Understanding the Basics of Fire Safety in Manufacturing Industry

Fire Safety in manufacturing is a must and is a basic requirement in every country and international policies. Understanding the basic principles in Fire Safety and prevention would help manufacturing industries cope up and improve its fire safety guidelines and procedures.

WHAT IS FIRE?

Fire is a chemical reaction between a flammable or combustible material and oxygen. It is frequently referred to as a “rapid oxidation with the evolution of light and heat”.

THREE BASIC COMPONENTS OF FIRE

1. Fuel – defined as any substance used to produce heat and power by combustion. Most ordinary fuels are compound of carbon and hydrogen in varying amounts. Even metals, which are not normally considered fuels, can be burned in some forms in an atmosphere of pure oxygen. There two basic fuel or material involve in producing a fire: Flammable and Combustible. Flammable materials have a flashpoint below 100°F or 38°C. Common example of a flammable materials are alcohol based chemicals and fossil fuel (e.g. gasoline) which ignite easily. Combustible materials have a flash point at or higher than 100°F.
2. Oxygen – the second element of the fire. -  Fire normally draws its oxygen from the air, which is a mixture composed roughly of 21%  oxygen and 78% nitrogen. When the oxygen content of air drops below 16%, the fire will normally go out for lack of oxygen. Note that the nitrogen in the air serves only to dilute the oxygen and does not ordinarily enter into the reaction. Whereas, in an atmosphere of pure oxygen or even oxygen-enriched air will produce fires of great intensity.
3. Heat or Source of Ignition (Temperature) – the last essential factor of fire. The temperature at which the substance gives off vapors or gases in, sufficient quantity to be ignited is called the “flash point” (as discussed earlier) of the substance. The substance itself will continue to burn when the source of the ignition is removed until it has reached the “ignition temperature”, which is the minimum temperature required to initiate or cause self-sustained combustion.

COMMON SOURCES OF HEAT

1. Electricity
2. Smoking
3. Friction
4. Cutting and welding
5. Spontaneous ignition
6. Static electricity
7. Chemical reaction

CLASSES OF FIRES

1. CLASS  “A”. Initial fires involving ordinary combustible materials such as wood, paper, textiles, rubbish, many plastic, etc.- in which the quenching and heat absorbing (cooling) effects of quantities of water, water solution or the cooling effects certain dry chemicals that retard combustion.
2. CLASS “B”. Initial fires in small quantities of rapidly burning materials (flammable or combustible liquid such as gasoline, oils, grease, paints, etc.- in which the blanketing or smothering effects of the extinguishing agent is of great importance.
3. CLASS “C”. Initial fires involving energized electrical equipment -- where safety to the operator requires the use of electrically non-conductive extinguishing agents.
4. CLASS “D”. Initial fires involving combustible metals such as magnesium, titanium, zirconium, aluminum, zinc,, potassium, etc.,-  requiring a heat-absorbing extinguishing medium not reactive with the burn metals.
5. CLASS “E”. Initial fires involving certain combustible metals, reactive chemicals that requires special extinguishing agent and techniques.  Still under development.

EXTINGUISHING METHODS OF FIRE

1. Starving – sopping formation or escape of vapor.
2. Cooling – reducing the burning substance to a point below the ignition temperature.
3. Smothering – keeping air from burning substance.

EXTINGUISHING AGENTS

1. Steam - Is effectively used in the extinguishment of solvent and gas fires.It has a smothering and cooling effect on the fire. When steam is applied under high pressure, it has a tendency to remove the heat (ignition) leg of the triangle by the cooling action of the steam on the burning material. Gassy areas are purged and gas concentrations are diluted by the application of steam in such area. As steam is possible conductor of electricity, it should not be used on the electrical equipment unless the power has been shut off.
2. Carbon Dioxide Extinguishers - Is effective in the extinguishment of electrical fires, solvent fires and most gas fires but is not effective on fires of wood, textile, paper, etc., where glowing members are present. Consists of one or more cylinders of liquid carbon dioxide, which vaporized when released to the atmosphere, and is blown through a horn over the fire area. This inert gas, being one and a half times heavier than air, dilutes the air (oxygen).Difficult in the  extinguishment in the open atmosphere under high wind velocities because of the difficulty experience in confining the gas to the fire.
3. Dry Chemical Extinguishers -   A fog of finely powered sodium bicarbonate (with a small amount aluminum sulfate as a drying agent or silicon zed  to repel moisture) is blown over the burning surface or in the case of a gas fire blown into the burning gas by the pressure of a cylinder of carbon dioxide gas. Removes the air (oxygen) and heat (ignition) and extinguishes by smothering and cooling. This powder being a non-conductor of electricity may be safety and effectively used on electrical fires.
4. Foam - Is the most effective of all extinguishing agents for fighting a solvent fire when the solvent is confined.,  where the liquid surface can be completely blanketed with a layer of foam. Foam extinguishes the fire by cutting off the solvent surface from the fire space and radiant heat above, thereby stopping the formation of vapor essential to the burning of the solvents and thus starves the fire by removing the air (oxygen) leg of the triangle. Foam also has a tendency to cool the solvent surface, but its greatest effectiveness is in starving. Being a conductor of electricity (foam is made up of about 95% water) foam should not be used on electrical fires until the electric power has shut off.

CLASSES OF FIRES AND ITS CORRESPONDING EXTNGUISHERS

1. On Class “A” Fires – use water, foam
2. On Class “B” Fires – use foam, CO2, Dry Chemicals and vaporizing liquid
3. On Class “C” Fires – use CO2, Dry Chemicals, vaporizing liquid
4. On Class “D” Fires – use water, Special Extinguishing agent

It has been said that the best time to stop fire is before it starts and the best way to prevent the occurrence of destructive fire is “TO HAVE NOFIRE AT ALL”. To date these statements are still true and will remain to be true. This is called “FIRE PREVENTION”. An effective fire prevention and fire fighting depend on two important factors:

1. Knowledge of the condition under which a substance will ignite.
2. Knowing how the substance burns once it is ignited.

The formula in the prevention of the occurrence of a destructive fire are,

1. Sound effective planning
2. Inter-department teamwork
3. Constant attention to details
4. Well trained security guard

In the present trend in all manufacturing industries, “SAFETY AND SECURITY IS A GROWING ALLIANCE”. In order to achieve this, there are four categories considered and is found to be very effective.

1. Engineering – implementation of fire protection codes in new buildings and reducing hazards in old buildings
2. Inspection – continuous inspection of fire fighting equipment and fire alarm system and trouble shooting all areas for possible fire hazards.
3. Education – poster campaign, published materials, films, lectures to all employees, intensive training for all including security guards and plant orientation for base firemen.
4. Research – investigation of specialized of specialized fire fighting technique necessary in dealing with unusual materials.

In Fire Safety Management, we should consider the 3 E’s,

1. Education – a must for all employees
2. Engineering – Prevention – Detection – Extinguishment.
3. Enforcement – Strict implementation of policies, rules and regulations of the      company

In extinguishing a fire, we need to consider four basic primary methods,

1. Removal of heat
2. Reduction of heat
3. Reduction of Air
4. Inhibition of flame chain reaction.

And the three auxiliary secondary methods of fire extinguishment,

1. Shock waves
2. Critical separation
3. Ion separation

In order to reach a fire safe workplace in a manufacturing firm, it is a must to organize a FIRE BRIGADE. The basic concept underlying this organization is “self-protection”. It is aimed of protecting life and minimizing damage to property in cases of emergencies of all causes. It should be developed and trained specially to provide the necessary protection of life and property in all type of emergencies. The primary objective in organizing the fire brigade is to control fires and providing maximum manpower for efficient operation in an emergency. Same prime objective in the discipline of fire loss control and industrial safety is the conservation of the company’s asset, property and human life alike. Its goal is to provide a safe physical environment such as elimination of fire, segregation and or protection of hazard and both utilities the same method of yardstick as a measure.

In modern fire loss programs, there are three basic elements:

1. Recognition. Have mental inventory of the material and conditions of the area that is to cause fire loss. Check your area and look at every situation in terms of the element needed for a fire. Enlist the said aid of everybody to prevent the occurrence of fire. He must recognize the hazards.
2. Evaluation. Classify the material and equipment in your area. Evaluate the possibility to become sources of fire. Consider modification of area and re-evaluate present set-up and conditions/situations.
3. Control. An experienced appraisal of what can be done to minimize or contain damage and the practical limits of available equipment can play a critical part in the control of the situation. Go over the list and select the most practical and effective means of control for each hazard or condition. Regular inspection and attention to all facets of the program will keep you going but there must be no end, otherwise if your effort and interest ends, the program ends.

And lastly, to have an effective protection and prevention program, a manufacturing firm must have a building administrator. He does not have to be an Engineer or he does not have to be expert in the chemistry of fire. But he does have to be interested and his desire to control losses from destructive fires. Thus he will be efficient and an asset to his company.