Crest White Strips: Do They Work After Expiration?

  • Thread starter Thread starter blimkie.k
  • Start date Start date
AI Thread Summary
Crest White Strips utilize hydrogen peroxide as their active ingredient, which is a strong oxidizer known for its whitening effects. However, hydrogen peroxide is unstable and can lose effectiveness after the expiration date. While some users may still find expired strips somewhat effective due to the formulation, it is generally advised not to use them past their expiration date. Signs of degradation, such as an inflated package, indicate that the product may no longer be safe or effective. Users report positive results when the strips are used within the expiration period.
blimkie.k
Messages
130
Reaction score
0
First of all the chemistry behind crest white strips, do they actually work?

I have a package of Crest White Strips Premium plus my friend gave me from his work they have expired are they still effective after expiration date?
 
Chemistry news on Phys.org
Check what active ingredient is - that's answer to both your questions :wink:

Hydrogen peroxide is a strong oxidizer - so it may work. It is also unstable - so they can be not effective after expiration date, or at least less effective.
 
Last edited by a moderator:
I would not use it after the expiration date.
 
Hydrogen peroxide decomposes at a fast rate in water, I would still use the product since these strips have Hydrogen Peroxide imbedded in something other than water, however they may not be a great as one which has not exceeded the expiration date. Observe the package , if it seems inflated , than it's probably no good.
 
My mother swears by them, they definitely work... within the expiration date, at least.
 
It seems like a simple enough question: what is the solubility of epsom salt in water at 20°C? A graph or table showing how it varies with temperature would be a bonus. But upon searching the internet I have been unable to determine this with confidence. Wikipedia gives the value of 113g/100ml. But other sources disagree and I can't find a definitive source for the information. I even asked chatgpt but it couldn't be sure either. I thought, naively, that this would be easy to look up without...
I was introduced to the Octet Rule recently and make me wonder, why does 8 valence electrons or a full p orbital always make an element inert? What is so special with a full p orbital? Like take Calcium for an example, its outer orbital is filled but its only the s orbital thats filled so its still reactive not so much as the Alkaline metals but still pretty reactive. Can someone explain it to me? Thanks!!
Back
Top