You want to assure your customers that your products contain exactly what is on your label. Limits of contaminants that may adulterate or lead to adulteration of the finished batch of your product is part of cfr 111. Exact Scientific Services, Inc has multiple ways of helping you with this.

Each component received from a supplier that is liable to contamination with microorganisms, filth, insect infestation, allergens, aflatoxins, other natural toxins, pesticides, organic impurities, residual solvents, inorganic impurities, elemental contaminants, foreign substances, or other extraneous substances that may be a source of contamination is objectionable in view of its intended use must be tested or examined against specifications for such contamination.

Applicable USP general chapters should be used, are included in the right column.

These chapters are used in accordance with the specifications written by the manufacturing of dietary supplement company.  They will be deployed over raw ingredients and finished product testing.  We typically see microbiological and heavy metals run on every batch of finished product. 

Residual solvents, pesticides, aflatoxins, microbiological and heavy metals are run on raw materials.  In leu of raw material testing.  Finished products may be tested for residual solvents, pesticides and aflatoxins.