Section 50.71 - Criteria for Establishing User Segments(1) Production units grouped into a user segment must contain similar products and processes.(2) For purposes of grouping similar products and processes into user segments, the department may consider, without limitation, the following criteria: (a) transferability or potential applicability of toxics use reduction techniques;(b) chemical use, byproduct, or emission;(c) potential health or environmental impact;(d) potential for improvement in environmental performance; or(e) type of equipment used.(3) User segments may be designated according to process codes set by the department and their associated products, or by other groupings of processes (e.g.,Clean Water Act categories, processes subject to MACT standards under the Clean Air Act) and their associated products. For purposes of 310 CMR 50.70, the department may, consistent with the definition of "product" in 310 CMR 50.10, designate the result of the process as the "product."