The single most common question I am asked is:
"What do all the symbols mean on a cosmetics label?"
Each symbol on the packaging is standardized information for the buying public to know exactly what to expect in regards to shelf life, reactions, usage, etc.
Let me break down some of the most common symbols on cosmetics labels:
PAO—Period After Opening
This symbol will tell you how long the formula will remain stable after you remove the factory seal. This is not a "best before" date, however—this symbol refers only to shelf life after the seal is removed. Shelf life, for most cosmetics with an intact factory seal, is 36-48 months.
This symbol indicates that the product is registered with a third party that will collect the empty package for recycling purposes. All cosmetics companies selling products in jurisdictions where curbside recycling programs do not exist, are required to provide services to recycle the packaging components. This symbol informs consumers that the manufacturer provides such services. In Canada, because most municipalities offer blue bin service, this symbol is often not required.
This symbol indicates that the outer packaging does not provide sufficient space to print all the pertinent information required to fully understand the usage of the product. When this symbol appears, there is always additional information available to the consumer not appearing on the outer packaging—either in the form of a leaflet, inside the outer packaging, or online.
Due to the evaporation rate of various formulas, each package fill is slightly different. This symbol indicates that at the time the jar was filled, it met the "average fill requirements" as set by law. For liquids it is in mL and for solids it is in g. A label may indicate 200 mL, but the product fill may actually be 201 mL or 197 mL due to the average fill requirements.
Some products are flammable. Nail polish and hair spray are good examples of flammable cosmetics. This symbol specifically indicates the danger of using open flames around this product.