Usually the process industry, is often confronted with problems where explosive atmospheres endanger safety and health of the personnel. A number of reported incidents with serious results for personnel and equipment confirm the meaning of that problem. Historically, fire and explosion are the predominant causes of chemical plant losses and adoption of effective measures for prevention, protection and mitigation of fire and explosion requires high priority.
The explosive and fire atmospheres usually happen inside the equipment as a result of normal prosses condition (indoor) and outside due to abnormal processes of system in that device as a result of failure protection of the shell of the component and releases of fire, explosive or oxidizing substances (outdoor). The phenomena may be considered for major accident hazards regulations (SEVESO regulation) or for atmospheric explosion regulations (ATEX regulations) depending on the type of the substance involved and the size of the release. SEVESO accidents normally produce on- and off-side unwanted effects with possible domino effects while ATEX accidents will connecting with local on-site effects that will harm to the workers and property.
The ATEX directives are used to measure a potentially explosive atmospheres caused by gases, dusts and mists, and apply to all equipment, not only to electrical ones. It also requires the industrial sector to identify and improve hazards and risks associated with those explosive atmospheres. Employers will identify the risks of explosion and to provide an appropriate worker protection against explosions.
1.1.DEFINITION OF RISK IN TERMS OF THE ATEX DIRECTIVE
The risk are defined as the possibility of an unwanted event, which is expressed by the product of probability of a hazardous event and the extent of its damage. In order to determine the risk of any process or activity, it required to assess both parameters without missing one of the components that will affected for risk assessment.
The first objective of this report regarding to the topic RISK OF FIRE AND EXPLOSION is to differentiate between fire and explosion. Then, we can identify the factors and effects that can lead to the fire and explosion. From that, we can overcome it before it become an uncontrollable hazard. Other than that, from this topic we can also figure out the history of fire and explosion in the hospital. Most important is this report objective is to teach standard operating procedures (SOP) that must be follow if the incident happen and its prevention to occur.
3.DIFFERENCES BETWEEN FIRE AND EXPLOSION
Fire is the substances from the combination of chemical with the oxygen in the air that will give out light and heat and lastly produce smoke. It is hot due to conversion of weak double bonds of oxygen and produce carbon dioxide to release certain energy. The substances of fire will consumes oxygen rapidly to produce heat and light. It will release energy slowly compared to explosion because it need certain amount of fuel and oxygen present that will come out to contact with it. Its really rely on the amount of oxygen from surrounding. Fire also cannot be detonated. Detonated is a process of intramolecular breakdown. The flame is the product from fire that consists of several different colors which have its own fire intensity. Its consist of carbon dioxide, water vapour, nitrogen and also oxygen. Fire is initiated after being exposed to heat source and any substances that will lead into combustion.
Explosion is the blowing apart of hazard chemical that cause like a bomb usually generate of high temperature and release the energy and gases. Explosions its energy will release rapidly and expands outward from the source then create damaging shock wave. An explosion is detonated. Explosions occurs after it is exposed to the heat or shock. Upon the application of heat or shock, it is from a compound of chemical explosive that decomposes with extreme rapidity and yield gas and heat. Explosive force is released in a perpendicular to the surface of the explosive. The direction of force then spread 360° if a grenade is in mid air during the explosion.
From the application of shock, a reaction must be capable of being initiated within a certain catalyst to a small portion of the mass of explosive material.
The natural explosions arise from volcanic processes of various sorts such as volcanic eruptions from a rising of occur magma that has much dissolved gas in it subsequently its reduction of pressure causes the gas to bubble out of solution, as a result it give a rapid increase in volume. Explosions also occur in phenomena such as hydrothermal explosions and outside of Earth in the universe in events such as supernova. Lastly, an electrical explosions can be created from high current electrical fault by forming a high energy electrical arc which rapidly vaporizes metal and insulation material. Its really danger to persons that working on energized switchgear.
4.THE FACTORS THAT CAN LEAD TO THE RISK OF FIRE AND EXPLOSION
Fires and explosions can occur when 3 components are assembled simultaneously; oxygen gas or nitrous oxide (in anaesthetic practice) which supports combustion, flammable material and a source of ignition.
There are a few main factors which are normally lead to the risk of fires and explosion in the hospital. First and foremost, the process of cooking using kitchen facilities of the hospital; electrical ovens, open flames and toasters. Oxygen is dangerous when in contact with oil or grease. The mixtures of flammable gases in oxygen can be ignited by sparks. Next, the people who are addicted to cigarette smoke, although cigarettes are banned in healthcare facilities but people still sneak them due to smoking outdoors do not properly dispose to them. Therefore, this kind of bad habit will normally cause tragedy which not deliberately.
Besides, hospitals have a lot of specialized medical electrical equipment, lasers and electrosurgical tools are ignition hazard, especially near oxygen tanks, places with beddings or surgical clothing, and flammable sterilizing liquids. A study done on fire code violations in hospitals showed that the top fire safety violations were they often have overworked or overloading sockets and cables, loose connections of the circuits, incorrect use of electronic equipment, damaged or inadequate insulation of the wire. They sometimes use extension cords and daisy chain various appliances and equipment together due to insufficient of the socket. The sharing of an electrical socket of the needs of the equipment to be plugged in which is a violation. The short circuits of the electricity can cause sockets and cable to become overheated thus sparking a fire.
Additionally, alcohol-based hand sanitizers or hand rubs are all over hospitals. They are highly flammable so they need to have a 6-foot breadth between the sanitation station and any ignition sources. Next, gas cylinders and medical oxygen compliance need to be properly stored and secured. Basically, the presence of oxygen, fuel and heat acts as a catalyst in spreading the fires in hospitals.
5.EFFECT OF FIRE AND EXPLOSION HAZARDS IN OPERATING THEATRES
Normally it is necessary to specify the criteria we have applied in deciding which of the past events qualify as domino events before proceeding with the past accident analysis. It also needed to recapitulate the different interpretations of domino effect that are currently in vogue, and see the direction in which a broader consensus is tending to converge. The term domino effect in the context of accidents where to describe situations wherein a loss of containment accident in a process unit becomes the trigger of one or more loss of containment accidents in one or more other process units.
In operation theatres, the patients will face not only normal risk of anaesthesia and surgery but also a possibility of fire or explosion is ever present and constitutes almost as much risk to staff and patients. Nowadays the incidence case of serious explosions has been decreases as a regulations governing the building and maintenance of premises and apparatus rather than by knowledgeable decisions by medical and nursing staff to prevent this risk. Some of these regulations have led to expensive expedients which have been quite disproportionate to the magnitude of the risks in order to try and obviate human fallibility and ignorance. For example, it was estimated in 1969 that, a quarter of a million pounds had been spent on spark-proof switches in locations where sparks in fact presented no hazard and in which no instance could be cited of an explosion having been caused since the inception of the National Health Service.