Essential oils are some of the most amazing products of our natural world - and I love being able to incorporate them into my soap and candle recipes.

The oils of aromatic plants have been used for centuries for both their smell and their medicinal applications. But just because something is natural doesn't mean it's good for you. Essential oils are powerful chemical compounds. They may smell wonderful but they need to be used (both by you, the soap and candle maker and by the people who will be using your soaps and candles,) carefully and conscientiously. All essential oils must be used with care, but here are 5 categories of essential oils that need to be used with extra care.

1.Sensitizing Essential Oils

There are some essential oils that will cause skin irritation in people with very sensitive skin. They affect some folks, but not others - and not always right away. People can have no reaction to an essential oil for a while and then suddenly have a reaction.

2.Irritating Essential Oils

Just because something is natural doesn't mean it's good for you. And just because something is good doesn't mean that more is better. There are some essential oils that can irritate the skin if used in too high a concentration.

3.Hazardous Essential Oils

Though they may smell great, there are some essential oils that just need to be left alone...or at the very least, only used only by someone with significant essential oil experience.

4.Essential Oils to Avoid During Pregnancy

Some essential oils have hormone-like effects, others stimulate the uterine muscles, others are just plain toxic. My rule of thumb, especially when there is a growing baby to consider, is an emphatic "better safe than sorry."

5.Toxic Essential Oils

There are a number of essential oils that have chemical components that, while completely natural, need to be used with caution. Some are just "photo" toxic - that is, they become toxic when exposed to the sunlight. Others are just plain toxic, and should be avoided.

Use with Caution - but by All Means Use!

With some basic understanding of some of the powers and effects of essential oils, you can use them safely and to great effect in your projects. There are many safe and affordable essential oils out there. Get some, share some, borrow some - and experiment!