A simple machine is a device that simply transforms the direction or magnitude of a force. It is a tool that consists of one or more parts, and uses energy to meet a particular goal. The evolution of machines started with the beginning of Industrial revolution, and brought changes in the fields of agriculture, manufacturing, mining, transportation, and technology, due to which there was a profound effect on the social, economic and cultural conditions of the times.
For potentially harmful substance exposures from machinery and equipment, such as mist, fumes, vapour or dust, and where it is not possible to control the emission at its source, ventilation and extraction systems are used to remove the hazardous emissions from the work environment.
Effective machinery and equipment risk controls reflect some or all of the following characteristics: • the hazard is controlled at its source • contact or access to the hazard is prevented • sturdy construction (correct materials with few points of potential failure) • fail-safe (failure of the control system to be effective will result in machinery shut-down) • tamper-proof design (as difficult as possible to bypass) • presents minimum impediment to machinery and equipment operator • easy to inspect and maintain • does not introduce further hazards through the risk control action.
A tool generally is any physical item that can be used to achieve a goal, especially if the item is not consumed in the process. Informally, it also describes a procedure or process with a specific purpose.