Why SS316L is only used for product contact in Bilogics Manufacturing

During any URS preparation for production, I have observed that “All product contact parts shall be made up of SS316L”. Why is it so? What is main reason behind it? Why we cant use SS304 or just SS316, why it is preferred SS316L only.

It is chooses Based on their corrosion resistant properties.it is iron based, low carbon alloy and non magnetic and owes its high corrosive resistance to chromium…

But why its SS316L only, coz SS304 also have similar properties of alloy right.?

304 is an excellent general purpose grade and is used for non contact applications.
However as mentioned earlier post, 316L grade with its lower carbon content and added molybdenum provides greater corrosive resistance. It is the preferred choice in most instances particularly within the Pharmaceutical Industry. With other words 316L reduce corrosive resistance due decontamination or other cleaning materials, which is saver to use with products. In the Pharmaceutical industry safety is important factor. In customer URS 316L for product contact parts is often mentioned.

As a general rule 316L is used in all product contact applications and 304 used in non contact applications.