Safeguard measures defined: provisional and final protections triggered by increased imports threatening serious injury to domestic industry. Definitions for safeguard proceedings under the Customs Tariff Act define critical circumstances as clear evidence that increased imports, in absolute terms or relative to domestic production, cause or threaten serious injury and that delay in provisional measures would cause irreparable damage. 'Increased quantity' includes imports rising absolutely or relative to domestic output. Provisional measures and safeguard measures are distinguished, with safeguard measures including safeguard duty, tariff rate quotas, or other measures. 'Interested party' covers exporters, foreign producers, importers, exporting governments, and domestic producers or trade associations; undefined terms take their meaning from the Act.