Cyber Beautybox

Questions & Answers On

Sun Protection Factor
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Question

Dear Pierre,

I read some of your replies in the Q&A sections and I must say
that you are such an expert on skincare in the internet. I
wish I had found your beauty box much earlier.

I really need your help this time.

(1) I am a devoted user of sunscreens. The other day, I read
an article saying that "if you're using an SPF 15 moisturizer
under an SPF 8 foundation, the protection you end up with may
be about SPF 12 due to dilution". If someone uses a moisturizer
(without SPF) and an SPF 20 sunscreens, does it end up to be
only SPF 10???????

(2) What is the sequence of applying physical and chemical
sunscreens? Should a physical sunscreen be applied under or
over a regular chemical sunscreen?

(3) As regards maximization of UVA protection, will the
sequence of layering in (2) be different if chemical sunscreens
of Parsol 1789 is used together with another physical sunscreens?

Please help! The hot summer is here already.

Thanks & regards,
Kim

(submitted by alias: KIM)

Answer
Yes, that's right if you apply both on top of one another
immediately without waiting for one to dry up a little -
that's quite a close approximate. That's because the amount
of concentration of the anti UV ingredients in the cream is
the primary determinant of the SPF value. So when you mix up
one with SPF 15 and 8, you get the average of SPF 12.

Example:
if you have a gram of sugar mixed in 50 grams of water in one
cup, and another 3 grams of sugar mixed in another 50 grams of
a separate cup. Now each cup will have different degree of
sweetness, the latter cup being sweeter. If you now mix the two
cups of water, they will now be 4 grams of sugar in 100 grams
of water, or 2 grams of sugar in 50 grams of water. And 2 grams
of sugar is exactly the average of 1gm + 3 gms.

So, the sweetness now is between the 1st cup and 2nd cup.

If you apply one over another immediately when they are both
still liquid, and mixed them up on your skin, there isn't going
to be much of a difference for which one to be applied first.

But if you apply the chemical sunscreen first, and wait a while
for it to dry up, before applying the physical sunscreen, then
this is preferred. The chemical sunscreen works by absorbing the
UV rays, to prevent them from penetration, but by absorbing the
UV rays, the rays are accumulated and left on the skin surface.
This can be harmful over time. The physical sunscreen works by
reflecting the UV rays, thus without retaining the rays on the
skin surface.

So, it is better to reflect off the UV rays on first contact
with the skin, rather than to allow the rays first to be
absorbed and reatined on the skin surface, in which case the
inner layer will not be able to effectively reflect the rays.

The above suggestion is presumed that the person is not
sensitive to chemical sunscreens. The higher SPF value in a
chemicl sunscreen, the higher risk of its sensitizing effect
on skin, which can cause redness and swelling.

Parsol 1789 has been found to be a safe chemical sunscreen
agent. So the difference is that when it is applied as the
first layer(that is in direct contact with the skin), it is
very unlikely to cause any sensitizing effect on the skin. If
applied as 2nd layer it will still absorb UV rays and retain
them on the skin. Generally, sunscreens with very high SPF value,
will have to primarily depend on chemical UV absorbers, and this
is harmful. Physical sunscreens use only very
little chemical UV
absorbing agents, but more physical UV reflection agents, and
thus they are much safer.

It is better and safer to use a lower physical SPF cream, and
wipe off and apply more often, than applying
a high chemical SPF
cream and left on the skin for several hours of exposure to the
sun. It is reported that
the UV rays absorbed and retained on the
skin for a long period of time can lead to skin cancer too.

Hope the above helps.

Regards: Pierre
________________________________________

Question
I am 27 years old, Japanese and living in the States for
6 years. My acne has started since when I was 14 or so.
(After I started my period.) Although my acne on the
cheek is gone, the openpores and redness remained and the
skin got rougher. And the worse thing is the part is
expanding year by year. As I mentioned before, before the
menstoration, I get tiny acne inc. whitehead on the area
where I don't have acne before. So now clear skin is
almost gone from my face.
I am sure I usually have whitehead as well as the blackhead.
(I cannot squeese unless I use needle.) I have whitehead
near chin and neck now. I know it is something to do with
my hormone. So I have started to take birth control pill
called Oarth Tricyclen. It is less than a month so that I
cannot figure it has been good for me. Before I took
different kinds of antibiotics, Minocyn or monodox, but
didn't work. I also tryed topical products such as Metrogel,
Azlex(New brand), Neostrata, and all kinds of stuff I can
get from drug store. Only tings I haven't try are Retain-A
and Accutane.... I am not sure if you are familiar with
those products...
I am single, not pregnant.
I usually use facewash from salon, which is Dermelogica
"anti-back face wash" or Japanese CAC (Brand) powder type,
this one is very mild. For the toner I use Pola
(Japanese) Sekkisei, or Chanel for Oily skin. Lotion and
sun protection I am using Total Diffence from Chanel (Spf 15,
non-fre, oil control). I try not to use fregrance-in, and
avoiding oil contained. I don't usually put makeups. Night
time I am not using anything right now except Vitamin E oil
for aroud eyes and neck. I used to have very oily skin but
it is changing. So I have kind of oily skin but it is also
on the cheek. People usually tell me I got very sensitive,
or combi, or oily skin. Aroun my nose and cheek, I have
openpores and I can see oily-white stuff ( Are they comedos?)
coming out from pores. Sometimes I use twizler to take or
they can be squeezed out. I don't have Stress that much and
I can sleep soon after I am in bed. I think since I started
to take birthcontroll pills, I sleep well. (But I have very
hard time waking up, maybe because my body has been changed
as well as the bloodpressure.)
I also take vitamins, eat a lot of fruit, vegis, and don't
eat greasy that much.
I wash my face twice a day.
I went to see many dermetrogists and, some told me my problem
is genetic, but non of my family has this proble that I know.
I even went for lazer because of the spider vains. The
doctor said, most of the redness is caused by acne. So I
have combi of things going on my facial skin. But my acne is
almost unseen (They are looked more like rough skin because
they are small and not really poped out most cases)) with the
redness.
Well, when I take picture closeup of my face I will send it
to you. Meanwhile I just want to try your products.
I forgot to tell you that I use mask, Purifying Mask from
Shiseido and Chinaclay mask from Clentel (U.S. product). I
hardly use scrub since I know it might cause more broken
vassels.
Please give me suggestion, I will do anything for my skin.

Thank you very much for taking your time.

(submitted by alias: Sachiko)

Answer
Hi Sachiko,

I received your letter and 8 photographs.

Observing from your photos(although not very sharp), your
skin is now very sensitive and inflamed. You also mentioned
that you flushed easily even since childhood days. This means
you have got very fine(and fair/light) epidermis. As such, your
skin is quite easily reddened also by sunlight(photosensitive),
because your skin contains little amount of melanin pigment
cells(melanocytes), and thus cannot effectively protect it
from the harmful effects of the UV rays, which worsens your
current condition. Although you need protection from the sun
(especially during summer time, or whenever you are out in the
open), unfortunately it's not advisable for you to use
sunscreen of high SPF value. You should use only below SPF15
(try a small amount on your neck area first to test if your
skin can take it or not).

You also should not use any soap-base cleansers(like the fash
wash you mentioned) to wash your face, and you should not wash
more than twice a day for the time being. Soap-based cleansers
will cause superficial dehydration(though temporarily). When
this happens two events happened:

1. The skin cracks and ruptured(and became coarse), and allows
bacteria to penetrate freely. This worsens your acneic
condition.

2. Your skin will physiologically react on its own to try to
compensate the loss of moisture(due to the temporary dehydration
caused by the soap-based cleanser). When this happens there will
be excessive production of sebum underneath your skin, causing
your pores to clog. Soap-based cleansers also contain salt(part
of the ingredients to help increase the viscosity of the cleanser)
which contributes to the hardening of the sebum.

Cream cleansers are generally better for conditions like yours,
but some cream cleansers unfortunately contain large amount of
high viscosity wax. Such cleansers usually leaves stains of
hardened waxes on skin after rinsing, and thus also contribute
to pore-clogs. Cream cleansers with low viscosity wax and
oil are known as non or low-comedogenic and are safer and more
effective. The same applies to day cream and night cream which
are to be left on the face for long hours. Those containing
high viscosity wax and oil should be avoided. You can do a
simple test to find out if a cream(cleansers, day and night
creams, etc.) is non-comedogenic or hyper-comedogenic
(Non-comedogenic means not prone to contributing to comedo).
Just decant one to two ml of the cream and place it on a piece
of normal writing paper for one to two days, and observe again
(do not spread the cream. Just leave it as a lump like a small
moldhill). If after two days, most of the cream had disappeared
and are absorbed into the paper(you can see the oil patch
surrounding the cream), leaving very little or no traces of
any visible cream on the paper, then the cream is low or
non-comedogenic. If, on the other hand, you find the small
moldhill of cream is still there or has shrunked only slightly,
leaving a lump of hardened wax substance still there, then the
cream contains a high content of wax substance and should be avoided.

Too much of Vit E and Retin A will cause your skin to peel
often(not good for sensitive skin like yours currently). Clay
mask will also absorb(suck) moisture from your skin and cause
dehydration. I recommend you stop applying for now.

Now I'm going to recommend you a simple regime, usimg only four
of our products first. You should stop all others in order to
see fast results.

The 4 products are:

1. Pierre Chenxu No.17/F DeepCleanse Refreshening Fluid.
(This is a liquid cleanser/makeup remover).
2. Pierre Chenxu No.69 Licorice Toner.
3. Pierre Chenxu No.87 Azulene Active Cream.
4. Pierre Chenxu No.090 Wondergel Ginseng AC Cream
(Anti-Acne CReam).

Please follow and adhere to the following instructions closely:

A) Every morning:

Step 1 : Pour No.17/F on a cotton pad, and wipe face and
neck gently to remove staled grease, dirt, dead-cells and any
debris.

Step 2 : Rinse thoroughly with running water(Use a facial
sponge if desired, but wipe gently and lightly).

Step 3 : Tap dry with a tissue(avoid using towel for time being).

Step 4 : Apply No.69 with a cotton pad, by tapping lightly on
face and neck, and wait a while for it to dry and absorbed,
before going to next step.

Step 5 : Apply No.090 sparingly on acne spots(or acneic
areas). Apply No.87 on all other unaffected areas.

For the time being, please avoid applying any makeup(except
eyebrow and lip areas).

B) Every Evening/Night:

Step 1: Pour No.17/F on a cotton pad, and wipe off makeup
first(in your case eyebrow and lip areas only, if you do
apply), then wipe face and neck gently to remove staled
grease, dirt, dead-cells and any debris.

Step 2 : Rinse thoroughly with running water(Use a facial
sponge if desired, but wipe gently and lightly).

Step 3 : Tap dry with a tissue(avoid using towel for time being).

Step 4 : Apply No.69 with a cotton pad, by tapping lightly on
face and neck, and wait a while for it to dry and absorbed,
before going to next step.

Step 5 : Apply No.090 sparingly on acne spots(or acneic areas).
Apply No.87 on all other unaffected areas.

Other Hygiene/Health Aspects to observe:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. Tie your hair up when sleeping to avoid bacteria from hair
from spreading to your ruptured skin.

2. Change your pillow case as often as possible - preferably
cover it with a clean towel and change it daily.

3. Wash your hair daily if possible(avoiding the shampoo from
flowing down on your face!!!).

4. Avoid squeezing, fiddling and pricking your acnes(or face)
with bare hands/fingers.

5. Avoid the sun.

6. Avoid fried food.

7. Drink plenty of plain water.

8. Go to bed on time and sleep at least 7 to 8 hours nightly.
Do not stay up late at night.

9. Avoid dusty places or places near chemicals, where chemical
gas/fumes are likely to be present.

Above steps are also applicable for your hands and other parts
of the body as well.

Samples will be sent to you this week, and should receive them
next week. Keep in touch with us, and let us know of your
improvement, or if you have any further clarification to make,
please don't hesitate to email me.

Best Regards: Pierre
________________________________________

Question
I have a question. Isn't a suntan just a precursor to a sunburn?
In other words, wasn't every sunburn a suntan a few hours
earlier. What does suntan lotion do? My theory is that it does
nothing more than lengthen the amount of time before everything
happens. If you would get a tan in 40 minutes and a burn in 60
w/o lotion, then wouldn't putting on #2 just make it take 80
minutes to tan and 120 to burn? Please help me. If you have
a web page i could reference it would be great

thanks

cameron

(submitted by alias: Cameron)

Answer
Hi Cameron,

A suntan may usually appear as a precursor to a sunburn,
but not always, and not under all circumstances.
The sun's rays comprise a portion of spectrum classified by
scientists as Ultra-Violet(UV) rays. These are further
divided into UV-A, UV-B and UV-C. UV-C is mostly shielded
by the earth's ozone layer, leaving UV-A and UV-B to
penetrate our atmosphere. UV-A penetrates both our epidermis
and dermis skin layers. Since the basal layer(the last layer)
of the epidermis and the prickle-cell layer(the first layer)
of the dermis both contain melanin cells(melanocytes), these
two layers of cells are stimulated simultaneously by the UV-A
rays to produce more melanocytes - a natural chemical
reaction geniously created by our God Almighty - to prevent
the harmful effects of the UV rays against the underlying
cells. In other words, the hyper-production of more melanin
(melanin means black) cells is to provide a more opaque skin
layer(which otherwise would be more translucent) in order to
obstruct penetration of the UV rays. It is for this reason
(that is, two layers of skin containing melanin cells being
stimulated to multiply melanocytes simultaneously), that UV-A
causes sun-tanning. Tanning-beds in beauty salons also emit
UV-A rays to produce quick tans. However, the energy in UV-A
is weaker than in UV-B. That is why the tan doesn't last long
(ususally disppeared after one to three weeks), and that is
also why UV-A doesn't cause sun-burn on its own.

On the other hand, UV-B's energy is much greater than UV-A's,
and thus, it causes the burning sensation very quickly.
However, the penetration level of UV-B is only upto the
epidermis. Thus, UV-B causes only the epidermal layer(that
is, only one layer) to multiply the production of its melanin
cells. That is why a tan is not produced as instantly as
exposure to UV-A rays. Due to its high energy, UV-B rays once
absorbed into the skin do not deplete quickly, but retained
for a long time. UV-B accumulates to cause a slow 'tan' which
results in delayed pigmentation of the skin(that is, those
unsightly brown blocky patches).

Since both UV-A and UV-B are found in the sun's rays, exposure
to the sun will cause the skin both to tan and to burn - the
tan manifesting faster than the burn as explained above -
appearing as if a tan always precedes a burn. But one can
obtain a tan without a burn(or less degree of burn) by the
following methods:

1. By exposure to a salon's sun-tanning bed(which emits only
UV-A rays).
2. By applying a sunscreen that blocks out only the UV-B
rays(that is preventing a burn caused by the UV-B rays but
allowing the UV-A rays to penetrate the skin to cause the
tan). Some screens even contain active ingredients to speedify
the taning effect, by amplifying the UV-A rays penetration.
There are also suntan products which can amplify tanning -
and within 10 to 15 minutes - under room lighting, without
exposure to the sun. Such products are often named as suntan
lotions(milk, or the like). Note that if one doesn't want to
have a tan as well, then he/she should not apply a suntan
lotion, but a broad spectrum sunscreen lotion instead(meaning
a sunscreen with total block action - blocking UV-A and UV-B).

So do not get mixed up between suntan and sunscreen products.

Sunscreens are available in various strengths, measured in
SPF terms. SPF stands for Sun Protection Factor.
The SPF of a sunscreen is determined by sampling a group of
people by the following steps(usually not less than 25 people
of various skin color tone):

1. The human samples are made to expose their back to the
sun. Most parts of the body are covered, except the parts
which are to be tested and measured. Let's say there are 5
sunscreen products(named A, B, C, D, and E) of varying
anti-UV strengths which need to be measured. Then the person's
back will have 6 holes, cut out from the shirt(or any covering)
exposed to the sun. One hole will have nothing applied on it.
The other five holes will each have one of the five sunscreens
applied, and marked.

2. After every 5 or 10 minutes, the back of the human samples
are examined to determine if a burn has occurred.
To elaborate, let's say after examining one of the human
samples, the unprotected part was found to blister in 10
minutes, while the other 5 parts(on the back of the same
person) each took 100, 150, 180, 200 and 220 minutes
respectively to form the first sign of blisters. The SPF is
then computed by dividing each of these 5 values by 10
minutes(when it was unprotected). Thus, the SPF value for the
5 sunscreens will be:

Sunscreen A = 100/10 = SPF 10
" B = 150/10 = SPF 15
" C = 180/10 = SPF 18
" D = 200/10 = SPF 20
" E = 220/10 = SPF 22

It can be comprehended clearly that SPF is therefore a
measure of the number of times a sunscreen will be able to
protect a person before blister occurs as compared to his/her
exposure to the sun if unprotected.

3. The readings of all the human samples are noted, averaged
and compiled, to provide the SPF values for the respective
sunscreens measured.

Since SPF is a measure of the number of times(and not
absolute hours or minutes), and since such measurement is
conducted on sampling of a small group of people, and taking
their mean value(averages), note that a darker complexioned
person may apply, say, an SPF 10 sunscreen and yet is better
and more effectively protected than one who is fairer-skinned
and wearing an SPF18 sunscreen. Why so? Well, if the darker
complexioned person were to take 30 minutes to blister under
unprotected exposure, then applying an SPF 10 sunscreen will
enable him/her to expose for 300 minutes before blistering
occurs. On the other hand, the fair-skinned person may get
blisters after only 10 minutes of unprotected exposure. So,
an SPF 18 sunscreen will only protect him/her for 180 minutes.
Moreover, every person is different constitutionally. A
person's skin, although applying the same sunscreen, may not
react exactly in the same manner as that which was determined
from the small group of human samples. Yet another factor. The
sampling that was conducted in a cold 4-seasonal climate(even
if done during summer time with lots of sunlight) may not
apply well to people living in the tropical and sub-tropical
climates. Therefore, one may find an SPF sunscreen good for
protecting him/her upto, say, 200 minutes of exposure in a
colder country, but realized that the same sunscreen could
not last longer than 100 minutes at one of the beaches in
Singapore, Malaysia, or Australia. Different times of the year
within one country will also have different amount of UV-A and
UV-B rays, and as such, a sunscreen's protection time will
vary according to the time of the year.

UV-rays are also absorbed and retained in swimming pools and
in sea-water for some time even after the sun has set.
Therefore, swimming immediately after sunset may not be all
that safe as most people presumed. I would recommend morning
swim instead.

Staying at home or carrying an umbrella does not mean that
one is not exposed to any UV rays absolutely. The ground,
the walls, the glass, the surroundings, all reflect light and
UV-rays. So long we are able to see any object(that is objects
are visible to our eyes), there are UV rays present, though in
different degree depending on the time of the day and year.
This is so because we can see only when there's visible ray,
and visible ray is just next to the UV-ray spectrum. Therefore,
whenever there is visible ray, there are UV-rays.

Moreover, higher SPF sunscreen doesn't necessarily mean better
and more effective(especially those containing inorganic
substances). Higher SPF requires higher concentration of UV
absorbers in the sunscreen, and thus a higher risk of
developing skin reaction and allergy. Sunscreens using organic
substances such as TiO2(Titanium Dioxide) is safer, not only
in that it is organic and less susceptible to allergy, but it
also works by deflecting the UV-rays, rather than absorbing
them and retaining on the skin's surface as in cases of
inorganic UV absorbing agents. I believe such retention of
UV-rays on the skin's surface(especially those with higher SPF)
will in the long run promote skin complications too. However,
unfortunately, organic substances alone do not seem to work
more effectively than the synergistic effect of skillfully
combining both organic and inorganic substances.

I hope the above explanation will help you and others in
buying suncare products and in the choice of their relative
SPF values more intelligently and more rationally.

Best Regards: Pierre

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