In today’s blog, I’m focusing on a product that becomes unsuitable for use and how to recognize the signs.
I’ll answer given my experience as a cosmetic formulator.
In my work ( and products that I use) I try and use as much as possible cold-pressed, organic, non deodorized oils. (Deodorized oils ( eg) argan oil involve the strong smell being removed ).
The reason to do this is that I can control to an extent, the nutrients that are present in my final product.
( You may find it odd that I use the word ‘’nutrients’’ but if your topical skincare is not feeding and replenishing your skin, like the food you eat, then what is its purpose?)
For example, I’d use organic, cold- pressed rosehip oil, if I want the product to have vitamin A
Similarly, I may use carrot seed oil, mulberry seed oil because of the colour of these oils. The color is impacted by compounds called anthocyanins. Anthocyanins act as anti-oxidants.
Unfortunately, organic, cold-pressed oils are less stable than their corresponding refined oil counterparts, which means they have shorter shelf -life.
Factors that reduce shelf life of oils include :
- Temperature
- U V Radiation
- Exposure to air (Oxidation)
How do I know when an oil is no longer suitable for use?
Observe the smell of the oil and its appearance the first time you open it:
If an oil has gone RANCID- You’ll unmistakeably smell it .If oil is heavily fragranced you’ll have to rely on your memory. It smell drastically stronger or just different
If oil changes the colour ( eg Becomes darker ) or becomes cloudier
Keep an eye out for odd growths in your oil – I’ve seen crystalline structure in educational videos. You want to be weary of those.
These are some of the things that I personally do as a formulator and would suggest you do as well.
- Store all oils in dark coloured containers, out of sunlight
- Avoid buying oils that are in non-coloured transparent containers
- Buy oils in small quantities: Less is always more
- Limit the time you open a bottle and leave it uncovered, to prevent oxidation
- Always use oil within its use by date