Why can we use plastic to make cans? State the reason!

Plastic is chemically inert, it will not react with acid or alkali present in the material in the cans.

In older days, zinc plated iron sheet were used to make cans. However, zinc plated iron sheet will be oxidized or corrode eventually by the water or other material inside the cans, leading to rupture of the can or potential threat of human health.

Moreover, plastic is an inexpensive material. So, the cost of can making can be lowered.