Safety
Safety
is the state of being "safe" (from French sauf), the condition of
being protected against physical, social, spiritual, financial, political,
emotional, occupational, psychological, educational or other types or
consequences of failure, damage, error,
accidents, harm
or any other event which could be considered non-desirable. This can take the
form of being protected from the event or from exposure to something that
causes health or economical losses. It can include protection of people or of
possessions.
There
also are two slightly different meanings of safety, for example, home
safety may indicate a building's ability to protect against external harm
events (like weather, home invasion, etc), and the second that its internal
installations (like appliances, stairs, etc) are safe (not dangerous or
harmful) for its habitants.
Safety
can be limited in relation to some guarantee or a standard of insurance to the quality and un harmful
function of an object or organization. It is used in order to ensure that the
object or organization will do only what it is meant to do.
It's
important to realize that safety is relative. Eliminating all risk,
if even possible, would be extremely difficult and very expensive. A safe
situation is one where risks of injury or property damage are low and
manageable
Types of safety
It is important to distinguish
between products that meet standards, that are safe, and those that merely feel
safe. The highway safety community uses these terms:
Normative safety is a term used to describe products
or designs that meet applicable design standards.
Substantive safety means that the real-world safety
history is favorable, whether or not standards are met.
Perceived safety refers to the level of comfort of
users. For example, traffic signals are perceived as safe, yet under some
circumstances, they can increase traffic crashes at an intersection. Traffic
roundabouts have a generally favorable safety record, yet often make drivers
nervous.
Safety
is generally interpreted as implying a real and significant impact on risk of
death, injury or damage to property. In response to perceived risks many
interventions may be proposed with engineering responses and regulation being
two of the most common.
Probably
the most common individual response to perceived safety issues is insurance,
which compensates for or provides restitution in the case of damage or loss.
System safety and reliability engineering
System safety and reliability engineering is an
engineering discipline. Continuous changes in technology, environmental
regulation and public safety concerns make the analysis of complex safety-critical systems more and more
demanding.
A
common fallacy, for example among electrical engineers regarding structure
power systems, is that safety issues can be readily deduced. In fact, safety
issues have been discovered one by one, over more than a century in the case
mentioned, in the work of many thousands of practitioners, and cannot be
deduced by a single individual over a few decades. A knowledge of the
literature, the standards and custom in a field is a critical part of safety
engineering. A combination of theory and track record of practices is involved,
and track record indicates some of the areas of theory that are relevant. (In
the USA, persons with a state license in Professional Engineering in Electrical
Engineering are expected to be competent in this regard, the foregoing
notwithstanding, but most electrical engineers have no need of the license for
their work.)
Safety
is often seen as one of a group of related disciplines: quality, reliability,
availability, maintainability and safety. (Availability is sometimes not
mentioned, on the principle that it is a simple function of reliability and
maintainability.) These issues tend to determine the value of any work, and
deficits in any of these areas are considered to result in a cost, beyond the
cost of addressing the area in the first place; good management is then
expected to minimize total cost.
Safety measures are activities and precautions
taken to improve safety, i.e. reduce risk related to human health. Common
safety measures include:
Visual examination for dangerous
situations such as
emergency exits blocked because they are being used as storage areas.
Visual examination for flaws such as cracks, peeling, loose
connections.
X-ray analysis to see inside a sealed object such
as a weld, a cement wall or an airplane outer skin.
Destructive testing of samples
Stress testing subjects a person or product to
stresses in excess of those the person or product is designed to handle, to
determining the "breaking point".
Safety margins/Safety factors. For instance, a product rated to
never be required to handle more than 200 pounds might be designed to fail
under at least 400 pounds, a safety factor of two. Higher numbers are used in
more sensitive applications such as medical or transit safety.
Implementation of standard
protocols and procedures so that activities are conducted in a known way.
Training of employees, vendors, product
users
Instruction manuals explaining how to use a product or perform an activity
Instructional videos demonstrating proper use of
products
Examination of activities by
specialists
to minimize physical stress or increase productivity
Government regulation so suppliers know what standards their product is expected
to meet.
Industry regulation so suppliers know what level of
quality is expected. Industry regulation is often imposed to avoid potential
government regulation.
Self-imposed regulation of various types.
Statements of Ethics by industry organizations or an
individual company so its employees know what is expected of them.
Drug testing of employees, etc.
Physical examinations to determine whether a person has a physical condition that
would create a problem.
Periodic evaluations of employees, departments, etc.
Geological surveys to determine whether land or water
sources are polluted, how firm the ground is at a potential building site, etc.
Standards organizations
A
number of standards organizations exist that promulgate safety
standards. These may be voluntary organizations or government agencies.
A
major American standards organization
is the American National
Standards Institute (ANSI). Usually, members of a
particular industry will voluntarily form a committee to study safety issues
and propose standards. Those standards are then recommended to ANSI, which
reviews and adopts them. Many government regulations require that products sold
or used must comply with a particular ANSI standard.
Product
safety testing, for the United States, is largely controlled by the Consumer
Product Safety Commission. In addition, work-place related products come under
the jurisdction of OSHA[which certifies independent testing companies
as Nationally Recognized Testing Laboratories (NRTL), .
For
other countries, there are many other organizations that have accreditation to
test and/or submit test reports for safety certification. These are typically
referred to as a Notified or Competent Body. The most common is the IECEE
Certification Body Scheme,
Electricity
(from New
Latin ēlectricus, "amber-like")
is a general term that encompasses a variety of phenomena resulting from the
presence and flow of electric
charge. These include many easily recognisable phenomena
such as lightning and static electricity,
but in addition, less familiar concepts such as the electromagnetic field
and electromagnetic induction.
In
general usage, the word 'electricity' is adequate to refer to a number of
physical effects. However, in scientific usage, the term is vague, and these
related, but distinct, concepts are better identified by more precise terms:
Electric
charge – a property of some subatomic particles,
which determines their electromagnetic interactions.
Electrically charged matter is influenced by, and produces, electromagnetic
fields.
Electric
current – a movement or flow of electrically
charged particles, typically measured in amperes.
Electric
field – an influence produced by an electric charge on
other charges in its vicinity.
Electromagnetism
– a fundamental interaction
between the electric field and the presence and motion of electric charge.
Electricity
has been studied since antiquity, though scientific advances were not
forthcoming until the seventeenth and eighteenth centuries. It would remain
however until the late nineteenth century that engineers
were able to put electricity to industrial and residential use, a time which
witnessed a rapid expansion in the development of electrical technology.
Electricity's extraordinary versatility as a source of energy means it can be
put to an almost limitless set of applications which include transport,
heating,
lighting,
communications,
and computation. The backbone of
modern industrial society is, and for the foreseeable future can be expected to
remain, the use of electrical pow.
The presence of charge
gives rise to the electromagnetic force: charges exert a force on each other, an
A fire extinguisher is an active fire protection device used to extinguish or control small fires, often in
emergency situations. Typically, a fire extinguisher consists of a handheld
cylindrical pressure vessel containing an agent
which can be discharged to extinguish a fire.
The typical steps for operating a stored pressure fire
extinguisher (described by the acronym "PASS") are the following:
P
- Pull the safety pin
A
- Aim the nozzle at the base of the fire, from a safe distance (*about 1 to 3
meters (4 to 10 feet) away)
S
- Squeeze the handle
S
- Sweep the extinguisher from side to side while aiming at the base of the fire
The
approximate starting distance varies by the size and type of the extinguisher.
If
using a cartridge operated extinguisher you must push down on the cartridge
puncturing lever to pressurize the extinguisher after pulling the pin.
CO2
fire extinguishers usually have a horn-shaped nozzle. Do not touch this horn
(or the pipe linking it to the extinguisher) when attempting to put out a fire
- your hand may freeze to the extinguisher, unless it is equipped with what is
called a Frost Horn.
There
are various types of extinguishers, which are used for different types of
fires; using the wrong type can worsen the fire hazard, but using the right one
can better the situation.
The first automatic fire extinguisher of which there is any record
was patented in England in 1723 by Ambrose Godfrey, a celebrated chemist. It
consisted of a cask of fire-extinguishing liquid containing a pewter chamber of
gunpowder. This was connected with a system of fuses which were ignited,
exploding the gunpowder and scattering the solution. This device was probably
used to a limited extent, as Bradley's Weekly Messenger for November 7, 1729,
refers to its efficiency in stopping a fire in London.
Fire classes
In firefighting, fires are
organized into several fire classes that describe what kind of fuel or
heat source it has, and by extension what methods will be necessary to contain
it or put it out.
This article primarily deals with the United States system of
classifying fires. See the section below for the European and Australasian
classifications, and note the table to the right which indicates the
relationship between the two sets.
Class-A fires:
Class-A fires are the most common type of fire, that occurs when a
material such as wood becomes sufficiently hot, and has oxygen available to it, causing combustion. At this point the material bursts into flame, and will continue
burning as long as the fire tetrahedron (heat, fuel, oxygen, and chemical
reaction) continues to be available to it.
Class-A fires are used all around buildings and everywhere in the
world in controlled circumstances, such as a campfire, lighter, match, or candle. This makes an example easy to come by. For example, a campfire
has a fire triangle - the heat is provided by another fire (such as a match or
lighter), the fuel is the wood, and the oxygen is naturally available in the open-air
environment of a forest. This fire is not dangerous, because the fire is
contained to the wood alone and is usually isolated from the ground by rocks.
However, when a class-A fire burns in an environment where fuel and oxygen are
in accessible positions, the fire can quickly grow out of control; this is the
case where firefighting and fire
control techniques are required.
Class-A
fires are fairly simple to fight and contain - by simply removing the heat or
oxygen (or in some cases fuel), the fire triangle collapses and the fire dies
out. The most common way to do this is by removing heat and oxygen by spraying
the burning material with water.
Other means of control or containment would be to "smother" the fire
with carbon dioxide
or nitrogen
from a fire extinguisher,
cutting off its oxygen and causing the fire to die.
Class-A
fires are the most commonly encountered fires, and as such most fire
departments have equipment to handle them
specifically. While this is acceptable for most ordinary conditions, most
firefighters find themselves having to call for special equipment such as foam
in the case of other fires.
Class-B fires: Class-B
fires involve flammable or combustible fuels. These fires follow the same basic
fire triangle (heat, fuel, and oxygen) as class-A fires, except that the fuel
in question is a flammable liquid such as gasoline. A solid stream of water
should never be used to extinguish this type because it can cause the fuel to
scatter, spreading the flames. The most effective way to extinguish a class B
fire is by inhibiting the chain reaction of the fire, which is done by dry
chemical and halon extinguishing agents, although smothering with CO2 or foam
is also effective. Some newer clean agents designed to replace halon work by
cooling the liquid below its flash point, but these have limited class B
effectiveness.
Class-C fires: Class-C
fires are electrical fires, where the heat
side of the fire triangle is caused by, for example, short-circuiting machinery
or overloaded electrical outlets. These fires can be a severe hazard to
firefighters using water: when the solid stream of water hits the electrical
fire, the electricity is conducted through it and into the hose, then into the
firefighter's body. Electrical
shocks have caused many firefighter deaths.
There
are two main ways of fighting a class-C fire: cutting off its oxygen, or simply
turning off the electricity to the fire from a breaker.
A class-C fire can be put out with a fire extinguisher rated for class-C fires,
or with protein foam, but the primary approach is to simply turn off the power
as noted above. This causes the fire to become an ordinary class-A fire, or
perhaps to die out entirely. The agents used to extinguish fire of class-c are
sodium bicarbonate, carbon dioxide, halons, potassium bicarbonate and PKP.
Class-D fires: Class-D
fires are metal fires. Certain metals, such as sodium,
titanium,
magnesium,
potassium,
uranium,
lithium,
plutonium,
calcium
and others are flammable. Magnesium and titanium fires are common. When one of
these combustible metals ignites, it can easily and rapidly spread to
surrounding class-A materials.
Generally,
masses of combustible metals do not represent unusual fire risks because they
have the ability to conduct heat away from hot spots so efficiently that the
heat of combustion cannot be maintained - this means that it will require a lot
of heat to ignite a mass of combustible metal. Generally, metal fire risks
exist when sawdust, machine shavings and other metal 'fines' are present.
Generally, these fines can be ignited by the same types of ignition sources
that would start other common fires.
Water
and other common firefighting materials can excite metal fires and make them
worse. The NFPA recommends that class D fires be fought with 'dry powder'
extinguishing agents. Dry Powder agents work by smothering and heat absorption.
The most common of these agents are sodium chloride granules and graphite
powder. In recent years powdered copper has also come into use.
Some
extinguishers use dry chemical extinguishing agents. This is easily
confusable with dry powder. They are quite different, and using one of
these extinguishers in error in place of dry powder can actually increase the
size of a class D fire much like water.
Class-D
fires represent a unique hazard because people are often not aware of the
characteristics of these fires and are not properly prepared to fight them.
Therefore, even a small class-D fire can spread class-A fires to the
surrounding combustible materials. Most fire stations do not have class-D
extinguishing agents available to them, making fighting these fires a
logistical problem - however, in most places where these materials are found
there is a hopper filled with the proper extinguishing agent.
Though
by definition, Class-K is a subclass of Class-B, the special characteristics of
these types of fires are considered important enough to recognize. Saponification
can be used to extinguish such fires.
Appropriate
fire extinguishers may also have hoods over them that help extinguish the fire.
Types of extinguishing agents
Dry
Chemical Powder based agent that extinguishes by separating the four parts of
the fire tetrahegon. It prevents the chemical reaction between heat, fuel and
oxygen. Thus extinguishing the fire. Contrary to some beliefs dry chemical
agents do not cool or smother a fire.
Ammonium phosphate,
used on class A, B, and C fires. It receives its class A rating from the agents
ability to melt and flow at 177 °C (350 °F) to smother the fire. More corrosive
than other dry chemical agents. ABC
Dry Chemical
Sodium bicarbonate,
used on class B and C fires. Interrupts the fire's chemical reaction.
Potassium bicarbonate
(aka Purple-K), used on class B and C fires. About two times as effective on
class B fires as sodium bicarbonate. The preferred dry chemical agent of the
oil and gas industry. The only dry chemical agent certified for use in AR-FF by
the NFPA.
Potassium
bicarbonate & Urea Complex (aka Monnex), used on
Class B and C fires. More effective than all other powders due to its ability
to decrepitate (where the powder breaks up into smaller particles) in the flame
zone creating a larger surface area for free radical inhibiton.
Foams:
Applied to fuel fires as either an aspirated (mixed & expanded with air in
a branch pipe) or non aspirated form to form a frothy blanket or seal over the
fuel, preventing oxygen reaching it. Unlike powder, foam can be used to
progressively extinguish fires without flashback
AFFF
(aqueous film forming foam), used on A and B fires and for vapor suppression.
The most common type in portable extinguishers. It contains flour tensides which can be accumulated in human body.
AR-AFFF
(Alcohol-resistant aqueous film forming foams), used on fuel fires containing
alcohol. Forms a membrane between
the fuel and the foam preventing the alcohol from breaking down the foam
blanket.
FFFP
(film forming fluoroprotein) contains naturally occurring proteins from animal
fats to create a foam blanket that is more heat resistant then the synthetic
AFFF foams.
CAFS
(compressed air foam system) Any APW style extinguisher that is charged with a
foam solution and pressurized with compressed air. Generally used to extend a
water supply in wildland operations. Used on class A fires and with very dry
foam on class B for vapor suppression.
Arctic
Fire
is a liquid fire extinguishing agent that emulsifies and cools heated materials
quicker than water or ordinary foam. It is used extensively in the steel
industry. Effective on classes A, B, and D.
FireAde,
a foaming agent that emulsifies burning liquids and renders them non-flammable.
It is able to cool heated material and surfaces similar to CAFS. Used on A and
B (said to be effective on some class D hazards, although not recommended due
to the fact that fireade still contains amounts of water which will react with
some metal fires).
APW
(Air pressurized water)
cools burning material by absorbing heat from burning material. Effective on
only Class A fires, but has the advantage of being cheap, harmless, and
relatively easy to clean up.
Water
Mist uses a fine misting nozzle to break up a stream of deionized water to the
point of not conducting electricity back to the operator. Class A and C rated.
Used widely in Hospitals.
Wet
Chemical (potassium
acetate) extinguishes the fire by forming a soapy foam
blanket over the burning oil(saponification)and by cooling the oil below its
ignition temperature. Generally class A and K (F in Europe) only.
Wetting Agents
Detergent based additives used to break the surface tension of water &
improve penetration of Class A fires. Enables a 3 litre water extinguisher to
achieve the fire fighting capacity of a 9 litre plain water type
Agent
does not extinguish by smothering, but displaces oxygen, or inhibits chemical
chain reaction. They are labeled clean agents because they do not leave any
residue after discharge which is ideal for sensitive electronics and documents.
Halon
(including Halon 1211
and Halon 1301),
a gaseous agent that inhibits the chemical reaction of the fire. Classes B:C
for lower weight fire extinguishers (2.3 kg ; 5 lbs or less) and A:B:C for
heavier weights (4.1-7.7 kg ; 9-17 lbs). Banned from new production,
except for military use, as of January 1, 1994 as its properties contribute to
ozone depletion and long atmospheric lifetime, usually 400 years. Halon was
completely banned in Europe resulting in stockpiles being sent to the United
States for reuse. Although production has been banned, the reuse is still
permitted. Halon 1301 and 1211 are being replaced with new halons which have no
ozone depletion properties and low atmospheric lifetimes, but are less
effective.
CO2,
a clean gaseous agent which displaces oxygen. Highest rating for 7.7 kg (20
pound) portable CO2 extinguishers is 10B:C. Not intended for Class A
fires.
Sodium
Chloride/Bicarbonate Urea Graphite
and Copper
forms a crust over the burning metal and performs like a heat sink to draw heat
away from the burning material, also smothers to a degree. Copper dry powder
was developed by the U.S. Navy for lithium fires and will cling to vertical
surfaces.
Australia
Type
|
Pre-1997
|
Current
|
Class
|
||||
Water
|
Solid red
|
A
|
|||||
Foam
|
Solid blue
|
Red with a blue band
|
A
|
B
|
|||
Dry Chemical (Powder)
|
Red with a white band
|
A
|
B
|
C
|
E
|
||
Carbon dioxide
|
Red with a black band
|
A (limited)
|
B
|
C
|
E
|
F
|
|
Vapourising liquid
(not halon)
|
Red with a yellow band
|
A
|
B
|
C
|
E
|
||
Halon
|
Solid yellow
|
—
|
A
|
B
|
E
|
||
Wet Chemical
|
Solid oatmeal
|
Red with an oatmeal
band
|
A
|
F
|
|||
UK
Type
|
Old Code
|
BS EN 3 Colour Code
|
Fire Class
|
|||||
Water
|
Signal Red
|
Signal Red
|
A
|
|||||
Foam
|
Cream
|
Red with a Cream panel
above the operating instructions
|
A
|
B
|
sometimes E
|
|||
Dry Powder
|
French Blue
|
Red with a Blue panel
above the operating instructions
|
A
|
B
|
sometimes C
|
E
|
||
Carbon Dioxide CO2
|
Black
|
Red with a Black panel
above the operating instructions
|
B
|
E
|
||||
Halon
|
Emerald Green
|
Pre-03- Signal red
with a green panel
|
A
|
B
|
E
|
|||
Wet Chemical
|
No F Class
|
Red with a Canary
Yellow panel above the operating instructions
|
A
|
F
|
||||
Class D Powder
|
French Blue
|
Red with a Blue panel
above the operating instructions
|
D
|
|||||
A fire alarm system is an active fire protection system that detects fire or the effects of fire, and as a result
provides one or more of the following: notifies the occupants, notifies persons
in the surrounding area, summons the fire service, and controls all the fire
alarm components in a building. Fire alarm systems can include alarm initiating
devices, alarm notification appliances, control units, fire safety control
devices, annunciators, power supplies, and wiring
Fire alarm systems have devices connected to them to detect smoke
and heat, or to alert the occupants of an emergency. Below is a list of common
devices found on a fire alarm.
Manual pull stations/manual
call points - Devices to allow people to manually
activate the fire alarm. Usually located near exits. Also called "manual
pull boxes". Other countries have different devices as standard, for
example the UK uses 'break-glass callpoints', when people break a small pane of
glass to activate the alarm.
Smoke
detectors - Spot type: Photoelectric and Ionization; Line
type: Projected Beam Smoke Detector; Air-Sampling type: Cloud Chamber
Water
Flow Switches - Detect when water is flowing through the fire sprinkler system
Rate-of-Rise
and Thermostat (heat) Detectors - Detect heat changes
Valve
Supervisory Switch - Indicates that a fire sprinkler system valve that is
required to be open, is now closed (off-normal).
Carbon Monoxide Detectors
- Detects poisonous carbon
monoxide gas and usually only connected to household fire
alarm systems. Very rarely seen in commercial systems.
A fire sprinkler is the part of a fire sprinkler system that discharges water when the effects of a fire have been
detected, such as when a predetermined temperature has been reached.
Fire sprinklers can be automatic or open orifice. Automatic fire
sprinklers operate at a predetermined temperature, utilizing a fusible link, a
portion of which melts, or a frangible glass bulb containing liquid which
breaks, allowing the plug in the orifice to be pushed out of the orifice by the
water pressure in the fire sprinkler piping, resulting in water flow from the
orifice. The water stream impacts a deflector, which produces a specific spray
pattern designed in support of the goals of the sprinkler type (i.e., control
or suppression). Modern sprinkler heads are designed to direct spray downwards.
Spray nozzles are available to provide spray in various directions and
patterns. The majority of automatic fire sprinklers operate individually in a fire.
Contrary to motion picture representation, the entire sprinkler system does not
activate, unless the system is a special deluge type.
Gaseous fire suppression is a term to describe
the use of inert gases and chemical agents to
extinguish a fire. The system typically
consists of the agent, agent storage containers, agent release valves, fire
detectors, fire detection system (wiring control panel, actuation signaling),
agent delivery piping, and agent dispersion nozzles.
Less typically, the agent
may be delivered by means of solid propellant gas generators that produce either
inert or chemically active gas.
Canisters containing Argon gas for use in extinguishing fire in a server room without damaging
equipment
A heat detector is
a device that detects heat and can be either electrical or mechanical in
operation. The most common types are the thermocouple and the
electro-pneumatic, both respond to changes in ambient
temperature. Typically, if the ambient temperature rises above a
predetermined threshold, then an alarm signal is
triggered.
Heat detectors can also
be further broken down into two main classifications, "rate-of-rise"
and "fixed" or "rate compensated."
Electro-pneumatic heat detector, rate of rise and fixed
temperature operation.
A smoke detector or smoke alarm is a device that
detects smoke and issues an alarm to alert nearby people that there is a potential fire. A household smoke detector will typically be mounted in a disk
shaped plastic enclosure about 150mm in diameter and 25mm thick, but the shape
can vary by manufacturer.
A fire drill is a method of practicing the evacuation of a
building for a fire or other emergency.
Generally, the emergency system (usually an alarm) is activated and the building is evacuated as though a real fire
had occurred. Usually, the time it takes to evacuate is measured to ensure that
it occurs within a reasonable length of time.
Security
Security
is the condition of being protected against danger or loss. In the general
sense, security is a concept similar to safety.
The nuance between the two is an added emphasis on being protected from dangers
that originate from outside. Individuals or actions that encroach upon the
condition of protection are responsible for the breach of security.
The
word "security" in general usage is synonymous with
"safety," but as a technical term "security" means that
something not only is secure but that it has been secured. In telecommunications,
the term security has the following meanings:
A
condition that results from the establishment and maintenance
of protective measures that ensure a state of inviolability from hostile acts
or influences.
With
respect to classified matter, the condition that prevents unauthorized persons
from having access
to official information that is safeguarded in
the interests of national security.
Measures
taken by a military unit, an activity or installation to protect itself against
all acts designed to, or which may, impair its effectiveness.
Security
has to be compared and contrasted with other related concepts: Safety,
continuity,
reliability.
The key difference between security and reliability is that security must take
into account the actions of active malicious agents attempting to cause
destruction.
Security concepts:
Certain concepts recur throughout different fields of security.
Risk
- a risk is a possible event which could cause a loss
Threat
- a threat is a method of triggering a risk event that is dangerous
Vulnerability
- a weakness in a target that can potentially be exploited by a threat
Exploit
- a vulnerability that has been triggered by a threat - a risk of 1.0 (100%)
Countermeasure
- a countermeasure is a way to stop a threat from triggering a risk event
Defense
in depth - never rely on one single security measure alone
Assurance
- assurance is the level of guarantee that a security system will behave as
expected
A
security guard or security officer is usually a privately and formally employed
person who is paid to protect property,
assets, and/or people. Often, security officers are uniformed
and act to protect property by maintaining a high visibility presence to deter
illegal and/or inappropriate actions, observing (either directly, through
patrols, or by watching alarm
systems or video cameras)
for signs of crime,
fire or disorder; then taking action and/or reporting any incidents to their
client, employer and emergency services
as appropriate. Since at least the Middle
Ages
in Europe,
the term watchman was more commonly applied to this function.
"detect, deter, observe and report" methodology
Occupational safety and health (OSH) is a cross-disciplinary area concerned with
protecting the safety, health and welfare of people engaged in work or employment and entrants. As a
secondary effect, OSH may also protect co-workers, family members, employers,
customers, suppliers, nearby communities, and other members of the public who
are impacted by the workplace environment.
Since 1950, the International Labour Organization (ILO) and the World
Health Organization (WHO) have shared a common definition of occupational health. It
was adopted by the Joint ILO/WHO Committee on Occupational Health at its first
session in 1950 and revised at its twelfth session in 1995. The definition
reads: "Occupational health should aim at: the promotion and maintenance
of the highest degree of physical, mental and social well-being of workers in
all occupations; the prevention amongst workers of departures from health
caused by their working conditions; the protection of workers in their
employment from risks resulting from factors adverse to health; the placing and
maintenance of the worker in an occupational environment adapted to his
physiological and psychological capabilities; and, to summarize, the adaptation
of work to man and of each man to his job."
The reasons for
establishing good occupational safety and health standards are frequently
identified as:
Moral
- An employee should not have to risk injury at work, nor should others
associated with the work environment.
Economic
- many governments realize that poor
occupational safety and health performance results in cost to the State (e.g.
through social security
payments to the incapacitated, costs for medical treatment, and the loss of the
"employability" of the worker).
Employing organisations also sustain costs in the event of an incident at work
(such as legal fees, fines, compensatory damages, investigation time, lost
production, lost goodwill from the workforce, from customers and from the wider
community).
Legal
- Occupational safety and health requirements may be reinforced in civil law
and/or criminal law; it is accepted that
without the extra "encouragement" of potential regulatory action or
litigation, many organisations would not act upon their implied moral
obligations.
The
terminology used in OSH varies between states, but generally speaking:
The
outcome is the harm that results from an uncontrolled hazard.
A
risk is a combination of the
probability that a particular outcome will occur and the severity of the harm
involved.
“Hazard”, “risk”, and “outcome” are
used in other fields to describe e.g. environmental damage, or damage to
equipment.
Modern
occupational safety and health legislation usually demands that a risk assessment be carried out prior to making an
intervention. This assessment should:
Identify
the hazards
Identify
all affected by the hazard and how
Evaluate
the risk
Identify
and prioritise the required actions
The
calculation of risk is based on the likelihood or probability of the harm being
realised and the severity of the consequences. This can be
expressed mathematically as a quantitative assessment (by
assigning low, medium and high likelihood and severity with integers and
multiplying them to give a risk factor), or as a description
of the circumstances by which the harm could arise i.e. qualitative
Workplace hazards are often grouped
into physical hazards,
physical agents,
chemical agents,
biological agents,
and psychosocial issues.
Physical hazards include:
Physical agents
include:
Chemical agents, include
Psychosocial
issues include:
Violence from outside the organisation
Other
issues include:
Government organizations
WSIB
(Ontario, Canada)
International
Labour Organisation (United Nations)
Process Safety Management is a
regulation, promulgated by the U.S.
Occupational Safety and Health Administration (OSHA),
intended to prevent an incident like the 1984 Bhopal
Disaster. A process is any activity or combination of
activities including any use, storage, manufacturing, handling or the on-site
movement of Highly Hazardous Chemicals (HHC's). A process includes any group of
vessels which are interconnected or separate and contain HHC's which could be
involved in a potential release. A process safety incident is the
"Unexpected release of toxic, reactive, or flammable liquids and gases in processes involving highly hazardous chemicals. Incidents continue to occur in various industries that use
highly hazardous chemicals which exhibit toxic, reactive, flammable, or even explosive properties, or may exhibit a combination of these properties.
Regardless of the industry that uses these highly hazardous chemicals, there is
a potential for an accidental release any time they are not properly controlled. This, in turn, creates
the possibility of disaster. To help assure safe and healthy workplaces, OSHA
has issued the Process Safety Management of Highly Hazardous Chemicals
regulation (Title 29 of CFR Section
1910.119)[1] which contains requirements for the management of hazards
associated with processes using highly hazardous chemicals.
A great many industrial facilities must comply with OSHA's Process
Safety Management (PSM) regulations as well as the quite similar EPA Risk Management Program (RMP)
regulations (Title 40 CFR Part 68). The EPA has published a model RMP plan for
an ammonia refrigeration facility[3] which
provides excellent guidance on how to comply with either OSHA's PSM regulations or the EPA's RMP
regulations.
The Center for Chemical
Process Safety (CCPS) of the American Institute of Chemical Engineers (AIChE) has published a widely used book that
explains various methods for identifying hazards in industrial facilities and
quantifying their potential severity
Today I will say that this is an amazing article that's all I can say. If you want to read something amazing then you must read this article that will provide you an ample ammount of Information.
ReplyDeleteProperty in Adai