservative" for anhydrous products are further broken down into:
If the product is normally used away from the water (like face anhydrous creams, body butters, hand salves,…), YOU DON'T NEED A PRESERVATIVE SYSTEM.
If the product is used under the shower or is likely that the water will be introduced to the product during usage (cleansers, scrubs,…), YOU SHOULD CONSIDER USING A BROAD-SPECTRUM PRESERVATIVE.
But some of the formulations used with running water like shampoo bars or clay bars are still made without preservatives.
How is that possible?
The answer lies in a synergy of multiple important and complex factors that only experienced and well-educated formulators should and could be executing. For example:
- detailed scientific research of ingredients was implemented in the formulation process, - drying process after production was done well,
- the packaging was selected wisely,
- the products had been tested properly - lab tests included,
- usage instructions (dry well after each use) were well communicated, and so on.
To go through the safety checklist of your anhydrous products and learn more about methods & tricks on how to formulate without preservatives - check out my e-book FORMULATING WATERLESS: Professional approach to developing safe & trouble-free anhydrous products that sell.