Hazards.of.Nitrogen.and.Catalyst.handling

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Hazards ofNitrogen and

Catalyst Handling

BookletTen


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Hazards of Nitrogen and Catalyst Handling

Booklet Ten in a series designed topoint out potential hazards in refinery andrelated operations and suggest ways and

means of correcting or eliminating them.

Copyright 2002.

First Edition 2002.

Questions regarding distribution of this booklet should be brought to the attention of Frdric GIL,BP HSE Shared Resource B122, Chertsey Road, Sunbury on Thames, TW16 7LN UK. Email:

[email protected]


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"It should not be necessaryfor each generation torediscover principles ofprocess safety which thegeneration before discovered.We must learn from theexperience of others ratherthan learn the hard way. Wemust pass on to the next

generation a record of whatwe have learned."

- Jesse C. DUCOMMUN


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AcknowledgementThe cooperation of the followingin furnishing data and illustrationsfor this edition is gratefullyacknowledged:

- BP Refining Process Safety Network- EURECAT France- SGAE- BUCHEN ICS- American Industrial Hygiene Association- CAT TECH

ABS Consulting was the contractorappointed by the BP HSE Shared Resource

for the preparation of this booklet.

This booklet is intended as a safety supplement to operator training courses, operatingmanuals, and operating procedures. It is provided to help the reader better understandthe "why" of safe operating practices and procedures in our plants. Importantengineering design features are included. However, technical advances and otherchanges made after its publication, while generally not affecting principles, could affectsome suggestions made herein. The reader is encouraged to examine such advancesand changes when selecting and implementing practices and procedures at his/herfacility.

While the information in this booklet is intended to increase the store-house ofknowledge in safe operations, it is important for the reader to recognize that thismaterial is generic in nature, that it is not unit specific, and, accordingly, that itscontents may not be subject to literal application. Instead, as noted above, it issupplemental information for use in already established training programs; and it

should not be treated as a substitute for otherwise applicable operator training courses,operating manuals or operating procedures.

This document has been prepared for use by members of the BP Group of Companiesand, if it should come into the possession of third parties, the advice contained hereinis to be construed by such third parties as a matter of opinion only and not as arepresentation or statement of any kind as to the effect of following such advice and noresponsibility for the use of it can be assumed by BP.


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HAZARDS OF NITROGEN ANDCATALYST HANDLING

Contents

1. SAFE USE OF NITROGEN......................................................................4 1.1 Introduction ........................................................................................................4 1.2 Properties of Nitrogen........................................................................................5 1.3 Uses and Hazards of Nitrogen...........................................................................6 1.4 Hazards of Open Manholes ...............................................................................8 1.5 Hazards of Temporary Confined Spaces ........................................................14 1.6 Hazards of Piping Under Nitrogen Purge ........................................................17 1.7 Hazards of Confusing Nitrogen with Air...........................................................18 1.8 Hazards of Trapped Pressure..........................................................................20 1.9 Hazards of Liquid Nitrogen ..............................................................................22 1.10 Hazards of Explosimeter Use in Nitrogen Atmospheres .................................23 1.11 General Advice and Safe Practices.................................................................25

2. SAFE HANDLING OF CATALYST........................................................27 2.1 Properties of Catalysts.....................................................................................27 2.2 Fire Hazards ....................................................................................................28 2.3 Health Hazards ................................................................................................32 2.4 Spent Catalyst..................................................................................................33 2.5 Nickel Carbonyl................................................................................................34 2.6 Crushing Hazards ............................................................................................35

2.7 Other Hazards associated with Catalyst Handling ..........................................36 2.8 Catalyst Unloading...........................................................................................37 2.9 Catalyst Labelling.............................................................................................38 2.10 Catalyst Disposal .............................................................................................38 2.11 Respiratory and Protective Equipment Requirements.....................................39 2.12 Catalyst Specialist Contractors for Inert Gas / Nitrogen Reactors ..................45

3. Points to Remember for Tool Box Meetings......................................50

4. Test Yourself .........................................................................................56


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1.2 Properties of Nitrogen

Nitrogen is not toxic since about 79% of the air we breathe contains this gas. Themechanism of nitrogen gassing is different to that of hydrogen sulphide (H 2S). WhilstH2S has a direct toxic effect which is well documented, nitrogen rich atmospheres will

asphyxiate due to a reduction in the oxygen content of the inhaled gases. The typical physiological effects of varying degrees of oxygen deficiency are also welldocumented:

Oxygen(%vol) Effects & Symptoms

23.5 Maximum Safe Level (23% is often the High level alarm of most O 2 detectors)21 Typical O 2 concentration in air

19.5Minimum Safe Level (19% is often the Low level alarm of most O 2 detectors)

15-19First sign of hypoxia. Decreased ability to work strenuously. May induceearly symptoms in persons with coronary, pulmonary or circulatoryproblems

12-14 Respiration increases with exertion, pulse up, impaired muscularcoordination, perception and judgment10-12 Respiration further increases in rate and depth, poor judgment, lips blue

8-10 Mental failure, fainting, unconsciousness, ashen face, blueness of lips,nausea, vomiting, inability to move freely

6-8 6 minutes - 50% probability of death8 minutes 100% probability of death4-6 Coma in 40 seconds, convulsions, respiration ceases, death

When a person enters an oxygen-deprived atmosphere, the oxygen level in the arterial blood drops to a low level within 5 to 7 seconds. Loss of consciousness follows in 10-12 seconds and if the person does not receive any oxygen within 2-4 minutes, heartfailure and death ensue.

NOTE: There is also a risk of suffocation with all compressed gases (for example argon, CO 2, helium, etc.), which either replaces the oxygen or consumes it. This riskalso exists in situations where there is a large consumption of oxygen (fires, andrusting in ballast tanks of a ship or water tanks, etc.)

Nitrogen (N 2) is a very common and extremely dangerous gas that you maybe exposed to at a refinery or chemical plant.

You must always be on your guard.

Moving affected and unconscious persons from a N 2 atmosphere into fresh airis not enough to promote recovery, the patient has to be physically

resuscitated in order to restore the oxygen supply to the brain.


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HC

N2

N2

HC

1.3 Uses and Hazards of Nitrogen

What Is Nitrogen Used For?

Nitrogen has numerous safety applications in our plants:

As a gas: for inerting equipment to prevent flammable atmospheres. for preparing equipment for maintenance by purging out hydrocarbons. for removal of air / oxygen in equipment before start up. for blanketing tanks to prevent the ingress of air. for specific welding operations. for mothballing equipment to avoid the rusting process. for use as fire-fighting agent as it removes air.

As a liquid: for cooling purposes in the laboratory, freezing a pipeline, etc. for storage and transportation of nitrogen in large quantities.

Removal ofhydrocarbon vapour

prevents possibility ofa flammableatmosphere in

preparation formaintenance.

Most Useful or Most Dangerous Gas???


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What are the Hazards of Nitrogen?

Nitrogen is not toxic since about 79% of the air we breathe contains this gas.However, it is not harmless and it has NO SMELL.

As a gas: It can cause suffocation by replacing the oxygen in a confined area. Its presence will give false readings when using explosimeters or flammable

gas detectors. And, like other compressed gases, there are the risks related to its pressurised

containment when it is stored in high pressure cylinders.

As a liquid: The same as the gas, when it evaporates.

By creating an intense coldness (-196o

C) that can cause frostbite, crack steelequipment and explode tyres. It boils at a colder temperature than oxygen thereby condensing the oxygen in

the air (which can then form explosive mixtures with other vapours or causea violent reaction in contact with organic substances).

What is an Asphyxiant?A chemical (gas or vapour) that can cause death or unconsciousness bysuffocation. Simple aphyxiants such as nitrogen, displace oxygen in air.They become especially dangerous in confined or enclosed spaces.Chemical asphyxiants , such as carbon monoxide and hydrogen sulfide,

interfere with the bodys ability to absorb or transport oxygen to the tissues.

THINKOF THE

DANGERS


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1.4 Hazards of Open Manholes

The Invisible Killer: A danger commonly found in Refineries

Previous Incidents with Open Vessels under Nitrogen Sampling a nitrogen atmosphere for hydrocarbons in the reactor without wearing

breathing apparatus. Attempting to rescue inert entry technicians without suitable breathing apparatus

and rescue plan. Recovering entangled rope or equipment from inside a reactor. Helping inert entry technicians to move ladder from the outside. Performing work activities outside reactor e.g. cleaning reactor interior from

outside adjacent to open manhole. Technicians installing blinds nearby an open manhole during catalyst unloading,and were not adequately protected from nitrogen and catalyst dust.

Top manhole of a vessel was opened under nitrogen purge with unprotectedworkers located in an oxygen deficient atmosphere.

HazardousArea

N2

OpenManhole

Oxygen Deficient Atmosphere: An atmosphere with an oxygen content below19.5% by volume. (OSHA Definition)


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No! And how are yousure it is safe to enter?What are your precau-tionary measures beforeentry? Do you carry a

portable gas detector that beeps if oxygen falls below 19%? Do you have

a standby attendant?

Do you know that you can be overcome by N 2 by justlooking into the manholewithout wearing breathingapparatus?

What happenedWhile in the process of taking a sample of the atmosphere from a reactor, under nitrogen purge, a process operator became asphyxiated and fell to his death throughthis open manhole. He was found on the second tray approximately 6m (20ft) belowthe manhole.

CAN YOU SEE OR SMELL THE INVISIBLE KILLER?!!


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Employee Overcome byOxygen Deficient Atmosphere !!!In one incident, a subcontractoremployee (not wearing breathingapparatus or safety harness) enters the

barricaded area atop a reactor to assist

a confined space entry attendant to liftthe internal access ladder. He wasovercome by an oxygen deficientatmosphere around the manhole andfalls into the reactor. Without the vitaloxygen to sustain respiration, it is veryunlikely that anyone could exit thereactor alive!

It should also be noted that instruction manuals / handbooks on gas-testing, confinedspace entry, etc must raise awareness on the risk to the operator of doing a gas testor taking a sample from the outside of a vessel. Pictures below are typical illustrationsof poor practices.

Initial gas testing should be performed from outside the space by inserting a probe or piece of flexible tubing. However, ensure that the contractor or employee performinggas testing is adequately protected with breathing apparatus and accompanied by asecond person.


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THE VESSEL COULD BE DEFICIENT OF OXYGEN

TECHNICIANS PUT THEIR HEADS INSIDE

N2 OxygenDeficient

Atmosphere

Nitrogen Purge

DO NOT PUTYOUR HEAD

INSIDE OPENMANHOLES

N2

Nitrogen Purge

Nitrogen can create an oxygendeficient atmosphere outside the

vessel/piping that is being purgedwith this medium.

You are asphyxiated with only yourhead inside an oxygen deficient

atmosphere not your whole body.


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PREVENT ACCESS

KEEP TECHNICIANS AWAY FROM AREAS OUTSIDE MANHOLESTHAT COULD BE DEFICIENT IN O 2 (UNLESS AUTHORISED

THROUGH A CONFINED SPACE ENTRY PERMIT)

NitrogenPurge

ASPHYXIATIONHAZARD: NO

ENTRYWITHOUT SCBA

WarningBarrier

MONITOR OUTSIDEENVIRONMENT FORO2 CONTENT ANDALARM AT LOWLEVEL. 19.5%

Reactor Top

N2


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Misadventure !!!A fixed bed reactor was filled with catalyst under a nitrogen blanket. At the start of anew shift the operator went to inspect the reactor top alone. When he failed to return,a colleague went to look for him and eventually saw him lying on top of the catalyst in

one of the reactors. He put his head inside an oxygen deficient atmosphere, knowingall the hazards but for a moment ignored them.

Good PracticeA device was developed for placing across manholes and other openings toconfined spaces which may contain an oxygen deficient atmosphere. The devicecan be locked into place to prevent unauthorized removal and physically preventsaccess. Removal would only be allowed as a condition of a confined-space entry

permit.

NitrogenPurging


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1.5 Hazards of Temporary Confined Spaces

Fatality in a Temporary Confined Space !!!

A process column had been taken out of service for maintenance for several weeks.The column had been cleaned, several manholes were open, and a nitrogen purge wason the column. Two experienced workers were examining the flange surface of aremote manhole for stress cracks. They sprayed dye on the flanges and used a blacklight to identify the suspect areas. The weather conditions were sunny, windy and

mild.A tarpaulin was draped over the flange but it is unclear whether this was to block thewind while they were using dye penetrant or to facilitate using the black light, or both.The confined space created by the tarpaulin was soon filled with nitrogen whichasphyxiated both men. One man died as a result of the exposure and the othersurvived because he collapsed face down on the expanded metal grating, whichallowed sufficient oxygen to sustain his life.

tent as weather protection

temporaryconfined

s ace

N 2

Outside areas can be deficient in oxygen which are exacerbated by any form ofclosure or tent.


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Vessel Skirts are Confined Spaces !!!

A technician was overcome by an oxygen deficient atmosphere while connecting up amotor. The catalyst had been removed and the reactor was floating on nitrogen. The

pump seal on the reactor was leaking allowing N 2 to enter the reactor skirt. The

supervisor assumed that the reactor seal was tight and there was no requirement foreither:- air-line breathing apparatus- air movers- continuous oxygen monitoring with alarm

Skirts surrounding the bottom of vessels must be considered a Permit-RequiredConfined Space.

HYDROTREATERREACTOR EMPTY OF

CATALYST

UNDERNITROGEN

PURGESEAL

CONNECTION NOT

FULLY TIGHTENED

NITROGEN LEAK

OXYGENDEFICIENT

ENVIRONMENT

TECHNICIANCONNECTING

UP MOTORSEMI

ASPHYXIATED

Ebullating BedPump

Reactor Skirt

Sketch of situation when Technician was semi-asphyxiated


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1.6 Hazards of Piping Under Nitrogen Purge

Beware of changing fittings on piping being purged with nitrogen Changing a valve Replacing a section of pipe Turning a spectacle plate Installing or removing full face blinds

Nitrogen Gassing Incident !!!A technician collapsed during reinstallation of valve and section of pipe shown bydotted line.

oxygendeficientatmosphere

Ground Level

1.44m(4 9)

Technicians faceclose to flange in the

path of escapingnitrogen


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Good PracticeBreathing apparatus must be worn where there is risk of exposure to a level ofnitrogen that could cause oxygen deficiency in the local surrounding atmosphere.All persons and in particular supervisors must be made aware of the risksassociated with nitrogen to ensure that suitable precautionary measures are taken

when vessels and pipelines are being purged with nitrogen.

1.7 Hazards of Confusing Nitrogen with Air

Previous Incidents of confusing nitrogen with air No unique bayonet fittings for breathing air supply Air line system was not checked or verified prior to connection Air line system isolated and used as a nitrogen header, but operator was not aware

of the change, after returning from his rest days

Nitrogen Line confused with Breathing Air Line !!!An incident occurred on a Monday when the foreman instructed the technician toconnect up the breathing air supply to the air receivers of the plants instrument airsystem, as he had done the previous Friday. Instead the technician connected the hosesto a regeneration air manifold which had been blinded / blanked from the air systemand was being used as a nitrogen header. No reason for this change has beenestablished other than it may have been more convenient. The Management ofChange procedure had not been initiated prior to making this temporary modification.

Nitrogen

Air


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Good Practice: Never use nitrogen instead of compressed air (for instance with pneumatic tools).Use different couplings: although special couplings for nitrogen connections are agood practice, they should not be relied upon during turnarounds. The valveshould be kept chain-locked as contractors have all kind of couplings to defeat the

system. Locking of the isolation valves should be mandatory on utility stations fornitrogen to prevent misuse by contractors and control usage through the Lockout-Tagout Procedure.

Never store bottles of compressed nitrogen in confined unventilated areas (a 50-litre bottle at 200 bars can cause the oxygen level in an average 9 sq. metre [97ft 2]room to drop to 12%).

Never use N 2 to back-up an air system without a formal risk assessment.

Nitrogen to back-up an air system results in a fatality!!!Following a total power black out at the process site, an instrument technician wasfound unconscious in an analyser house. He was rushed to a local hospital but

pronounced dead on arrival. During the power failure, instrument air was replacedwith nitrogen. It was suspected that a nitrogen leak was the cause of the fatality.

Do Not Confuse N 2 with Air !!!

Always Use Dedicated Breathing Air SupplyA mobile, self-contained, high pressure cylinder storage system undoubtedly

provides the highest integrity, freedom of operation and safety when usingairline breathing apparatus. Most sites prefer to either use bottled air, suppliedfrom a trolley set (wheeled trolley with air bottles on it) or from a bank odedicated air bottles located on the plant. There is a requirement to ensure thatthe quality of air in supply bottles is correct, whether they are refinery filled or

otherwise by a respectable external company.

Compressed N 2 Compressed Air

Use DifferentConnections /

Couplings, CorrectLabels & Different

Colour Hoses

Keep IsolationValve Locked


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1.8 Hazards of Trapped Pressure

Contractor Fatality during Reactor Catalyst Removal !!!A contract employee was fatally injured while removing catalyst from a

Hydrodesulfurization (HDS) Reactor.After shutdown and a nitrogen purge, the reactor inlets and outlets were blinded, and anitrogen hookup provided to supply a continuous purge for use by the catalystunloading contractor. The atmosphere at the reactor top opening was checked foroxygen, flammable material and hydrogen sulphide and found to be satisfactory.Wearing respiratory equipment suitable for inert gas entry work, the worker wentinside the top of the reactor to remove the internal structure.

There was a crusted layer on top of the catalyst bed below the distribution tray in thetop of the reactor. What was unknown to everyone was the build-up of nitrogen

pressure under the crusted layer. When the worker inside the reactor chipped the crust,the sudden release of pressure killed him. His equipment and part of the reactorcontents were expelled upwards through a 22" (0.6 m) diameter manhole.

Crust

PressureBuild-up

N2 N2

Catalyst

N2


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1.9 Hazards of Liquid Nitrogen

Bulk Nitrogen Plants Risk of Low Temperature Failure !!!A 30 ft. (9 m) section of a 2 (0.05 m) carbon steel nitrogen transfer line at a refinery

failed as a result of brief low temperature embrittlement arising from the malfunctionof a solenoid valve. The failure was potentially serious and one witness described thenoise as an explosion and saw the line lift 6 ft (1.8 m) into the air beforedisintegrating. At the time of the fracture part of the pipe was covered by a layer offrost about 1/8 (0.003 m) thick. Hazardous bulk nitrogen systems at four differentsites were modified by fitting a low temperature sensor connected to magnetic or air operated shutoff valves.

Liquid Nitrogen Inadvertently Enters High Pressure HydrogenationUnit !!!

When a High Pressure Lube Oil Hydrogenation Unit (HPH) was beingdecommissioned and cooled down for a statutory overhaul, liquid nitrogen from theassociated nitrogen vaporizer was inadvertently discharged into three reactors viatemporarily installed hoses. The initial cooling rates for the reactor were found to betoo low so the decision was taken to abandon the normal decommissioning procedureand instead supply nitrogen using hoses from a nitrogen vapouriser. This new

procedure represented a major departure from the existing one, and no hazard analysiswas undertaken as part of a Management of Change procedure, prior to making thechange. The injection of liquid nitrogen caused damage to the vessel. Magnetic crackdetection and dye penetrant methods carried out detected several cracks in the weldmetals. Three thermowell nozzles on the top of the reactor were severely damagedthrough excessive shrinkage caused by thermal shock. The cracks, which were aslong as 40mm (1.6), were grinded out and made good by rewelding. Repair costswere significant.


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1.10 Hazards of Explosimeter Use in Nitrogen Atmospheres

Explosimeters (flammable gas detectors) do not tell the truth in NitrogenAtmospheres

Explosimeters or gas detectors give false readings in an oxygen deficientatmosphere.

The types of portable flammable gas detectors in use in refineries usually operate by the catalytic combustion of a flammable gas on a heated filament (usually platinum), to give a reading of the %LEL* / LFL*. Accordingly, there must beapproximately 21% oxygen in the sample to give an accurate reading. If theatmosphere being tested is deficient in oxygen, for example when purging withnitrogen, it is not possible to use a standard type of flammable gas detector in its

normal mode of operation to detect hydrocarbon vapours. A standard catalytic gas detector, therefore, can only be used to give a reading of

flammable gas in an inert atmosphere by using special techniques involving airdilution attachments. The interpretation of results is difficult, and hence for day-to-day plant use, it is not recommended.

A review of operating and commissioning procedures highlighted a common practice of purging equipment and plant free of hydrocarbon vapours with

nitrogen using hydrocarbon / air flammable gas detectors at sample points todetermine the presence of hydrocarbon gas. The use of a standard flammable gasdetector is not suitable for this purpose.

Portable instruments are currently available that can be used in Hazardous Areasand which can give true indication of the level of flammable gas in a nitrogenatmosphere. These include infrared sensors and Tankscope gas indicators usedon ships.

* LEL = Lower Explosive Level* LFL = Lower Flammable Level

Always check the oxygen level first before carrying out a flammable gas testusing an explosimeter in preparation for hot work or confined space entry.


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Must haveair/oxygen insample.

Working Principle of an Catalytic Explosimeter

Controlled combustion takes place here:Oxygen + Flammable gases => CO 2 + H 2O + Heat.


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All personnel required to wear BA must be properly trained and refreshercourses incorporated into the annual training program.

Evaluate the use of portable gas detectors that will give off alarms when the

oxygen concentration in the vicinity of the vessel drops below a critical level.Typically, normal oxygen level is 21%, and alarm levels on gas detectors are19.5% (low O 2 alarm) and 23.5% (high O 2 alarm).

If the oxygen content ever goes above 21%, there is something wrong like aleaking oxygen cylinder. Investigate the situation first before allowing personnelin the confined space.

Unacceptable Behaviour

Peeking into reactor without respiratory protection.

Working near open manholes of a vessel under nitrogen without wearing adequate breathing apparatus (cartridge or dust masks are unacceptable).

If you see someone lying unconscious on the ground or through theopening of a tank or pipe: Call the fire department / rescue team

NEVER ENTER A CONFINED SPACE ORAREA ALONE TO GIVE HELP. CALL FOR ASSISTANCE .


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2. SAFE HANDLING OF CATALYST

2.1 Properties of Catalysts

Catalysts are substances that increase the rate of reaction in certain processes.

Catalysts are available in many forms (e.g. cylinders, tubes, balls, granules, powder)and colours. They are used in a number of processes at refineries that include naphthahydrotreatment, hydrocracking, resin hydroprocessing, alkylation, fluidized catalyticcracking, sulfur recovery, chloride removal and in absorbers and dryers.

Some common catalysts used in the refinery and petrochemical plants.

Some catalysts must be handled under a nitrogen atmosphere due to their pyrophoricand self-heating characteristics. Two types of substances distinguished by theirspontaneous combustion properties are:

Pyrophoric substances : even in small quantities, will ignite within 5 minutes ofcoming in contact with air; most liable to spontaneous combustion.

Self-heating substances : substances in contact with air, without energy supply areliable to self-heating; ignite only when in large amounts (kg) and after long periods oftime (hours or days) e.g. presulfided new catalyst or used catalysts.

The increasing use of nitrogen in catalyst charging and changeout has no doubtincreased the number of fatal nitrogen gassing incidents in the industry reported overrecent years. Today, nitrogen is becoming as serious a gassing hazard as H 2S.Therefore, it is vital to fully understand the hazards of catalyst charging and changeoutand how it can be carried out safely.

Unregenerated catalyst is normally a self-heating substance and oftenpyrophoric. On exposure to air, it can rapidly catch fire.


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2.2 Fire Hazards

Caused by reaction of catalyst with oxygen (in theair) if the heat developed is not conducted awayrapidly enough to the surroundings

Spontaneous combustion occurs when rate of heat production exceeds the rate of heat loss

When the auto-ignition temperature is reached

Good Practice:Storage and transport of self-heating catalyst carried out in accordance withUN/IMO regulations.Always securely seal prescribed containers to prevent contact with air.

Certain conventional methods include storage and transport of catalyst under oil /water cover or nitrogen blanket.In case of fire, fire fighters should wear self-contained breathing apparatusWater is the best extinguishing media; CO 2, powder or foam can also be used(refer to the MSDS for each catalyst).Safety showers should be available near catalyst unloading manholes to allowtotal removal of catalyst dust from surface of protective clothing that could

potentially ignite when in contact with the air.For extremely pyrophoric catalyst, fire resistant throw-away coveralls should be

provided to catalyst handling personnel. See section 4.4.

Poor Practices: Never store presulfided new catalyst in bags (except for a very short period of

time; e.g. for loading reactor). Use metallic drums or containers.

BAG


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Fire from presulphidednew catalyststored in largecartons.

Metallic containers and UN/IMOdrums for the transport andstorage of preactivated new

catalyst or spent catalysts.

Do not reuse the drums.

Wear the correct personal protective equipment and use thecorrect storage containers when handling catalyst .


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Exothermic Reactions

Risk of an exothermic reaction usually occurs during plant operations (not duringloading or unloading of catalyst)

When catalyst is exposed to abnormal chemicals, water or under abnormal

temperature/pressure conditions (e.g. during start-up or shutdown), exothermicreactions may develop. Kinetics of reaction may be very fast, with risk of metal overheating and over

pressuring.

Wrong Catalyst loaded results in Exothermic Reaction !!!CoMo catalyst in its oxide form, not in its sulphided form, was loaded into thehydrodesulphurization (HDS) reactor. Due to the incorrect catalyst used in thereactor, a runaway temperature reaction (hydrocracking) took place anddeformed/bulged the bottom head of the HDS reactor and the top head of adownstream vessel, indicating direct exposure to operating temperatures over 620C.The HDS reactor also suffered a leak on a flanged joint at the reactor outlet. The

resultant fire at the flange damaged instrument cabling in the vicinity of the reactor,causing an emergency shutdown of the unit.

The deformed / bulged section of the overheated reactor from a runaway reaction .


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INHALATIONOF DUST

LLuu nn gg pp nn ee uu mm oo nn iiaa

LLuu nn gg f f iibb r r oo ss iiss

HHee aa r r tt aa nn dd tt hh yy r r oo iidd

dd iiss oo r r dd ee r r ss

SS ee nn ss iitt iiss aa tt iioo nn oo f f r r ee ss pp iir r aa ttoo r r yy tt r r aa cc tt

aa nn dd ss kk iinn

SS uu ss pp ee cc tt ee dd cc aa r r cc iinn oo gg ee nn ss ((cc aa nn cc ee r r --

cc aa uu ss iinn gg aa gg ee nn tt )) ee ..gg .. nn iicc kk ee ll,, cc oo bb aa lltt

Catalyst dusts are a hazard to health wear the stipulatedrespirator that provides the appropriate level of

protection.

2.3 Health Hazards

Health hazards are mainly associated with metallic dusts that are toxic wheninhaled.

Exposure occurs during the handling of catalyst at site during loading and

unloading of reactors. Catalysts can enter the body by a number of routes including skin absorption;long-term exposures to low concentrations can cause serious chronic illnesses.


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2.4 Spent Catalyst

Spent catalyst exhibit the same hazards as new catalysts as well as other hazardsassociated with the products they come into contact with. For example, steam

cracker gasoline hydrogenation catalysts may contain high concentrations of benzene. Therefore, more extensive precautions should be exercised whenhandling spent catalysts.

Typical catalyst used in hydrogenation units contains between 4 to 21% carbon and 5 to 10% sulfur. Reprocessed or regenerated catalyst is considered spentcatalyst and not new catalyst, as trapped products may be released duringhandling. Beware that hydrocarbon vapours can be released in very highconcentrations when handling the spent catalyst.

Intoxicated by vapors from reprocessed catalyst !!!Reprocessed catalyst was being loaded into a reactor. After each bed loading, aninspector went in to check the partition of the catalyst. He was protected only by adust mask, and was overcome by hydrocarbon vapors and collapsed. Fortunately, hewas quickly rescued and fully recovered.

When stipulating precautionary measures, the hazards to be considered are not limitedto skin absorption of catalyst but must include the flammability, reactivity,corrosiveness and toxicity of the hydrocarbons present.

Example of protecting workersat bottom of reactor fromcatalyst dust using full lifesupport system that is designedfor entry into inert gas

atmosphere.

Another good example is touse hoods pressurised with afresh air supply (not a dustmask).


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Good PracticeAn occupational health risk assessment must be undertaken using MSDS andother information available from the suppliers / manufacturers of the catalyst andlicensor of the process technology to prevent harmful effects.

Undertake airborne monitoring of the atmosphere and regularly carry out amedical evaluation of the technicians.Clean full body clothing should be provided at the beginning of each shift andremoved prior to breaks/meals.Contaminated clothing must not be taken home. It must be discarded into

properly labeled drums for disposal or laundered on site under specialinstructions.A person entering the exclusion zone must wear the appropriate approvedrespirators.All personnel wearing respiratory protection must conform with the sites safetyrequirements and be instructed in its proper use and limitations as part of anystatutory written program on respirators.Personnel entering vessels must conform with the minimum precautionarymeasures stipulated under the sites safety standards.All personnel should be trained on the hazards of the dust and operationsaccording to the local statutory hazard communication standard.If in doubt, overprotect the workers e.g. use air line respirators that provide ahigher protection factor than air purifying respirators. See section 5.

2.5 Nickel Carbonyl

Nickel carbonyl [Ni(CO) 4] is used as a catalyst in some plastic, rubber, and petroleumindustries. Nickel carbonyl vapour may also be formed inadvertently in refiningcracking processes that use nickel as a catalyst. Nickel carbonyl is highly irritating tothe lungs and can produce asphyxia by decomposing to liberate carbon monoxide.Lethal human exposures have been estimated as 30 ppm for 30 minutes inhalation, and50 to 500 mg/kg if ingested. Initial symptoms include headache, dizziness, nausea, andvomiting, which disappear when exposure ends. Vapor also irritates the eyes, nose,and throat. Nickel contact dermatitis is the most common skin reaction to nickelcarbonyl, often referred to as "nickel itch." It is also a suspected carcinogen (cancer-causing agent).

Carry out an occupational health risk assessment beforeundertaking any work associated with the handling ocatalysts.


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2.6 Crushing Hazards

When digging through catalyst, specialist contractors must take care that no highwall of catalyst is left in place, ready to cave in if disturbed.

A recommended maximum height is 0.8 to 1.0 m (2.6 3.3 ft).

Entry personnel should be properly trained on this issue and a good control othe work by both the specialist contractor and the refinery team is essential.

Specialist contractors are responsible for rescue of personnel from a confinedspace that is knowingly under 100% nitrogen.

The specialist contractors emergency response team must always be wellequipped and ready to enter the reactor in case of an incident.

Maximum0.8 1.0m

(2.6 3.3 ft)

Spent catalystunloaded tovacuum truck

Breathing airsupply tospecialrespirator


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2.7 Other Hazards associated with Catalyst Handling

It is worth noting that other more conventional incidents frequently occur duringcatalyst loading and unloading operations, for example: Fork-lift overturns and crushes operator while transporting catalyst on pallets.

Operator falls while handling catalyst at height (e.g. use of rope ladder in 30meter high reactor is unacceptable). Weak internal structure of reactor collapses under the weight of operator.

Forklift Truck Fatality, while moving catalyst !!!

A forklift truck was moving catalyst drums to the hydrofiner loading area. It collidedwith a lamp-post and knocked it down. The driver was thrown out, the vehicleoverturned trapping him underneath. The driver died from the injuries he receivedduring this incident.

Provide an exclusion zone around catalyst handling areas.Conditions for entry shall be stipulated on work permit and

procedures.


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2.8 Catalyst Unloading

Typical discharge of unregenerated catalyst to prevent pyrophoric activity.

Provide adequateengineering controls to

prevent emission of dustto atmosphere.

REACTOR

DustAbatementSystem(e.g. vacuumtruck)

Drum

Nitrogenpurge

Valve

Nitrogen

Plastic insertbag

Nitrogenblanket atall times

Dust

Breathing airfrom supply

PersonalO 2 monitor

Operator mustwear airlinerespirator

Water hose toextinguish any small

pyrophoric fire and tokee dust wetted

LABEL


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2.9 Catalyst Labelling

Drums of spent or unregenerated catalyst must be properly labelled e.g.

Danger contains nickel

pyrophoric; will catch fire on exposure to air avoid dust inhalation and skin contact cancer suspect agent

2.10 Catalyst Disposal

The last word is for the protection of our environment. Ensure unregenerated catalystsand used catalysts are sent to an approved recovery plant through a reputablecontractor meeting all statutory requirements for shipment and handling.

Wrong way to dispose of spent catalyst

Melted metals recovered from used catalysts

Unregenerated catalysts shall only be sent off site in highintegrity containers correctly labelled to approved

reprocessing plants.


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39

HAZARD

Toxic Catalyst Dust

*IDLH Not IDLH

Specialist Contractorwith Life Support

System

CombinationAir-line / Air-purifying

Respirator

Air-lineRespirator

Air-purifyingRespirator

Dust FilterRespirator

PoweredAir-purifying

Respirator

2.11 Respiratory and Protective Equipment Requirements

Guide to respirator selection *(IDLH = Immediately Dangerous to Life & Health)


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Air-purifyingRespirators

CombinationRespirators

Air-line Respirators

have filters, cartridges, orcanisters that removecontaminants from the air

by passing the ambient airthrough the air-purifyingelement before it reachesthe user. E.g. dust mask,gas mask.

Continuous flow air-line/air purifying respiratorwith full facepiece.Filters are facepiece-mounted.

supply clean air directly tothe user from a source otherthan the air surrounding theuser. E.g. air-line respirator,self-contained breathingapparatus (SCBA).

* Refer to manufacturers literature, national standards and NIOSH Pocket Guide toChemical Hazards for further information. Visit NIOSH web pageshttp://www.cdc.gov/niosh/homepage.html for details.

Respirator Assigned Protection FactorThe assigned protection factor of a respirator reflectsthe minimum level of protection that a properlyfunctioning respirator would be expected to provide toa properly fitted and trained user. For example, a

protection factor of 10 for a respirator means that auser could expect to inhale no more than one tenth othe airborne contaminant present.

Permitted maximumairborne concentrationof catalyst dust aroundtechnicians

Protection Factorof Respirator*

Maximum permissible exposurelimit for the

particulate /contaminant*

x

Note: = Less Than

Highest = Life SupportProtection System

Lowest = Dust maskProtection


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Respirator selection for various tasks involving use of nitrogen and catalyst handling.

Besides wearing the correct respirator when handling catalyst, it is also important toavoid skin contact with the catalyst by wearing appropriate dust proof coveralls.Ensure that coveralls are removed and properly disposed off at the end of eachshift/work period.

Ensure that workers are informed of the risks of not wearing the correct personal protective equipment (PPE) and are trained in the proper use (including fit test) ofthe appropriate respirator.

TASK

TYPES OFRESPIRATORS

E n t r y

i n t o b a r r

i e r e d o f

f a r e a

I n s i

d e i n e r

t e d r e a c t o r

S t a n d

b y a t

t e n d a n t a d

j a c e n t

t o

t o p m a n

h o l e

W o r

k i n g a d

j a c e n t t o u n r e g e -

n e r a

t e d c a

t a l y s t

d r u m

f i l l i n g

C a t a l y s

t d r u m

h a n d

l i n g o u

t s i d e

b a r r

i e r e

d o f

f a r e a

R e f

i l l i n g r e a c

t o r w

i t h c a

t a l y s t

i n

a i r ( n o r m a l a t m o s p

h e r e

)

R e f

i l l i n g r e a c

t o r u n

d e r n

i t r o g e n

R e s c u e

T e a m

( s p e c i a l

i s t

c o n t r a c t o r s o n

l y )

Dust mask

Air purifying respirator with fullface piece

Air line respirator with full facepiece

Positive pressure demandSelf Contained Breathing

Apparatus (SCBA)

Full life support system


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Dust Mask against Nitrogen !!!A contract labourer was asphyxiated as a result of working in an oxygen deficientatmosphere whilst wearing a dust mask. Prompt action by operating staff in rescue and

resuscitation saved this man's life. A "Confined Space Entry Permit" was issued toallow men to enter the Reactor, which clearly stated that the vessel was: (a) under anitrogen purge, (b) deficient in oxygen, and (c) that breathing apparatus must be worn.However, conditions were not explained to the person in charge of the job, and theman carrying out the work was not informed that the vessel was under a nitrogen

purge and the atmosphere deficient in oxygen. Previously the workman had workedinside a similar vessel near the one where the incident occurred. The previous vesselhad been gas freed and its oxygen content was acceptable so the men assumed that theconditions were the same and worked inside wearing only dust masks.

Good PracticePersonnel must be trained to realise that each vessel entry is a separate jobcovered by a separate confined space entry permit with different conditions and

precautionary measures. Working conditions differ from vessel to vessel and fromday to day.


Air-line respirators are available in many types of configuration. Each type hasspecific limitations that must be considered when selecting an air-line respirator. Onemajor advantage is that air-line respirator can protect against both gases and dusts, andits use is not limited by filter loading or cartridge capabilities (except for combinationair-purifying and air-line respirators). These devices tend to consist of morecomponents that air-purifying respirators, perhaps making them more complex. Inaddition care must be taken to provide the following:

Good quality air for breathing to a recognized standard Sufficient quantity of air to meet the respirators operating requirements (asindicated on the approval label) and use duration.

A vortex fitted to the air supply to provide cool air to prevent heat stress in hotclimates. This requires a much bigger air flow rate. The cool air must not be socold that condensation occurs on the mask and impair vision.


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Schematic diagramof a typical air-linerespirator withauxiliary escape airsupply worn on thewaist.

Continuous flow air-line respirator with vortex for airflow control valve.Vortex provides cooler air to worker. Note the filter and regulator panel in

upper right-hand corner.

NOTE: This is not a fulllife support system.

Air line respirator and SCBA are NOT life support systems suitable for workinside a nitrogen atmosphere.


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Investigations concluded that the man workinginside the vessel had a poor seal around theface mask with a faulty air line and wasunaware that the air he was breathing wasslowly becoming deficient in oxygen (thesymptoms of asphyxiation in the early stagescan be loss of judgment and loss of ability tothink clearly). The look out' man was foundinside the vessel without breathing apparatusand it was assumed that he must have goneinside the vessel to rescue his fellow worker.

Inadequate respiratory equipment for work inside an inert gas / nitrogenenvironment !!!Two men were found dead inside the CO converter in an ammonia plant during theremoval of catalyst from the converter under nitrogen cover. One operator was

working inside the CO converter which was under a nitrogen blanket wearingconventional compressed air breathing apparatus; the air was supplied from bottlessituated outside the vessel. He was also equipped with a separate emergency air supplyfrom a small bottle attached to his waist but he had made no attempt to switch it on.The other man remained outside the vessel to act as a safety look out'.

The precautions for work in an inert atmosphere must reflect the possibility andseriousness of an incident occurring and therefore requires the use of verysophisticated equipment and experienced personnel not normally available atrefineries. This equipment and the expertise that goes with it is only available fromoutside specialist contractors.

Refer to Section 6 on Specialist Contractors.

SPECIALIST LIFE SUPPORT SYSTEM

Unlike the Specialist Life Support System, breathing apparatus normally available at

refineries and chemical plants does not providean adequate safeguard to cover the risks

associated with work in an inert gas or nitrogenatmosphere. This work can ONLY be carried

out by specialist contractors.

Poor face seal(see respiratorselection matrixon page 41).

Lockable helmet connected

to Specialist Full LifeSupport System (refer to

page 48 for details)


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2.12 Catalyst Specialist Contractors for Inert Gas / Nitrogen Reactors

Management must thoroughly scrutinize the management systems and associated procedures employed by inert gas specialist contractors prior to the award ofcontract.

In view of the restricted space inside reactors and the limited time available to save anunprotected operative inside an nitrogen atmosphere specialist contractors must

prove that they have the required back-up respiratory and other emergency / rescueequipment to handle the range of potential failures.

Pre-Contractual Arrangements

Pre-requisite for Specialist Contractors Effective safety management system including a drug /alcohol abuse policy. Certified life support equipment. Safety and operations manual covering procedures to undertake such hazardous

work. Inert gas confined space training document / certificate for each potential entrant. Proven medical fitness of personnel (current certificate). Detailed emergency rescue plan.

Written reports of past similar works undertaken.

Site Management Prior discussions involving site safety advisor,

maintenance and operations personnel, specialistcontractors project leader. Final approval o

procedures by Site Manager.

Precautionary measures must be agreed andresponsibilities assigned. Emergency response / egress procedures to be

agreed. Trial rescue must be carried out beforework commences.

Visit a site to witness similar work being carriedout by proposed specialist contractor.

Formal appointment of site representative tomanage the project.

Due to the hazards of working in nitrogen atmospheres, alternative processesnot requiring entry into an inert atmosphere must be considered and, whenappropriate, become the preferred alternative.


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Areas of Responsibilities (should be clearly defined in writing)

Site Owner / Representative Specialist Contractor Specify all hazards to contractors

and own staff Enforce Permit to Work System and

agreed procedures Isolate equipment for entry Minimise presence of other

contaminants during the shutdownand purging operations

Provide reliable N 2 supply, ifsupplied by site

Provide safe access to place ofwork

Prevent unauthorized access to thearea

Provide continuous supervision ofwork; monitor N 2 purge and

provide standby fireman Provide FM radio sets for

communication between siterepresentative and contractorssupervisor

Monitor outside barricaded area for

O2, toxics and flammables.

Responsible for the safety of personnel

Compliance to agreed protectiveequipment requirements.

Ensure adequate number ofqualified, experienced and properlyequipped personnel

Brief employees of any additionalhazards and take appropriatemeasures

Monitor local working environmentand arrange additional precautionsif necessary e.g. oxygen andflammable gas detectors.

Ensure Emergency Response /Egress Plan in place and ready

Comply to site safety rules and procedures

Ensure any change to agreed procedures is authorized through thesites Management of Change

procedure

Joint Responsibilities To ensure O 2 level is kept down to a safe level (below 2 % v/v) inside reactor Number of N 2 injection points Purge position and monitoring of N 2 supply Number and position of sampling heads for O 2 meters/alarms and person to

calibrate and monitor this equipment. Both inside and outside reactor. Minimum N 2 flow and daily consumption Continuous temperature monitoring within the vessel

Specialist contractors including their safety management system,equipment, working methods and previous work experience must be

thoroughly reviewed before being awarded a contract to remove catalystfrom an IDLH atmosphere.


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PANELPANEL

BACK-UPSYSTEM)

1 m(3.28 ft)

Secured WoodenLadder

(Not Rope Ladder)

Available Rescue Lifelines OnSecure Anchorage (FullSafety Harness Must Be

Worn)TopsideSupervisorMonitoring

CommunicationAnd Panels

Barriered OffArea

Standby AttendantWearing Back-Up

Life Support System

Typical Personnel Arrangements at top of Reactor

Working Platform

Topside AssistantWearing Airline BA

In


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3. POINTS TO REMEMBER FOR TOOL BOX MEETINGS

! Moving affected and unconscious persons from a N 2 atmosphere into fresh air is not enough to promoterecovery. The patient has to be physically resuscitatedin order to restore the oxygen supply to the brain.

! Nitrogen (N 2) is a very common and extremelydangerous gas that you may be exposed to at a refineryor chemical plant. You must always be on your guard.

! Most Useful or Most Dangerous Gas???

! An asphyxiant is a chemical (gas or vapour) that cancause death or unconsciousness by suffocation.Simple aphyxiants such as nitrogen, displace oxygen inair. They become especially dangerous in confined orenclosed spaces. Chemical asphyxiants, such ascarbon monoxide and hydrogen sulfide, interfere withthe bodys ability to absorb or transport oxygen to thetissues.

! An Oxygen Deficient Atmosphere is an atmospherewith oxygen content below 19.5% by volume. (OSHA

Definition)

NN2

N

USEFUL ?

DANGEROUS ?

20

19 21

%O 2


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! Nitrogen can create an oxygen deficient atmosphereoutside the vessel/piping that is being purged with thismedium.

! You are asphyxiated with only your head inside anoxygen deficient atmosphere - not your whole body.

! Keep technicians away from areas outsidemanholes that could be deficient in oxygen(unless authorized through a Confined SpaceEntry Permit).

! Do not confuse N 2 with air !!!

! A mobile, self-contained, high pressure cylinderstorage system undoubtedly provides the highestintegrity, freedom of operation and safety when usingairline breathing apparatus. Most sites prefer to eitheruse bottled air, supplied from a trolley set (wheeledtrolley with air bottles on it) or from a bank ofdedicated air bottles located on the plant. There is arequirement to ensure that the quality of air in supply

bottles is correct, whether they are refinery filled orotherwise by a respectable external company.

N2

N2

N2

N2

N2

O2 Deficient Atmosphere

Inside Reactor


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! If you see someone lying unconscious on the ground orthrough the opening of a tank or pipe. Call the firedepartment / rescue team. Never enter a confined spaceor area alone to give help. Call for assistance.

! Unregenerated catalyst is normally a self-heatingsubstance and often pyrophoric. On exposure toair, it can rapidly catch fire.

! Wear the correct personal protective equipment anduse the correct storage containers when handlingcatalyst .

! Catalyst dusts are a hazard to heath wear thestipulated respirator that provides the appropriate levelof protection.

! Always check the oxygen level first before carryingout a flammable gas test using an explosimeter in

preparation for hot work or confined space entry.

! Provide an exclusion zone around catalyst handlingareas. Conditions for entry shall be stipulated on work

permit and procedures.

CATALYSTDRUM

20

19


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! Preference should always be given to thedumping of catalyst that is wetted withspecial additives i.e. will not cause a dusthazard and as such is encapsulated to

prevent pyrophoric activity. This wouldallow workers to enter reactors not deficientin oxygen since it would not require the

presence of an inert gas or nitrogen filledatmosphere.

! Due to the hazards of working in nitrogenatmospheres, alternative processes notrequiring entry into an inert atmospheremust be considered and, when appropriate,

become the preferred alternative.

If you have any doubts,please consult the safety procedures.

Do not hesitate to ask your Safety Departmentfor more information.

RiskAssessment

HAZARDS SAFEGUARDS


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4. TEST YOURSELF

1 Whatever its state, the only risk related to nitrogen is suffocation.True False

2 The smell of nitrogen immediately identifies an oxygen deficientenvironment.

True False

3 Testing for flammable gases in pipes purged with nitrogen does not poseany problems with explosimeters.

True False

4 There is no risk in leaving a bottle of nitrogen in a small room.True False

5 An air purifying respirator will adequately protect me in an oxygendeficient atmosphere.

True False

6 It is safe to pour liquid nitrogen on myself.True False

7 Even if I inhale pure nitrogen, I will be safe for a few minutes thanks tothe oxygen stored in my blood.

True False

8 Nitrogen is not the only gas that can cause suffocation.True False

9 Nitrogen is only used on the site for preparing equipment formaintenance (never for other purposes or in the tank farms ).

True False

10 Unregenerated catalyst can be pyrophoric.True False

11 Handling, unloading, storage and shipment of unregenerated catalysts isnormally carried out under nitrogen cover.

True False


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12 Catalyst dust is not a threat to our health and therefore air-linerespirators are not required.

True False

13 Dust masks always provide adequate protection to prevent inhalation ofcatalyst particles.True False

14 Specialist contractors for inert gas confined space entry projects useconventional SCBA because they are trained underwater divers.

True False

15 Providing the atmosphere is between 19.5% and 23.5% oxygen, it is

always safe to enter the confined space.True False

16 Open manholes are dangerous because technicians are likely to put theirheads inside.

True False

17 Oxygen deficient atmospheres can be created outside a confined space.True False

18 An occupational health risk assessment is required prior to any possibleexposure to catalyst, to protect the technicians and the environment fromharmful effects.

True False

19 Conventional breathing apparatus normally found in refineries providesadequate protection for working in an inert / nitrogen-filled confinedspace.

True False

20 All air compressors provide the quality of air necessary for breathingapparatus.

True False


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(Tear-away Sheet)

1. HAZARDS OF NITROGEN1.1 ASPHYXIATION HAZARD

1.1.1 Temporary enclosed spaceNitrogen Gassing Incidents 1982 / 3Q

Asphyxiation Hazards - Chimney Effect 1993 / 4QFatality from a Temporary Confined Space in Chemical Plant 1998 / 2QTechnician Overcome by Oxygen Deficient Environment 2001 / 4Q

1.1.2 Coming too close to a nitrogen ventFatal Accident - Nitrogen Asphyxiation 1981 / 4QGassing Incidents 1993 / 4QGassing incident due to air system backed-up with nitrogen 2002 / 3Q

1.1.3 Incidents that occurred in vesselsHazards From Nitrogen - Risk to Employees 1974 / 4QNitrogen Gassing 1976 / 3QGassing Incidents 1977 / 4QTwo men asphyxiated during removal of catalyst under N2 cover 1978 / 4Q

Asphyxiation Death of a Contract Worker 1991 / 2QNitrogen Gassing Incidents 1998 / 4QFatality during Removal of Catalyst under N2 Cover 2001 / 2QInert Gas Entry Fatality 2001 / 3Q

1.1.4 Incidents while working on pipingMaintenance Fitter Gassed by a Mixture of H2S and N2 1980 / 1QNitrogen Gassing Incidents 1980 / 2QGassing Fatality during work at Molecular Sieve 1991 / 1QNitrogen Asphyxiation 2000 / 1Q

Danger of Nitrogen 1979 / 1QNear Nitrogen Fatality 2001 / 2Q1.1.5 Personal Protective Equipment Incidents

Asphyxiation Incidents 1971 / 2QFatal Accident during Welding On a Spiral Wound Exchanger 1985 / 1QNitrogen Gassing Incidents - Audit Lessons 1989 / 4Q

1.2 PRESSURE HAZARDLaboratory Incident 1975 / 2QExplosion in Flare Stacks during Maintenance 1992 / 4QContractor Fatality during Reactor Catalyst Removal 1995 / 2Q

1.3 PRECAUTIONARY MEASURES

Safe Handling of Liquid Nitrogen in Laboratories 2000 / 3Q

2. HAZARDS OF CATALYST HANDLING2.1 FIRE HAZARD

Catalyst Sampling from Cat Reformers 1973 / 4QChemical Warehouse Fire 1993 / 1Q

2.2 LOSS OF CONTAINMENT HAZARD

FCCU Release of 80 Tonnes of Catalyst during Turnaround 1998 / 2Q2.3 RUNAWAY REACTION

INCIDENTS

PAST INCIDENTS RECORDED IN QSB

YEAR / QUARTER

Documents

Hazards.of.Nitrogen.and.Catalyst.handling