Okay kiddo, so you know how we use things like cups and plates to hold our food and drinks? Well, sometimes we need bigger things to hold really big things, like chemicals or water.
When we need big things like that, we use things called storage tanks. These tanks can be made out of different materials, like plastic, metal, or even concrete.
But we need to make sure that these tanks are safe to use and won't leak or break. So, grown-ups made a set of rules called BS EN 13121-3 that say how to make safe tanks out of plastic.
These rules are really detailed, and they tell grown-ups how to design the tanks, what kinds of plastic to use, and how strong they need to be. They also tell them how to test the tanks to make sure they're safe to use.
So, if you ever see a big plastic tank holding something important, like chemicals or water, you can feel safe knowing that grown-ups followed these rules to make sure it's safe.