教学课件 《安全工程专业英语（第2版）》司鹄.ppt

递序而下，顺序法 All commercial iron and steel contains iron as chief constituent, but the percentages of carbon and other elements and the methods by which iron and steel is produced, as well as the processes to which they may be subjected, so change the characteristic properties that there are many distinct forms of iron and steel, some of which have properties so different as to appear like different metals. The development of rockets has made possible the achievement of speeds of several thousand miles per hour, and what is more important it has brought within reach of these rockets heights far beyond those which can be reached by aeroplanes, and where there is little or no air resistance, and so it is much easier both to obtain and to maintain such speed. UNIT FOURTEEN HAZARDOUS CHEMICAL AND ITS IDENTICATION 句子分析 The Occupational Safety and Health Administration (OSHA) defines a hazardous chemical as any chemical which is a physical hazard or a health hazard.? Health hazard means a chemical for which there is evidence that acute (immediate) or chronic (delayed) health effects may occur in over-exposed people.? Although safety hazards related to the physical characteristics of a chemical can be objectively defined in terms of testing requirements (e.g. flammability), health hazards definitions are less precise and more subjective.? Physical hazards may manifest as fires, explosions, excessive temperatures, or the release of large volumes of gas or toxic or flammable gases or vapors.? Although they are individual accidents, different in the way in which they happened and the chemicals that were involved, they have one common feature: they were uncontrolled, involving fires, explosions or the release of toxic substances that either resulted in the death and injury of large numbers of people inside and outside of the factory or caused extensive damage to the property and the environment As well as toe boards or similar protection at the edge of the platform, the p