1.  INTRODUCTION

The chemical industry is more diverse than virtually any other process industry. Its products are omnipresent. Chemicals play a major role in manufacturing, essential to the entire range of industries such as pharmaceuticals, automobiles, textiles, paper and paint, agriculture, electronics, appliances and services. It is difficult at the same time to fully specify the uses of chemical products and processes. A world without the chemical industry would lack modern medicine, communications, and consumer products.

The modern technology in developing these tailor made chemicals has been quite successful. However , the process and manufacturing facilities are challenged to maintain their edge in a highly competitive culture while facing continual scrutiny from the public and government to improve the safety of processes involving hazardous materials. The continuous burden of increasing the production of flammable organics, the competition to bring new products from laboratory scale to full scale production, the problem of familiarization with a stream of new technology have all extended the probabilities of hazards. The major hazards encountered in the operation of the plant in the chemical industries are toxic and corrosive chemicals release, fires, explosions, falls and faulty mechanised equipments. In many instances, more than one of these hazards occur either simultaneously or in tandem of each other. For example, a fire may lead to explosion which subsequently causes more fire and toxic release. Therefore, the design engineer must be aware of these hazards and must make every attempt to present a design which needs to be protective of the environment and of human health. Environmental issues must be considered not only within the context of chemical production but also during other stages of a chemical's life cycle, such as transportation, use by customers, recycling activities, and ultimate disposal.

2. ANALYSIS OF HAZARDS

An initial process hazard analysis must be made of the probable sources of hazards and it is performed on the processes, appropriate to the complexity to identify, evaluate and control the hazard. Take corrective measures to improve the safety of the process and plan actions that would be necessary if safety controls failed. Process hazard analysis is required for any process involving a highly hazardous chemical as identified in the standard. A process includes any manufacturing or use of a highly hazardous chemical, including storage, handling or movement of the chemical. Most simplified, any facility that has a designated hazardous chemical on-site in the quantities named in the standard must conduct a process hazard analysis for the equipment and process in which the material is used. The entire approach can be summarized as follows:

1.  Identify the hazards:	“ what can possibly go wrong ”
2.  Evaluate the hazards:	“ what are all the causes and how bad it can be ”
3.  Control the hazards:	“ what should be done about it ”

The sources of the hazard can be divided into two categories, namely, material hazards and process hazards.