More on Zinc Oxide – Nano-scale Micronized Sunscreen: Should You Be Concerned?
Short answer is no. But if you are going to use nano-sized/micronized/ultrafine zinc oxide commercial sunscreens, use the lotion or cream and not the spray kind. When nano-sized zinc oxide particles were first introduced in sunscreen, there were some concerns that these ultrafine particles would absorb into the skin causing more harm than good. These claims have since been alleviated and studies have proven that these nano-scale particles will not pass through the skin. However, there are still unresolved concerns over the risk of inhaling nano-sized zinc oxide and titanium dioxide. That is why the Environmental Working Group “discourage[s] the use of powder or spray sunscreen, particularly those with titanium and zinc.”
Other than its extremely small particle size, there’s nothing special about micronized zinc oxide with regards to its UV blocking effectiveness. It is not even necessary. Its demand sprung out of purely aesthetic reasons. Conventional sized zinc oxide sunscreens have a thick, white, opaque appearance but micronized zinc oxide makes the sunscreen more transparent and therefore, more desirable especially compared to its translucent chemical-based counterparts. Some patents and experts involved in its nanotechnology would argue that ultrafine zinc oxide gives better UV protection. But not even Applied Therapeutics, the maker of SunSmart sunscreens, would claim on their website that their sunscreen which incorporates Z-Cote micronized zinc oxide is more effective than conventional zinc oxide. Only that it’s effective. An excerpt from their Skin Care Information web page reads:
“…Most people associate zinc oxide with the white thick paste lifeguards used to use. It was known to be the best sunblock available but it was cosmetically unacceptable and therefore used only by lifeguards or skin cancer patients. Fortunately, things have changed and you can now get physical sunscreens that are transparent. Zinc oxide, for example, is now manufactured so that the particles are small enough that you can not see them… One example is Z-COTE® (microfine zinc oxide). Sunscreen manufacturers now use Z-COTE® and other microfine powders as ingredients in their sunscreens. Zinc oxide is the primary active ingredient in many baby care products and thus has a very long history of safe use and is not associated with any allergic reactions. Because of this, physical sunscreens, like zinc oxide, are ideal for beach products and for products such as moisturizers and make up that are used every day and need to be as gentle as possible. “
Thick Layer
Thin Layer
My conclusion? Make your own zinc oxide sunscreen. It is way cheaper and just as effective. If you don’t like the opaque white look, apply a thin layer and apply more often. I purchase the zinc oxide in all my sunscreen and diaper rash formulation online through Liberty Natural. I’m not affiliated with them in any way. After a long and exhaustive search, it’s the only place I can find where I can get a small amount for personal use. I have talked to and confirmed with Liberty Natural that the zinc oxide they distribute is the conventional kind, 0.51 um (510 nanometers) average size. Based on its MSDS and general safety information on zinc oxide, you can safely use it the way I do. After all, zinc oxide has a long history of usage in medical treatments and cosmetics. When mixing, do it away from the stove and don’t do it in windy conditions or inhale it ;). Basically, use common sense. I’m not even sure where one would get micronized zinc oxide so if any of you know, kindly post it here.
Comments
Comment from wabisabi
Time October 2, 2008 at 2:56 pm
I don’t know anything about coated vs uncoated zinc oxide. BUT, the concerns with those minerals’ photoreactivity and potential to induce free radical formation has to do with nanoparticles penetrating the skin layer. Conventional sized particles do not penetrate and studies show that nanoparticulates also do not penetrate HEALTHY skin. See the sunscreen review from the Australian Therapeutics Good Administration tga.gov.au. Nothing from the FDA that I can find.
Comment from Sabrina
Time October 2, 2008 at 4:59 pm
Do you put beeswax to your zinc oxide cream to seal it? I guess I’ll order the regular zinc oxide then.
Comment from wabisabi
Time October 2, 2008 at 10:42 pm
Only when I’m making a water-resistant sunscreen
Comment from fay
Time January 5, 2009 at 11:24 am
How about titanium dioxide, versus zinc oxide for making sunscreen?
Also, I think small amounts are available at e the camdengrey.com site. Is it the same as what you buy?
Comment from Wabi Sabi Baby
Time January 13, 2009 at 2:16 pm
-Fay
I don’t use titanium dioxide. See previous post on sunscreen and note the links to articles in the Federal Register. I haven’t ordered from the site you mentioned so I don’t know if it’s the same.
Comment from deemarie
Time February 7, 2009 at 3:07 pm
Libertynatural.com
For new customers who prefer not to pay by credit or debit card the1st three orders must be COD (Certified check or money order). We do not accept prepaid orders with checks by mail.
$50 Minimum order amount is waived for new customers on the first order.
Comment from Steph
Time March 12, 2009 at 5:37 pm
How do you calculate the SPF of your homemade sunscreen?
Comment from Wabi Sabi Baby
Time March 14, 2009 at 3:00 pm
I don’t. SPF ratings mean that it will take you the SPF factor times longer to get burned than without it – (i.e. if it normally takes you 10 minutes to burn and you apply a sunscreen with an SPF of 15, then you have 15 x 10min = 150 minutes of protection). BUT, SPF alone is not a good indication of protection and there are many other factors that affect its effectiveness. The best advice is to just know your skin regardless of the sunscreen and SPF you use: when you start feeling the heat, it’s time to reapply. Or, take mental note of how long it took you to burn with one type of sunscreen and reapply more often next time. For more info, check out these two links: http://vm.cfsan.fda.gov/~dms/fdacsun.html (read the SPF debate) and
http://health.howstuffworks.com/spf.htm
Comment from kathy
Time March 22, 2009 at 2:20 pm
Today, I found that I can order small amounts of zinc oxide from labellefemmecosmetics.com. They have 3 particle size choices. No minimum order.
Comment from Wabi Sabi Baby
Time March 25, 2009 at 1:31 pm
Thanks! I was wondering where to find micronized zinc oxide.
Comment from joann
Time April 5, 2009 at 11:00 am
essentialwholesale.com has micronzied zinc oxide but it is quite spendy for 1lb size.
Comment from jenna
Time April 25, 2009 at 10:04 am
How much zinc oxide should I buy to make a bottle of sunscreen?
Comment from Wabi Sabi Baby
Time April 25, 2009 at 8:22 pm
Hmmm…it depends on your needs. I recommend mixing zinc oxide in about 7-12% concentration. I.e., a 10 oz lotion would contain 0.7 to 1.2 oz zinc oxide by weight.
Comment from Jenny
Time May 13, 2009 at 10:28 pm
Two questions. 1. So really all you NEED to protect the skin is zinc oxide (I realize some use titanium dioxide)? The rest of the ingredients in natural suncreens are not necessary for sunscreen protection?
2. If a person bought micronized zinc oxide and mixed with my current lotion would I be correct is saying it would go on the skin easier and wouldn’t be as pasty looking?
Comment from Wabi Sabi Baby
Time May 16, 2009 at 8:37 pm
1. Yes – TiO2 is redundant if you already have ZnO. Sunscreen base is not as important with respect to sun protection itself. But it is important with respect to other factors like water resistancy.
2. No – It depends on the concentration you use and also your blending technique. Improper technique will result in clumps whether you use micronized or not (though the sunscreen is still useable – you just have to rub and spread more). That’s the short answer. Long answer is in the upcoming e-report ;-)
Comment from Nicolas
Time May 27, 2009 at 4:33 am
Thanks for the great info.
Also, you can buy micronized zinc oxide over @
http://www.makingcosmetics.com/
http://www.makingcosmetics.com/Zinc-Oxide-micronized–p195.html
They also ship to Europe. :)
Comment from Sabrina
Time October 1, 2008 at 8:11 pm
I got a sample of regular zinc oxide and I have been mixing it with my lotion. I just put a bit of lotion on my palm and small amount of zinc oxide on to lotion then rub in together. You are right, it’s pretty white, but it’s not too bad. Do you know anything about coated and uncoated zinc oxide? I wonder if the regular one is uncoated? There is information about uncoated zinc oxide is photoreactive. Coated Zinc Oxide is NOT photoreactive and therefore does not product hydroxyl ions (free radicals in question) whereas uncoated Zinc oxide and Titanium Dioxide, coated or uncoated do.
Do you know where I can get coated Zinc Oxide from?