Physan 20

[quiltergal]

I just mixed up a gallon's worth of Physan 20 and have about half of it left. I have put it in a half gallon milk jug with the lid on and plan to store it under the kitchen sink. How long will it remain effective in the container? I know certain chemicals and fertilizers degrade over time. Is it worth saving or should I just dump it out? TIA

[Ray]

Actually most chemicals, and all inorganic fertilizers are stable as all get-out, once diluted - including Physan.

The primary reason there are instructions "DO NOT STORE UNUSED MATERIAL" is more for safety sake than anything else. An astronomically HUGE number of poisonings occur annually because chamicals are placed in food containers (like milk jugs) and left unlabeled.

[quiltergal]

Mine is most definitely labeled in permanent ink. Thanks Ray!

[Dorothy]

Should the container be covered as some chemical become denatured by sunlight?

[Ross]

Originally Posted by Dorothy

Should the container be covered as some chemical become denatured by sunlight?

Actually Physan appears to be a finely ground powder in suspension so I doubt fading is an issue. My experience however is that any long term chemical storage is best done out of sunlight just to be cautious.