Don't DIY Your Sunscreen

DIY is all the rage these days. Everyone seems to be DIYing this, hacking that, and knocking off everything else. And you know what, I’m one of the worst offenders. Anytime I get the idea that I want something new for my home or my kids, I look on line to see if I can make it myself first. DIY is awesome . . . unless it’s not.

Case in point. I recently found an idea for an Ikea-hacked farm table. It looked awesome, easy to put together, and ridiculously inexpensive.

However after my husband was 80% done with it, we started to see there were going to be problems with it and scraped that project entirely. (That did however lead to a much better farm table project, that I will be writing about very soon.)

It turns out that while DIY is fun, inexpensive, and resourceful, it isn’t always the best idea.

Here’s another questionable DIY practice being promoted on the internet – DIY sunscreens.

Sun = Ultraviolet Light Exposure = Sunburned Cells = Skin Damage = Increased Risk for Skin Cancer

According to our working knowledge the sun and its effects on our skin, sunburns increase our risk of skin cancer. Therefore, screening ourselves from these ultraviolet rays – specifically UVB, though the others might be damaging - is of utmost importance. Sunscreen helps to block the harmful rays, protect our skin, and prevent skin cancer. Unfortunately, some sunscreens are pretty toxic and might even be worse for you than getting a sunburn in the first place. This conundrum is what leads people to start whipping up their own DIY sunscreen in the kitchen.

You can’t calculate the Sun Protection Factor (SPF) in your kitchen

We’ve all heard about SPF. When I was a kid, they were in the range of 4-8 SPF and sunscreen with an SPF of 15 was considered ultra-protective. Today, sunscreens are in the range of 30-50 SPF, and sometimes as high as 70 SPF. But what is SPF and more importantly, how is it determined.

The SPF, or Sun Protection Factor, essentially means you can spend a certain amount of time in the sun longer than you would with unprotected skin. If you’d normally burn in 20 minutes but applied a sunscreen with an SPF of 15, you’d be able to spend about 5 hours in the sun, which is 15 times longer than normal (20min/60min = .33 hours X 15 = 5 hours). If you used an SPF of 50, you’d theoretically burn after 16.7 hours in the sun.

But how is SPF calculated? This is more important to understand.

Imagine you’re a sun-sensitive person – in other words, light-skinned and blonde hair). You and 19 of your friends get recruited by a research company. They make sure you don’t have any skin allergies and then put a small patch of your skin under a Ultra-Violet emitting light – a fake sun of sorts – and see how long it takes before your skin begins to turn a light shade of red, called the “minimal erythema dose”.

Then they apply a small amount of sunscreen to your skin, use the artificial sun lamp on you again, and once again wait until your skin starts to turn red. Then they divide the two numbers, round to the nearest 5, and there you have your SPF.

So let’s say you started to turn red after 15 minutes without sunscreen and started to turn red after 7 hours of UV stimulation with sunscreen. That sunscreen would have an SFP rating of 30 (420 minutes/15 minutes = 28 SPF; rounded to the nearest five = 30 SPF).

Why go into this? SO many reasons . . .

  1. Firstly, researchers use light skinned people - the SPF of a sunscreen may be longer for some darker skinned people or shorter for some even lighter-skinned people.
  2. Just because one natural product (ie Coconut oil with an SPF of 2 to 8) is combined with another natural product (ie carrot oil with an SPF of 38 to 40), does NOT mean you add them up together to create a higher SPF. Unless it is scientifically tested, it does not work that way. Therefore to say that coconut oil with carrot oil (SPF of 8 + SPF of 40, respectively) has an SPF of 50 is completely made up. That would be like saying oxygen causes cancer, because oxygen causes oxidative stress, which can lead to DNA damage, which can lead to cancer. Sorry but that just doesn’t add up.
  3. The amount of sunscreen the FDA requires manufactures to use in these SPF experiments equates to approximately 25% (1/4) of an 8oz bottle of sunscreen every time you go out into the sun. That means if you go on vacation and sit outside for four days, you would use up an entire bottle of sunscreen by yourself. Sorry, but no one uses that much.

But isn’t coconut oil sun protective?

Listen, I love coconut oil as much as the next girl. Great for cooking, great as a moisturizer . . . but not as a sunblock. Coconut oil only has a reported SPF of somewhere between 2 to 8. Incidentally, this study, suggests that chicken oil (translation – chicken fat) is far superior at absorbing UV rays and therefore protecting us than coconut oil is. Chicken oil is natural, so why are people not recommending it over coconut oil? Oh yeah, it is not nearly as sexy as the tropical fruit that we make pina coladas with.

[And for the record, the researchers made their own chicken oil. They took the meat off, boiled the rest of the chicken to 284 degrees, and extracted the oil. They reported it had a “pale yellow colour with a chicken smell”. Too bad. It seems like a much better sunblock than coconut oil.)

And this study, which is often used by people to prove that coconut oil has an SPF of 2 to 8, was done in vitro, which means not actually calculating SPF on people as described earlier, but calculating the SPF based on how coconut oil behaved in UV light in a research lab. Interestingly, olive oil scored slightly higher than coconut oil in this study, but oddly, no one is reporting that. I guess coconut drinks with little umbrellas are more exciting than salad dressing.

But what about essential oils as sun block?

I’ve been asked many times recently if carrot seed essential oil is an adequate sunscreen.

Here’s the story . . .

There is one single “study” in an open-access journal that tested a number of different herbal sunscreens. They took 14 different herbal sunscreens, all of them purchased from a “local dealer” in India, and tested them using a variety of tests and parameters.

Most of the times studies don’t name the specific products they use for reasons of lawsuit and/or potential bias in the study. So instead of naming the sunscreens they used, they gave them code names ranging from HS1-HS14.

A single herbal product they used (HS3) had carrot oil in it (not necessarily carrot seed essential oil, which it didn’t differentiate, but is a different compound entirely), along with wheat germ, and symplocos. In other words, it was merely an herbal sunscreen that had some type of carrot ingredient in it among a number of other ingredients.

The study seemed to do a good job of reporting their findings, but nothing – I mean nothing – suggests that carrot seed essential oil can act as a sunblock, let alone has an SPF of 40.

Here's a table from the study:

This table is showing some of the ingredients of the herbal sunscreen they used, called HS3. Question number one – how much carrot oil was in it, was it carrot seed essential oil or just carrot oil, what were the other ingredients in it, and in what quantities? Obviously, FAR more questions than answers here.

Here’s another table:

This is single section of the study where people are referencing their information from. Oddly (or not), look at the “In vitro” and “In vivo” numbers for HS3 and see if that matches up to all the scientifically illiterate out there saying carrot seed essential oil has an SPF of 38 – 40.

But here’s the thing – anyone quoting this study as evidence that carrot seed essential oil acts as a sunblock likely 1) hasn’t even read the study, 2) doesn’t know how to read a scientific study, 3) doesn’t know what they are talking about, and 4) are potentially making false claims. I say “potentially” because who knows, maybe carrot seed essential oil has an SPF of 40, but there are zero good-quality studies suggesting this that I am aware of.

Unfortunately many essential oil distributors are using this study as a reference, promoting carrot seed oil of having and SPF of 40. But as you can see, that is based on pretty much nothing, and likely is being parroted from one distributor to the next, without really looking at the study.

The Bottom Line

I really like essential oils. I really do. But every time I turn around someone is spouting off misinformation like its gospel. That is one big reason I didn’t get involved with essential oils for years and the reason I'm starting to get turned off about them now.

These scientifically unsubstantiated claims being parroted by a number of different distributors makes it really difficult for people to learn out to truly use essential oils as part of a healthy lifestyle. Not to mention it cheapens the value of essential oils and worsens the image of the natural health industry as a whole.

So now that it’s summer, given the toxicity of many commercial sunscreens, you might be tempted to create a DIY sunscreen for yourself and your family. I don’t blame you – I’d do that, too.

But given what I know, be very wary about what you read on the internet. It not only has zero scientific basis, but may end up doing more harm than good.

Until better scientific studies are done, I’ll forgo the DIY project this time, and put my trust in finding a good, non-toxic sunscreen to the good people at the Environmental Working Group.

PS: Here's 5 Tips to keep in mind when picking out a healthy sunscreen.