Have had numerous things in the jars and only 1 went bad so honestly i dont even think it was the jar, more like the product that got put in it.
Have been using these jars for approximately 2 months and I personally am not seeing any kind of noticeable degradation to the products inside.
So far I find the products to be sufficiently air tight, due to the previously mentioned as well as not having strong smells in the area where the jars are kept.
Personally I love the way my area looks that was organized by utilizing these infinity jars. And that is just a side benefit on top of all the other reasons you would buy jars like these.
Great products. Great customer service. Solid purchase.