Why Oil Doesn't Work as a Heat Protectant

By Sabrina Perkins · Published March 16, 2022

oil heat protectant

Photo by Kadarius Seegars on Unsplash

Most curlies know about heat protectants that lessen the damage from heat styling. Whether you blow-dry, flat iron, or use a curling iron, you need a heat protectant. No one told me this back when I used relaxers, so I must have fried my hair to death back then, but now, most of us know better. Currently, an interest for purer products is growing, and more women are turning to natural oils in their hair care regimens. But where heat damage is concerned, oil might not be your best bet. Let’s consider the benefits and disadvantages.

What are carrier oils?

Most carrier oils are vegetable oils derived from the fatty portion of a plant in the seeds, kernels, or even the nuts. However, not all of them come from vegetables, such as emu and fish oil. Carrier oils, also known as fixed oils because they are less volatile in nature than essential oils, can be cold-pressed (mechanical”>, expelled (mechanical”>, or extracted with a solvent (chemical”>. Cold-pressed oils are preferable as they retain the highest nutritional value.

Most carrier oils are chock-full of organic acids such as oleic acid, palmitic acid, and stearic acid, which make them excellent emollients that nourish your skin and hair. We use them in cosmetics, cooking, and to dilute highly concentrated essential oils. Here are some of the oils most commonly used as heat protectant.

Argan oil circulates among natural hair blogs as a suggestion for protecting hair from heat
Grapeseed oil is said to have a high smoke point and adds shine to flat ironed curls.
Coconut oil is a popular solution known for helping to repair hair damage.
Shea Butter is considered a great heat protectant because its thermal conductivity is almost as good as popular silicones used in most heat protectants, namely dimethicone and cyclomethicone.

But the natural hair community might be missing some important information about the properties of the oils they’re using as heat protectants.

What are smoke points?

Now, it is time to put the lab coat on and see whether these oils can actually protect you from dryness and heat damage. Chemist Yolanda Anderson explains that the smoke point, called the burning point in chemistry, refers to the temperature at which an oil begins to smoke, discolor, and decompose.

Oil smoke points

via Cooking for Engineers

Fat	Smoke Point °F	Smoke Point °C

Unrefined sunflower oil	225°F	107°C
Unrefined high-oleic sunflower oil	320°F	160°C
Extra virgin olive oil	320°F	160°C
Coconut oil	350°F	177°C
Macadamia nut oil	390°F	199°C
High quality (low acidity”> extra virgin olive oil	405°F	207°C
Grapeseed oil	420°F	216°C
Virgin olive oil	420°F	216°C
Sunflower oil	440°F	227°C
Refined high-oleic sunflower oil	450°F	232°C
Semi refined sunflower oil	450°F	232°C
Olive pomace oil	460°F	238°C
Extra light olive oil	468°F	242°C
Avocado oil	520°F	271°C

Oils should never be heated to their smoke points. Scientists believe that fats heated past their smoke points contain a large quantities of free radicals and a substance called acrolein, which contributes to a higher risk of cancer, according to Anderson. As a fat degrades, it also gets closer to its flash point, where it will begin producing ignitable gases. This means that using hot tools on oiled hair may risk some toxic outcomes.

Using oils as heat protectants

According to the cosmetic scientists and writers at The Beauty Brains, “Heat tolerance (in this case measured by smoke point of the oil”> is only one factor to consider. You also need to look at how the product lubricates hair. You can experiment with oils if you want DIY heat protection but be careful: oils alone can create drag which could slow down the flat iron as it passes through your hair, so it could end up doing more damage. Good heat protectants should also help offset the drying effects of heat. Ideally you want a combination of glycerin or other moisturizers to lock in water and a low molecular weight polymer that can penetrate and help prevent heat from cracking the cuticles.”

Using silicones as heat protectants

Cosmetic scientist and NaturallyCurly contributor, Erica Douglas aka Sister Scientist, told us that “Oils behave very similarly to silicones by creating protective barriers from bad things like heat…Some oils can remain intact at extremely high temperatures, but they are often the heavier oils that can weigh the hair down. This is why formulating chemists will combine synthetic ingredients like silicones with the natural goodness of oils to provide an improved customer experience when using the product.” Therefore, silicone-based heat protectants are more likely to give you the benefits you originally wanted out of oils. If you follow the Curly Girl Method then silicone-based products are off limits, but so is heat styling.

If you follow the Curly Girl Method then silicone-based products are off limits, but so is heat styling.

Conclusion

Just because an ingredient is natural does not always make it the most effective candidate for the job. Avoiding smoke points is incredibly important for your safety, and your hair definitely needs ingredients that combat moisture depletion. Many heat protectant products contain silicones like cyclomethicone and dimethicone, which work extremely well at coating the hair and creating a thin, water repelling, heat-resistant coating. Yes, there are natural oils that act like silicones and will protect the hair from heat, but as Sister Scientist suggests, there are many great products created using natural and synthetic ingredients to give you a healthier and safer heat protectant.

If you are going to use an oil, be careful and make sure to apply a lightweight leave-in conditioner or a moisturizer as well; a pure oil alone will likely leave you with dry, fragile strands.

Ultimately, if you are going to heat style your hair then we recommend using a product that has been formulated specifically for the purpose of protecting your hair from heat damage because once you have inflicted heat damage on your hair it is practically impossible to reverse.

What are your favorite heat protectants?

This article was originally published in 2017 and has been updated to incorporate reader feedback.