Checking if your sunscreen is still effective involves examining its physical characteristics and considering its expiration date (though the FDA doesn't mandate expiration dates on all sunscreens). It's impossible to definitively say how long sunscreen remains effective after its expiration date.
Visual and Sensory Checks for Sunscreen Effectiveness
The most reliable way to determine if your sunscreen has gone bad is by observing its physical properties:
- Consistency: A significant change in texture is a red flag. Look for:
- Wateriness (thinning)
- Chunky or grainy texture
- Clumping or pilling
- Color: Any alteration in color from its original shade suggests degradation.
- Smell: An unusual or off-putting odor indicates spoilage. The scent may become stronger or completely different.
- Separation: If the sunscreen has separated into layers, it's likely no longer effective.
Example: If your typically creamy sunscreen is now watery and has a sour smell, it should be discarded.
Expiration Dates and Shelf Life
While not legally mandated by the FDA for all sunscreens, many brands include an expiration date on the packaging. This date signifies when the manufacturer guarantees full effectiveness. However, even before the expiration date, visual and sensory checks should be performed.
Note: Even if the sunscreen appears unchanged, using it after the printed expiration date is not recommended.
Effective SPF Remains a Factor
The SPF (Sun Protection Factor) number on the bottle indicates the level of protection provided when the product is fresh. Even if the sunscreen looks and smells normal, the SPF might not be as advertised if it's significantly past the expiration date or has been improperly stored (e.g., exposed to high heat).
Conclusion
To ensure your sunscreen provides adequate protection, always check its appearance, smell, and consistency. If anything seems amiss, discard it.
