[Code of Federal Regulations] [Title 9, Volume 2] [Revised as of January 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 9CFR318.303] [Page 286-287] TITLE 9--ANIMALS AND ANIMAL PRODUCTS CHAPTER III--FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE PART 318_ENTRY INTO OFFICIAL ESTABLISHMENTS; REINSPECTION AND PREPARATION OF PRODUCTS--Table of Contents Subpart G_Canning and Canned Products Sec. 318.303 Critical factors and the application of the process schedule. Critical factors specified in the process schedule shall be measured, controlled and recorded by the establishment to ensure that these factors remain within the limits used to establish the process schedule. Examples of factors that are often critical to process schedule adequacy may include: (a) General. (1) Maximum fill-in weight or drained weight; (2) Arrangement of pieces in the container; (3) Container orientation during thermal processing; (4) Product formulation; (5) Particle size; (6) Maximum thickness for flexible, and to some extent semirigid containers during thermal processing; (7) Maximum pH; (8) Percent salt; (9) Ingoing (or formulated) nitrite level (ppm); (10) Maximum water activity; and (11) Product consistency or viscosity. [[Page 287]] (b) Continuous rotary and batch agitating retorts. (1) Minimum headspace; and (2) Retort reel speed. (c) Hydrostatic retorts. (1) Chain or conveyor speed. (d) Steam/air retorts. (1) Steam/air ratio; and (2) Heating medium flow rate.