risk assessment work place
Post on 01-Jun-2018
223 Views
Preview:
TRANSCRIPT
-
8/9/2019 Risk Assessment Work Place
1/54
Risk Assessment &
Management
Health & Safety Management for Quarries
Topic Five
-
8/9/2019 Risk Assessment Work Place
2/54
Objectives of this Section
• Introduce the concept of risk assessment andrisk management and its role within UK health
and safety legislation.
•To define the principle components of riskmanagement.
• To outline advanced risk assessment
methodologies for use in QRAs.
• To outline a practical risk assessmentprocess.
-
8/9/2019 Risk Assessment Work Place
3/54
Principals of Risk Management
Risk management can !e defined as"
The eradication or minimisation of the adverseaffects of risks to which an organisation is
exposed.
-
8/9/2019 Risk Assessment Work Place
4/54
Stages in Risk Management
• Identifying the ha#ards.
• $valuating the associated risks.
• %ontrolling the risks.
-
8/9/2019 Risk Assessment Work Place
5/54
Activity%haracterisation
&a#ard Identification
Risk $stimation
Implementation
Monitoring
Audit or Review
'ption Analysis
(ecision )aking
RI*K )A+A,$)$+T
RI*K A**$**)$+T
RI*K R$(U%TI'+
-
8/9/2019 Risk Assessment Work Place
6/54
Regulation -/0 of the 1)anagement of &ealthand *afety at 2ork Regulations /334 states"5
• ‘very mployer shall make a suita!le and efficientassessment of"#
a$ The risks to the health and safety of his employees to
which they are exposed whilst they are at work.!$ The risks to the health and safety of persons not in his
employment arising out of or in connection with the conduct !yhim or his undertaking%
• or the purpose of identifying the measures he needs
to take to comply with the re'uirements and prohi!itions imposed on him !y or under the relevantstatutory provisions.(
-
8/9/2019 Risk Assessment Work Place
7/54
Risk assessment can !e a
1very straightforward process !ased on
)udgement re'uiring no specialist skills orcomplicated techni'ues.
This approach is commonly known as'alitative or s'bjective risk assessment(
-
8/9/2019 Risk Assessment Work Place
8/54
Major )a*ar+s
• )a6or ha#ards associated with comple7chemical or nuclear plants8 may 1warrant the
need of such techni'ues as Quantitative *isk
+ssessment .
• In Quantitative Risk Assessment ,-RA. a
numerical estimate is made of the pro!a!ility
that a defined harm will result from the
occurrence of a particular event.
-
8/9/2019 Risk Assessment Work Place
9/54
The Risk Management Process
)a*ar+ I+entification
Hazard :
The potential to cause harm. Harm including ill
health and in)ury, damage to property, plant,
products or the environment, production losses
or increased lia!ilities.
-
8/9/2019 Risk Assessment Work Place
10/54
)a*ar+ I+entification
• Comparative Methods. e.g. checklists andaudits.
• Fundamental Methods" e.g. (eviation Analysis8 &a#ard and 'pera!ility *tudies8$nergy Analysis8 9ailure )odes : $ffects
Analysis.
• Failure Logic " e.g. 9ault Trees8 $vent Trees :%ause5 %onse;uence diagrams
-
8/9/2019 Risk Assessment Work Place
11/54
Assessing the Risks
Risk:
The likelihood that a specified undesired
event will occur due to the realisation of aha-ard !y, or during work activities or !ythe products and services created !ywork activities.
-
8/9/2019 Risk Assessment Work Place
12/54
Assessing the Risks
Quantitative risk assessment
• %ommonly used in the high technology
industries
• QRA tends to deal with the avoidance of
low pro!a!ility events with serious
conse;uences to the plant and the
surrounding environment.
-
8/9/2019 Risk Assessment Work Place
13/54
Assessing the Risks
Su!)ective risk assessment
•Qualitative risk assessment involves making a formal 6udgement on the conse;uence and pro!a!ility using"
*isk Severity x /ikelihood
-
8/9/2019 Risk Assessment Work Place
14/54
Assessing the Risks
$7ample"The likely effect of a ha#ard may for e7ample !e rated"
/( Major
(eath or ma6or in6ury or illness causing long term disa!ility
0( Serio's
In6uries or illness causing short5term disa!ility
1( Slight
All other in6uries or illnesses
-
8/9/2019 Risk Assessment Work Place
15/54
Assessing the Risks
The likelihood of harm may !e rated
/( )igh
2here it is certain that harm will occur
0( Me+i'm
2here harm will often occur
1( !o2
2here harm will seldom occur
-
8/9/2019 Risk Assessment Work Place
16/54
Assessing the Risks
Risk
<
*everity of &arm
7=ikelihood of occurrence
• This simple computation gives a risk value of !etween / and 3
ena!ling a rough and ready comparison of risks.• In this case the lower the num!er8 the greater the risk8 and soprioritises the ha#ards so that control action can !e targeted athigher risks.
-
8/9/2019 Risk Assessment Work Place
17/54
3ontrolling Risk
• Risk Avoi+ance > This strategy involves aconscious decision on the part of the organisation to
avoid completely a particular risk !y discontinuing the
operation producing the risk e.g. the replacing a
ha#ardous chemical !y one with less or no risk
potential.
• Risk Retention > The risk is retained in theorganisation where any conse;uent loss is financed
!y the company. There are two aspects to consider
here8 risk retention with knowledge and risk retention
without knowledge.
-
8/9/2019 Risk Assessment Work Place
18/54
3ontrolling Risk
• Risk Transfer > This refers to the legalassignment of the costs of certain potential losses
from one party to another. The most common way is!y insurance.
• Risk Re+'ction > &ere the risks aresystematically reduced through control measures8
according to the hierarchy of risk control descri!ed inearlier sections.
-
8/9/2019 Risk Assessment Work Place
19/54
A!ARP
• =egislation re;uires employers to reducerisks to a level that is as low as is reasona!lypractica!le sometimes a!!reviated as
A=AR?0.
• To carry out a duty so far as is reasona!ly practica!le means that the degree of risk in aparticular activity or environment can !e!alanced against the time8 trou!le8 cost andphysical difficulty of taking measures to avoidthe risk.
-
8/9/2019 Risk Assessment Work Place
20/54
T4pes of Risk Assessment
0ithin 1ndustry, three types of riskassessment can !e distinguished"
• Assessments of large scale comple7 ha#ard sites8
such as those found in the process and nuclear
industries. These re;uire QRAs• ,eneral assessments of the complete range of
workplace risks > as re;uired under the )anagement
of &ealth : *afety at 2ork Regulations8 /333.
• Risk Assessments re;uired under specific legislation > for e7ample for ha#ardous su!stances %'*&&
Regulations8 /33@08 )anual &andling )anual
&andling 'perations Regulations8 /3340.
-
8/9/2019 Risk Assessment Work Place
21/54
-
8/9/2019 Risk Assessment Work Place
22/54
-'antitative Risk Assessment ,/.
• In+ivi+'al Risk is defined as 1the fre;uency atwhich an individual may !e e7pected to sustain a
given level of harm from the realisation of specificha#ards.
• Societal Risk
-
8/9/2019 Risk Assessment Work Place
23/54
Usually e7pressed as risk contours"
%&='RI+$
I+*TA==ATI'+
/5BCyear
risk contour
.-D/5BCyearrisk contour
*ite for
proposed
developmen
EI==A,$
/5FCyear
risk contour
/ km
-
8/9/2019 Risk Assessment Work Place
24/54
-'antitative Risk Assessment5
Acceptance 3riteria
• The &*$ state that 1!roadly, a risk of death of 2 in
2333 42x23#5
$ per annum is a!out the most that isordinarily accepted under modern conditions for
workers in the 67 and it seems to !e the dividing line
!etween what is tolera!le and what is intolera!le( .
-
8/9/2019 Risk Assessment Work Place
25/54
Fail're Mo+es an+ #ffect Anal4sis
The system is divided into su! systems that
can !e handled effectively.
1t involves"• Identification of the component and parent system.
• 9ailure mode and cause of failure.
• $ffect of the failure on the su!system or system.
• )ethod of detection and diagnostic aids availa!le.
-
8/9/2019 Risk Assessment Work Place
26/54
Fail're Mo+es an+ #ffect Anal4sis
A typical format"
%omponent 9unction 9ailure
)ode
9ailure
Rate
9ailure
$ffect
%riticality (etection
)ethod
?reventative
)easures
-
8/9/2019 Risk Assessment Work Place
27/54
Fail're Mo+es an+ #ffect Anal4sis
• 9or each components functions8 every conceiva!lemode of failure is identified and recorded.
• It is also common to rate the failure rate for each
failure mode identified.• The potential conse;uences for each failure must !e
identified along with its effects on other e;uipment8components within the rest of the system.
• It is then necessary to record preventative measuresthat are in place or may !e introduced to correct thefailure8 reduce its failure rate or provide someade;uate form of detection.
-
8/9/2019 Risk Assessment Work Place
28/54
)a*ar+ & Operabilit4 St'+ies
• &a#ard and 'pera!ility *tudies&AG'?0 have !een used for manyyears as a formal means for the reviewof chemical process designs.
• A &AG'? study is a systematic searchfor ha#ards which are defined asdeviations within these parameters thatmay have dangerous conse;uences.
• In the process industry8 these deviations
concern process parameters such asflow8 temperature8 pressure etc.
-
8/9/2019 Risk Assessment Work Place
29/54
-
8/9/2019 Risk Assessment Work Place
30/54
The process is as follows"
The system is divided into suita!le parts or su!5systems8which are then analysed one at a time.
9or each su!5system each parameter flow8 temperature8pressure8 volume8 viscosity etc.0 that has an influence on it8is noted.
,uidewords are applied to each parameter in eachsu!system. The intention is to prompt creative discussion ofdeviations and possi!le conse;uences
9or each significant deviation8 possi!le causes are
identified.
)a*ar+ & Operabilit4 St'+ies
-
8/9/2019 Risk Assessment Work Place
31/54
)a*ar+ & Operabilit4 St'+ies
+' or +'T +o part of the design intent occurs8 such as no flow in a
pipeline due to !lockage.
)'R$ or =$** A ;uantitative increase or decrease of some parameter8 such
as flow8 temperature etc.
A* 2$== A* All the design intentions are fulfilled and something happens
in addition
?ART '9 'nly part of the design intention is fulfilled
R$E$R*$ The logical opposite of the design intention occurs
,uideword (efinitions
'T&$R T&A+ *omething completely different than attended occurs
-
8/9/2019 Risk Assessment Work Place
32/54
)a*ar+ & Operabilit4 St'+ies
#6ample• %onsider the simple process diagram !elow. It
represents a plant where su!stances A and H react
with each other to form a new su!stance %. If there is
more H than A there may !e an e7plosion.
A
H
E/E4
E-
E
EF
A 7 8 9 #6plosion %
$7ample from &arms Ringdahl = /33F08 *afety Analysis" ?rincipals and ?ractice in
'ccupational *afety8 $lsevier Applied *cience.
-
8/9/2019 Risk Assessment Work Place
33/54
The &AG'? sheet for the section of the plant from A to % will !e as
follows"
,uide 2ord (eviation ?ossi!le %auses %onse;uences ?roposed
)easures
+'8 +'T +o A Tank containing A is empty.
E/ or E4 closed.
?ump does not work.
?ipe !roken
+ot enough A <
$7plosion
Indicator for low
level.
)onitoring of flow
)'R$ Too much A ?ump too high capacity
'pening of E/ or E4 is too
large.
% contaminated !y
A. Tank overfilled.
Indicator for high
level.
)onitoring of flow
=$** +ot enough A
E/8E4 or pipe are partially!locked. ?ump gives low flow or
runs for too short a time.
+ot enough A <$7plosion
*ee a!ove
A* 2$== A* 'ther
su!stance
E- open > air sucked in +ot enough A <
$7plosion
9low monitoring
!ased on weight
R$E$R*$ =i;uid
pumped
!ackwards
2rong connector to motor +ot enough A <
$7plosion
A is contaminated
9low monitoring
'T&$R
T&A+
A !oils in
pump
Temperature too high +ot enough A <
$7plosion
Temperature and
flow0 monitoring.
$7ample from &arms Ringdahl = /33F08 *afety Analysis" ?rincipals and ?ractice in
'ccupational *afety8 $lsevier Applied *cience.
-
8/9/2019 Risk Assessment Work Place
34/54
-
8/9/2019 Risk Assessment Work Place
35/54
-
8/9/2019 Risk Assessment Work Place
36/54
-
8/9/2019 Risk Assessment Work Place
37/54
Fa'lt Tree Anal4sis
#6ample• %onsider the simple circuit diagram shown !elow"
J
5
=A)?
*2IT%&9U*$
HATT$R
?'2$RU+IT
$7ample from &arms Ringdahl = /33F08 *afety Analysis" ?rincipals and ?ractice in
'ccupational *afety8 $lsevier Applied *cience.
-
8/9/2019 Risk Assessment Work Place
38/54
Fa'lt Tree Anal4sis
• The corresponding fault tree for the a!ove circuit8 with the top
event or ha#ard0 !eing the lamp not working is as follows"
=amp does notlight
+o currentthrough the lamp
+o power supplyto the lamp
Hroken circuit+o power feed
9aulty=amp
+o ?ower from !attery
+o ?ower from unit
Hroken%ircuit
(efectiveswitch
(efectivefuse
$7ample from &arms Ringdahl = /33F08 *afety Analysis" ?rincipals and ?ractice in
'ccupational *afety8 $lsevier Applied *cience.
Practical Risk Assessment
-
8/9/2019 Risk Assessment Work Place
39/54
Practical Risk Assessment
,from 8S::;;.
%lassify work activities
Identify ha#ards
(etermine risk
(ecide if risk is tolera!le
?repare risk control action plan
if necessary0
Review ade;uacy of action plan
-
8/9/2019 Risk Assessment Work Place
40/54
-
8/9/2019 Risk Assessment Work Place
41/54
I+entif4 )a*ar+s
Broad categories of hazard To help with the process of identifying
ha#ards it is useful to categorise ha#ards in
different ways8 for e7ample !y topic8 e.g."
• )echanical.
• $lectrical.
• Radiation.
• *u!stances.• 9ire and e7plosion.
H*@@"/33B
-
8/9/2019 Risk Assessment Work Place
42/54
Hazards prompt-list
8uring work activities could the followingha-ards exist9
• Slips:falls on the level.
• alls of persons form heights.
• alls of tools, materials, etc., from heights.
• 1nade'uate headroom.
• Ha-ards associated with manual lifting:handling oftools, materials, etc..
• Ha-ards from plant and machinery associated withassem!ly, commissioning, operation, maintenance,modification, repair and dismantling.
H*@@"/33B
-
8/9/2019 Risk Assessment Work Place
43/54
Hazards prompt-list
• ;ehicle ha-ards, covering !oth site transport, and travel!y road.
• ire and explosion.
• ;iolence to staff.
• Su!stances that may !e inhaled.• Su!stances or agents that may damage the eye.
• Su!stances that may cause harm !y coming intocontact with, or !eing a!sor!ed through, the skin.
• Su!stances that may cause harm !y !eing ingested4i.e., entering the !ody via the mouth$.
• Harmful energies 4e.g., electricity, radiation, noise,vi!ration$.
H*@@"/33B
-
8/9/2019 Risk Assessment Work Place
44/54
Hazards prompt-list
• 0ork#related upper lim! disorders resulting from
fre'uently repeated tasks.
• 1nade'uate thermal environment, e.g. too hot.
• /ighting levels.
• Slippery, uneven ground:surfaces.
• 1nade'uate guard rails or hand rails on stairs.
•
-
8/9/2019 Risk Assessment Work Place
45/54
=etermine risk
The risk from the ha#ard should !e
determined !y estimating the potential
severity of harm and the likelihood that harmwill occur.
-
8/9/2019 Risk Assessment Work Place
46/54
Severit of harm
Information o!tained a!out work activities is avital input to risk assessment. 2hen seeking
to esta!lish potential severity of harm8 the
following should also !e considered"
• ?arts0 of the !ody likely to !e affectedM• +ature of the harm8 ranging from slightly to e7tremely
harmful"
> /0 *lightly harmful8 e.g."
• *uperficial in6uriesM minor cuts and !ruisesM eye irritationfrom dust.
• +uisance and irritation e.g. headaches0M ill5health leading
to temporary discomfort.
H*@@"/33B
-
8/9/2019 Risk Assessment Work Place
47/54
-
8/9/2019 Risk Assessment Work Place
48/54
Likelihood of harm
2hen seeking to esta!lish likelihood of harmthe ade;uacy of control measures already
implemented and complied with needs to !e
considered.
Issues considered"•+um!er of personnel e7posed.
•9re;uency and duration of e7posure to the ha#ard.
•9ailure of services e.g. electricity and water.
•9ailure of plant and machinery components and safety devices.•$7posure to the elements.
H*@@"/33B
-
8/9/2019 Risk Assessment Work Place
49/54
-
8/9/2019 Risk Assessment Work Place
50/54
=eci+e if risk is tolerable
'ne simple method for estimating risk levels and for
deciding whether risks are tolera!le. Risks are
classified according to their estimated likelihood and
potential severity of harm.
Slightly harmful
Harmful
Extremely
harmful
Highly unlikely
TRIVIAL RIS
T!LERA"LE
RIS
#!DERATE
RIS
$nlikely
T!LERA"LE
RIS
#!DERATE
RIS
S$"STA%TIAL
RIS
Likely
#!DERATE
RIS
S$"STA%TIAL
RIS
I%T!LERA"LE
RIS
H*@@"/33B
-
8/9/2019 Risk Assessment Work Place
51/54
A simple risk5!ased control plan.
-
8/9/2019 Risk Assessment Work Place
52/54
RISK !#$#! A3TIO A= TIM#S3A!#
TRI$IA! +o action is re;uired and no documentary records need to !e kept.
TO!#RA8!# +o additional controls are re;uired. %onsideration may !e given to
a more cost5effective solution or improvement that imposes no
additional cost !urden. )onitoring is re;uired to ensure that the
controls are maintained.
MO=#RAT# $fforts should !e made to reduce the risk8 !ut the costs of
prevention should ! e carefully measured and limited. Risk
reduction measures should !e implemented within a defined time
period.2here the moderate risk is associated with e7tremely harmful
conse;uences8 further assessment may !e necessary to esta!lish
more precisely the likelihood of harm as a !asis for determining the
need for improved control measures.
S%8STATIA! 2ork should not !e started until the risk has !een reduced.
%onsidera!le resources may have to !e allocated to reduce the risk.
2here the risk involves work in progress8 urgent action should !e
taken.
ITO!#RA8!# 2ork should not !e started or continued until the risk has !een
reduced. If it is not possi!le to reduce risk even with unlimited
resources8 work has to remain prohi!ited.
H*@@"/33B
-
8/9/2019 Risk Assessment Work Place
53/54
Prepare risk control action plan
The action plan should !e reviewed !efore
implementation8 typically !y asking"
• 2ill the revised controls lead to tolera!le risk levelsN
• Are new ha#ards createdN• &as the most cost5effective solution !een chosenN
• 2hat do people affected think a!out the need for8 and
practicality of8 the revised preventive measuresN
• 2ill the revised controls !e used in practice8 and notignored in the face of8 for e7ample8 pressures to get
the 6o! doneN
H*@@"/33B
-
8/9/2019 Risk Assessment Work Place
54/54
Changing Conditions and Revising
Risk assessment should !e seen as a
continuing process. Thus8 the ade;uacy of
control measures should !e su!6ect tocontinual review and revised if necessary.
H*@@"/33B
top related