Deciphering the label on your sunscreen bottle

Every summer, millions of Australians lather up with sunscreen. But what are we actually rubbing in to our skin?

If you turn your sunscreen over you’ll find a list of ingredients that is pretty indecipherable to most of us. Some of these ingredients are ‘active’, meaning they do the ‘screening’—that is, filter or absorb UV radiation. The other ingredients are non-active—things like emulsifiers and preservatives, which help stabilise the active ingredients and give the final cream its consistency.

There are currently 33 active sunscreen ingredients that have been approved by the Australian Therapeutic Goods Administration (TGA), and sunscreen manufacturers are required to list all the active ingredients contained in their sunscreens on the label. Here are some of the most common ones.

Organic sunscreens

• Camphor-based compounds
  • Camphor-based compounds filter UVB. 
  • What you might see on the bottle:
    • Benzylidene camphor sulfonic acid;
    • N,N,N-Trimethyl-4-(oxoborn-3-ylidenemethyl) anilinium methyl sulphate;
    • 4-Methylbenzylidene camphor.
• Benzophenone (and derivatives)
  • Benzophenone and its derivatives are commonly used UVB absorbers. 
  • What you might see on the bottle:
    • Benzophenone
    • Benzophenone-2
    • Dioxybenzone
    • Oxybenzone
    • Sulisobenzone
    • Sulisobenzone sodium.
• Benzotriazoles 
  • Benzotriazoles are fairly new broad spectrum sunscreens which scatter, reflect and absorb UVB and some UVA. 
  • What you might see on the bottle:
    • Bemotrizinol
    • Methylene bis-benzotriazolyl tetramethylbutyl phenol.
• Cinnamates
  • Cinnamates, as you can probably tell from the name, are chemically related to cinnamon oil. They’re often used in toiletries and cosmetics as flavouring or fragrance. They’re also good UVB absorbers, hence their use in sunscreens (often in combination with benzophenones). 
  • What you might see on the bottle:
    • Isoamyl methoxycinnamate
    • Octyl methoxycinnamate
    • Cinoxate.
• PABAs
  • PABA stands for para-aminobenzoic acid. Most often you’ll see PABAs listed on your sunscreen bottle as something that isn’t in the ingredients, rather than something that is. That’s because, while PABAs are very good at absorbing UVB, they can cause adverse reactions, such as photoallergy. While PABAs were widely used in early sunscreens, these days, cinnamates tend to be used instead.
  • What you might see on the bottle:
    • Aminobenzoic acid
    • Padimate O
    • Ethoxylated ethyl 4-aminobenzoic acid.
• Salicylates
  • Salicylates are weakly absorbing UVB filters. Some, such as octyl salicylate, are also used to help other UV filters mix into the sunscreen. 
  • What you might see on the bottle:
    • Octyl salicylate
    • Homosalate
    • Isopropylbenzyl salicylate
    • Triethanolamine salicylate
    • Salicylic acid salts (potassium, sodium and triethanolamine).

Inorganic sunscreens

• Zinc oxide and titanium dioxide
  • Zinc oxide (ZnO) and titanium dioxide (TiO₂) are inorganic metal oxides, which are small particles that act as a physical blocker, absorbing and dissipating both UVA and UVB radiation. Usually recommended for people with sensitive skin, these sunscreens are less likely to cause irritation than organic sunscreens. These oxides may be in nanoparticle form, appearing on the label as ‘micronised’.

So now you know a little more about the ingredients in your sunscreen–even if you still can’t quite pronounce them.