Brief History of Sunscreen
Did you know sunscreen was originally designed to help you tan rather than protect you?
Sunscreen has been used in Australia since the 1930s, initially marketed to help people tan rather than prevent sun damage. With an SPF of just 2, early formulas like Hamilton’s “sunburn vanishing cream” promised you could “sunbathe in comfort.”
For most of the 20th century, Australians slathered on baby oil, coconut oil, and even olive oil, unknowingly turning themselves into human rotisseries. Back then, people believed only UVB rays caused burns, while UVA just gave you a nice, bronzed glow. Spoiler alert: UVA actually penetrates deeper, speeding up wrinkles, sunspots, and yep—skin cancer. It wasn’t until the 70s that scientists realized the truth.
This led to broad-spectrum sunscreens in the 80s and the game-changing SPF rating system, which finally let Aussies measure real sun protection. But here’s the real shocker: it wasn’t until 1999 that research proved sunscreen actually prevents skin cancer—reducing squamous cell carcinoma by 60% and nearly halving melanoma rates!Combined with public health campaigns like Slip! Slop! Slap!, Australians now have access to highly effective sunscreens that protect against both sunburn and long-term skin damage.
Why Should I Use Sunscreen?
Although the sun is necessary for life, too much sun exposure can lead to adverse health effects, including skin cancer. In Australia, around 400,000 people are diagnosed with non-melanoma skin cancer (NMSC) each year, and about 16,000 are diagnosed with melanoma. Skin cancer is the most common cancer in Australia, accounting for about 80% of all new cancer diagnoses, but it is largely preventable through a broad sun protection program. It is estimated that 90 percent of non-melanoma skin cancers and 65 percent of melanoma skin cancers are associated with exposure to ultraviolet (UV) radiation from the sun.
By themselves, sunscreens might not be effective in protecting you from the most dangerous forms of skin cancer. However, sunscreen use is an important part of your sun protection program. Used properly, certain sunscreens help protect human skin from some of the sun’s damaging UV radiation.
What is Sunscreen?
Sunscreen, also known as sunblock, sun lotion or sun cream, is a photoprotective topical product for the skin to reduce the intensity of the sun’s ultraviolet (UV) rays entering the skin and damaging vulnerable skin cells.
Sunscreens come as lotions, sprays, gels, foams (such as an expanded foam lotion or whipped lotion), sticks, powders and other topical products. Sunscreens are common supplements to clothing, particularly sunglasses, sunhats and special sun protective clothing, and other forms of photoprotection (such as umbrellas).
How Sunscreen Works
Sunscreen is one method of protecting your skin. Sunscreen ingredients work in two ways: reflectingand/or absorbing ultraviolet (UV) radiation to help stop it from reaching the skin.Some sunscreens utilise both absorbing and scattering ingredients.
What Is in Sunscreen
There are two main parts to all sunscreens. The active ingredient and the emulsion.
Active Ingredient
Sunscreens are made from a variety of ingredients, the most important being sun filters that block the UV rays and protect your skin from the sun. These are called the active ingredients. These come in two categories: UV absorbers and UV reflectors.
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UV absorbers are chemicals that absorb UV radiation and convert it to a very low level of heat. So low most don’t notice it, but a small proportion of people do report sunscreens make them feel uncomfortably warm.UV absorbers use ingredients such as Oxybenzone, Octocrylene, 4-Methylbenzylidene camphor and Butyl methoxy dibenzoylmethane.
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UV “reflectors” are mostly made up of oxides, like zinc oxide and titanium dioxide, that absorb and scatter UV radiation. There is normally more than one and often up to six or more active ingredients in most sunscreens.Examples of scattering ingredients include Zinc Oxide and Titanium Oxide.
There is normally more than one and often up to six or more active ingredients in most sunscreens. Note: Currently there are 33 active ingredients approved by the Therapeutic Goods Administration (TGA) as sunscreens in Australia
Emulsions
The emulsion – the lotion, milk, cream, oil, foam or gel – is what carries the active ingredient. It is usually made up of some combination of oil and water, plus other goodies. These are important as they preserve the product so it lasts on the shelf or in your cupboard. They also help with water resistance, influence how the sunscreen feels and smells, and how well it binds to the skin. https://www.cancercouncil.com.au/news/how-does-sunscreen-work/
How Does UV Radiation Affect My Skin? What Are the Risks?
There are two kinds of UV rays from the sun that people need protection from: UVA and UVB.
On the electromagnetic spectrum, UV light has shorter wavelengths than visible light, so your eyes can’t see UV, but your skin can feel it.Some effects are immediate, while others may not show up for years.
Think of it this way:
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UVB has a B for “burning” – these rays cause sunburn, aging, and potentially skin cancer
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UVA has an A for “aging” – these rays cause wrinkles and potentially skin cancer (although less than UVB) after repeated exposure. UVA rays make up more than 90% of all UV radiation, and penetrate clouds and glass, year-round.
Another type is UVC. UVC radiation from the sun does not reach the earth’s surface because it is blocked by the ozone layer in the atmosphere. Thus, the only way that humans can be exposed to UVC radiation is from an artificial source like a lamp or laser. https://www.skincancer.org/risk-factors/uv-radiation/.
Why You Need to Know about SPF
Sun Protection Factor or SPF stands for ‘sun protection factor’ – and we often see it used in conjunction with a number (such as ‘SPF30’).
TGA defines SPF as an indication of how effective sunscreen is against sunburn. The higher the number, the stronger the protection, as tehtabel shows:
How do they work out the rating? According to the TGA: If skin protected with sunscreen takes 300 seconds to burn [with sunscreen applied liberally], but only 10 seconds to burn without sunscreen, the SPF is 300/10, which is 30.
It's also important to note that in Australia, sunscreen is considered a "therapeutic good. Compared to many other countries, Australian SPF ratings are considered stricter and generally prioritize higher SPF levels due to the high UV radiation levels in the country, meaning that Australian sunscreens often have a minimum SPF of 30+ or 50+ and are heavily regulated by the Therapeutic Goods Administration (TGA), making them considered some of the most reliable on the market globally
Is higher SPF the better?
No sunscreen blocks all UV rays yet, which is why it is important to practice other sun-protective measures. While sunscreens with higher SPF block slightly more UV rays, they last the same amount of time as a lower-number SPF sunscreen and should be reapplied after two hours.
What SPF Doesn’t Mean
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Many people assume that a higher SPF (Sun Protection Factor) provides complete sun protection or reduces the need for reapplication. However, SPF only measures protection against UVB rays—the rays responsible for sunburn—not UVA rays, which cause skin aging and some cancers.
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SPF does not reflect the time that can be spent in the sun without getting sunburned, as various factorsimpact the amount of solar radiation. It measures the amount of sunburn protection and allows comparison between different sunscreens.
What does the plus after the SPF rating mean in Australia?
The plus in the SPF rating indicates that the actual protection is higher than the number indicates. For instance, a rating of SPF30+ will indicate that the SPF is higher than SPF30, while SPF50+ indicates that it’s higher than SPF50.
Why You Need to Know about Protection Grade of UVA or PA
You’vedefinitely seen the letters ‘SPF’ on your sunscreen bottle, but what about ‘PA’? The PA+ rating system is another measurement for sun protection, but what does it stand for and what do all the ‘+’ signs after it indicate?
Some sunscreens, most notably those in Asia, include PA+ rating on their products. The letters “PA,” which stand for “Protection Grade of UVA,” followed by plus signs (PA+, PA++, PA+++ and PA++++) that appear on labels are a rating system developed in Japan to represent how much UVA protection a product offers. This UVA “grading” system is now used throughout Asia and is becoming increasingly popular in Europe, but it’s not in Australia
The sun’s UVA rays do not cause sunburn; rather, they cause skin to turn brown. UVA rays are known as the sun’s silent killers because you don’t feel them affecting skin. Despite the lack of pain associated with UVA rays, they penetrate deeply into skin, causing a somewhat different type of damage than UVB rays.
This is what each PA rating means:
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PA+ = Some UVA protection.
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PA++ = Moderate UVA protection.
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PA+++ = High UVA protection.
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PA++++ = Extremely High UVA protection.
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PA + equals a 2–4 UVA-PF (50–75% protection against UVA rays)
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PA ++ equals a 4–8 UVA-PF (75–88% protection against UVA rays)
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PA +++ equals a 8–16 UVA-PF (88– 94% protection against UVA rays)
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PA ++++ equals a 16 or more UVA-PF (94% or higher protection against UVA rays)
Why You Need to Know about Broad-Spectrum Protection
Broad spectrum SPF refers to sunscreens that protect the skin from both UVA and UVB rays.Its the best choise of sunscreen.
However, take note that the level of UVA protection required for a sunscreen to be considered broad-spectrum differs between countries.
In Australia, broad-spectrum sunscreens must meet stricter rules, ensuring that UVA protection is at least one-third of the SPF value. This ensures broad-spectrum sunscreen in Australia truly protects against both UVA & UVB, reducing premature aging, sun damage, and skin cancer risk.https://cdnmedia.eurofins.com/apac/media/601423/new-australian-spf-and-uva.pdf
In the United States, broad-spectrum sunscreens only need to pass a wavelength test, meaning UVA protection is not directly linked to the SPF number. As a result, some US sunscreens may not offer as much UVA protection as those approved in Australia. https://cdnmedia.eurofins.com/apac/media/601376/fda-broad-spectrum.pdf
So, while broad-spectrum always means protection against UVA and UVB, Australian regulations ensure higher and more reliable UVA protection compared to the US.
Other Sunscreen Ratings
UVA Seal
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Used in: Europe, Australia
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Method: evaluates PPD using an in vitro model that attempts to be as similar to in vivo as possible, plus a critical wavelength standard
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Ratings:
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Just one symbol is used: the letters UVA inside a circle
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The sunscreen’s UVA protection level must be at least ⅓ of its SPF number It must have a critical wavelength greater than or equal to 370 nm
Star System
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Used in: UK
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Method: evaluates how well a sunscreen protects throughout UV spectrum (compares UVA protection against UVB protection)
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Ratings:
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3 stars equals 0.60 – 0.79 protection from UVA rays compared to UVB
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4 stars equals 0.80 – 0.89 protection from UVA rays compared to UVB
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5 stars equals 0.90 or more protection from UVA rays compared to UVB
Resources
https://www.fda.gov/radiation-emitting-products/tanning/ultraviolet-uv-radiation#:~:text=UVA%20rays%20have%20the%20longest,a%20small%20amount%20of%20UVB.
