Raw materials and processing aids used for API manufacturing include for instance the API starting material, but also less critical materials such as e.g., solvents or catalysts. These materials do not need to be manufactured in accordance with GMP but nevertheless a sufficient quality is required to avoid contamination and to ensure that the materials delivered consistently have the required purity. For example, starting materials or solvents may be contaminated with nitrosating agents, which may lead to N-nitrosamine formation during the further processing to produce an active ingredient. Contamination with N-nitrosamines is a serious concern for producers of APIs and medicinal products. It is therefore important to know how these materials are produced and whether multipurpose or dedicated equipment/facilities are used. Properly planned and performed audits help to identify those suppliers that pose a higher risk related to contamination and on the other side to confirm the suitability of the suppliers of the materials. blue’s auditors are experienced and trained in auditing all kind of raw materials and processing aids under consideration of specific risks related to the use in pharmaceutical manufacturing.