Calculation of detergent limit

I have a question. The limit of 10 ppm for detergents often comes up.
How is this limit establihed.

I would say 10 ppm in the next batch. ie if the next batch is 1000 kg, then 10g of deterget is allowed to be present in the next batch.

Divide this by the surface area will give g/cm2.

Now if only one piece of equipment is cleaned with detergent, which surface area do we use.

Any advice.


Hi Jay

The 10 ppm residue detergent is sometimes quoted, but the is no scientific backing to it. It must have been a thumb suck result, and itrepresent the total residue in the manufacturing train of equipment.

If one piece of equipment, surface area ycm2 is cleaned with the detergent

The limit is calculated as follows: 10 ppm x ycm2/total surface area of manufacturing train)