Podcast Summary: Short Wave — Why U.S. Sunscreens Don't Measure Up (August 29, 2025)

Episode Overview

In this episode of Short Wave, host Regina Barber is joined by Dr. Michelle Wong, chemistry PhD and creator of Lab Muffin Beauty Science, to explore why sunscreens in the United States fall behind those in other parts of the world. They discuss the science of UV protection, regulatory barriers, misconceptions about sunscreen safety, and practical advice for listeners looking to protect their skin effectively. The episode conveys complex science in an accessible, engaging style, using humor and clear analogies.

Key Discussion Points and Insights

1. The Science of Sun Protection and Sunscreen Basics

• Daily Use and Risks of UV
  • Regina opens with a morning wellness checklist that always includes sunscreen, highlighting growing public awareness of sun protection.
  • Dr. Michelle Wong explains:
    • UV radiation comes as UVA (longer wavelength, deeper penetration, linked to aging and cancer) and UVB (shorter wavelength, higher energy, causes burning and also contributes to cancer and aging).
    • "Sunburn starts when the DNA inside your skin cells absorb UV radiation." (Michelle Wong, 00:55)
• Changing Understanding of UVA
  • The science only recently identified UVA as a significant health risk, leading governments in the EU and elsewhere to upgrade sunscreen standards to address both UVA and UVB (01:34).

2. Limitations of U.S. Sunscreen Regulation

• Regulatory Differences

  • In most countries, sunscreen is considered a cosmetic, but in the U.S. and Australia, it's regulated as an over-the-counter drug (03:58).
  • This means every new ingredient must undergo extensive safety, efficacy—and crucially, animal—testing.
    • “In the US with any new drug ingredient, there’s a huge process that needs to be gone through... there’s also a requirement for animal testing... and that’s generally the biggest sticking point.” (Michelle Wong, 04:30)
  • Australia, despite similar regulations, approves new sunscreen ingredients faster, indicating the process itself (not just the category) slows U.S. innovation (04:30).

• Lack of New UV Filters

  • It's been over 20 years since a new UV filter was approved in the U.S. (01:53; 05:02).
  • Most U.S. products offer strong UVB but comparatively weak UVA protection.

3. What "Broad Spectrum" Means and Why It Matters

• Differing Standards

  • In the U.S., "broad spectrum" only requires the critical wavelength (370 nm) standard—a technical but minimum threshold for UVA protection.
  • In Europe and Australia, sunscreens must ALSO have at least one-third the UVA protection compared to their SPF (SPF is typically a measure of UVB protection):
    • "In the US they only need that 370 nanometer criteria… but in Australia, the EU, the rest of the world, you need that plus... one third SPF rating." (Michelle Wong, 07:17)

• SPF Myths and Proper Application

  • SPF 30 vs. SPF 60: The difference is more significant in terms of raw UV filtered than most realize, but only if applied perfectly.
    • “SPF 30 will let in twice as much UV as SPF 60… but that only works if you’re applying it perfectly with a massive amount, which most people don’t.” (Michelle Wong, 07:45)
  • Higher SPF is more forgiving for "imperfect" application, the norm for consumers.

4. Chemical Ingredients: The Global Discrepancy

• What’s Allowed Where?

  • U.S. sunscreens: Limited to older UV filters (zinc oxide, titanium dioxide, and a handful of dated “chemical” blockers).
  • Rest of the world: Newer filters provide broader, more stable UVA and UVB protection, tailored to be safer and more effective (08:49).
  • "The newer ones tend to absorb more of the longer wavelengths going into UVA... Those are the ones that aren’t allowed in the US." (Michelle Wong, 09:55)

• Safety Concerns and Testing

  • Modern filters are designed to be less likely to penetrate the skin and to minimize systemic exposure.
  • Other countries accept new safety testing methods (cell assays, “organs on chips”), whereas the U.S. still mandates animal studies.
    • “At the moment, the FDA still requires the animal studies, which has been the big hurdle... in places like Europe, animal testing is banned for cosmetics...” (Michelle Wong, 10:07)

5. Are Sunscreens Really Safe? Public Fears and Scientific Reality

• Lack of Evidence for Harm

  • Dr. Wong addresses online fears:
    • "A lot of the risks of sunscreen, the safety issues, those are mostly theoretical. The advantages are actually things that you see in humans." (Michelle Wong, 12:50)
    • She cites clinical studies showing significant reduction in skin cancer and skin aging with regular use.

• Ingredient Safety

  • “In any well regulated marketplace, sunscreen should be one of the safest things that you can put on your skin... as long as you’re not putting on a ridiculous amount... or eating it or inhaling a lot...” (Michelle Wong, 12:00)

6. Practical Advice for U.S. Listeners

• How to Use Sunscreen Effectively
  • Precise application:
    • 1 teaspoon per limb, body front, body back, and for head/neck/ears; ¼ teaspoon just for the face.
    • Reapply every 2 hours, and always after swimming or toweling off.
    • Don’t leave sunscreen in hot environments (cars, direct sun); heat degrades effectiveness (13:50).
  • Barriers to perfect protection:
    • Most people under-apply and forget to reapply; thus, combining sunscreen with clothing protection (UPF shirts, hats, sunglasses) is wise.
    • "The best sunscreen you can wear is the one that you enjoy, one that you can apply a lot of regularly." (Michelle Wong, 14:56)

Notable Quotes & Memorable Moments

• On UVA Danger
  • “Tanning beds are more strongly connected to skin cancer than smoking is to lung cancer.”
    — Michelle Wong (06:10)
• On Regulatory Hurdles & Hope
  • "I try to have hope, but at the same time, I have been hoping for this for the last 15 years."
    — Michelle Wong (11:35)
• On Sunscreen Efficacy Fears
  • “There’s never really been someone who’s had a massive health effect because of sunscreen, apart from things like allergic reactions.”
    — Michelle Wong (13:28)

Important Timestamps

• 00:36–01:16 — Dr. Wong introduces sunscreen science basics
• 01:34–02:06 — How sunscreen regulations have changed internationally, but not in the U.S.
• 03:50–05:02 — Why U.S. regulations create barriers to new sunscreen ingredients
• 06:11–07:30 — "Broad spectrum" standards: U.S. versus the world
• 07:45–08:36 — SPF math and the reality of real-world application
• 08:49–10:07 — Ingredient differences between U.S. and international sunscreens
• 12:00–12:34 — Safety of sunscreen ingredients; debunking dangers
• 13:44–14:56 — Step-by-step guide to effective sunscreen use

Conclusion

The U.S. lags behind much of the world in sunscreen innovation due to regulatory barriers, especially the ongoing requirement for animal testing and the categorization of sunscreen as a drug. While current U.S. sunscreens are still safe and effective if used properly, they offer less comprehensive UVA protection than many international products. Dr. Wong encourages listeners to focus on proper sunscreen application and to supplement with sun-protective clothing, while also dispelling myths about the dangers of sunscreen itself.

If you're frustrated by the limited selections in the U.S., know the issue is regulatory inertia, not a lack of science or intent. For now, diligent use (and re-application) of what is available remains your best defense.

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