I am a retired chemist and used very strong concentrations of hydrogen peroxide.
I bought some teeth whitener that uses hydrogen peroxide in a high percentage.
I was not happy with the results.
I noticed that it ate the rubber in the syringe where it was stored.
So, I started freezing the ones I was not using.
I decided to try to salvage it by washing out the H2O3 and using the syringe.
I found that the rubber on the syringe had "melted."
That, to me was scary.
Do you think the rubber was of low quality?
Andy