Water, Expiry & Everyday Choices
The sun may feel like a friend on spring days, but in New Zealand its UV rays are relentless year-round. That’s why smart sunscreen use goes beyond just choosing a high SPF. Small details, like reapplication, product expiry, and knowing your skin type, make all the difference in how well you’re actually protected.
Water-Resistant ≠ Waterproof
Many sunscreens proudly say “water-resistant”, but here’s the truth: no sunscreen is fully waterproof.
- Water-resistant 40 min: protects during light swimming or sweating, but must be reapplied after 40 minutes.
- Water-resistant 80 min: offers longer coverage, but still needs reapplication after towel-drying or extended time in water.
👉 The rule: Always reapply after swimming, sweating, or towel-drying.
Sunscreen Can Expire
Yes, SPF has a shelf life. An expired sunscreen may look or smell fine, but its UV filters can lose effectiveness.
- Check the open jar symbol (e.g., 12M = 12 months after opening, for symbols explanation see our blog Cosmetic Mystery of Information)
- Store your sunscreen in a cool, dry place. Not in the hot car or on the beach towel.
⚠️ Using expired sunscreen is almost like wearing none at all.
Skin Type Matters
Your skin’s natural pigment (melanin) offers some protection, but it isn’t enough. The Fitzpatrick scale shows how different skin tones respond to UV:
- Fair skin: burns quickly, needs high SPF and frequent reapplication.
- Medium to dark skin: burns less often, but is still at risk for pigmentation, premature aging, and melanoma.
✅ No skin type is “safe” without sunscreen.
Hybrid Sunscreens – A Smart Trend
Trending now: hybrid sunscreens, which combine both mineral and chemical filters.
- Mineral: instant shield, reflects rays.
- Chemical: lightweight, invisible finish, absorbs rays.
Together, they offer strong, broad-spectrum protection while avoiding the heavy white cast that pure mineral sunscreens often leave behind. Perfect for daily wear, especially under makeup.
Why These Details Matter
It’s not enough to own sunscreen, you need to know how to use it correctly:
- Apply 15–20 minutes before sun exposure.
- Reapply every 2 hours (or more if swimming/sweating).
- Don’t stretch out an expired bottle.
- Choose a formula suited to your skin type and lifestyle.
✨ Conclusion
Sun safety is more than SPF numbers. It’s about smart, consistent use, and understanding the small print on your sunscreen bottle.
In New Zealand’s harsh UV climate, these habits aren’t optional, they’re essential. Protecting your skin today means healthier, more radiant skin tomorrow.
Prepared by: A. Oblak, BSc in Chemistry
References:
- SunSmart New Zealand. sunsmart.org.nz
- Te Whatu Ora – Health NZ. Sun Safety. info.health.nz
- Royal Society of New Zealand. royalsociety.org.nz
- NIWA – National Institute of Water and Atmospheric Research. niwa.co.nz
- Baumann, L., MD. Cosmetic Dermatology (2nd ed.).
- Dermatology Times, 2024 – Hybrid Sunscreens Trend.
- Unsplash+ (image source)