From netdoctor.co.uk
Can I use sun lotion left over from last year?
Not with safety. Sunscreens have a shelf-life of more than two and a half years. This means the manufacturer is not obliged by law to quote an expiry date.
But both heat and bacteria damage sunscreens, so you should replace your lotion each year.
If your sunscreen smells off or separates, it is either full of bacteria or has been destroyed in some other way and should be thrown out.
Keep sun lotion in a shady and cool place when not in use, ideally in the refrigerator.



