Q.6 Knowledge of type/class of fire is important to effectively fight it out. Discuss.
Ans: - Knowledge of type / class of fire:
Fires are classified into four groups. When a fire occurs, it is important to know its classification, so the most appropriate suppression strategies, equipment and chemicals can be used to fight the fire. All employees especially security and safety personnel should know these four classifications.
· Fire Suppression:
Once a fire begins, quick suppression is critical. If a small fire is extinguished at its early stage, a huge potential loss can be avoided. Suppression includes a response from properly equipped fire fighters or from a worker who is able to take a fire extinguisher from a wall and douse the fire.
A major factor supporting fire suppression is preparation. Once a blaze begins, the earlier efforts in anticipation of a possible, fire prove their value. Sprinkelers and hose systems are illustrations of fire suppression methods.
· Automatic sprinklers:
Automatic sprinkler systems consist of piping suspended from the ceiling with sprinkler heads spaced along the pipes and fed by a water supply. When a blaze develops, heat
causes, each sprinkler head to open and discharge water. The National Fire Protection Association (NFPA) has developed standards for the installation of these systems that are followed by manufacturers, insurance companies and by federal state and local code enforcement agencies. Today many buildings are required to contain automatic sprinkler systems. The investment has repeatedly proven its value by saving lives and greatly reducing property damage. Insurance companies provide substantial premium reduction that can pay for a sprinkler system within a few years. The failure of these systems is primarily from human error. For instance, the water source was turned off.
Two major types of sprinkler systems are wet pipe and dry pipe. The first one always has water in the pipes. The second has air pressure in the pipes because in cold climates water in the pipes would freeze. When a fire takes place near a dry pipe system, the sprinkle heads rupture and air escapes followed by water. These systems are supplied by water through a large pipe called a riser often located in a stairway of a building. At this location, a valve can be closed to stop the water flow. Security officers should know the basics of the sprinkler system on the premises.
A sprinkler system is useless, if it has been turned off. Another problem occurs when items are stacked too close to the sprinkler heads and interfere with water flow. A space of at least eighteen inches is necessary.
· Stand pipes and Hoses:
Standpipes are similar to sprinkler systems in that a pipe system within a building provides water for fire suppression. A sprinkler system is automatic while a standpipe and hose system allows people to fight a fire manually and direct water onto the blaze. Horizontal standpipes are often in manufacturing plants, warehouses and shopping malls. Vertical standpipes are found in most buildings more than four stories high. These systems enable quicker and more convenient fire fighting in upper floors of buildings where aerial ladder equipment and fire department hoses will not reach. Combines sprinkler and standpipe systems have increased the flexibility of fire fighting although an adequate supply of water is vital.
Vertical standpipes usually run up the wall of a building or fire escape stairwells. The hose connections are on each floor near the stairs to permit ease of escape. A wall cabinet with a glass door contains a folded 2 ½” hose. Those hoses should be carefully handled by two people. The hose should be stretched completely and the nozzle held tightly before turning on the water. This prevents injury by any whipping action of the hose and nozzle.
Q.7. For best production without fatigue man machine relationship should be established. How is it achieved in industry and how work can be measured.
Ans: - Introduction:
In heavy work, energy expenditure is the principal limiting factory. To avoid fatigue and
to ensure efficiency in heavy work, it is necessary to regulate the metabolic rate during work so that the accepted norms are not exceeded. These norms based on research are generally specified in terms of the ratio of the metabolic rate during work to the maximal work capacity and the rise in heart rate and body temperature.
The metabolic rate is generally worked out indirectly from oxygen consumption. Oxygen consumptions are assessed by metering the quantity of air inhaled, with a max plank respirometer carried on the person and simultaneously finding out the oxygen and carbondioxide content of the expired air. From these values, the metabolic rate can be computed.
The technique can easily be utilized effectively to reorganize work and work methods for preventing fatigue and health risk in heavy industrial operations. Selection of persons with superior aerobic capacity for heavy jobs, making modifications in layout and material handling methods and introduction of mechanical aids in handling should be first stop in such endeavor so that the accepted norms are not exceeded in terms of metabolic rate or other parameters. If the energy demand of the job is still excessive, the severity of the job would have to be reduced by increasing and / or rearranging rest pauses.
In considering the rest allowance, the desired results cannot be achieved only through providing the required total allowance, but also through distribution of such rest allowance in a physiologically optimal manner, so that the fatigue in work is avoided or at least minimized. This can be illustrated by the following examples.
In one study, carried out in Eastman Kodak Company, the job consisted of lifting (from the floor) and placing a 40 pound case on a table of 20 inches height at the rate of 6 lifts per minute. The level of energy expenditure was 6.7 kcal per minute. Heart rates were recorded in two separate experiments with the following distribution of work / rest cycles.
In jobs which do not involve the major body musculature and where the emphasis should be on the load on particular body part or group of muscles, the above technique might not be valid and other methods are to be adopted. One of these is to assess through biomechanical models, torques induced on the different parts of the body by the job and to determine the limits relative to the through use of electromyography which is being increasingly use in research in the industrially advanced countries. Though recording and interpretation of electromyography, is relatively complicated, the technique can be used to find out the degree of muscle activity in the various elements of the job and also the state of fatigue of the muscles.
Ergonomics applications:
By and large, it may be intuitively surmised that the application of ergonomics can address some of the problems arising out of stress on job culture. In particular, harmful stimuli associated with high and low temperatures, noise, overly bring or glaring illumination, uncomfortable work posture and their eventual orthopedic effects are some
examples of the concern that lie within the realm of ergonomists. The areas in which application is deride by practitioners are as given below:
Ø The Anatomy of function.
Ø Physiologic measurements
Ø Work tolerance
Ø Hand tools
Ø Human energy optimizing its efficient use
Ø Applications of skeletal muscular forces
Ø Effects of climate
Ø Problems of body size and posture
Ø Limitations of sense organs
Ø Design of controls design of information displays
Ø Man / machine information exchange
Ø Age, fatigue, vigilance and accidents.
Q.8 What are occupational hazards. How can the effect be minimized by use of personnel protective equipment.
Ans :- Occupational hazards:
The following list describes some hazards in the workplace:
Ø Improperly stored flammable substances.
Ø Unusual odorous or noises
Ø Frayed electrical wires.
Ø Blocked or inoperable emergency exists.
Ø Burned out lights
Ø Slippery substances on floors that can cause a person to fall.
Ø Damaged floors or pavements that can cause an accident.
Ø Damaged security or fire protection equipment
Ø Workers not using protective equipment or clothing.
Ø Workers who circumvent safety measures when performing their job or operate machinery in a dangerous manner.
Ø Horseplay by workers operating cars trucks forklifts and equipment.
Ø Workers who are under the influence of drugs.
To minimize the effect by using Office equipments:
Equipment: Hats, caps and helmets
| S.NO. | Material | Hazard |
| 1 | Asbestos | |
| 2 | Plastic, rubber | Hot liquids, moisture, acids, alkalis, electric shocks and dermatitis. |
| 3 | Cotton wool | |
| 4 | Metal | Falling objects, flying particles, cuts and abrasions |
| 5 | Plastic | |
Soft caps and hoods are also used for protection against heat spark and other dangerous materials and are made or appropriate materials. Sometimes heads are made with rigid frame, which is held away from the head.
Eye and face protection:
Numerous eye injuries are caused by dusts, flying particles, splashes and harmful
radiations. It is difficult to cover precisely the various processes in which the worker may be required to wear goggles. The hazard encounted may be:
- Natively large flying - Chipping, felting, riveting sledging,
Caulking etc.
- Dust and small flying objects - Scaling, grinding, stone dressing,
Woodworking.
- Splashing of metals - Bob biting, pouring of lead joints,
casting of metals, galvanizing and
gripping in molten metals.
- Splashing of liquids gases - Handling of acids and other
and fumes chemicals
- Reflected light, glare and - Foundry work, glass furnaces, gas
radiant energy welding and cutting arc welding.
Eye protectors may be safety spectacles, mono-goggles, impact goggles, welding goggles, foundry goggles, chemical goggles, gas tight goggles, face shields, welding helmets etc.
Hand and arm protection:
Protection of hands and arm becomes necessary when workers have to handle materials having sharp end, sharp edges or hot and molten metals, chemicals and corrosive substances have to be handled. The protective equipment may be quantlet gloves, wrist gloves, mittons, hand pads and thumb and finger guards and sleeves. It is important not only that the various parts of arm and hand are adequately covered, but that they should be covered by a material suitable for withstanding the specific hazard involved.
Equipment: Sleeves, wrestle’s
| S.NO. | Material | Hazard |
| 1 | Asbestos | |
| 2 | Chrome leather | |
| 3 | Flame proofed duck | Sparks, hot materials, heat flying particles and machinery |
| 4 | Plastic | Hot liquids, moisture, acids, alkalis and dermatitis. |
| 5 | Rubber | Hot liquids, moisture, acids and alkalis and dermatitis. |
| 6 | Chemical resistant materials | Acids and alkalis |
| 7 | Reflective fabric | Hot liquids |
Equipment: Gloves, mittens, hand pads and finger guards
| S.NO. | Material | Hazard |
| 1 | Asbestos | |
| 2 | Chrome leather | |
| 3 | Rubber | Hot liquids, moisture, acids and alkalis, electric shocks and dermatitis. |
| 4 | Plastic rubber coated fabric | Hot liquids, moisture, acids, alkalis, electric shocks and dermatitis. |
| 5 | Metal mesh | Cuts and abrasions |
| 6 | Cotton canvas | Cuts and abrasions |
Foot and leg protection:
Adequate protection may have to be provided to the workers employed in certain jobs. Risk of injury may be in handling of heavy materials, caustic and corrosive liquids, wet conditions, molten metals etc. common foot and leg protective equipment are safety shoes and boots, leggings, foot guards and leg guards.
Equipment: Paints, kneepads, leggings:
| S.NO. | Material | Hazard |
| 1 | Asbestos | |
| 2 | Chrome leather | |
| 3 | Flame proofed duck | Sparks, hot materials, heat flying particles and machinery |
| 4 | Plastic | Hot liquids, moisture, acids and alkalis |
| 5 | Rubber | Dermatitis, hot liquids, moisture, acids and alkalis and electric shock |
| 6 | Fiber metals | |
| 7 | Chemical resistant | Acids and alkalis |
| 8 | Reflective fabric | Hot liquids |
Equipment: Shoes and boots:
| S.NO. | Material | Hazard |
| 1 | Steel toe caps | Flying objects |
| 2 | Non-skid shoes | Moisture |
| 3 | Wooden soles | Hot materials, heat, hot liquids, moisture, acids and alkalis, slips and falls, and cuts and abrasions |
| 4 | Chrome leather | |
| 5 | Rubber | Dermatitis, hot liquids, moisture, acids and alkalis and electric shock |
| 6 | Conductive rubber | Explosive |
Body protection:
Sometimes it becomes necessary to provide special protective equipment for the body in the form of aprons, overhauls, jackets and complete heat to toe protective equipments. Nature of potential hazard, degree of hazard involved and nature of activities of the user concerned are important considerations in the selection of safety clothing.
| S.NO. | Material | Hazard |
| 1 | Asbestos | |
| 2 | Chrome leather | |
| 3 | Plastic | Hot liquids, moisture, acids and alkalis |
| 4 | Rubber | Dermatitis, hot liquids, moisture, acids and alkalis and electric shock |
| 5 | Chemical resistant | Acids and alkalis |
| 6 | Reflective fabric | Hot liquids |
Respitatory protective equipment:
Atmospheric contaminants range from the relatively harmless substances to toxic dusts, fumes, smokes, mists, vapour and gases. Processes which presents hazards of exposure to
harmful substances should, if possible, closed or ventilated to eliminate or minimize the hazard. If, enclosure, ventilation or other engineering means of control are applied satisfactorily, a supply of appropriate protective equipment should be readily available for use, as there will be plant breakdown and repairs may have to be carried out in contaminated environments. Respiratory protective equipment should be considered as a last resort or as standby protection and never a substitute for effective engineering control.
No comments:
Post a Comment