Warning: long post. Scroll down for TL;DR version.
Just an FYI, I was more interested in the SPF protection for my own personal use, vs. claiming it on the label.
Here's what I was trying to say: Even for personal use, you need to have it tested to see if it's even working, and if it is, what the SPF is and whether it protects against UVA
and UVB. Without lab tests, you don't know if it's working unless you slather it on and sit in direct sunlight long enough to burn/age/get cancer. Testing it yourself, you can only test for whether it prevents sunburn. You can't test whether it prevents aging and cancer because you don't have the lab equipment to test whether it's effective against that particular wavelength of UV light.
There are ways of inactivating the UV absorbing/blocking ingredients that you may not be aware of. Just throwing UV blocking additives into your formula isn't guaranteed to prevent cancer or premature aging.
Then there is the fact that some UV blocking additives will deactivate certain preservatives. There is a lot more to it than simply dumping into your formula whatever a commercial manufacturer uses as their actives in a completely different formula.
Additionally, the following is my understanding regarding testing and natural ingredients in the U.S.:
1) the FDA doesn't test anything, merely approves the testing done by others as safe, does what it claims, etc.
True. The testing process must meet strict requirements, though.
2) as far as natural ingredients go, few companies are willing to go through the rigorous testing of natural ingredients as a cure, because they can't be patented. There are groups that do some testing, but generally don't have the financial resources to do the rigorous testing needed to get FDA approval.
I don't really buy the "can't be patented" thing. It isn't necessarily the patent holder who proves the ingredient's usefulness to the FDA, it's whoever has the resources and the desire to market a product with that ingredient sold as a drug. If patents really mattered so much, why are there already so many natural ingredients on the monographs in categories besides sunscreen?
The fact that there are no "natural sunscreen" (as in plant matter) ingredients included on the monograph for sunscreens should tell most people that "natural sunscreen" isn't a thing (unless you consider TiO2 and ZnO to be "natural"). There is enough of a market demand for "all natural" that
someone surely would have found a plant-derived sunscreen by now if such a thing were possible.
So it is possible that there are incredibly effective natural cures that haven't gotten approval. On the flip side there are plenty of natural remedies that do more harm than good.
I agree with both of these statements, speaking generally. But I suspect only the second statement applies to sunscreen.
I would love to be in the position to fund that kind of research, but sadly am not. Because, I do believe that, for the most part, natural remedies typically have the least long term unwanted side effects and are easier on your body; given that they work and have been tested.
Although some natural remedies have been adequately tested, most funding and effort goes into testing synthetic drugs. As for side effects, there are some pretty bad side effects from natural remedies, too. The long term effects of some of those haven't been nearly as well studied as any new drug the FDA has approved.
As for natural substances being easier on the body, there are some forms of eczema where the skin reacts badly to anything biologically derived, and only synthetics (petrolatum, cetyl alcohol, mineral oil, etc) can be used
because they are very inert when compared to naturals.
Oh, and by the way, one of my lip balms does have raspberry oil in it, but only at 5%. I, too, had read it had SPF 28 protection. But of course when it's only 5% of your product, then at most you have 1.4 SPF.
That is not quite how calculating SPF works.
Anyway, I don't claim any SPF on my product, but figured, what the heck, maybe it'll help a tad. But I will definitely do some more research about it, check out the reference
@Quanta refers to, and see if I can find others. Since I only use raspberry oil for this one product, I can stop stocking it and go back to sweet almond oil for this item. We will see. I will also look at some of the ingredients
@Zany_in_CO has mentioned and see what I can find. Again, it is hard to find reliable testing on natural ingredients, but I will look and we will see. So for now - On to soaping!!!
Yes, do lots of research. Don't read blogs though unless they are written by professional formulators instead of just some random guy trying to generate content to get page clicks for advertisers. In fact, start here (the FDA's guidance for small businesses wanting to make sunscreen):
https://www.fda.gov/regulatory-info...-products-over-counter-human-use-small-entity
After you've read that, then you are ready to research ingredients. Whatever ingredients you use, you have to know that ingredient thoroughly before you even try to make a sunscreen with it. Even with seemingly straightforward TiO2 and ZnO, you have to consider particle size, possible coatings that have been applied to those particles, how it will affect other ingredients, how it will be affected by other ingredients, and other things before you can even choose the form you want to use. You can't just grab any old zinc oxide off the shelf and expect it to block UV. And the form used is not required to be on the label of commercial products, so reverse engineering someone else's formula based on a list of ingredients will only get you so far.
TL;DR: Making sunscreen is way more complicated than most people think, and you'll only know if you got it wrong after it's too late... unless you have it lab tested.