The Trouble With Making Your Own Sunscreen
Yes I have gone sunscreen crazy a little over the last week or so but it is for a good reason. It’s hot here in Australialand right now, hot, UV rich and waaaay too long between pay checks to go buy a $20 bottle of SPF 30 something for some people. That and the fact that there are a growing number of people for whom consumer SPF 30 plus sunscreen no longer cuts the mustard – too many chemicals, what about nanoparticles, too much synthetic perfume, allergic to the preservatives and so on.
So is home-made sunscreen possible?
I would strongly advise against trying and that’s not because I have shares in a sunscreen company because I don’t. It’s hard. Very hard. It’s expensive and hard and more importantly sunscreens are not just any old cosmetic, they might just save your skin.
The googlesphere is jam-packed full with recipes teaching you how to make your own homemade sunscreen. A typical recipe looks something like this:
To make 100g
25g of Zinc Oxide powder
50g Shea Butter
10g Jojoba Oil
3g Cocoa Butter
10g Olive Butter.
Mix it all up and voila, your own sunscreen and as Zinc Oxide gives somewhere between 1-1.5 SPF unit per % added you have a product with an SPF of between 25-35. Amazeballs.
Only you probably don’t.
Having worked with zinc oxide sunscreens for the last three years with varying success (and lots of failures) I can assure you that it is a pig of an ingredient being both difficult to blend into a base and keep dispersed in said base. Being a strongly charged particle it tends to migrate towards its self and form big clumps at every available opportunity (think of it like a super charged magnet that it sitting just shy of the pulling ground of a complimentary magnetic item). It doesn’t take much before whoooooosh, it’s moved and attached its self to its neighbour to form a duo that is TWICE AS STRONG AS IT WAS WHEN ALOOOOOOONE. You can easily see what will happen next. It’s chemical carnage.
But you can’t necessarily see that and as I found to my detriment a couple of years ago, ignorance is bliss. Knowledge is pain.
I started off in 2009 by merrily mixing my zinc oxide into a base, not really aware of how bad it could get and enjoying each little win like I was some genius in a world filled with losers who just didn’t see what I saw. I wondered why everyone from within the industry shied away from this type of formula, why they refused to take on this work and why they looked at me with that “oh no you haven’t” look when I told them about my happy successes. I was happy because my creations had not yet been tested.
But then came the day of reckoning. I took them to the sunscreen testing lab and they failed.
I had various goes at testing my ‘babies’ SPF’s. Those that I expected would give me an easy 30 came in at a dismal 12, those that were a sure 15 were only a 7 and one that looked amazing and a sure-fire 35 ish read only 8 on the SPF scale. Epic failures all and what was worse was that this was all my own work. In the early days I wasn’t really doing this for customers, I was just teaching myself some bits and pieces. Trying it on for size and investing in my future. Well, at $700 ish a pop for the basic stuff sunscreen testing is NOT something that you want to keep getting wrong and each failure hit me like a brick. And keep in mind that by this stage I thought I was onto a good thing and knew what I was doing – I won’t even go there with the tens of formulation tweaks that I tried and subsequently failed at.
One thing that I realised early on was that just because you put zinc in, it doesn’t mean that it stays sitting in the formula in a useful place. A good sunscreen has to cover the skin evenly like a good coat of paint and unfortunately for zinc users, that chemical prefers to clump together giving you dense lumpy areas that you may or may not be able to see with the naked eye and then empty wasteland craters all of which can act as lenses for sunlight and actually magnify the rays as they come through.
Yes it is true, adding lots of zinc to your product COULD leave you with a hole infested sun magnifying glass rather than a nice, uniform sunscreen. Ouch!
Then came some progress. I read a bit more, observed a little closer and tweaked a few techniques until something started to stick. My reported SPF’s were still a bit lower than I wanted but we were on the right track, no zinc was cottage cheesing and the product was feeling good on the skin. But that was over one year and several thousands of dollars worth of investment in time, materials and testing later and that was BEFORE we started trying to change preservative systems, add different actives, change emulsifiers and add perfumes. Another thing I’ve learned with zinc only sunscreens is that every little change is a big deal and can make a big difference. And that’s where I’m up to today with a few ideas that work and a few that didn’t.
I’m not saying that I’m a genius and if I can’t do it you must be made to think that you can, honestly I’m not. What I am saying that even with all of my friends in the right places, chemical resources, laboratory equipment and analytical testing experience I still stuffed up a lot before I started to make progress and surely that has to count for something. I was lucky in as much as nobody was risking their lives with these failed formulations, the only thing being risked was my money at that stage and thankfully that is replaceable. Our health isn’t always so easy to claw back.
The trouble with making your own sunscreen is that while it looks ever-so-easy from the ingredients list in reality there is a whole chemical dance that has to go on to get these things singing. Now you may just hit the jackpot and come up with a beauty but it is more likely that you won’t so please, please, please be careful and if this is something that you are likely to dish out to babies, your children or your elderly relatives do consider investing in at least one proper SPF test, just to be on the safe side.
Home made sunscreen? In my eyes it is just not worth it unless your home made sunscreen is a nice big hat or burquini🙂
1st August 2015 Update:
This post has had a lot of traffic thanks to it being shared far and wide by various websites, blogs and forums. I wrote this in December 2012 and since then I’ve continued to work on a number of zinc based formulations. I have one tinted moisturiser which recorded an SPF of 12.8 on the market (a secondary sunscreen) and two zinc only formulations pending marketing that meet SPF 15. I also built a framework formula based on zinc oxide that went on to achieve an SPF of 40. In addition to that I’ve formulated an SPF 40 formula that contains organic pigments and another two formulations with titanium dioxide as the main filter that meet SPF 15 requirements. I’ve also worked on a number of natural sunscreen projects that for one reason or another failed to make it to market. It isn’t easy to meet everybody’s expectations. That said I achieved all of the above (which might not sound impressive, I don’t know) with the help of my homogeniser, propeller mixer, stability testing protocol, microscope and a huge investment in SPF testing (it costs around $300 per subject to get SPF tested and you need 10 people to form a panel). I still wouldn’t recommend anyone trying to short cut the big bad chemical industry by making your own products at home as even with the right equipment and a few years of trying behind you it is so easy to get it wrong. Even a change in fragrance can affect SPF.
It has been interesting to watch the comments roll in over the years (and on other forums) and yes, there are always people who read this and still feel that they know best. Good luck to them I say, may the force be with you.