Question:

I have been led to believe that suncreen will become less effective if left in a hot space e.g. a car in the summer for extended period of times. Is this true or will the sunscreen remain effective through the expiration period regardless of storage conditions?

Answer:

Yes, subjecting sunscreens to extremes of temperature is destructive of the chemicals, and certainly long periods in a hot car are not good because this causes deterioration of the product….not just of the active chemical but of the vehicle.  I would urge you to get fresh material.  Check the expiration date.  The expiration date is the date through which the material can be expected to function at 100% of its design and does assume a non-freezing and non-hyperthermic environment.  If in doubt, please replace the material for use for maximum effectiveness.

 

For more information:

Go to the Skin Care and Diseases health topic.