A machine guard means any enclosure, barrier or device constructed to prevent a person or his clothing coming into contact with dangerous parts of the machine.

1.    Point of operation: That area on a machine where material is positioned for processing by the machine and where work is actually being performed on the material.

2.    Zero Mechanical State (ZMS): The mechanical state of a machine in which every power source that can produce a machine member movement has been shut/locked off. This means de-energised, de-pressurised and neutralised condition of the machine or equipment which provides maximum protection against unexpected mechanical movement.

3.    Power off:  The state in which power (electric, pneumatic, hydraulic, atomic etc.) cannot flow to the machine is considered a power-off stage.

4.    Power-locked off: The state in which the device that turns power off is locked in the off position with the padlock of every individual who is working on the machine.

5.    Guarding: Any means of effectively preventing personnel from coming in contact with the moving parts of machinery or equipment which could cause physical harm to the personnel. In case of a power-press, a cover on point of operation (die and punch) is called ‘guard’ while those on other danger zones are called ‘enclosure’ or ‘safeguard’.

               Safety by Guarding is most important as other methods are not always possible. Depending upon the dangerous part, its size, position, speed etc., a guard should be selected. Generally the parts to be guarded fall within three categories :

1.  The prime mover.

2.  Transmission parts from the prime mover to the machine and the transmission parts in the machine itself. It is desirable to minimise them and enclose completely.

3.  Operating parts of a machine, of which the points of dangerous operation need effective guarding.

6.    A machine guard means any enclosure, barrier or device constructed to prevent a person or his clothing coming into contact with dangerous parts of the machine. The point of operation is that part of working machine at which cutting, shaping, forming or any other necessary operation is accomplished. A guard for that part is known as the point of operation guard.

7.    Enclosures: Guarding by fixed physical barriers that are mounted on or around a machine to prevent access to the moving parts.

8.    Fencing: Guarding by means of a locked fence or rail enclosure which restricts access to the machine except by authorised personnel. Enclosures must be a minimum 1 m (42 in) away from the dangerous part of the machine.

9.    Safety by Position or Location: It is a guarding as a result of the physical inaccessibility of a particular hazard under normal operating conditions or use. Words “Safe by location” or “Safe by position” are used to denote safety by distance.

The words “safe by position” are used by Section-21 of the Factories Act. It means the situation (out of reach) or position in such a way that normally it is not possible

Definitions : The Factories Act defines as   under :

          Power means electrical energy or any other form of energy which is mechanically transmitted and is not generated by human or animal agency.

          Prime mover means any engine, motor or other appliance which generates or otherwise provides power.

          Transmission machinery means any shaft, wheel, drum, pulley, system of pulleys, coupling, clutch, driving belt or other appliance or device by which the motion of a prime mover is transmitted to or received by any machinery or appliance.

          Machinery includes prime movers, transmission machinery and all other appliances whereby power is generated, transformed, transmitted or applied. Belt includes any driving strap or rope.

          Maintained means maintained in an efficient state, in efficient working order and in good repair.

Fencing of Machinery : Section-21 requires that every moving part of a prime mover, flywheel, headrace and tailrace of water wheel and turbine, lathe, electric generator, motor, rotary converter, transmission machinery and every dangerous part of any other machinery.

shall be securely constructed, positioned or fenced by safeguards of substantial construction and constantly maintained and kept in position while the parts of machinery they are fencing are in motion or in use.

Work on or near machinery in motion: Section-22 requires that any examination, lubrication, adjusting operation, mounting or shifting of belts while the machinery is in motion shall be carried out by a specially trained adult male worker wearing tight fitting clothing supplied by the occupier and his name shall be recorded in the register in Form No. 8. Such worker shall not handle a belt at a moving pulley unless the belt is not more than 15 cm in width, the pulley is a normal drive (no flywheel or balance wheel), the belt joint is laced or flush with belt, the pulley, joint and pulley rim are in good repair, there is reasonable clearance to work, secure foothold / handhold are provided and any ladder being used is secured fixed or held by a second person. At that time other parts in motion shall be securely fenced to prevent their contact. Woman or young person is not allowed to do such work.

Employment of young persons on dangerous machines : On power presses except hydraulic presses, milling machines, guillotine machines, circular saws and platen printing machines no young person shall work unless he has been fully instructed regarding their dangers and precautions to be observed and has received sufficient training to work on that machine and is under adequate supervision by a person who has a thorough knowledge and experience of that machine (Sec. 23 & Rule 57).

Striking gear and devices for cutting off power:  Suitable striking gear or other efficient device to move driving belts to and from fast and loose pulleys and to prevent the belt from creeping back on to the fast pulley, shall be used and maintained. Driving belts not in use should not rest or ride upon shafting in motion (for which belt hangers are necessary). Other devices for cutting off power are necessary in every work room. Such devices shall be so locked to prevent accidental starting of the machinery.

          Self acting machines : 45 cm or more clear space is necessary from the end of maximum traverse of any self-acting machine or material carried thereon.

Basics of Machine Safeguarding

   Crushed hands and arms,

    Severed fingers, blindness

    The list of possible machinery-related injuries is as long as it is horrifying. There seem to be as many hazards created by moving machine parts as there are types of machines. Safeguards are essential for protecting workers from needless and preventable injuries.

A good rule to remember is: Any machine part, function, or process which many cause injury must be safeguarded. When the operation of a machine or accidental contact with it can injure the operator or others in the vicinity, the hazards must be either controlled or eliminated.

Where Mechanical Hazards Occur
Dangerous moving parts in three basic areas require safeguarding:
The point of operation: that point where work is performed on the material, such as cutting, shaping, boring, or forming of stock.
Power transmission apparatus: all components of the mechanical system which transmit energy to the part of the machine performing the work. These components include flywheels, pulleys, belts, connecting rods, couplings, cams, spindles, chains, cranks, and gears.
Other moving parts: all parts of the machines which move while the machine is working. These can include reciprocating, rotating, and transverse moving parts, as well as feed mechanisms and auxiliary parts of the machine.

Mechanical Motions and Actions

A wide variety of mechanical motions and actions may present hazards to the worker.

The basic types of hazardous mechanical motions and actions are:

Motions

• rotating (including in-running nip points)
• reciprocating
• transversing

Actions

• cutting
• punching
• shearing
• bending

Motions

Dangerous parts to be guarded according to their motions are generally classified as follows :

          Group-1. Rotary Motions : (1) Rotating parts alone viz. shafts, coupling, spindles, projections on moving parts, fly-wheel, saw, gear, knife, cutting tool etc. (2) In-running nips subdivided as (a) Between parts rotating in opposite direction - gears, rolls etc. (b) Between rotating and tangential moving parts - conveyors, belt drives, rack and pinion etc. (c) Between rotating and fixed parts - grinding wheel, paper machine felt or roll, drums, cylinders, worms, spirals  etc.

          Group-2. Reciprocating Sliding Motions : (1) Reciprocating sliding motions and fixed parts (a) Approach type - danger of crushing viz. slides (rams) on power presses and forging hammers, pistons, cross rod of a steam engine and riveting machines (b) Passing types - danger of shearing, viz. planning machine, shaper, spot welder clamping fixtures, guillotine and the shear, power press etc. (2) Single sliding motion - abrasive or sharp nature of objects such as saws or crocodile clips on belts.

          Group-3. Rotating/Sliding Motion : A cam gear having sliding and turning movement etc. falls within this group.

          Group-4. Oscillating Motions : Trapping points between two moving parts or between a moving part and a fixed object viz. a pendulum, crankshaft, closing  platens etc.

Rotating motion can be dangerous; even smooth, slowly rotating shafts can grip clothing, and through mere skin contact force an arm or hand into a dangerous position. Injuries due to contact with rotating parts can be severe.
Common nip points on rotating parts
Nip points are also created between rotating and tangentially moving parts. Some examples would be: the point of contact between a power transmission belt and its pulley, a chain and a sprocket, and a rack and pinion.
 Nip points between rotating elements and parts with longitudinal motions.
Nip points can occur between rotating and fixed parts which create a shearing, crushing, or abrading action. Examples are: spoked handwheels or flywheels, screw conveyors, or the periphery of an abrasive wheel and an incorrectly adjusted work rest. Nip points between rotating machine components; (A - cover removed for clarity.)
Reciprocating motions may be hazardous because, during the back-and-forth or up-and-down motion, a worker may be struck by or caught between a moving and a stationary part. for an example of a reciprocating motion.
 Hazardous reciprocating motion.
Transverse motion (movement in a straight, continuous line) creates a hazard because a worker may be struck or caught in a pinch or shear point by the moving part.
Actions
Cutting action may involve rotating, reciprocating, or transverse motion. The danger of cutting action exists at the point of operation where finger, arm and body injuries can occur and where flying chips or scrap material can strike the head, particularly in the area of the eyes or face. Such hazards are present at the point of operation in cutting wood, metal, or other materials.
Examples of mechanisms involving cutting hazards include bandsaws, circular saws, boring or drilling machines, turning machines (lathes), or milling machines.
Typical punching operation.
Shearing action involves applying power to a slide or knife in order to trim or shear metal or other materials. A hazard occurs at the point of operation where stock is actually inserted, held, and withdrawn.

PRINCIPLES OF MACHINE    GUARDING

Prevent contact: The safeguard must prevent hands, arms, and any other part of a worker's body from making contact with dangerous moving parts. A good safeguarding system eliminates the possibility of the operator or another worker placing parts of their bodies near hazardous moving parts.
Secure: Workers should not be able to easily remove or tamper with the safeguard, because a safeguard that can easily be made ineffective is no safeguard at all. Guards and safety devices should be made of durable material that will withstand the conditions of normal use. They must be firmly secured to the machine.
Protect from falling objects: The safeguard should ensure that no objects can fall into moving parts. A small tool which is dropped into a cycling machine could easily become a projectile that could strike and injure someone.
Create no new hazards: A safeguard defeats its own purpose if it creates a hazard of its own such as a shear (cut off) point, a jagged edge, or an unfinished surface which can cause a laceration. The edges of guards, for instance, should be rolled or bolted in such a way that they eliminate sharp edges.
Create no interference: Any safeguard which impedes a worker from performing the job quickly and comfortably might soon be overridden or disregarded. Proper safeguarding can actually enhance efficiency since it can relieve the worker's apprehensions about injury.
Allow safe lubrication: If possible, one should be able to lubricate the machine without removing the safeguards. Locating oil reservoirs outside the guard, with a line leading to the lubrication point, will reduce the need for the operator or maintenance worker to enter the hazardous area.

Requisite Characteristics (Design principles) of    Guards:

Twelve characteristics, design principles, specifications, basic requirements or good guarding practice for machine guarding are:

1. With its primary purpose of protection, it should also facilitate the work i.e. it should be convenient, reliable and not hampering the work or rate of production.

2. It should fully satisfy the legal provisions and IS prescribed i.e. it should conform the standards, be a complete guard and not incomplete or giving any access to the part to be protected. It should be as close as possible.

3. It should be suitable and effective to the job and the machine. It should not weaken the machine.

4. It should allow for oiling, inspection, adjustment and repair. If it requires opening for this purpose, it should be easily and quickly replaceable.

5. It should withstand wear, shock, vibration and long use with minimum maintenance. If it requires frequent opening and closing, this factor becomes more important.

6. It should be of proper material and construction. It should be well fitted. Fire and corrosion resistant material is preferable.

7. It should be free from self-hazard such as sharp or rough edges, nails, splinters, more opening, noise, vibration etc.

8. If visual watch of operation is necessary, it should be transparent and yet durable.

9. If dusting is possible as in case of machining of wood, rubber, brass, cast iron etc., apart from the guard, dust suction device should also be fitted as a special guarding.

10.    It should be fail-safe i.e. if it fails or breaks it should stop the machine or at least it should give warning (alarm) to stop the machine.

11.    It should be interlocking type i.e. the machine will not start till it is not closed and will stop soon if it is opened.

12.    It should fulfil special requirement depending upon its purpose viz. distance guard should provide sufficient protective distance, trip guard must immediately trip the machine etc.

1. 

Industrial Noise

Industrial Noise refers to noise that is created in the factories which is jarring and unbearable. Sound becomes noise only it becomes unwanted and when it becomes more than that it is referred to as "noise pollution". Heavy industries like shipbuilding and iron and steel have long been associated with Noise Induced Hearing Loss (NIHL). 

Industrial Noise Pollution

This is posing to be a big challenge with very passing day and is a threat to safety and health of the people who are working in the industry and common people as well. It has been scientifically proved that noise more than 85 decibels can cause hearing impairment and does not meet the standards set for healthy working environment. Moreover it can also cause accidents. The problem has been viewed and analyzed from all the perspectives but the solution probably is not so easy to achieve since there is a lot of contradiction between legislation, guidance and documents.Industrial Noise resulting to noise pollution has many reasons such as industries being close to human habitats which prevents the noise from decaying before it reaches human ear. 




Effects of Industrial Noise Pollution

It has already been stated that continuous exposure to noise pollution leads to hearing impairment but it has various other effects as well which are as follows:

• It can result into increase in blood pressure
• Increased stress
• Fatigue
• Stomach ulcers
• vertigo
• Headaches.
• Sleep disturbance
• Annoyance
• Speech Problems
• Dysgraphia, which means writing learning impairment
• Aggression
• Anxiety
• Withdrawal

Industrial Noise adversely affects the workers and they suffer from various health problems as I have listed above. High volume leads to increased adrenaline levels, which leads to the constriction of blood vessels, which normally happens when the individual is tensed, afraid, anxious or extremely happy and excited. The work pressure and the noise pollution both lead to a fairly typical situation, which leads to clinical as well as psychological stress. The blood pressure, due to the constriction of blood vessels (vasoconstriction), remains high for the major part of the day. The human dislike towards anything that is not pleasant, yet compelling leads to emotional stress and depression which is a term for a quite a severe situation. Statistically there is a rise in the number of workers dying of cardiac arrests and cerebral attacks is on an increase considerably due to industrial noise pollution in railway yards, factories etc.

Some people also suffer from headaches, which decrease their efficiency levels and hamper the quality of their work. That leads to crises in workplace as well as home. Workers are always agitated and excited that result into carelessness. Workers also become fatigued and in some cases over fatigued which should ring the alarm for organizations that want to grow. The worst part of Industrial Noise pollution is it affects the unborn baby in a womb and that too in the early days after conception since the fetus is sensitive to sounds and high decibels affects the growth of its organs.

The problems that the Industrial workers face are sleep disorders and behavioral changes. They experience increased levels of stress. They fail to achieve harmony thus leading to a lot of minor psychological problems, which are too common to be noticed. They are irritated and annoyed; therefore fail to interact with a person around them and this gradually leads them to become "loners". They withdraw from the society and some in extreme circumstances might have "tremors", speech problems and many other behavioral problems. It is high time that the rules and regulations that are already made should be applied and followed so that we can cope with the ever-increasing problem of noise pollution that is concentrated in the industry environment.

Employee Participation

Employee Participation (Health & Safety)

A fundamental ingredient in reducing the rate of accidents and deaths in New Zealand workplaces is to ensure workers play an active and equal role in all areas of Health & Safety management.  Almost without exception studies and research, whether they’re union funded or independent reach the same conclusion.  That is that effective Health & Safety can only be achieved if workers participate in the development, implementation, enforcement and monitoring of health and safety programmes.

While this common feature runs through most successful H&S systems the systems themselves vary considerably.  Obviously factors such as the size of the organisation, available resources and legislative framework will influence the form of any given H&S programme takes. 

Effective employee participation means more than worker representatives on H&S committees, although this is obviously very important. The basic premise is that workers have a greater knowledge of the health and safety issues involved in their job than management and union officials do.  Therefore the best solutions will only be achieved if an environment is created where workers are actively encouraged to identify and report hazards.

We are beginning to recognise more and more workplace hazards.  Many of them are not unique to a given industry.  It is important that unions provide information and training on such hazards.  For example, stress and fatigue, workplace violence and drug and alcohol impairment are all examples of hazards that are sometimes not immediately recognised.  It is important therefore that employee representatives are provided with all the necessary information and support to promote these issues as genuine health and safety concerns that need to be addressed through whatever H&S management system is in place.

There are other opportunities for workers to be actively involved in health and safety.  For example, workers in companies that are part of the ACC partnership programme need to be involved in areas such as the auditing process.  It is a requirement that participating companies involve workers in health and safety but the reality is that very often it does not happen. 

Non-compliance with Partnership requirements should be partially addressed with the amendments to the HSE Act.

Participation means Unions

The April 1999 issue of Hazard Magazine reported on an American study on “Factors that support effective worker participation in heath and safety”.

The key findings of the report were,

1.    Effective strategies for involving workers appear to be conditional on a number of variables, most importantly on worker activism and the effective use of formal union negotiations. 

2.    Union education and training is also a critical variable in achieving effective arrangements for worker participation. 

3.    The probability of an OSH inspection, duration of the inspection, and sized of the penalties were significantly higher in unionised work sites.

The report highlights the important role of unions in assisting workers in accessing and understanding health and safety information, negotiating agreements that protect workers who refuse dangerous work and confront management about their health and safety concerns. 

The report is consistent with other studies that emphasize the role of unions in shaping opportunities for effective worker participation.  The challenge for unions is to develop strategies that will ensure workers are both given the opportunity to play an active role in health and safety and make the most of the opportunity.  This means that workers need to be playing an active role at all levels of health and safety.  This includes industry level (National Safer Industry Groups) and enterprise level (H&S committees and H&S representatives).  Unions need to provide the training, information and ongoing support for workers. 

It is important to recognise that throughout the often tragic history of worker health and disease, the worker played a primary role as the basis of every significant improvement in legislation, factory inspection compensation, correction and prevention.

The Canadian Ministry of Labour conducted a survey in 1993 that reached the conclusion that “union supported health and safety committees have a significant impact in reducing injury rate”.

The Ontario Workplace Health and Safety Agency found that 78-79 per cent of unionised workplaces reported high compliance with health and safety legislation while only 54-61 per cent of non-unionised workplaces reported such compliance. 

Research in the United Kingdom, Canada, Australia and the United States all reach the same general conclusion.  That is that unionised workplaces with effective worker participation in health and safety are far safer than non-union workplaces with poor worker participation. 

There are numerous examples and models for effective worker participation.  It is not practicable to go into any great detail in this paper.  However, it is important to identify the different steps at which workers must be fully involved.  By way of example of the different stages workers should be involved in.

Policy

From the beginning workers need to be involved in developing the overall objectives of the H&S programme.

Organising

Workers need to take responsibility for specific tasks, training and communication.

Planning

Workers need to be a part of designing and implementation of the programmes.

Measurement

It is important that workers are continually monitoring and striving to improve the agreed H&S programme

Audit & Review

The purpose of the audit process is to identify any existing or potential flaws in the programme.  Therefore it is important that workers are involved in this process. 

The role of the Union is to provide all the support, information and training that workers need to properly and confidently participate in the management of health and safety.  

Physics of Sound

Physics of Sound

• The vibration of a source causes pressure changes in air which result in pressure waves
• Perceived sound is comprised of numerous pressure waves of varying characteristics
• Pressure wave characteristics
• Amplitude—The amount of sound pressure measured in decibels (dB)
• Frequency—The rate of vibration per unit time measured in cycles per second, more commonly known as hertz (Hz); 
• range of normal perception for young person is 20–20,000 Hz

Octave Bands

• Quantifies effective frequencies without looking at each frequency one at a time
• Standardized notation used to characterize the frequency dependence of noise
• Characterized by center frequency
• Covering range of human hearing(20–20,000 Hz)
• fc= (f1f2)1/2–Where: fcis center frequency and f1and f2are lower and upper band edges respectively
•                                               Hz                                      

                     31.5, 62, 125, 250, 500, 1K, 2K, 4K, 8K, 16K



Sound Pressure
Pressure is fundamental to acoustics

-Definition

Pressure = force per unit of area
-Units
  Newtons per square meter (N/m2)—Called a Pascal(modern unit)
  Dynes per square centimeter (D/cm2)—Not commonly used



Human hearing covers a wide range of sound pressures
–Threshold of hearing: 0.00002 Pa
–Loud noise: 200 Pa



Decibel (dB) scaleis a log-based scale developed to quantify sound
–Compresses range to 0–140 dB
–Scale starts at zero when sound pressure equals the threshold of human hearing



Sound Pressure Level (SPL) and Sound Pressure (Pa)

Decibel scale–
Reference energy is the threshold of human hearing
10 * Bel = decibel (dB)
Sound pressure level (SPL)

for more calculative forms...mail me.i will sent you important pdf..

Occupational History elements

Elements of the Occupational History

List of jobs Lifetime history, with dates of employment and job duties Military history Exposures Type Chemicals (e.g., formaldehyde, organic solvents, pesticides) Metals (e.g., lead, arsenic, cadmium) Dusts (e.g., asbestos, silica, coal) Biologic (e.g., HIV, hepatitis B, tuberculosis) Physical (e.g., noise, repetitive motion, radiation) Psychologic (e.g., stress) Assessment of dose Duration of exposure Exposure concentration Route of exposure Presence and efficacy of exposure controls Quantitative exposure data from inspections and monitoring Timing of symptoms in relation to work Symptoms occur or are exacerbated at work and improve away from work Symptoms coincide with the introduction of new exposure at work or other change in working conditions Presence of similar symptoms among co-workers with the same type of job and exposures Evaluation of nonwork exposures Home environment (e.g., water, air, soil contamination) Hobbies or recreational activities

Common Health Conditions Associated with Occupational Exposure

Common Health Conditions Associated with Occupational Exposure
Condition	Selected exposures	Selected occupations
Musculoskeletal
Carpal tunnel syndrome	Repetition Vibration Awkward postures Cold temperature	Letter sorting Assembly work Computer work Food processing
De Quervain's tendinitis	Repetition High force	Meatpacking Manufacturing
Cervical strain	Static posture	Computer work
Thoracic outlet syndrome	Static posture, repetition	Assembly work
Respiratory
Interstitial fibrosis	Asbestos Silica Coal	Mining, construction trades, building maintenance Mining, foundry work, sandblasting Mining
Asthma	Animal products Plant products Wood dust Isocyanates Metals (e.g., cobalt) Cutting oils Irritants (e.g., sulfur dioxide)	Laboratory work Baking Furniture making Plastics manufacturing Hard metals manufacturing Machine operation Various occupations
Bronchitis	Acids Smoke Nitrogen oxides	Plating Fire fighting Welding
Hypersensitivity pneumonitis	Moldy hay Cutting oils	Farming Machine operation
Upper airway irritation	Indoor air pollution (i.e., sick building syndrome)	Office work Teaching
Neurologic
Chronic encephalopathy	Organic solvents Organophosphate pesticides Lead	Painting, automobile body repair Pesticide application Bridge work, painting, radiator repair, metal recycling
Peripheral polyneuropathy	Organophosphate pesticides Methyl butyl ketone	Pesticide application Fabric coating
Hearing loss	Noise	Many occupations
Infectious
Bloodborne infections	HIV, hepatitis B	Health care work, prison work
Airborne infections	Tuberculosis	Health care work, prison work
Infections transmitted fecally or orally	Hepatitis A	Health care work, animal care
Zoonoses	Lyme disease	Forestry and other outdoor work
Cancer
Lung	Asbestos Chromium Coal tar, pitch	Construction trades Welding, plating Steelworking
Liver	Vinyl chloride	Plastics manufacturing
Bladder	Benzidine	Plastics and chemical manufacturing
Skin
Contact dermatitis	Organic solvents Nickel Latex	Many occupations Hairdressing Health care work
Reproductive
Spontaneous abortion	Ethylene oxide	Sterilizing
Sperm abnormalities	Dibromochloropropane	Pesticide manufacturing
Birth defects	Ionizing radiation	Radiographic technicians
Developmental abnormalities	Lead	Bridge work, metal recycling
Cardiovascular
Coronary artery disease	Carbon monoxide Stress	Working with combustion products Machine-paced work
Gastrointestinal
Hepatitis	Polychlorinated biphenyls	Electrical equipment manufacturing and repair

Screening Questions
Key screening questions include the following^8,19:

1.      What type of work do you do?

2.      Do you think your health problems might be related to your work?

3.      Are your symptoms different at work and at home?

4.      Are you currently exposed to chemicals, dusts, metals, radiation, noise or repetitive work? Have you been exposed to chemicals, dusts, metals, radiation, noise or repetitive work in the past?

5.      Are any of your co-workers experiencing similar symptoms?