Part I: Sunscreen 101 - filters, amt to use, application and more.

Part II: Battle of the Sunscreens can be found here!

When I first started my research on this, it was just meant to be an easy read to compare several sunscreens and perhaps touch a'lil on ingredients. I have done a post on sunscreens before but looking back, that was truly an amateur piece and I apologize. Most of the stuff there are accurate but nothing was in-depth and it was really a touch-and-go piece. Not good, Pea lol. 

So, I am here today to try and break down what I have researched into little bits to make this more coherent. I am by no means, an expert. Just someone who really loves studying about anything skincare-related. 

I started my sunscreen journey really young - around 12 or 13 years old, thanks to Seventeen, Teenage and Cleo magazines. I would pour over them voraciously and eat up any tips and tricks the mags provided. I truly wish I hadn't cause a lot of them are bullshit, upon looking back now. Advice on using astringent toners for oily skin, wrong treatments to target blemishes etc. were just a few of them. However, they started me on using sunscreen from young so that I am grateful for. 

There are a gazillion sunscreens out there, each claiming to have SPF or protection higher than the other. I would stand befuddled at the counter just trying to figure out all the different terms and if its really better to have on an SPF of 100 LOL (the answer is no.) 

Before I can delve into the different ones I used, I thought I would talk about ingredients first and this time, slightly more in-depth, and include other stuff regarding sunscreen. 

I included the main ingredients found in sunscreens and the other names they go by. You can simply compare that to your own sunscreen's ingredient list. HAVE FUN LOLOL 🎊🎉

I have also included other properties of the ingredients.

(Most filters' info is taken from but I have included my own research from other sources)

Sunscreen Filters

And before I can even dive into filters, I have to talk about what filters filter right? (LOL OMG THIS POST IS NEVER GONNA END FAK LOLOL)

UV rays are generally separated into UVA and UVB rays. UVB rays are the main cause of damage to skin's surface - sun burn & reddening of skin. UVB rays DO NOT penetrate thru glass. 

UVA rays are the ones that are truly hateful. It is the one that causes skin aging and wrinkles, and also the dominant tanning rays. They are present in equal intensity during daylight hours and are able to pass through clouds and glass. This just means I'm gonna say......pls wear sunscreen on the plane!!!!! 

UVA are split into UVA1 (long) and UVA2 (short) with UVA1 rays being able to penetrate deeper into the skin. 

We generally want to protect against all kinds rays so when the words 'broad-spectrum protection' appear, it means that it protects against a wide spectrum of the UV rays. 

UVA1: 340-400nm
UVA2: 320-340nm
UVB: 290-320nm

Chemical UV filters are synthetic chemicals that have narrow ranges of UV protection and often requires more than 1 filter to cover the entire range/spectrum. 

Physical UV filters are insoluble mineral particles that exist in nature and protect against UV rays in a broader range. However, a mix is still better when it comes to covering entire range.

Physical Filters

Titanium Oxide:

  • also known as: 
    • CI 77947
    • Nogenol
    • Pigment white 4
    • Zinc gelatin
  • UV-reflective properties
  • remain stable when exposed to UV rays
  • reflects and blocks/protects against UVB and UVA2)

Zinc Oxide

  • also known as:
    • CI Pigment white 6
    • Titanium peroxide
    • CI 77891
    • Pigment white 6
  • mostly manufactured synthetically
  • scatters and reflects UV rays so they don't touch surface of skin
  • absorbs and protects against both UVB and UVA1/2)

Chemical Filters


  • also known as:
    • Butyl methoxy-dibenzoyl-methane
    • Parsol 1789
    • Eusolex 9020
    • Escalol 517
    • BMBM
    • BMDBM
  • limited skin penetration (no evidence of hormone disruption)
  • requires stabilizers: octocrylene, oxybenzone, HelioplexTM
  • absorbs UVA1


  • also known as:
    • Octyl salicylate
    • Ethylhexyl salicylate
    • EHS
    • Escalol 587
  • helps stabilize Avobenzone but undergoes some degradation to sunlight
  • has emollient and water-resistant properties
  • oil-soluble (but can be a little greasy)
  • absorbs UVB rays


  • also known as:
    • Homomethyl salicylate
    • HMS
  • aids penentration of sunscreen and once the ingredient has been absorbed, homosalate accumulates in our bodies faster than we can get rid of it, becomes toxic and disrupts our hormones***
  • oil-soluble
  • absorbs UVB rays

***(It is rated safe for use in low amount but studies do show that sunlight breaks it down into harmful byproducts. My take is just to skip it if u can.)


  • also known as:
    • Octyl methoxy-cinnamate
    • OMC
    • Ethylhexyl methoxycinnamate
    • EHMC
    • Escalol 557
    • Parsol MCX
    • Eusolex 2292
    • Tinosorb OMC
    • Uvinul MC80
  • readily absorbed by skin and chemical's effects on estrogen can be harmful for humans*** and wildlife
  • requires stabilizer
  •  absorbs UVB rays

***(it is rated safe in low amounts but would just skip it esp. if you're pregnant!)


  • also known as:
    • Benzophenone-3
    • BP3
    • Uvinul M40
    • Eusolex 4360
    • Escalol 567
  • acts as stabalizer
  • highest percentage skin penetration but not harmful in small amount applied topically
  • harmful to coral reefs
  • might cause allergic reactions
  • absorbs UVB & UVA2 rays


  • also known as
    • Uvinul N539T
    • OCR
    • Eusolex OCR
  • acts as stabalizer
  • seemed to increase skin's photosensitivity to sun and increase free radicals (need more studies)
  • absorbs UVB & UVA2 rays

Tinosorb S

  • • also known as
    Bis-ethyl-hexyloxyphenol methoxyphenyl trazine
    Escalol S
    Tinosorb S Aqua
  • acts as stabalizer mostly
  • minimal skin penetration but NOT FDA approved
  • absorbs UVB & UVA1/2 rays

Uvinul A PLus

  • also known as
    • Diethylamino hydroxybenzoyl hexyl benzoate
    • DHHB
  • provide some protection against free radicals
  • absorbs UVA1 rays


  • avobenzone + oxybenzone
  • not waterproof
  • absorbs UVB + UVA1
  • patent held by Neutrogena

Mexoryl SX

  • also known as:
    • Terephthalylidene dicamphor sulfonic acid
    • TDSA
    • Ecamsule
  • water-soluble
  • doesn't degrade in sunlight
  • protects against UVA1/2 rays
  • patent held by L'Oreal 
  • Anthelios SX - broad spectrum sunscreen most recently approved by FDA that includes the ingredient Mexoryl SX (Mexoryl SX + avobenzone + octocrylene)

Mexoryl XL

  • also known as:
    • Drometrizole trisiloxane
    • Ecamsule
  • Oil-soluble
  • protects against UVA2 rays
  • used synergistically with Meroxyl SX

I'm listing these as individual ingredients but quite rarely would u find just 1 of it in a sunscreen as some of them are unstable - which means they will degrade quickly. This is when stabilizers are added to prevent this from happening and stabilizers can also come in the form of filters which is why I am not listing which is unstable. Less confusion, I hope.


Antioxidants in sunscreen can to some degree, neutralize damaging 'free radicals'. Free radicals are unstable, highly reactive oxidized molecules believed to cause tissue damage. However, the impact is still not universally accepted. 


PA ranking refers to the amount of protection the sunscreen offers from UVA rays while SPF ranks protection from UVB rays. 

PA rankings are listed with the number of '+'. The more '+' symbols, the more protection from UVA rays - the rays that may cause longterm skin damage and age the skin overtime.

Why physical sunscreen is preferred over chemical:

Physical sunscreen has the ability to protect against a broad spectrum compared to chemical filters which are only able to protect against either UVB or UVA rays and more than 1 chemical filter is often required to get full protection.

Physical sunscreen creates a shield on the skin to reflect away rays whilst chemical sunscreen transform the rays into heat instead.

Physical sunscreen can be applied after moisturizer and can work immediately. However, chemical filters take up to 30 mins to work. Many people think that chemical sunscreen needs to be applied directly onto the skin to work but the truth is, it doesn't need to be absorbed for it to work but it does help the protection last longer. 

Physical filters are often more stable unlike chemical sunscreen which requires stabilizers. 

Chemical sunscreens are also often the cause of skin irritation or allergic reactions. 

Application + Reapplication: 

I apply my sunscreen using rubycell puff mainly because of the additional benefit of it being anti-bacterial. I still wash it after about 5 uses cause idw to accumulate bacteria on it and then use it straight on my face.

I apply my sunscreen by placing it on my face first before using the puff to pat it in. I normally do this 2-3x to ensure that I cover EVERY BIT of my face, before letting it set for awhile and then continuing with my makeup. 

I also fold the puff into two, dab some into sunscreen and pat around my eye areas. If your eyes are sensitive to chemical filters, try using a physical one around instead! 

Even if I'm indoors the whole day, I do this. I don't step out to any sunlight, be it any time of the day, till I put on my sunscreen. UVA rays pass through glass so even if ur window is closed and your curtains are not, UVA rays are still getting thru. 

Patting on sunscreen is very very important. Don't rub your sunscreen! Sunscreen is supposed to sit in an even layer on the surface and rubbing or buffing your sunscreen will affect the effectiveness.

I'm a total freak when I'm home. My curtains are drawn 24/7 LOL

Even then, UVA rays still can pass through cloth so we really are never safe, are we? HAHAHAHA No judging, you guys. 

The million-dollar question is often, 'how do I reapply sunscreen over makeup?' 

I think there are more to it than just that. 

• Are u indoors mostly? (Going out for lunch/leaving office at around 6pm) 
• Even if you're indoors, are u seated by a window thats not closed/covered up? 
• Did u perspire profusely from the time u apply ur sunscreen? 

Reapplication every 1-2 hours is highly necessary if you are doing outdoor sports and perspiring profusely. I assume when you're doing outdoor sports and all, you're not really wearing makeup (pls don't lol) so reapplication isn't an issue here. 

According to the Skin Cancer Organization, if your face is UNTOUCHED and you're not perspiring, it IS acceptable to apply sunscreen just once at the beginning of the day. I

However, I did more googling into this and broke it down: 

• Are u indoors mostly? (Going out for lunch/leaving office at around 6pm) - if you did not perspire much during this period, it isn't really necessary but a simple touch up can be done (explained below) 

• Even if you're indoors, are u seated by a window thats not closed/covered up? - u should try and reapply lightly since UVA rays can pass through glass

• Did u perspire profusely from the time u apply ur sunscreen? - yes, reapply if you're perspiring! 

Ok, I'm only referring to face reapplication here. For body, just keep a bottle by your desk/drawer/bag and reapply. No harm done.

For reapplication on face, if you're wearing makeup, it's really quite crazy to remove all of it to put on sunscreen and it's not necessary imo - esp. if you're just touching up from a little perspiration or sitting by the window. 

U can:
1. Get a spray-on sunscreen where you can mist them on and pat it in to avoid minimal interference with make up
2. Get a translucent compact that comes with SPF so u can touch up throughout the day without caking up your makeup

How much sunscreen to wear?

1/4 teaspoon is a good estimate on amount of sunscreen to apply to get an adequate coverage. Unfortunately, we tend to only use 1/3 - 1/2 of the amount of sunscreen needed to achieve the SPF rating on the bottle. So your SPF 30 sunscreen is more like an SPF 10-15 with the average application. APPLY MOOORRREEEE.

Sunscreen's SPF also do not have an addictive effect; meaning SPF 50 + SPF 20 DO NOT make it SPF 70. Sunscreen limit the amount of UV rays that get through but you can't really raise it above the limit of the highest amount....which leads me to my next statement.

Sunscreen manufacturers are now not allowed to really claim SPF rating as more than 50 and only at 50+. Procter & Gamble tested a competitor’s SPF 100 product at five different labs, the results varied between SPF 37 and SPF 75. They wrote a letter to the FDA regarding this and it is concluded that SPF values should be capped at 50+.

The FDA has long contended that SPF higher than 50 is misleading. Australian authorities cap SPF values at 30; European and Japanese regulators at 50, and Canada allows a maximum of 50+. (This info is taken off

Make-up as sunscreen

A lot of foundations, bb-cream and base products all come with sunscreen and a common answer when I ask if someone has a habit to wearing sunscreen is - My foundation got SPF!

Unfortunately, dermatologists have clarified that makeup base alone does not provide enough coverage. You will actually need about 7x the normal amount of foundation and 14x the normal amount of powder to get the SPF stated on the label. LOL Imagine the cakinesssss omg. 

Wheeeee. This Sunscreen 101 Guide took way longer than expected. I hope it has been useful and see you soon on the Battle of Sunscreens post! Part II: Battle of the Sunscreens can be found here!