Received today via email:
I am interested in buying your e-book to make my own sunscreen but worry about two things:
Efficiency : How do you know if it did block the sun/UVA?
Construction: does the oil separate later on? I sometimes get the sunscreen where the oil will be separate from the cream which makes it very difficult to put on. I’m wondering how the recipe of your sunscreen works.
This is such a great question I had to turn my answer into a blog post.
Let me start with how I decided to make sunscreen.
Zinc oxide has been a part of my apothecary ever since I noticed the 40% zinc oxide on a Desitin label when I was changing my child’s diaper. Knowing zinc oxide was a safe mineral, I started making my own diaper rash cream using zinc oxide, coconut oil and beeswax. I found it worked like a charm.
Recently sunscreen has made top news and according to various sources, like the Environmental Working Group and Dr. Mercola, zinc oxide was (and is) touted as a safe, effective ingredient for sunscreen.
From Mercola’s website: “Two non-toxic ingredients that scatter both UVB and the more damaging UVA rays are titanium dioxide and zinc oxide. They’ve been used all over the world for over 75 years as safe sunscreens.” http://articles.mercola.com/sites/articles/archive/2008/07/01/four-out-of-five-sunscreens-may-be-hazardous-to-your-health.aspx
I researched more and found that zinc oxide is even more safe than titanium dioxide, and that some sunscreen products use it exclusively as a sunscreen. I chose to keep it simple and only use zinc oxide.
Then there’s the whole nano war waging on what size the zinc oxide should be. I found these two quotes from Badger Balm, who did extensive research and product testing. They state the reason we don’t need to fear nano zinc. First, the risk comes if you inhale the powder (which isn’t a concern if it’s already blended into a cream, and also isn’t a concern for those of us who know better than to inhale .) Second, let me let the Badger take over here: “There are no studies showing that nanoparticles of zinc oxide can penetrate healthy human skin, whereas there are several studies showing that chemical sunscreen ingredients, which are molecular in size and thus significantly smaller than nanoparticles, are absorbed into the blood.” http://www.badgerbalm.com/s-33-zinc-oxide-sunscreen-nanoparticles.aspx
So how much SPF protection does zinc oxide offer? Again, Badger Balm does my research for me (and I saw similar quotes on Mercola’s site): Zinc oxide should be 20% of the formula in order to get an SPF30. The recipe in my e-book is right at 20% so this gives an SPF30. Natural protection does come at a cost, however. Because it takes a hefty amount of zinc oxide, you’ll notice a little whitening on the skin. On a hot day, it absorbs quickly. Or, just adjust the recipe for less zinc oxide and a little less SPF.
As for the construction of the recipe in my e-book, we have a jar of sunscreen I made two months ago and it’s still perfectly blended, even with frequent traveling to and from the pool. If your homemade sunscreen does separate, just stir it up. It’s a fresh product!
In addition to being easy to make, and safe for children, it’s effective. On the days that we apply the sunscreen before the second hour of full sun exposure, we’ve kept our skin burn-free.
Let me conclude with this: I believe a slow adaptation to sun exposure without sunscreen is better than lathering it on every time you walk out the front door. When summer starts, begin with 10-15 minutes out in the sun and then return indoors. You need that UVB – it’s the one that helps your skin produce vitamin D. Don’t block it out. On the other hand, you do not want to burn. So decide ahead of time how long you plan to be out in the sun and plan accordingly.