Why Essential Oils and Water Don’t Mix (and How to Use Them Safely)

If you’ve ever added essential oils to a spray bottle of water, shaken it up, and thought “that should work”—you’re not alone. It’s one of the most common DIY mistakes when working with essential oils. Unfortunately, it’s also one that can lead to skin irritation, uneven dosing, and unsafe products.

There have been so many posts lately about these unsafe products people and large businesses are selling it is not only scary for the consumer, it is very concerning these products are being sold!

Let’s break down why essential oils and water don’t mix, what actually happens when you try, and how water-based products can be formulated in a way that’s truly safe and skin-friendly. And yes, we will talk about the "P" word too! Water-based products need to be preserved! Water = water; aloe vera gel, witch hazel, castile soap, ANY water-based ingredient does not mix with oil.

Oil + Water = Not Friends

Essential oils are oils. Water is water. And just like salad dressing, they naturally separate.

From a chemistry standpoint, essential oils are lipophilic (oil-loving), while water is hydrophilic (water-loving). Because of this fundamental difference, essential oils do not dissolve in water.

Even when shaken, the oils simply break into tiny droplets that quickly float back to the surface. This means the essential oil is not evenly diluted—it’s temporarily dispersed and then re-concentrates. Just shaking before use, DOES NOT WORK!

When you spray or pour that mixture, you might get mostly water… or you might get a concentrated dose of essential oil directly on your skin. That uneven exposure is what can lead to irritation, redness, or sensitization, especially with repeated use.

Adding more water does not make essential oils safer if they aren’t properly mixed.

How Essential Oils Can Be Used in Water-Based Products

To safely use essential oils in sprays, mists, or toners, you need a formulation ingredient that allows oil and water to coexist.

Dispersants: The Link Between Oil and Water

Dispersants are designed to bind essential oil molecules to water molecules, keeping them evenly dispersed throughout the product. This is what makes products like:

• Room sprays

• Linen sprays

• Facial mists

• Toners

safe and consistent from the first spray to the last.

Without a dispersant, essential oils are not truly diluted in water—no matter how vigorously you shake the bottle.

Two types of dispersants are solubolizer and alcohol. Solubolizers are available in synthetic form and naturally-accepted form. A few are polysorbate 20,or 80, and PEG-free/naturally derived solubilizers. Follow specific ingredient usage rates, usually it is a 1:2 or a 1:4 ratio.

Alcohol should be used at 20% or more of your total formula. This amount will disperse essential oils into water. This is 95% alcohol or 190 proof; Everclear is one example. If you are using a lower proof alcohol like vodka, you will need to use more. For example, if you are making 2 ounces of room spray, to properly dilute the essential oils into the water base, you will need to use at least .40 ounces (2 ounces x 20%). You can also use perfumer's alcohol.

Witch hazel will NOT work! If you only added a few drops of essential oil into 2 ounces of witch hazel, then yes, you might get full dispersion. However, if you are mixing with anything else and a higher amount of essential oils, it will not blend.

Emulsifiers: For Creamy Products

If a product contains both oils and water—such as lotions, creams, or emulsified serums—an emulsifier is required. Emulsifiers create a stable blend so the oils don’t separate over time, ensuring consistent performance and safety throughout the life of the product. These are specific ingredients like fatty alcohols, gums, and some waxes.

Why Water-Based Products Need a Preservative

Any product that contains water—even distilled water—creates an ideal environment for bacteria, mold, and yeast to grow.

This includes products made with:

• Water

• Witch Hazel

• Hydrosols

• Aloe juice

• Floral waters

Here’s an important myth to clear up:

Essential oils are not preservatives.

While some essential oils show antimicrobial activity in laboratory settings, they do not provide broad-spectrum protection in real-world cosmetic products. They cannot reliably prevent the growth of bacteria, yeast, and mold during normal use.

A safe water-based product must contain a broad-spectrum preservative and be formulated within the correct pH range to protect the user from microbial contamination.

Even more concerning? Products can look and smell perfectly fine and still be unsafe.

Witch hazel is NOT a preservative! It has enough alcohol content to preserve itself. Once you add other ingredients to it, that preservative system is unsafe. Alcohol proof of 190 can preserve your formula as long as you are using at least 20% of your total formula.

The Bottom Line

If a product contains water and essential oils:

• The oils must be properly solubilized or emulsified

• The formula must be preserved

• “Shake before use” is not enough

Safe formulation isn’t about fear—it’s about respecting chemistry and protecting your skin. It can't be more simple, oil and water do not mix and water based products need to be preserved.

When water-based products with essential oils are made correctly, they can be beautiful, effective, and safe. When they’re not, they can cause irritation, sensitization, or microbial exposure.

References

• Tisserand, R., & Young, R. (2014). Essential Oil Safety: A Guide for Health Care Professionals (2nd ed.). Churchill Livingstone.

• Geis, P. A. (2006). Cosmetic Microbiology. Taylor & Francis.

• Personal Care Products Council. Preservation of Cosmetics.

• U.S. Food & Drug Administration (FDA). Cosmetic Microbiological Safety.

• International Fragrance Association (IFRA). IFRA Standards and Safety Assessment Guidance.