I have seen claims of 5 years shelf life for MMS and HCL.
Just recently while running some tests, I was not getting the results I expected, so I began to replace each ingredient with new, freshly made solutions.
I found that the HCL I was using had lost strength which caused incomplete release of CLO2 from MMS (22.4% sodium chlorite solution). When I used newly purchased HCL, there was more CLO2 in the test solution. But, the CLO2 amount was still too low.
So, I made a fresh batch of MMS, reran the test and this time got the expected CLO2 concentration.
The ages of the original HCL was 4 years old and MMS was 18 months old.
To be sure your MMS and HCL will produce the amount of CLO2 you expect, I would say both ingredients should be no more than 1 year old.
The shelf life of sodium chlorite flakes is quite long, perhaps 20 years if stored properly. The flakes I used to make this new batch of MMS were 7 years old. You can buy fresh HCL in the form of muriatic acid at most hardware stores, etc.
shelf life
