The only reason for taking action without injury is to give local industries an advantage, and international trade law does not allow that. The International Trade Commission makes the injury call. First the fact of injury is investigated. Actually, this inquiry involves determining if there is injury, a threat of injury, or material retardation of the establishment of a US industry and not merely to a part of an industry, or simply to a firm. So the determination of what is the industry is crucial and sometimes difficult.
Industry is defined in the law as the domestic producers as a whole of a like product.
Then, if one of the previous determinations is made, causation analysis takes over. Volume analysis may focus on import market share, but sheer market share would not be dispositive if such a share had been maintained by an importer for a significant amount of time. However, even a smaller market share produced from a sudden surge in imports may be more significant. The next element is the effect on US prices. The next element requires an examination of the effect on US producers of like products.