i just had a look at the website i ordered it from but it doesn't actually say the grade? it states it's used for cleaning (something about descaling and pH) – the website i bought it from supplies all sorts of things (not just cleaning chemicals) to industrial kitchens. ANYWAYS, on the container itself, the SN does state it's for food preservation, colouring for processed meats etc, but also medical corrosion inhabitation(?).
i could only buy it in bulk (5kg – very overkill lol), and i paid about $140 AUD. i want to test it with the strips, but then i know opening the container and exposing it to air will ruin it

i don't want it to be less effective when i choice to use it…
You're absolutely right

it's highly unlikely for it to be 100%.
If it's okay to ask, how many grams, what grade (technical, food grade etc.) and how much did you pay for your SN? Most tech and food grade are around 98-99%.
i just had a look at the website i ordered it from but it doesn't actually say the grade? it states it's used for cleaning (something about descaling and pH) – the website i bought it from supplies all sorts of things (not just cleaning chemicals) to industrial kitchens. ANYWAYS, on the container itself, the SN does state it's for food preservation, colouring for processed meats etc, but also medical corrosion inhabitation(?).
i could only buy it in bulk (5kg – very overkill lol), and i paid about $140 AUD. i want to test it with the strips, but then i know opening the container and exposing it to air will ruin it

i don't want it to be less effective when i choice to use it…