"Sunblock" is more than an old-fashioned name for sunscreen. In the United States, it's a prohibited labeling term. The FDA does not allow sunscreen manufacturers to describe their products as "sunblock" — for the straightforward reason that no topical product can completely block the sun's ultraviolet radiation.
Why This Matters
The word "sunblock" sounds reassuringly absolute. It suggests that once the product is applied, UV radiation is stopped by a complete barrier. But that isn't how sunscreen works.
Sunscreen can filter, absorb, and reflect a portion of the UV radiation that reaches the skin. It cannot block 100% of UV rays. Calling a product "sunblock" therefore promises a level of protection that a topical product simply cannot provide.
That distinction is why the FDA prohibited manufacturers from using "sunblock" on sunscreen labels. The restriction was part of a rule announced in June 2011 governing the labeling of over-the-counter sunscreen products in the United States, which took effect in June 2012. The FDA prohibited two other familiar claims at the same time — "waterproof" and "sweatproof" — for the same reason: they imply complete or unconditional performance that the product can't guarantee.
Australia's Therapeutic Goods Administration takes the same position. Australian sunscreen manufacturers also cannot use "sunblock," "waterproof," or "sweatproof" on their labels, because the terms are considered potentially misleading. In both countries, the underlying principle is the same: product language shouldn't imply total protection where total protection doesn't exist.
Public interest in sunscreen language also continues to evolve. A 2018 study examining Google searches across the US, UK, Canada, Australia, and New Zealand from 2004 through 2017 found that "sunscreen" and "sunburn" were the most-searched sun-protection-related terms in those countries, while search interest in "skin cancer" and "melanoma" had actually been declining. Australia showed notably greater search volume for skin cancer and melanoma terms than the other countries studied — consistent with its high melanoma rates. Separately, a 2022 US-focused study found rising search interest in "mineral sunscreen" and "tinted sunscreen" relative to "chemical sunscreen" between 2016 and 2021, reflecting growing interest in sunscreen ingredient types — though regardless of type, none of them is a literal total UV "block."
What to Do Instead
Use the word "sunscreen," and take that wording seriously. It isn't merely the modern replacement for an outdated term — it's a more accurate description of a product that filters, absorbs, or reflects part, but not all, of the UV radiation reaching the skin.
When reading a label or product description, be cautious with language that implies certainty. "Sunblock," "waterproof," and "sweatproof" all suggest an absolute level of protection that regulators in both the United States and Australia consider misleading. The same applies when comparing mineral, chemical, or tinted sunscreens — those labels describe different product categories, but none of them changes the central fact: no topical sunscreen blocks 100% of UV rays.
Key Takeaway
Think of sunscreen as a filter, not a force field. Accurate language supports accurate expectations — and "sunblock" promises something no topical product can actually deliver.
UVTREK reminder: there's no such thing as sunblock. Only sunscreen, applied and reapplied correctly.
U.S. FDA: 2011 rule prohibiting "sunblock," "waterproof," and "sweatproof" claims on OTC sunscreen labels, effective June 2012.
Australia's Therapeutic Goods Administration (TGA): sunscreen labelling regulations prohibiting the same claims.
Whitehead, R. et al. (2018): international comparison of Google searches for sunscreen, sunburn, skin cancer, and melanoma across the US, UK, Canada, Australia, and New Zealand, 2004–2017.
Maghfour, J. et al. (2022): "Evaluating the USA population's interest in sunscreen: a Google Trends analysis," Clinical and Experimental Dermatology.