c4-01 storage & handling of dangerous substances

NEBOSH DIPLOMA LEVEL 6NEBOSH DIPLOMA LEVEL 6

STORAGE & HANDLING OF DANGEROUS STORAGE & HANDLING OF DANGEROUS SUBSTANCESSUBSTANCES

UNIT C4UNIT C4

REVISION1. What is meant by “Exothermic”. . 2.2. What is meant by “Endothermic”What is meant by “Endothermic”3.3. What is the FP of a flammable liquid What is the FP of a flammable liquid 4.4. Name three measures which can be Name three measures which can be

introduced to the design of a system aimed introduced to the design of a system aimed at controlling pressure.at controlling pressure.

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REVISION1. What is meant by “Exothermic”.. – reaction gives – reaction gives

out heat energy out heat energy 2.2. What is meant by “Endothermic”.What is meant by “Endothermic”. – reaction – reaction

absorbs heat energy.absorbs heat energy.3.3. What is the Flash Point of a flammable liquidWhat is the Flash Point of a flammable liquid. - . -

lowest temperature at which a flame will lowest temperature at which a flame will propagate through the vapour of a combustible propagate through the vapour of a combustible material to the liquid surface. material to the liquid surface.

4.4. Name three measures which can be introduced Name three measures which can be introduced to the design of a system aimed at controlling to the design of a system aimed at controlling pressure.- Pressure detectors & alarms. pressure.- Pressure detectors & alarms. Bursting discs, relief valves. Suppressant to Bursting discs, relief valves. Suppressant to stop reaction.stop reaction.

CONTENT

STORAGE & HANDLING OF STORAGE & HANDLING OF DANGEROUS SUBSTANCESDANGEROUS SUBSTANCES

Storage of Storage of Dangerous SubstancesDangerous Substances

REGULATIONS• DANGEROUS SUBSTANCE?

Dangerous Substances & Explosive Atmosphere Reg ’02 (DSEAR) define them as:-

a. Substance or preparation which is:-

Explosive.Oxidising.Extremely flammable.Highly flammable. Flammable.


Dangerous Substances & Explosive Atmosphere Reg ’02 (DSEAR) define them as:-Substance or preparation which because of its chemical properties, the way it is used or presence in the work place creates a risk of explosion or fire.


Dangerous Substances & Explosive Atmosphere Reg ’02 (DSEAR) define them as:-

c. Any dust, either particle or fibrous or otherwise which can form an explosive mixture with

air or an explosive atmosphere.


Dangerous Substances & Explosive Atmosphere Reg ’02 (DSEAR) defines an explosive atmosphere as:-

“one which has an accumulation of either gas, mist, dust or vapour in air which if mixed, could catch fire or explode.”

COMAH 1999• DANGEROUS SUBSTANCE?

Control of Major Accident Hazard ’99 (COMAH) define them as:-

A substance, mixture or preparation listed in Column 1 of Part 2 of Schedule 1 or within category specified in Column 1 of Part 3 of Schedule 1.

COMAH 1999 • CLASSIFICATION

Very ToxicToxicOxidizingExplosiveFlammable FP 21oC – 55oCHighly Flammable FP below 21oCExtremely Flammable FP below 0oCDangerous to the Environment

EXPLOSIVE• HAZARDOUS ATMOSPHERE

Classified within schedule 2 of COMAH ’99 in to three zones:-

Zone 0 Explosive atmosphere is present or expected to be present.

Zone 1 Explosive atmosphere is likely to occur.

Zone 2 Explosive atmosphere is unlikely to occur.

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Zone 0

Zone 1

Zone 2

EXPLOSIVE• HAZARDOUS ATMOSPHERE

Classified within schedule 2 of COMAH ’99 in to three zones in relation to dust :-

Zone 20 Explosive atmosphere is present or expected to be present.

Zone 21 Explosive atmosphere is likely to occur.

Zone 22 Explosive atmosphere is unlikely to occur.

RISK ASSESSMENT• VARIOUS

The extent and detail of the assessment should be relative to the complexity of the hazard and the severity of the possible

consequences. Should include safety, health and environment.

General Risk AssessmentCOSHH Risk AssessmentHAZOPFault Tree AnalysisFailure Mode & Effect Analysis

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Questions

• As far as the risk of explosion or fire is concerned, provide an accepted definition of the term ‘dangerous substance’ under DSEAR.

• List the physico-chemical properties that make a substance ‘dangerous’

• Describe the conditions that are defined as Zone 0, Zone 1 and Zone 2 under DSEAR.

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Group Exercise• In groups, research and summarise the

contribution of systems failures and mechanical failures in the following major accidents. From Element C2 and C4 in RMS Study Book:– Flixborough– Abbeystead– Piper Alpha– Hickson & Welch– Grangemouth– Allied Colloids– Buncefield

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Group Work

• From the conclusions of the previous group work on Major Accidents, try to allocate the failure modes to the following list:

FAILURE MODESSite Design Fault ImpuritiesExternal Event Overheating Fire/Explosion OverpressureHuman Error OverfillingImpact Structural FailureContainer Failure Incorrect

Procedure Maintenance Failure Vibration

Subsidence (shifting)

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STORAGE

STORAGE• METHODS

The method of storage and the supporting arrangements required to safely store a

dangerous substance depends on:-

a. The nature of the substanceb. The quantityc. The ambient conditions

STORAGE• TYPES

Bulk Storage Tanks

Intermediate tanks & Cylinders

Drums

Individual packaging

External – Tanks and compounds

Internal – Store Rooms, Compartment

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BULK STORAGE

CONTROLS (Preventative)• BULK STORAGE

Facilities & process design, meters & vents Automatic alarms and fail safe systems

Flood, wind & lightning protection Protect against static electricity Fire/heat detection, alarm and actionTraining, supervision, notices, permits to workGood lighting, crash barriers, traffic controlInspections, security, standard proceduresStructural & alteration inspection/checks

CONTROLS (Mitigating)• BULK STORAGE

Automatic active fire precautionsEmergency response plans Evacuation and Close Down procedureEmergency trained staffPollution control, emergency spaceSecondary containment, bundingSegregationPPE

External Storage• BUNDING

Bunded area able to hold 110% of largest tank. Intermediate walls to reduce surface areaHeight of outer wall 1.5 m – 2 m Height of intermediate walls 0.5m

Construction material imperviousRain water disposalDrains protectedPrevention of weeds. (Don’t use sodium chlorate!!)

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INTERMEDIATE BULK CONTAINERS

FAILURE MODES• DRUM, IBC & LPG Storage

Poor Work Systems Site Design Fault Container Failure Fire/Explosion External Event Overheating Impact Human Error Maintenance Failure

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Question• Describe, with examples, three failure modes

that may result in spills and loss of contents from drums, IBC’s and LPG containers.

• Group 1: Poor Work Systems, Site Design Fault, Container Failure

• Group 2: Fire/Explosion, External Event, Overheating

• Group 3: Impact, Human Error, Maintenance Failure.

• For the examples you have identified, suggest control measures that may be introduced to reduce the risk of accidents.

CONTROLS (Preventative)• INTERMEDIATE, DRUMS & GAS

CYLINDERSStored outside, 2m fenced, secure compound Flood, wind and lightning protectionPassive fire precautionsTraining, supervision, notices, permitsLighting, crash barriers, traffic control Inspections, tests, securityIn load and out load proceduresSegregationStacking, signage

CONTROLS (Mitigating)

• INTERMEDIATE, DRUMS and GAS CYLINDERS

Impervious hard standing Active fire precautions or cooling (Deluge)Emergency response plans Emergency trained staffSpillage control & bundingMinimal holding

Segregation

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Deluge System

STORAGE• SEPARATION (LPG Cylinders)

Distance from boundary and any risk of ignition 50 kg = 1m : 5000 kg = 9 m.

Distance from top of fence to cylinders not less than 1.5 m.

Low concentrations present hazardHeavier than air and travels quicklyOdourless, difficult to detect

CONTROLS • DRUMS

No drum stored within 2m of any door, plain glazed window or emergency exit.Stored upright no more than 4 high.If stored on side they should be chocked.Drum handling equipment, not rolled.Subject to inspection.Used only for the substance designed for.Spillage control & bunding.Minimal holding.

INTERNAL STORAGE

FLAMMABLE SOLIDS• CONTROLS

Held in suitable storage, dry & ventilated Quantities kept to a minimum.Retained in correct packaging.Clear & correct labelling.Segregation related to hazard.Subject to inventory control.

Subject to regular inspections.

FLAMMABLE LIQUIDS• CONTROLS

Separate store with 4 hrs fire protection. Suitably located, fire routes and other hazards. At ground level.Bunded to prevent liquid escape.All ignition sources eliminated.Vented to the open air. Store and containers mark.Combustibles in area removed. 50lt max in workplace in suitable container

STORAGE• ROOMS OR BUILDING

Stores are for storing not work practicesFit with non hazardous heatingElectrical equipment fit for zoneVentilated, dry and free of rubbishWell marked and signedFire protection, detection & fightingAccess controlledSuitable storage and walkwaysEmergency procedures in place

NOTIFICATION• QUANTITIES

Each dangerous substance has a limit on quantity prior to notification to the authorities.

Dangerous Substances (Notification & Marking of Site) Regs ‘90.

Planning (Hazardous Substances) Regs ‘92

Control of Major Accidents Hazards Regs ’99

Fire Certificate (Special Premises) Regs ‘76


25 tonnes or more of a Dangerous Substance on any site is subject to:-

Dangerous Substances (Notification & Marking of Site) Regulation ‘90.

This requires notification to the fire authority and the enforcing agencyDisplay warning and information signs at all points of entry


60 gallons or more of a petroleum mix that gives of vapours at a temperature less than 23oC is subject to:-

Petroleum Consolidation Act ‘28

This requires a licence to be held which issued by the local authority

TOXIC & CORROSIVE• DESCRIPTIONS

Toxic Dangerous to the living things around them.

Corrosive Include acids acid anhydrides and alkalis. They can be volatile and create toxic or explosive fumes. They can destroy living tissue and structural materials

TOXIC & CORROSIVE• SAFETY PRINCIPLES

Use the safest practicable substance.

Retain minimum amount in appropriate storage bringing in to use the minimum amount.

Segregate substance which react with each other.

Acid Inorganic

Acid Oxidizing

Acid Organic

Alkali Oxidizers Poison inorganic

Poison organic

Water re active

Organic solvents

Acids, Inorganic

X X X X X X

Acid Oxidizing

X X X X X X

Acid Organic

X X X X X X X

Alkali X X X X X X

Oxidizers X X X X

Poison inorganic

X X X X X X

Poison organic

X X X X X X

Water re active

X X X X X X

Organic solvents

X X X X X

TOXIC & CORROSIVE• STORAGE SEPARATION

Examples of separation in storage:-

Carbon Tetrachloride exposed to high temperatures will form highly toxic phosgene gas

Acid reacts to cyanides, sulphides, fluorides, carbides, phosphides to produce toxic fumes

Alkaloids react to release hydrogen on contact with aluminium

GROUP WORK 6 - 1In your groups design a

suitable storage facility for:-

60 tonnes of toxic chemical held in 6 10

tonne tanks4,000 Lt of toxic liquid

held in 200Lt steel drums

1,000 Lt of corrosive chemical held in 1Lt

glass bottles

NEBOSH DIPLOMA LEVEL 6NEBOSH DIPLOMA LEVEL 6

HANDLING & USEHANDLING & USE

OF DANGEROUS SUBSTANCESOF DANGEROUS SUBSTANCES

UNIT C4UNIT C4

CONTENT

STORAGE & HANDLING OF STORAGE & HANDLING OF DANGEROUS SUBSTANCESDANGEROUS SUBSTANCES

Handling and UseHandling and Useof Dangerous Substancesof Dangerous Substances

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REGULATION• USE & HANDLING

Both of these functions are regulated by COSHH 2002, together with other relevant legislation.

Additional regulations govern the storage and transportation of specified dangerous substances in given quantities.

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PIPELINES• CONTROLS – Remember Flixborough!

The accident was traced to a poorly qualified design team that was asked to design and install temporary piping in a Cyclohexane Oxidation Unit. That temporary piping catastrophically failed, releasing 50 tonnes of hot, pressurized cyclohexane.

Correct design for content & stressesSuitable construction, valves & gauges Maintenance of correct pressure & flowStatic electricity managedEmergency planning & responseMaintenance & inspections - corrosion & fractures, Security: Pipelines Safety Regulations ‘96

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FILLING CONTAINERS• CONTROLS

Assess the riskCheck contents or past contentsIf required clean containerEliminate sources of ignitionTrained and supervised staffPut earthing/bounding in place

Display warning signs.Persons involved to the minimumPPE & Fire precautions with First Aid

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EXPLOSIVE LEVELS

Vapour/Gas Concentration in Atmosphere

Lower Explosive Level (LEL)

Upper Explosive Level ( UEL)

Maximum Explosive Pressure

Flammable Range

Too Little Too Much

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• PETROLEUM (CONSOLIDATION) ACT ’28

Premises which dispense petrol into vehicles, ships, boats or planes require a licence to do so under the above.

Premises which store petrol for other purposes do not, but they must comply with DSEAR ’02, or if quantities dictate COMAH ’99 plus other relevant regulations

DISPENSING

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• FLAMMABLE LIQUIDSVapours pose a risk of fire/explosionConfined spaces will create concentration Vapours are heavier than air, settle and spreadLow ground, pits and sumps Liquid floats on water, distance travelled

IND(G) 227 Safe working with flammable substances

DISPENSING

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• FLAMMABLE LIQUIDSControls

Assess the riskControl vapours by ventilation/extractionMaintain below the lower explosive limit Eliminate all sources of ignitionSpray booths are Zone I areasEarth equipment, anti static measures

SPRAYING

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• FLAMMABLE LIQUIDSMovement can produce staticPlant may produce sparkIntrinsically electrical safe plantWell maintained and inspected plantedEarthing & BondingSwitched off and locked Safe distanceSafe tools and lighting

ELECTRICITY

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• SAFETY PRINCIPLESVentilation: Avoids fume concentration

Ignition: Remove all sources

Containment: Suitable containers/bunds

Exchange: Reduce the risk by substitution

Separation: Physical barrier or distance

IND(G) 227 Safe working with flammable substances

FLAMMABLE SUBSTANCES

ASSESSMENTStage 1

Obtain details on all hazardous substances from supplier and other

sources

Stage 2

Identify maximum holdings and location of

substances. Assess safeguards in place

Stage 3

Provide additional measures if needed to meet legal standards. Consult with authorities and check if licensing or

certificates are needed.

Stage 4

Monitor to ensure substances and quantities remain unchanged and standards are maintained

HOMEWORK 4Outline the safety

provisions required for the design, operation and maintenance of a water treatment plant which

must store in bulk large quantities sulphuric acid and caustic soda. Both substances are delivered

by road tankers

c4-01 storage & handling of dangerous substances

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