Repairing your items is a great way to reduce your ecological footprint. If ever you need to replace a silicone seal to make your container last a little longer, you can use something like this. This small tube contains Earth-friendly FDA 21 CFR 177.2600 food grade certified silicone.
Here is how to use it!
Remove the existing silicone seal.
Wash container and let dry thoroughly.
Open new silicone tube and squeeze it so a bit of silicone starts to come out.
Rather than squishing the silicone directly into the rim of a container, continue to squeeze the tube so that the silicone comes out and allow the silicone simply to fall out into the concave rim of the lid.
Very slowly, continue to push out the silicone and let it fall into the rim until there is silicone covering the entirety of the rim.
It will not be perfectly even so we suggest taking a small piece of cardboard with the width of the rim to skim and flatten the silicone. By doing this, you will fill any air pockets and make the silicone more even.
Remove any excess silicone. Do not make it thicker than 6 mm / 0.25". It should set in 20 minutes but let it dry overnight.
If you test your container and it is still not watertight, fill your container with water, close the lid with fully dried silicone, and hold it over a sink to find where the leak is occurring. Dry the lid thoroughly and patch those areas that might be thin on the silicone.