Incidentally-introduced chemical

means an industrial chemical:

• that is introduced, either with or subsequent to the introduction of another industrial chemical, as a result of any of the following:
   
  • the incomplete reaction of starting materials or reaction intermediates used in the manufacture of the other industrial chemical;
  • an unintended constituent present in the starting materials used in the manufacture of the other industrial chemical;
  • the exposure of the other industrial chemical to light, heat or other environmental conditions in the course of handling or storage;
  • the occurrence of a chemical reaction during the manufacture or use of the other industrial chemical;
     
• and the introduction of which has no commercial value separate from the other industrial chemical.