Quality Control for the Formulator

Receiving inspection is the first step in the total control program. This generally consists of comparison of what is received to the specification used in developing the purchase order. Acceptance tests on raw materials should be directed toward assurance that the incoming materials are correct and identical from lot to lot. 

A receiving inspection program consists of comparison of the purchase order with what is received. If the vendor s test reports are required with the shipment, it is verified that they were received and that the test values are acceptable, as defined by the original material specification. 

It may also be necessary to test the incoming bulk materials in-house. These inspections usually consist of an evaluation of physical and chemical properties, such as color, viscosity, percentage of solids, weight per gallon, and moisture content. The tests should be those that can quickly and accurately detect deficiencies in the materials physical or chemical properties or differences from lot to lot. ASTM lists various test methods that are commonly used for acceptance of raw materials. Several of the more common test methods are described in Chap. 20. 

Because of the cost and time required for extensive in-house testing, the trend today is to have most of the quality control tests done by the supplier. The supplier then provides a certified test report to the customer with shipment of the product. The test program that is used by the supplier, internal controls, etc., are usually verified and approved by the customer on a periodic basis, such as once per year. The approval tests are used to determine the adequacy of the particular materials in question and the production methods that will be employed. The tests that are done with every lot and submitted on delivery usually are made to ascertain the consistency of the product from lot to lot. 

Once identified and approved for receipt, all incoming material should be labeled with a receipt date. This date is prominently shown on the container or material while it is in inventory. The approved incoming material should then be stored in a controlled storage facility. Precautions must be taken to ensure that the oldest material is used first and that the shelf life of the product does not expire before it is used. The date stamp on the product is the most reliable method of doing this. 

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