The choices of materials of construction for manufacturing facilities are numerous. Some examples are presented subsequently. It is important, when choosing a material, to keep in mind the characteristics of the manufacturing process. Parenteral manufacturing operations have different requirements than oral-dosage manufacturing operations. Similarly, biotech and vaccine manufacturing operation requirements can differ. It is imperative that these requirements be considered when specifying wall, floor and ceiling construction, and finishes. The ISPE Guides provide guidance on these choices (refer to Suggested Readings).