8 risk assessment

Copyright@NIOSH 2005(2) 1

Risk Assessment And Management

Safety And Health Officer Certificate Course


Learning Objectives• To define what is hazard, risk and danger

• To explain the risk assessment process

• To describe the method of identifying hazard

• To use the risk assessment matrix

• To explain the hierarchy of control


Scope

• Overview of risk and risk assessment

• Planning for risk assessment

• Risk control


Overview Of Risk And Risk Assessment


Definitions• Hazard: A source or a situation with a

potential for harm in terms of human injury or ill health, damage to property, damage to the environment or a combination of these

• Danger: Relative exposure to hazard


Definitions

• Risk: A combination of the likelihood of an occurrence of a hazardous event with specified period or in specified circumstances and the severity of injury or damage to the health of people, property, environment or any combination of these caused by the event


Risk Assessment

• What is Risk assessment: The process of evaluating the risks to safety and health arising from hazards at work

• Risk assessment results is documentedand used for:

1. Risk control in OSH management2. Future reference and review


Basic Principles Of Risk Management

1. Integrate Risk Management as part of planning at all levels of business

2. Accept all risks3. Make risk decisions appropriately

(depending on level of risk)4. Manage the risk


Why Carry Out Risk Assessment?

• Gives organisations a more effective way of managing hazards

• Requirement of the law e.g.– OSHA 1994, CIMAH Regulations 1996 &

USECHH Regulations 2000• Requirement of OSH management

system standards:– MS 1722:2003, – OHSAS 18001 and – ISO 14001, etc.


Risk Assessment Should Be Carried Out For:

• Routine and non-routine activitiesincluding emergencies

• Activities of all personnel having access to the workplace (including subcontractors and visitors)

• Facilities at the workplace, whether provided-by the organization or others


When To Carry Out Risk Assessment

• Before Operation

• During Operation

• After Operation


When To Review Risk Assessment

• Types of review: – initial review– periodic review


When To Review Risk Assessment

• Review whenever there are changes:– internal

• Before modification, changes or introduction of new

– Materials, machinery or processes, working procedures

– external• Amendments of national laws and regulations • Developments in OSH knowledge and technology


Who Will Carry Out Risk Assessment

• Person or persons trained to identify hazard and risk assessment– In some cases legally competent person,

example : Chemical Health Risk Assessor

• Consultation with and involvement of workers– Safety and Health Committee OR workers

and their representatives

• Involvement of supervisors


Basic Components Of Risk Management

• Hazard Identification

• Risk Assessment

• Risk Control

• Review


The Process of Risk Management

Classify Activities(Work, Product, Services, Activities)

Determine Risk

Decide if Risk is Tolerable

Risk Control Action Plan

Identify Hazards

Review Adequacy of Risk Control

Start

Risk = Severity X Likelihood


Hazard Identification


SOURCES OF HAZARDSMan Unsafe actsMachinery Installation, layout and design of

equipmentMaterials Substances such as chemicals and

gases use in the workplaceMethod The way people carry out their

workMedia Workplace condition i.e. air quality,

ventilation, lighting, noise, vibration etc.


Classification and Potential Sources of Hazards

Exposed to airborne and blood borne viruses, bacteria and fungus

Biological

Electrical cord insulation damaged, electrical face plate or cover broken or missing and fan cord insulation pulled loose

Electrical

Pinch points, sharp points and edges, overload or force a tool beyond its capabilities and grinding wheel without guard

Mechanical

Example of Potential Sources of Hazards

Classification of Hazards


Classification and Potential Sources of Hazards

Stress, sexual harassment and violent at work.

Psychological

Repeated exposure to unnatural postures and unnatural movement, wrong design of workstation, tools and task.

Ergonomics

Exposed to carcinogens chemicals, sensitizers and corrosive chemicals.

Chemical

Example of Potential Sources of Hazards

Classification of Hazards


Pre-Assessment –Information Gathering

• Information on the facilities, processes and activities of the organization, including:– Area Map– Site plan(s); own and neighbor– Process flow-charts– Inventory of materials (raw materials,

chemicals, wastes, products, sub-products)– Toxicology and other health and safety data– Monitoring data


Pre-Assessment –Classifying Work Activities

• Geographical areas within/outside the premises

• Stages in a production process, or in the provision of a service

• Defined the tasks (e.g. driving, window cleaning)

• Identify the working groups• Land use, previous property use, future use


Methods Of Identifying Hazards

• Review of documents and publications

• Inspection and observation at the workplace

• Measurement of the atmosphere, monitoring the environment or medical surveillance of workers

• Hazard Analysis


Document Review

• Reports of accidents, accident investigation and audits

• Information from publications– Acts, Regulations and Codes of Practice– Statistics– Handbooks – Chemical Safety Data Sheet (CSDS)


Inspection and Observation

• Types of inspections: statutory inspection, periodic inspection, formal and informal inspection

• Documentation - Checklist and inspection worksheet (standard approach and record)


Inspection and Observation

• Activities - to involve supervisors, managers and employees

• Inspection outcome - to include actions and timeframes

• Ensure follow up on action - to ensure effectiveness


Exposure Monitoring• Types of monitoring: area and personal

monitoring.

• Monitoring of:– Noise– Heat– Radiation – Air contaminants– Chemicals etc.


Biological Monitoring• Biological monitoring is a regular

measuring activity where selected validated indicators of the uptake of toxic substances in the human body are determined in order to prevent health impairment

• This form of monitoring could entail examination of, for example, blood, urine, saliva and expired air


Biological Monitoring

• Biological monitoring commonly features in the health or medical surveillanceof persons exposed to hazardous environments especially complying to legal requirement i.e. USECHH Regulations 2000 etc.


Medical Surveillance

• Health Surveillance is Warranted if:– Substance is used in workplace

– Substance is hazardous

– Evidence or reason to suspect injury

– Atmospheric monitoring insufficient


Hazards Analysis

• Method use: (example)

– Job Safety Analysis (JSA)

– Hazards and Operability Studies (HAZOP)

– Fault Tree Analysis etc.


Job Safety Analysis (JSA)

• Job described in less than 10 steps

• Action verb used to describe job

• List things that can go wrong


Job Safety Analysis (JSA)

• Note:– The term JSA includes the formulation

of safe work procedures using written instructions for workers

– May still require other risk controls

– Supervisor and workers assist

– Ideally all jobs should have a JSA


Hazards And Operability Studies (HAZOP)

• To identify and evaluate safety hazard in the process plant

• To identify operability problems• New design or process • Multidisciplinary brainstorming • “What If” questionnaire method• Focus on fire, explosion, toxic release

etc.


Fault Tree Analysis• To analyse how and why incident could

occur

• Graphic technique - traces branches of events

• To calculate probability of end event

• Example: Water pumping system


Fault Tree Analysis

Pump failure (A) Pump failure (B)(automatic

standby pump)

Pump failure Control valve (C)failure to regulate

flow of water throughpump

No Flow (T)

•No water flow occurs if both pumps fail or if the control valve fails.•If the individual initiating event probabilities P(A), P(B), and P(C) are known, then the probability of P(T) the top or end event can be calculated.


Risk Assessment


Types of Risk Assessment

Approach:

• Qualitative Risk Assessment

• Semi-Quantitative Risk Assessment

• Quantitative Risk Assessment


Determining Severity

• Severity in terms of:

– Harm to health– Damage to property– Damage to environment– Or the combination of the above


SeverityDetermine severity categories i.e.:• Fatality

• Major injuries (normally irreversible injury or damage to health)

• Minor injuries (normally reversible injury or damage to health requiring days off work)

• Negligible injuries (first aid)


Determining Likelihood of Occurrence of Hazard

• Based on statistic & data, professional judgement.

• Determine likelihood categories i.e.:– highly likely, – likely, – highly unlikely.


Likelihood

• Very likely - could happen frequently

• Likely - could happen occasionally

• Unlikely - could happen, but only rarely

• Highly unlikely - could happen, but probably never will


Qualitative Risk Table

Severity LikelihoodVery Likely Likely Unlikely Highly Unlikely

Fatality High High High MediumMajor Injuries High High Medium MediumMinor Injuries High Medium Medium LowNegligible Injuries Medium Medium Low Low


Semi - Quantitative Risk Assessment

Determine severity categories i.e.:• 4: Fatality & Permanent Disability

• 3: More than 4 days MC

• 2: Less than or 4 days MC

• 1: First aid and near misses


Semi - Quantitative Risk Assessment

Determining Likelihood of Occurrence of Hazard

• 4: Daily

• 3: Weekly

• 2: Monthly

• 1: Yearly


Semi-Quantitative Risk Assessment

LIKELIHOOD

SEVERITY

1612844Fatality &

Permanent Disability

129633More than 4 days MC

86422Less than or 4 days

MC

43211First Aid and Near Misses

4321

Daily Weekly Monthly Yearly


Quantitative Risk Assessment

• Where the hazards presented by the undertaking are numerous and complex, and may involve novel processes, for example in the case of large chemicals process plants, detailed and sophisticated risk assessments will be needed, and it is appropriate to carry out a detailed quantitative risk assessment



• Quantitative risk assessment involves obtaining a numerical estimate of the risk from a quantitative consideration of event probabilities and consequences



• In carrying out quantitative risk assessments, special quantitative tools and techniques will be used for hazard identification, and to estimate the severity of the consequences and the likelihood of realization of the hazards



• Where such methods and techniques are used it is important that they are carried out by suitably qualified and experience assessors


LEVEL

OF

RISK

AS LOW AS REASONABLY PRACTICABLE (ALARP) PRINCIPLE

Risk cannot be justifiedon any grounds

ALARP

Risk is undertaken if a benefit is desired

Reduce risk

No need for detailedaction

TOLERABLE IF:Reduction

Impracticalor

Cost / gain grosslyDisproportionate

Decision For Action

Intolerable (e.g. H,H or >10)

Trivial


Risk Assessment Form

Risk Activities / process / facilities/

equipment Hazard Effect Current Risk Control

Legal Reqmt Severity. Likelihood. Risk

Rating

Action & Recommendations


Risk Control


Principle of Control

•Substitution•Modify process•Enclosure•Local exhaust •Fugitive emission control•Isolation

•Housekeeping•General ventilation•Continuous area monitoring•Dilution ventilation•Automation or remote control

•Training and education

•Worker rotation•Enclosure of worker

•Personal monitoring•Personal protective devices


Consideration In Implementing Risk Control

• Review measures regularly; modify if necessary

• Comply with national laws and regulations

• Reflect good management practice; and


Consideration In Implementing Risk Control

• Consider the current state of knowledge

• Include information or reports from organizations such as:– DOSH, OSH services, and others


Hierarchy Of ControlMOST EFFECTIVE

Elimination - remove the hazard.

FAIRLY EFFECTIVESubstitution - use less hazardous one.Isolation – isolate the work area i.e. X-ray machine in restricted roomEngineering Control – design, isolation at source, barricade, guarding,

LEAST EFFECTIVE Administrative Control – safe work procedure, isolation i.e. reduce exposure time and limit, training, signage etcPPE - last resort.


Summary

• The basis of OSH management is the identification of hazard, risk assessment and control

• Ways of identifying hazards varies from inspection of the workplace to reviewing legislation

• Risk assessment allows an organisation to build a sound basis for managing hazard

• Hierarchy of hazard control starts by elimination; use PPE as protection is the last resort

8 risk assessment

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