Tuesday, December 17, 2013

What do you want to know? Best before dates

In the What do you want to know post, Lucy asks: How do you determine best before dates?

In general, we look at all the ingredients and determine which has the shortest shelf life. If we have a lotion with olive oil, grapeseed oil, e-wax, cetyl alcohol, water, green tea extract (water soluble), and preservative, the shortest lived ingredient is the grapeseed oil with three months. So this lotion would have a life span of three months. If we have a body wash with decyl glucoside and cocamiodpropyl betaine as the main surfactants and a ton of extracts with a one year life span, the product has a one year life span. It's about the shortest lived ingredient...

...most of the time. If you have something like grapeseed oil with a three month life span, can we make it a little longer? We could add some anti-oxidants to the mix, but we don't know exactly how much life we offer to the product, so the life span would still really be three months for the purposes of labelling.

Related posts:
Shelf life of our products (part 1)
Shelf life of our products (part 2)
How can we determine shelf life?
How do anti-oxidants affect our shelf life?
Frequently asked questions section on shelf life (scroll down, it's alphabetical)

3 comments:

Michelle D said...

Funny you should mention GSO as I just looked up the ingredients for my favorite lip balm (Nivea A Kiss of Smoothness). The ingredients list GSO, but the tube has an expiration date of 4/2014, and I bought it three months ago. How do they do this?

Jane L said...

I thought all cosmetics lasted forever! Wow - I have used many products after they have been sitting at someone else's place for years. So what is the side effect if you use an expired product like conditioner?

Susan Barclay-Nichols said...

Hi Michelle! I wonder if they are using a ton of anti-oxidants. As well, they have the ability to do greater testing than we can, so I wonder if they were able to add some anti-oxidants then test how long the product took under testing before it went off? This is just a guess...

Hi Jane! In general, the side effect is that the product can be contaminated or might just smell awful due to rancidity!