What should we know DMD and PAO?

PaO symbols

When it comes to providing information to consumers, one requirement is the inclusion of the minimum durability date, also known as the Date of Minimum Durability, on the product labeling in a clear and understandable manner so that the consumer is aware of the date until which the product, when stored properly, continues to perform its original function and is safe (DMD). The following sign or the words “best used before the end of” must come before the date itself or specifics about where it appears on the packaging:

dmd cosmedesk
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The DMD must be described properly and must include either the day, month, and year in this order or the month and year. When applicable, it should also be accompanied by a description of the requirements that must be met in order to ensure the claimed durability.

Cosmetic items having a minimum endurance of more than 30 months are not required to indicate the DMD. Unless the idea of durability after opening is irrelevant, as in the case of single-use products, products not at risk of degradation, or products that do not open, the consumer should be notified of the Period after Opening (PaO) for which the product is safe and can be used without harm.

The following symbol must be used to represent the PaO, followed by the duration (in months or years):

pao cosmedesk
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According to the “Recommendations related to the assessment of the period after ouverture (PAO)” given by the Agence Française de Sécurité Sanitaire des Produits de Santé, the PaO can initially be theoretically approximated. In order to calculate the theoretical risk (TR), which estimates the theoretical PaO, five factors—intrinsic resistance of the formulation to microbial contamination, interface product/environment related to use (type of packaging), duration of foreseeable use (adequacy of volume, dose, and frequency), area of application, and target population—are rated from 1 to 4, respectively, from lowest risk (1 to 2) to the most important (3 to 4).


Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products

Cosmetics Europe: Guidelines on cosmetic product labelling, 2011

Agence Française de Sécurité Sanitaire des Produits de Santé. Recommandations relatives a l’estimation de la periode apres ouverture (PaO). 2006

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