With low hydrolysis of dye molecules, dyebaths may be recharged with bath chemicals and reused repeatedly. Dyebath analysis tends to be difficult with reactive type dyes due to the difficulty of differentiating unhydrolyzed and intact colorant using spectrophotometry . According to Smith , the easiest systems to manage for dyebath reuse are dye classes which give high affinity (exhaustion) and which undergo minimum changes during the dyeing processes.
The features mentioned in the consulted bibliography are:
References from reviewed literature:
In  B. Smith, A Workbook for Pollution Prevention by Source Reduction in Textile Wet Processing, Pollution Prevention Pays Program, North Carolina Department of Environment, Health, and Natural Resources, Raleigh, N.C., 1988