OSH midterm

1\. an individual making unwanted contact with a moving part of a machine. 2. something flying from the machine.3. a machine malfunction, including mechanical and electrical energy sources failure. 4. workpiece movement during a forming or cutting process

Machine accidents is caused of any of the following actions:

Can Result to Severe Injuries, Loss of Trained and Skilled Employee, Loss in Productivity, Damaged Equipment

Effects of Machine Related Accidents

The point of operation

That point where work is performed on the material, such as cutting, shaping, boring, or forming.

Power transmission apparatus

All components of the mechanical system that transmit energy to the part of the machine performing the work

flywheels, pulleys, belts, connecting rods, couplings, cams, spindles, chains, cranks, and gears

components of a power transmission apparatus

Rotating

– turning around on an axis or center

Reciprocating

the back and forth movements of a machine part

Traversing

continuous straight line motion of a machine element in either direction

caught by, flying particles, sparks

Cutting hazards in a rotating machine movements

Pinch Points / Nip Points Hazards

In-running nip points draw objects in and the effect is crushing or shearing injury.

Reciprocating Machine Movements

During the back-and- forth or up-and-down motion, a worker can be struck by a moving part or caught between a moving and a stationary part.

Hazards in a traversing machine movements – Punching, shearing, bending

Traversing Motion

This motion is hazardous due to continuous straight line action and in-running nip points.

Guards

are barriers that prevent entry of an individual’s hands or other body parts into a hazard area.

Fixed Barrier Guard

This type of guard is attached to a fixed surface and encloses the hazard. When in place, it prevents anyone from going over, around, under or through it to the hazard. The principal advantage of the fixed enclosing guard is that it always prevents access to the hazard area.

Movable guards w/ interlocking switches

This type prevents machine motion until the guard is moved into place. The interlocking method may be mechanical, electrical, pneumatic, or a combination of these

Adjustable Guard

This type of guard can be positioned to accommodate a variety of operations or work and when properly adjusted provides adequate protection from the hazard at the point of operation.

Self-Adjusting Guard

Provides a barrier which moves according to the size of the stock entering the danger area.

Safety Devices

Any mechanical or electrical devices designed to protect a worker’s hands or other body parts from coming into contact with a hazardous motion of a machine.

Pullbacks and Restraint Devices

Holdout and restraint devices are cable and wristlet systems that attached to an operator’s hands and to the machine’s moving slide or ram, or to a fixed object away from the point of operation.

Pullbacks and Restraint Devices

They are usually used on machines having reciprocating motions.

Two hand controls

Two- hand controls are operator controls that require an operator to hold both controls down during the hazardous portion of the machine’s stroke.

Presence-sensing Devices

These are designed, constructed, and arranged to create a sensing field, area, or plane that will detect in its field the presence of an opaque object.

Emergency Stop

Emergency stop button, Grabwire switch or tripwire switch

Protective Shields

Provides some protection from flying particles, splashing cutting oils or coolants

Lock-out/Tag-out System (LOTO)

The standard for the control of hazardous energy sources which covers maintenance of machines in which the unexpected start up of machines or release of stored energy could cause injury to employees.

Electrical, Mechanical, Thermal, Potential

Sources of Hazardous Energy

Electrical

the uncontrolled current and voltage in electrical circuits

Mechanical

exposed crushing or cutting parts of equipment or loose parts

Thermal

such as steam or due to chemical reaction

Potential

stored energy that may be due to gravity, hydraulics, pneumatics, vacuum or springs

Lockout devices

A device that utilizes a positive means such as a lock either key or combination type, to hold an energy isolating device in the safe position and prevents the energizing of a equipment

Tagout devices

A warning device, such as a tag and a means of attachment

Tagout devices

Can be securely fastened to an energy isolating device in accordance with an established procedure to indicate that the energy isolating device and the equipment being controlled can not be operated until the tag is removed

Electricity

is our most versatile form of energy.

Electron

The word electricity comes from the word \____

Causes of electrical accidents

Contact with live conductor, Short circuiting, Arcs and sparks, Overloading, Non-usage of standard replacement, Wet environment

Effects of Electrical Hazards – Electrocution, Falls, Fire, Electric Shock, Bur

Current (ampere)

is the amount of electricity flow in a Conductor

Voltage (volts)

is the force which causes electrons to flow in a conductor

Resistance (ohms)

is the opposition of a material to the flow of electricity

Power (watts)

is the amount of energy or work that can be delivered by the current and the voltage

Circuit

is the path of flow of electricity

Circuit Elements

are objects which are part of a circuit and through which current flows

Fault

is a current flow through an unintended path

Ohm’s Law

defines the relationship of the voltage, the current and the resistance in the electrical circuit.current and the resistance in the electrical circuit

660 Volts – A high voltage has \___ volts or more

Transmission lines

Power lines that has high voltage

Distribution lines

Power lines that has low voltage

Line to line, Line to ground

Electrical Wiring system

Direct Current (DC)

An electric current flowing in one direction only

Alternating Current (AC)

Electric current that reverses its direction of flow (polarity)periodically according to a frequency measured in hertz, or cycles per second.

Conductor

any material that offers little resistance to the flow of an electric current

Insulator

any material that is a very poor conductor of electricity and prevent current from taking unwanted paths

500 to 1000 ohms

The inner resistance of a human body is about \_____

At 0.4 ma or more – current that has no sensation

At 1.8 ma

current that can create slight tingling sensation

More than 3 ma

current that can create painful shock

At 5 to 16 ma

safe “let-go” current but can cause secondary accident

More than 16 ma

muscle contraction “no-let-go” danger (involuntary grip)

At 30 ma to 50 ma current that can create lung paralysis

usually temporary

More than 50 ma

current that can create possible ventricular fibrillation

At 100 ma or more

current that can create certain ventricular fibrillation, could be fatal

Primary Injuries

physical damage directly to the body from the electrical current

Secondary Injuries

physical damage to the body resulting from accidents caused by the shock.

Occupational Safety and Health Standard Rule 1211

The Philippine Electrical Code is hereby adopted and the standards contained therein shall be considered safety standards to the extent that they safeguard any person employed in any workplace and control the practice of electrical engineering

Circuit Breakers

Provided to protect EQUIPMENT not people

Circuit Breakers

These are calibrated conductors which will melt and break (open) the electrical circuit when too much current flows through them. This stops the flow of electricity before any problem can develop.

Ground -fault circuit interrupter (GFCI)

is a fast-acting circuit breaker which senses small imbalances in the circuit caused by current leakage to ground and, in a fraction of a second, shuts off the electricity.

Grounding

is a conductive connection between electrical circuit or equipment and earth or ground plane creates a low resistance to the earth.

Grounding

is a protection from electric shock

Proper use of extension cords

Stay away from wet areas, sharp objects heat & oil, Check cords periodically for nicks and cuts, Always use the correct wire gauge and cord length for its intended use:

Lock-out/Tag-out System (LOTO)

These are the standard procedures for the control of hazardous energy sources which covers maintenance of machines in which the unexpected start up of machines or release of stored energy that could cause injury to employees

Lockout device

A device that utilizes a positive means such as a lock to hold an energy isolating device in the safe position and prevents the energizing of an equipment

Tag out devices

A warning device, such as a tag and a means of attachment. Can be securely fastened to an energy isolating device in accordance with an established procedure to indicate that the energy isolating device and the equipment being controlled can not be operated until the tag is removed

Electricity, Path, Time

Electrocution triangle

Keep away, Ground, GFCI

Prevention triangle

Machine

is a combination of rigid or resistant bodies, formed and connected so that they move with definite relative motions and transmit force from the resistance to be overcome.

Machine safety

It is the prevention of accidents when working with machines.

RULE 1200: Machine Guarding.

It is prescribed in the Occupational Safety & Health Standards

Fixed Guard

Provides a barrier, it is a permanent part of the machine, preferable to all other types of guards

Interlocked Guard

When this type of guard is opened or removed, the tripping mechanism and/or power automatically shuts off or disengages, and the machine cannot cycle or be started until the guard is back in place

Adjustable Guard

Provides a barrier which may be adjusted to facilitate a variety of production operations.

Self-Adjusting Guard

Provides a barrier which moves according to the size of the stock entering the danger area

PROTECTIVE SHIELDS

Provides some protection from flying particles, splashing cutting oils or coolants

RESTRAINT DEVICE

Uses cables or straps attached to the the operator's hands and a fixed point hands. Must be adjusted to let the operator’s hands travel within a predetermined safe area. Hand-feeding tools are often necessary if the operation involves placing material into danger area

Two-Hand Control

Requires constant, concurrent pressure to activate the machine.

Two-Hand Control

The operator’s hands are required to be at a safe location (on control buttons) and at a safe distance from the danger area while the machine completes its closing cycle.

Gate

Movable barrier device which protects the operator at the point of operation before the machine cycle can be started.

POWER TRANSMISSION APPARATUS

Safety: less than 7 feet from the floor or working platform must be guarded

SAFEGUARDING BY LOCATION

Locate the machine or its dangerous moving parts so that they are not accessible or do not present a hazard to a worker during normal operation.

1.Failure to stop equipment 2.Failure to disconnect from power source 3.Failure to dissipate (bleed, neutralize) residual energy 4.Accidental restarting of equipment. 5.Failure to clear work areas before restarting

“Fatal Five” Main Causes of Maintenance Injuries

MANAGEMENT

Ensure all machinery is properly guarded.

SUPERVISORS

Train employees on specific guard rules in their areas. Ensure machine guards remain in place and are functional. Immediately correct machine guard deficiencies

EMPLOYEES

Do not remove guards unless machine is locked and tagged. Report machine guard problems to supervisors immediately. Do not operate equipment unless guards are in place

Lock-Out / Tag-Out System (LOTO)

A system designed to protect against the unexpected startup of machine that is supposed to be “OFF” or unexpected release of energy.

Group Lockout Devices

Used when more than one person doing maintenance or repair on same machine or equipment.

Hazardous Energy

Energy that can cause injury or even death

Authorized Employee

A person who is certified to lockout/tagout equipment or machinery.

Affected Employee

An employee whose job requires him/her to operate or use a machine or equipment on which servicing or maintenance is being performed under lockout or tagout, or whose job requires him/her to work in an area in which servicing or maintenance is being performed