|
Sunscreens are a lotion, spray, gel or other topically-applied product
that reflects or absorbs some of the sun's UV radiation on the skin, and
helps prevent sunburn. Light skin is more susceptible to sun damage than
darker skin, so people with lighter skin tones need stronger sunscreen
(The melanin in darker skin affords some natural skin protection.) The
higher the SPF, the more protection a sunscreen is supposed to offer against
UV-B rays (typically the part of the spectrum that causes sunburn.) (You
can also see the eMedicine article linked below on sunscreens and photoprotection
for more information.)
This is NOT an increase in time before you burn!
It is a measure of how much UV radiation you can handle WITH the sunscreen
before you burn, relative to how much you can handle WITHOUT the sunscreen.
The time you have will always vary, with such factors affecting it as
time of day, your latitude (how far north/south of the equator you are),
whether it's winter or summer, whether you have scattered cover (in and
out of wooded areas or buildings), etc.
BASIC SUN PROTECTION TIPS
- Stay in the shade, when possible, between 10am and 4pm
- Avoid tanning booths of any type
- Cover up with tight-weave clothing, including a broad-brimmed hat
and UV-blocking sunglasses
- Apply 1 ounce (apx 2 tablespoons) of sunscreen/sunblock to body 15-30
minutes before going outside
- Reapply 15-30 minutes after exposure
- Reapply again after activity involving things such as swimming, sweating,
toweling off, and vigorous rubbing.
UV WAVELENGTHS
UV rays are classified into at least three different
groupings, depending on the size of the wavelength. These are:
- UV-C: 200 - 290 nanometers (Commonly
given off by welding equipment)
- UV-B: 290 - 320 nanometers
- UV-A: 340 - 400 nanometers (UV-A 1,
or "long" UV-A)
- UV-A: 320
- 340 nanometers (UV-A 2, or "short" UV-A)
The UV-A / UV-B wavelengths are the ones commonly
referred to on packages of sunscreen lotion (and now you know the wavelengths!)
but UV-C should be kept in mind as a factor as well - especially with
exposure to sunlight and high-UV generating light sources - even if
it's not as commonly understood. UV-C is typically given off by various
types of welding equipment, so those of you who may be welding for a
living, or know someone who is, will already understand to take this
into account.
UV-B is particularly effective at damaging DNA,
and is a cause of melanoma and other types of skin cancer. As the ozone
layer is depleted, this effect will become worse over time (shortening
the time it's safe to be in the sun too, incidentally.)
SUNSCREEN OR SUNBLOCK?
It is important to understand the difference in terms - while they
are often used interchangeably, they really should NOT be, as they are
describing two different methods of sun protection.
"Sunscreens" absorb UV light so that it (theoretically) does
not reach your skin.
"Sunblocks" will physically reflect the suns rays without
absorption. (In practical terms, the difference you FEEL will likely
be that the pure sunblocks will make your skin feel cooler when exposed
to sunlight than the chemical sunscreens do - above and beyond any reaction
or lack of reaction to the ingredients.)
- Sunblocks - Inorganic particulate UV-A
and UV-B blockers:
Titanium Dioxide, Zinc Oxide
Sunscreens - Chemical compounds - example UV-A Absorbers:
4-Aminobenzoic acid / PABA, Bisdisulizole disodium (Neo Heliopan AP),
and others
Sunscreens - Chemical compounds - example UV-B Absorbers:
4-Aminobenzoic acid / PABA, Homosalate, Octyl salicylate / Octisalate,
Phenylbenzimidazole sulfonic acid / Ensulizole and others.
- Sunscreens - Chemical compounds - Example
UV-A and UV-B Absorbers:
Benzophenone 1–12, Octocrylene, Oxybenzone / Eusolex 4360 (derivitive
of Benzophenone), Sulisobenzone, and others.
Anything that blocks UV-A and UV-B is considered to be "broad
spectrum" in most descriptions.
WHAT'S THE BIG DEAL?
Chemical Compounds
Some people find the sunscreen chemicals to be irritating to one degree
or another, such as a rash or massive itching, and do not tolerate them
on the skin for long at all. Also, there are recent studies coming out
showing that these chemicals may do more harm than good in the long
term, causing skin damage (doi:10.1016/j.freeradbiomed.2006.06.011
- see "Free Radical Biology & Medicine" link below),
DNA or internal organ changes because they're absorbed through the skin
(doi:10.1289/ehp.11269 - see "EHP" link below), cancer
(doi:10.1016/0014-5793(93)80141-G - see "FEBS Letters"
link below), and so on. Most chemical sunscreens have between 3-7
of the available sunscreen ingredients in an attempt to provide a broad-spectrum,
higher protection rating.
Patients with photodermatitis, eczema, or other skin conditions where
the external layers are compromised need to be aware that chemical based
sunscreens MAY aggravate the existing conditions, or provide new and
even more annoying symptoms to deal with. Rashes that some people experience
MAY be a simple allergic reaction OR may be a photocontact (only on
exposure to UV radiation) reaction instead.
Personal Notes -
Chemical Compounds
I have not had much success using these types of sunscreens myself;
to my skin they're not protective at all. One recently purchased tube
of "Baby Block" sunscreen gave me a sun-induced rash for a
week; checking the label revealed that in addition to the titanium dioxide
usually listed, the manufacturer this time around had also added three
of these newer chemical compounds as well.
Titanium Dioxide
On the sunblock end of things, there is some debate as to whether the
microfine/nanosized particulates for Titanium Dioxide [TiO(2)] manage
to get absorbed into the skin and cause damage. There are studies such
as a toxicology study (doi:10.1016/j.tiv.2005.08.008 - see "Toxicology
in Vitro" below) that was unable to prove this using pig skin
(pig is often used as a human replacement in more dangerous experiments)
- but also other studies (Australas J Dermatol. 1996 Nov;37(4):185-7
- see "Pubmed - pilot study" link below) showing evidence
of penetration into the epidermis
and dermis layers of the skin. At the moment there doesn't seem
to be a definitive consensus, bear this in mind while you decide for
yourself.
Zinc oxide
Whether microfine or not, zinc oxide seems to be both safe and UV-stable
in my research results. If you can find a sunblock with ONLY zinc oxide,
it appears to be the best choice with least side effects or problems.
(See "Pubmed: Microfine zinc oxide" links below.)
Personal Notes -
Titanium Dioxide / Zinc Oxide
Both of these particulates have been well tolerated by me in the past
and have not caused any issues. I do experience a "cooling"
effect - where the particulate sunblocks are applied, I don't feel the
heat from the sun exposure as much as I do on untreated areas.
Zinc Oxide is showing the least amount of reactivity issues in my
research, so if you normally have problems with sunscreens, or are concerned
about long-term effects, I would recommend a zinc-only sunscreen - and
adequate additional protection - to be safe. My research is showing
that a sunblock with only Zinc Oxide is unlikely to get over an SPF
of 10 without additional chemical compounds, so additional protection
WILL be required, especially if you'll be outdoors for long periods
of time.
READ THE FINE PRINT ON LABELS!
Some sunscreens advertising themselves as "Zinc Oxide"
with a medium to high SPF, but ALSO also contain between 2-5 of the
chemical compounds in addition to the zinc oxide.
RECOMMENDED SUNSCREEN
BRANDS AND TYPES (June 2010)
Interestingly, the "high SPF" sunscreens (70+, etc.) are
NOT necessarily the best ones, at least in my experience. These are
typically the chemical compound based sunscreens, and may or may not
be mixed with titanium dioxide.
The inorganic particulates alone typically result in an average SPF
of 30ish, but give me the most effective sun protection with the least
amount of problems. You will have better luck locally finding many of
these particulate-only sunblocks in stores that specialize in organic
products, or that have a specific section for organic products.
Here is a list of particulate-only sunscreens that I can find this
year (2010) by brand, then type. This list was compiled by combing the
 drugstore.com
website, but many of these are also available via amazon as well as
your local retailers. Unless otherwise noted, items in this list have
a combination of both Titanium Dioxide and Zinc Oxide as their only
active ingredients:
All Terrain KidSport 15 (Zinc Oxide only;
microparticle)
All Terrain KidSport 30 (Zinc Oxide only; microparticle)
All Terrain TerraSport 15 (Zinc Oxide only; microparticle)
All Terrain TerraSport 30 (Zinc Oxide only; microparticle)
All Terrain AquaSport 15 (Zinc Oxide only; microparticle)
All Terrain AquaSport 30 (Zinc Oxide only; microparticle)
Avalon Organics: Baby Natural Mineral Sunscreen SPF 18 (Titanium Dioxide
only)
Badger: All Natural Sunscreen, SPF 15 (Zinc
Oxide only)
Badger: All Natural Sunscreen, SPF 30 (Zinc
Oxide only)
Blue Lizard: Australian Sunscreen, Sensitive, SPF 30+ (available by
the gallon!)
Burt's Bees: Chemical Free Radiance SPF 15 Day Lotion
Burt's Bees: Chemical Free Sun Screen SPF 30 (Titanium Dioxide only)
California Baby: SPF 30+ Sunblock Stick (microparticle Titanium Dioxide)
California Baby: Water Resistant, Hypo-Allergenic Sunscreen, SPF 30+
(microparticle Titanium Dioxide)
California Baby: SPF 18 Moisturizing Sunscreen, No Fragrence (Titanium
Dioxide only)
Cotz: Face Cotz, Sensitive Skin Sunscreen, SPF 40 (microparticle Titanium
Dioxide and Zinc Oxide)
Cotz Sunscreen, Water Resistant SPF 58 (microparticle Titanium Dioxide
and Zinc Oxide)
Kiss My Face: Non-Chemical Sunscreen Lotion, SPF 18
MyChelle Dermaceuticals: Sun Shield SPF 28
Neutrogena: Pure & Free Baby Sunblock Stick, SPF 60+
Neutrogena: Sensitive Skin Sunblock Lotion, SPF 30 (Titanium Dioxide
only)
Neutrogena: Sensitive Skin Sunblock Lotion, SPF 60+
Nia24: Sun Damage Prevention 100% Mineral Sunscreen (microparticle
Titanium Dioxide and Zinc Oxide)
Ocean Potion Suncare: Natural Mineral Sunblock, Active Wear SPF 30
Ocean Potion Suncare: Natural Mineral Protective Lotion, Faces SPF
45
Ocean Potion Suncare: Natural Mineral Sunblock, Kids SPF 45
Ocean Potion Suncare: Natural Daily SPF 30
J/A/S/O/N Natural Cosmetics: Sunbrella MINERAL Natural Sunblock, SPF
30+
J/A/S/O/N Natural Cosmetics: Earth's Best Organic Sunblock, Chemical
Free SPF 30+
Little Twig: Non Chemical Sunscreen 30+ (microparticle Titanium Dioxide
and Zinc Oxide)
Nature's Gate: Mineral Kidsblock SPF 20
Nature's Gate: Mineral Sunblock SPF 20
UV Natural: Baby Sunscreen SPF 30+ [Australia]
(Zinc Oxide only)
UV Natural: Sport Sunscreen SPF 30+ [Australia] (Zinc Oxide only)
UV Natural: Sunscreen SPF 30+ [Australia] (Zinc Oxide only)
Vanicream Sunscreen: Sensitive Skin, SPF 30
** If any of these are not available, try any brand of diaper rash
ointment - at least in the USA, it's zinc oxide only. **
Avoid any sunscreens with any of these phrases on the label:
"Anti-aging"
"Continuous Spray" (particulates don't spray well in a pressurized
sprayer)
"Dark tanning" (won't ever have particulates since they
block both UV-A and UV-B, and UV-B promotes tanning)
"Dry touch"
"Fast Absorbing"
"Non-Greasy"
"Oil Free"
"Ultra Sheer"
"Ultra Light"
...or any similar phrases - these are going to have either just the
chemical compounds in them, or the particulates will be mixed with the
chemical compounds, and anyone sensitive to the chemicals will STILL
have a problem even though the particulates are also in it.
MAKING YOUR OWN (IN A PINCH)
- 1.5 oz Sunblocking agent - zinc oxide recommended - available
online
- 8 oz of carrier: lotion, oil, etc. - your choice
- 1oz emulsifing wax (what
is emulsifying wax?)
- 1 mixing container (bowl, etc.)
- 1 clean storage container to put all this in when done
** Wear gloves and facemask at all time to avoid inhaling dust **
- Heat the wax until it melts
- Add the carrier lotion, mix thoroughly
- Add the sunblocking agent
- Blend thoroughly, scraping down container sides
- Spend still more time blending thoroughly (You want this to actually
be effective!)
- Put into jar for use
** Remember this has no preservatives, so only make small batches you'll
use in a couple months **
~SphynxCatVP, June 2010
This site contains articles on various medical
topics; however, no warranty whatsoever is made that any of the articles
are accurate - and even if a statement made about medical matters is
accurate, it may not apply to you or your symptoms. These
medical articles are provided on a general informational basis only
- nothing on this site should be construed as an attempt to offer or
render a medical opinion or otherwise engage in the practice of medicine.
Even though the authors may be capable of
doing extensive research, it must be understood that neither SphynxCatVP,
nor the rest of the contributors, are doctors, despite the presence
of any books of the medical profession in the personal libraries of
any of the authors. Any such articles are thusly written, in part or
in whole, by nonprofessionals. Consequently, there is absolutely no
guarantee that any statement contained or cited in an article touching
on medical matters is true, precise, or up-to-date.
At best, you can use the article to strike
up a conversation with your doctor or other medical professional ABOUT
your symptoms, and share any concerns you may have for them to investigate.
The medical information provided by this site is of a general nature
and CANNOT legally be considered a substitute for the advice of a medical
professional.
|
