Sun screen life

Monanore

Sun screen bottles have a "12m" mark but no dates for either expiry or manufacture.  So I have to replace every year in case it loses efficacy - and for all I know it may be old stock. 

Does anyone know why this is, and how long does it remain fully effective.

Mands

Monanore said:

Sun screen bottles have a "12m" mark but no dates for either expiry or manufacture.  So I have to replace every year in case it loses efficacy - and for all I know it may be old stock. 

Does anyone know why this is, and how long does it remain fully effective.

12m means 12 months from the date you opened it. 

Emmia

I write the month and the year opened on the base of the bottle with a marker pen / Sharpie and then do 12 month's from then. Saves confusion.