Plastic cap

My collection is getting wider. Some time ago I found this nice plastic box. It is made of transparent polypropylene (PP). However,  I am not sure about the plastic cap - it is blue and nontransparent. As always, I am pretty unsure about if the cap is ok. Could it release something bad over time? Your opinion? Have you got any similar boxes / experiences? 

I suggest you put each of your coins into a plastic balloon and string them up under your ceiling. Up to you to select the color and how much air (hydrogen, oxygen, helium or what have you) in each balloon.

How can you believe, we would know the physical properties of your plastic box?

Try a better storage method I can suggest Schulz coin albums they are excellent and pvc free 

Put your coins in a clay pot and bury them in your garden for at least 1 meter deep.