Liquid cargo notes

8/12/2019 Liquid cargo notes

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DEVELOPMENT OF TANKERSCHEMICAL TANKERS

Sea transport of chemicals started with the chemicalindustries rapid growth in the year after World War Two

At first, chemicals were transported in bottles or drums on drycargo ship; larger quantities were shipped in bulk in the deep

tanks of these ships As the worlds demand for chemicals increased, the need fora new type of seagoing ship became evident

The first chemical tankers were converted war-built Americanoil tankers (T2 tankers)

Conversion work usually included: adding bulkheads to provide more and smallertanks extending the line system Installing additional cargo pumps


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DEVELOPMENT OF TANKERS

The first conversion of this type was done in 1948 onthe R.E. Wilson. of 9073 tons gross tonnage

In addition to these converted, relatively big chemical

carriers, smaller tankers specially designed andconstructed for the carriage of acids e.g. sulphuricacid, were built during the early 1950s, the cargo tanksof which were made of special alloy steel, strengthenedfor cargo densities up to 2.0 kg/l

In order to carry chemicals of high purity and sensitiveto contamination, coating techniques were developedfor cargo tanks of mild steel.


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The first real chemical tanker specially designedfor the carriage of liquid chemicals in bulk wasthe Norwegian M/T Lind, delivered in 1960; thiswas the first tanker equipped with stainless cargotanks

A modern chemical tanker has a large number ofcargo tanks and is designed for carriage of a widevariety of cargoes

The cargo-tank section on these modern ships isnormally divided into some stainless steel tanksand some coated mild-steel tanks, each of whichis normally equipped with deep well pumps and aseparate piping system.


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GAS CARRIERS

Gas shipping began in the late 1920s

The earliest ship were designed to carry liquefied gasin pressure vessel at ambient temperature The first cargoes on the market were butane and

propane Development of refrigeration techniques and metals

suitable for low temperature made it possible tocarry liquefied gas at temperatures low than ambient


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Around 1959, semi-pressurized ships entered

the market and liquefied gas was now

transported under lower pressure, which wasmade possible by lowering the temperature

By 1963, fully refrigerated ships for LPG, LNGand certain chemical gases were in service,carrying cargo at atmospheric pressure



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CHEMICAL TANKERS- IMO SHIP TYPE

1. IMO Ship Type 1 is a chemical tanker intended for the transportationof products considered to present the greatest overall hazard, andType 2 and Type 3 for products of progressively lesser hazards. Thequantity of cargo required to be carried in a Type 1 ship should notexceed 1,250 m3 in any one tank.

2. IMO Ship Type 2 is intended to transport products with appreciablysevere environmental and safety hazards which require significantpreventive measures to preclude escape of such cargo. The quantityof cargo required to be carried in a Type 2 ship should not exceed3000 m3 in any one tank.

3. IMO Ship Type 3 is a chemical tanker intended to transport productswith sufficiently severe environmental and safety hazards. Theseproducts require a moderate degree of containment to increasesurvival capability in a damaged condition. There is no fillingrestriction for chemicals assigned to Ship Type 3.



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CARGO CONTAINMENT SYSTEM


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GAS CARRIERS FULLY PRESSURIZED GAS CARRIERS

LPG carriers fitted with two or three horizontal, cylindricalor spherical cargo tanks and have capacities up to 6,000m

3. However, in recent years a number of larger-capacity

fully pressurized ships have been built with sphericaltanks, most notably a pair of 10,000m

3 ships, each

incorporating five spheres. Fully pressurized ships are still

being built in numbers and represent a cost-effective,simple way of moving LPG to and from smaller gasterminals.



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Semi-pressurized ship These ships carried gases in a semi-pressurized/semi-

refrigerated state

ship owners' choice by providing high flexibility in cargohandling.

These carriers, incorporating tanks either cylindrical,spherical or bi-lobe in shape, are able to load or discharge

gas cargoes at both refrigerated and pressurized storagefacilities.



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Ethylene carriers are the most sophisticated of the Gas tankers able to carry most liquefied gas and ethylene at its

atmospheric boiling point of -104C. Features cylindrical, insulated, stainless steel cargo

tanks able to accommodate cargoes up to a maximum

specific gravity of 1.8 at temperatures ranging from aminimum of -104C to a maximum of +80C and at amaximum tank pressure of 4 bar.



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Fully refrigerated ship built to carry liquefied gases at low temperature

and atmospheric pressure .

Prismatic tanks enabled the ship's cargo carryingcapacity to be maximized thus making fully refrigerated ships highly suitable

for carrying large volumes of cargo such as LPG,ammonia and vinyl chloride over long distances.

Independent tanks with rigid foam insulation arethe most common containment system utilized



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Semi-membrane tanks are a non-self-supporting tanks in the loaded condition andconsist of a layer, parts of which are supported

through insulation by the adjacent hullstructure whereas the rounded parts of thislayer connecting the above mentioned

supported parts are designed also toaccommodate the thermal and otherexpansion or contraction



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Independent tanks are self-supporting; they do not form part of the shiphull and are not essential to the hull strength.

Type A Independent Tanks prismatic and supported on insulation-bearing blocks typically consisting of wooden chocks and located byanti-roll chocks located at the top of the tank inside the void spaceand anti-flotation chocks located inside the void space usually justabove the double bottom tanks. The tanks are normally divided by acenterline liquid-tight bulkhead;. When these cargo tanks aredesigned to carry LPG (at -50C), the tank is constructed of fine-grained low carbon manganese steel or even stainless steel. Thehold space (void space) in this design is normally filled with dry inertgas or Nitrogen but may be ventilated with air during a ballast or gasfree passage. The Conch design has been developed for carriageof LNG (at-163C). The material for these cargo tanks has to beeither 9% nickel steel or aluminum. The maximum Allowable reliefvapour setting (MARVS) is < 0. 7 bar.

http://en.wikipedia.org/wiki/LNGhttp://en.wikipedia.org/wiki/LNG


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Type B Independent Tanks are generally spherical andwelded to a vertical cylindrical skirt, which is the loneconnection to the ship's main hull. The hold space (voidspace) in this design is normally filled with dry inert gas or

Nitrogen but may be ventilated with air during a ballast orgas free passage. A protective steel dome covers theprimary barrier above deck level, and insulation enclosesthe outside of the primary barrier surface. This

containment system has been used for carriage of LNG.The material of construction is either 9% nickel steel oraluminum. The maximum Allowable relief vapour setting(MARVS) is < 0. 7 bar.



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Type C Independent Tanks are deck pressurevessels or cylindrical pressure tanks mountedhorizontally on two or more cradle-shaped foundations.The tanks may be fitted on, below or partly below deckand be both longitudinally and transversely located.Lobe-type tanks are commonly used at the forward endof the ship, to improve the poor utilization of the hullvolume. This containment system is used for LPG and

in Ethylene carriers. The material, if used for theconstruction of tanks designed to carry ethylene, is 5%nickel steel. The maximum Allowable relief vapoursetting (MARVS) is > 0. 7 bar.



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HYDROCARBONS

A hydrocarbon is a natural compound thatcontains hydrogen and carbon. Hydrocarbons areclassified as organic and can have single(saturated), double or triple (unsaturated) bondsbetween the carbon atoms. Most hydrocarbonsoccur naturally in crude oil. Crude oil is thedecomposed organic matter formed by millionsof years of heat and pressure under the earth's

crust. The hydrocarbons found in oil are typicallycalled fossil fuels and are the primary source ofthe world's energy.


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HYDROCARBONS

Sources of Hydrocarbons Fossil Fuels (Crude Oil & Natural Gas)

Crude Oil is a mixture of hydrocarbons rangingfrom those which are partly gaseous undernormal atmospheric conditions to those whichare liquid and solid.

The petroleum remaining after the removal of productssuch as methane is termed crude oil


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HYDROCARBONS


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HYDROCARBONS


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CHEMICAL CARGO

A chemical tanker is primarily designed for thecarriage of dangerous chemicals in bulk andin addition to the cargoes listed in the IBCCode, chemical tankers may carry a widevariety of other liquid products which would

normally be considered to be unrelated tochemicals.


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CHEMICAL CARGO

Cargoes in chemical tankers may be dividedinto 4 groups as follows: petrochemicals alcohols and carbohydrates vegetable and animal oils and fats

inorganic chemicals


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PETROCHEMICALS

organic products derived wholly or partly fromcrude oil, natural gas or coal. Examples of petrochemicals:

solvents aromatics intermediates or refined products

CHEMICAL CARGO


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The group of alcohols and carbohydratesincludes products which may be producedby fermentation, such as:

liquor wine molasses

CHEMICAL CARGO


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Fermentation

is the process of extracting energy fromthe oxidation of organic compounds, suchas carbohydrates, using an endogenous electronacceptor, which is usually an organic compound .


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VEGETABLE & ANIMAL OILS- are products derived from seedsof plants and from the fat of animals, including fish. They areinsoluble in water and oily or greasy to the touch. Theircomposition is quite different from mineral oils, which arealmost completely composed of hydrocarbons. Fats or oil

containing saturated fatty acids are generally in the solid formand are required in the manufacture of soap and margarine,while fats or oils containing unsaturated fatty acids usually areliquid at room temperature .

Examples of vegetable and animal oils and fats: soya bean oil cottonseed oil lard and lard oil beef and mutton tallow whale oil sardine oil

cod oil

CHEMICAL CARGO


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Inorganic chemicals are products which are notof organic origin. These are carried in largequantities because they are virtually utilized byevery manufacturing industry. Although otherpetrochemicals are carried in bulk this dealsspecifically for mineral acids which is sometimescalled heavy chemicals

Examples of inorganic chemicals are: sulphuric acid phosphoric acid nitric acid caustic soda

CHEMICAL CARGO


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ACID and BASE

ACID the term acid was first used in the seventeenth century; itcomes from the Latin root ac -, meaning sharp, as inacetum , vinegar. Some early writers suggested that acidicmolecules might have sharp corners or spine-like projectionsthat irritate the tongue or skin.

An acid is a substance that yields an excess of hydrogen ionswhen dissolved in water.

A characteristic sour taste (think of lemon juice!); ability to change the color of litmus from blue to red react with certain metals to produce gaseous H 2 react with bases to form a salt and water


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BASE The word alkali is often applied to strong inorganic bases. It

is of Arabic origin, from al-kali ("the ashes") which refers tothe calcined wood ashes that were boiled with water to obtain

potash which contains the strong base KOH, used in soap

making. The element name potassium and its symbol K (fromthe Latin kalium) derive from these sources The name base has long been associated with a class of

compounds whose aqueous solutions are characterized by: bitter taste

A soapy feeling when applied to the skin; ability to restore the original blue color of litmus that has been turned

red by acids ability to react with acids to form salts react with certain metals to produce gaseous H 2

ACID and BASE


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A base is a substance that yields an excess ofhydroxide ions when dissolved in water.

An acidic substance is one whose molecularunit contains at least one hydrogen atom thatcan dissociate, or ionize , when dissolved inwater, producing a hydrated hydrogen ion andan anion."

ACID and BASE


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ACID and BASE


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http://secure.sciencecompany.com/pH-Fix-Paper-0-14-Pk100-P6406C625.aspx


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http://secure.sciencecompany.com/Hanna-pH-Meter-pHep4-HI98127-P6261C679.aspxhttp://secure.sciencecompany.com/pH-Paper-1-14-range-15-ft-roll--P6263C625.aspxhttp://secure.sciencecompany.com/pH-Fix-Paper-0-14-Pk100-P6406C625.aspx


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LIQUIFIED GAS CARGO

Liquefied gas is the liquid form of a substancewhich at ambient temperature and atmosphericpressure would be a gas.

Liquefied gases are those substance having a vapourpressure exceeding 2.8 bars absolute at a

temperature of 37.8C and certain other substancesspecified in the Gas Code.


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Liquefied ethylene gas (LEG) is produced by cracking ofLPG

Chemical gases are a group of liquefied gases producedthrough a chemical process

Chlorine, ammonia and vinyl chloride monomer (VCM)as examples of chemical gases

Certain other substances in the borderland betweenliquefied gas and chemicals are carried on gas tankers

Acetaldehyde and propylene oxide as examples of suchcargoes

LIQUIFIED GAS CARGO


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METHODS BY WHICH GAS IS LIQUIFIED1. Liquefaction by removal of heat

-Liquefaction of gas cargoes on ships other than fully

pressurized ships is done by removal of heat- The heat to be removed from the cargo is called latentheat of condensation

2. Liquefaction by pressurizing

Gas carrier is a cargo ships constructed or adapted andused for the carriage in bulk of any liquefied gas or otherproducts listed in the table of chapter 19 IGC Code

LIQUIFIED GAS CARGO


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CHARACTRIESTICS OF CARGO States of Aggregation- A substance (matter) can present itself to us in three

different forms or phenomena. These are called states of aggregation. The threeforms are:

The solid or crystalline state -There is a strong attraction between themolecules of the substance. Therefore, these molecules are closely together inmore or less fixed positions, e.g. in a crystal. A solid substance has its own formand volume.

The liquid state -The powers of attraction between the molecules are muchsmaller, so that the mutual distances are bigger, and the molecules can movewith respect to one another. Although there is still a connection, the liquids donot have a form of their own and they are movable; they do have their ownvolume.

The gaseous state -There are hardly any powers of attraction between themolecules which move completely free in respect of one another. They have noform of their own, no volume of their own; a gas completely fills the containerin which it is present; therefore so to speak, takes on the form and volume ofthis container.


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The stage of aggregation of a substancedepends on pressure and temperature. Athigh pressures and low temperatures we

usually have to do with solid substances; lowpressures and high temperatures stimulatethe existence of gases.

CHARACTRIESTICS OF CARGO


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THE HYDROCARBON STRUCTURE crude petroleum as discharged at the well head is a mixture

of about one thousand of different hydrocarbon molecules the molecules are termed light or heavy according to

the number of carbon atoms forming the molecule very light molecules such as methane, butane and propane

tend to be gaseous under normal atmospheric conditions very heavy molecules such as asphalt and bitumen tend to

be solid under normal atmospheric conditions intermediate molecules such as petrol (motor spirit) and

diesel oil tend to be liquid under normal atmosphericconditions



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THE HYDROCARBON STRUCTURE very light gaseous molecules such as methane are

extracted at the well head the petroleum remaining after the removal of products

such as methane is termed crude oil crude oil is a mixture of hydrocarbons which under

normal atmospheric conditions are gaseous, liquid andsolid

an oil refining process termed distillation , crude oil issplit into a number fractions

each petroleum fraction has a range of physicalproperties specified to itself



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DISTILLATION - is a method of separating mixtures

based on differences in volatilities of components ina boiling liquid mixture. It is used to separate crudeoil into several specific fractions.

How does distillation works in Petroleum refinery?Since crude oil is a raw material and unusable. It undergothrough the process of distillation to produce different

fractions (or products such as gasoline etc.) Crude oil isheated and the different fractions are pulled out by theirvaporization temperatures or commonly called as boilingpoint.


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CRACKING - cracking is the process whereby complex

heavy hydrocarbons such as heavy gas oil that isproduced from distillation are broken down into lighthydrocarbons such as gasoline.

Why do we have to crack petroleum products when it

already underwent the process of distillation?In the early days of crude oil refining, the process cracking donot exist, it was later used during the world war 2 1940s dueto the high demand of the US for gasoline. Scientist werechallenged how can a greater proportion of gasoline be

extracted from the crude oil than that obtain from distillationprocess alone. Scientist look for any products other thangasoline which are drawn from the crude oil, studied theirmolecules and found a way to change them into gasolinehence the result was CRACKING


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Characteristics of Cargo

VOLATILITY - is the tendency of a substance to vaporize.Volatility is directly related to a substance's vapour pressure. At agiven temperature, a substance with higher vapour pressurevaporizes more readily than a substance with a lower vapour

pressure. Volatile petroleum has a flashpoint below 60 oC (140 oF), asdetermined by the closed-cup method of testing.

VAPOR PRESSURE- The pressure of the vapour that isformed above its liquid or solid is called the vapour pressure.

Vapour pressure is a force exerted by the gaseous phase of atwo phase gas/liquid or gas/solid system.


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TRUE VAPOR PRESSURE (TVP) is a common measure of the volatility of petroleum

distillate fuels. the bubble point vapor pressure is the equilibrium vapor

pressure of a mixture when the gas/liquid ratio iseffectively zero. It is the highest vapor pressure which ispossible at any specified temperature.

As the temperature of the of a petroleum mixtureincreases, its TVP also increases. If the TVP exceedsatmospheric pressure the liquid commence to boil.

TVP of a petroleum mixtures provides a good indication ofits ability to give rise to gas.

TVP differs slightly with RVP.



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Flashpoint the lowest temperature at which a liquid gives off

sufficient vapour to form a flammable mixture with airnear the surface of the liquid. The flash point temperature

is determined by laboratory testing in a prescribedapparatus. There are two methods: either by closedmethod in the closed cup (c.c.) or by open method- in theopen cup (o.c.)

Melting Point the temperature at which the states of aggregation is

changed from solidifying to melting .If the TVP exceedsatmospheric pressure, the liquid begins to boil.


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Boiling Point the temperature at which the vapour pressure of a liquid is

equal to atmospheric pressure .

Flammability When a petroleum is ignited it is the gas progressively given off

by the liquid which burns as a visible flame. The quantity of gasavailable to be given off by a petroleum liquid depends on itsvolatility which is frequently expressed for purposes ofcomparison in terms of Reid Vapour Pressure RVP). A moreinformative measure of volatility is the True Vapour Pressure(TVP) but unfortunately this is not easily measured. It is referredto in this guide only in connection with venting problems withvery volatile cargoes, such as some crude oils and naturalgasoline.


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Auto-ignition temperature The lowest temperature to which a solid, liquid or gas

requires to be raised to cause self-sustained combustionwithout initiation by a spark, flame or other source ofignition. The auto-ignition temperature of vapors of fueland lubricating oils are much lower than those of thevapors from more volatile petroleum liquids. Fuel andlubricating oils are thus more liable to ignite if they are

allowed to fall or sprayed on hot surfaces despite theabsence of external flame or spark. Care must also be takento avoid rags soaked in fuel or lubricating oil coming intocontact with hot surfaces


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Reactivity The accidental mixing of one chemical product with

another inside a cargo tank or pipe may result in a vigorouschemical reaction. Binary combinations that generate

significant heat or produce gas can be very hazardous topersonnel and property. In rare cases the reaction of twocomponents (even though non-hazardous) may produce aproduct which is significantly more flammable or toxicthan the original materials. Even the water washing of

cargo tanks and slop tanks containing residues of certainsubstances may produce dangerous reactions. Dangerousreactions are polymerization, oxidation, mutual reactionsbetween chemicals.


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Toxicity It means a poison in the Greek language (toxikon).Toxicity is the

ability of a substance to cause damage to living tissue, impairment ofthe central nervous system, illness or in extreme cases death wheninhaled, ingested or absorbed through the skin.

Corrosivity Corrosion hazards are dangerous to Personnel and to metal. Some

liquid cargoes are so corrosive that in contact with the skin willcompletely or partly destroy living tissue. Less corrosive liquids mayonly be irritating to the skin but can result in serious damage to the

eyes. Corrosion is the etching or attack of metals on the surface.Corrosion can have different causes and it can present itself in manymanifestations. Consequently, both personnel and metals have to beprotected against activity of corrosion.


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TOXICITY and OTHER HAZARDS

Toxicity in General Most of the cargoes on tankers have some hazardous properties.Poisoning may occur orally, through inhalation or by skin contact.Poisoning may be acute or chronic . Exposure to oil, chemical or gascan have acute or chronic effects on a persons health.

ACUTE EFFECT (SHORT TERM) -defined as effect of single exposureof short duration to relatively high concentration of vapor.

CHRONIC EFFECT (LONG TERM)- defined as accumulative effect ofprolonged exposure to relatively low concentrations of vapor over along duration of time.

The vapour from some cargoes may have both acute and chronic effects,whilst others may have one or the other more prominent


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Threshold limit value (TLV)- The time-weighted average concentration of asubstance to which workers may be repeatedly exposed, for a normal 8-hour workday or 40-hour workweek, day after day, without adverse effect.

The term TLV has been in use within the industry for a number of years andis often expressed as a Time Weighted Average (TWA). The use of the termPermissible Exposure Limit is becoming more commonplace and refers tothe maximum exposure to a toxic substance that allowed by an appropriateregulatory body. The PEL is usually expressed as a TWA, normally averagedover an eight hour period, or as a Short Term Exposure Limit (STEL),normally expressed as a maximum airborne concentration averaged over a15 minute period. The values are expressed as parts per million (ppm) byvolume of gas in air (ISGOTT 16.1).

TLV examples : Acetic acid 10 ppm, Benzene 10 ppm plus skin absorption,Chlorine 1 ppm, Nicotine 0.07 ppm plus skin absorption, n-Pentane 600ppm, Toluene 100 ppm plus skin absorption


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Cargoes also may be harmful to the environment There are five points under which Marpol Convention was

developed and adopted : 1. Marine pollutants discharged into the sea are rigorously

controlled and are only permitted under the specific conditiondepending on the type of ships and their tonnage.

2. There are special areas where all discharge are controlled orprohibited.

3. Each state is obliged to provide port reception facilities for thereception and treatment of polluting substances.

4. Each master must have on board a special record book whichmust be kept up to date, specifying all cargo loading and unloadingoperations.

5. Consequently, the designs of ships, as well as, their equipmentmust, in the future, satisfy those very specific requirements


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The quantity of gas available to be given off by a petroleum liquiddepends on its volatility which is frequently expressed for purposesof comparison in terms of Reid Vapour Pressure (RVP): the higherthe RVP the higher volatility . The RVP test is related with a standardapparatus and in a closely defined way. RVP is useful for comparingthe volatilities of a wide range of petroleum liquids. The volatility(i.e. the tendency of the liquid or petroleum product to producegas) is characterized by the vapour pressure. There is also atendency for this gas to re-dissolve in the liquid, and an equilibriumis ultimately reached with a certain amount of gas evenlydistributed throughout the space. The True Vapour Pressure (TVP)or bubble point vapour pressure is the equilibrium vapour pressureof a mixture when the gas/liquid ratio is effectively zero. As thetemperature of a petroleum mixture increases its TVP alsoincreases and more vapors of liquid is produced.


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Volatility increases with temperature andreaches a maximum at the boilingtemperature of the petroleum

The concentration of hydrocarbon vapour presentin air is used to define flammable range:

Gas: UFL: LFL:

Propane 9.5 2.2 Butane 8.5 1.9 Pentane 7.8 1.5


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The flammability diagram When an inert gas is added to ahydrocarbon gas/air mixture the result is to increase thelower flammable limit hydrocarbon concentration and todecrease the upper flammable limit concentration. The flashpoint of an oil indicates the lowest temperature as

which the oil will give off sufficient hydrocarbon vapour to forma flammable gas mixture with air near the surface of the oil.Therefore, we can say that flash point is also the uppertemperature explosive limit only for the many kind of crude oil.

Only the vapour from a flammable material will combine withoxygen to produce fire. An explosive mixture may be producedwhen chemical cargo vapors are mixed with air. An explosion can be described as a sudden, violent event accompanied withnoise and fire which has a destructive effect on itssurroundings.


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Explosion can be distinguished as follows: physical explosion - a sudden expansion, mostly of

a gas, whereby pressure increase can no longer becaught by the (closed) drum (steam boilerexplosion, explosion of a cylinder withcompressed nitrogen);

chemical explosion -a rapid, exothermic, chemicalreaction, mostly accompanied with temperatureand pressure increase and the setting free ofgases, whereby energy is supplied by the reaction


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Static electricity can arise when two dissimilar materials (solids,liquids or gases) come in contact and charge separation occurs atthe interface. When two different materials, suited for the purpose, are brought into

contact with each other in a certain way, an electric charge will develop in

each of the materials. These charges are of the same size, but is positiveand negative: so, the sum of both charges is nil. These electric charges,which stay behind on the material, are called static electrical charges , andwe are here dealing with the phenomenon of static electricity. This incontrast with the best-known form of electricity which expresses itself inelectric currents in conductive materials. When these materials are

separated, an electric field develops between the positive material andthe negative material. The accumulated electricity will try to dischargeitself in order to neutralize the electric field. An electric field can alsodevelop when an electrically charged material approaches a non-chargedmaterial. Discharge often takes place in the form of sparks which,generally, have sufficient energy to ignite explosive vapour/air mixtures.


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Corrosive liquids can become flammable and produceflammable gases when in contact with certain materials

HYDROGEN GAS (H2) is EXPLOSIVE e.g.!

A mixture of vapour and air will only ignite and burn if its composition

is within the flammable range. Within the flammable/explosive range, if a heat source is introduced,then it will result in a fire.

Sources of ignition as: direct heat mechanical sparks chemical energy electrical energy electrostatic discharge


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Static electricity can cause sparks capable ofigniting flammable mixture List of causes of electrostatic charge generation

as: flow of liquids through pipes or filters setting of solids or immiscible liquids through a liquid ejection of particles or droplets from a nozzle splashing or agitation of a liquid against a solid surface vigorous rubbing together and subsequent separation

of certain synthetic polymers


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Electrostatic charges: Person and objects: walking over poorly conductive surface, charged clouds (fog),

touching of charged objects Particles or droplets

Examples: steam hoses, water hoses, sandstorms, hail Liquids:

Depending on: electrical conductivity, liquid flow, solid particles (rust, sludgeetc.) Some tanker operations can give rise to electrostatic charge generation examples of

such tanker operations: cargo pumping COW cargo tank cleaning

cargo tank steaming, etc. Certain cargoes are accumulators of static electricity because of their low

conductivity Light distillates: Pure Hydrocarbons, Xylene, Toluene, benzene, heptanes; Propane Crude oil Acetone


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The three essentials necessary for a fire to comm ence, maybe represented by the side of a triangle, and the completetriangle represents a fire or an explosion. The way toprevent a fire is to prevent the formation of such a triangle.The removal of any side of the fire triangle will extinguish

the fire. Removal of the flammable material is usually notpossible with petroleum in bulk. It is essential to keepignition sources away from cargo area, where flammablevapors are likely to be present. It is essential to avoid theentry of flammable vapors into areas where ignition

sources are present, such as living accommodation, engine-room, galley, etc. The use of inert gas in cargo tanks canreduce the oxygen content below that necessary toproduce a flammable mixture.


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If content of oxygen is reduced flammable rangeis reduced, too. Starving a gas fire by stopping the source of gas

leak may be the most effective way to control a

gas fire. Covering the surface of a flammablematerial with a blanket of inert material willprevent oxygen from making contact with thevapors from the flammable material. Water insufficient quantity can provide cooling. Comparedwith oil and other hydrocarbons, some liquidchemicals have unusual properties with regard tofire-fighting procedures.


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Toxicity of inert gasThe main hazard associated with inert gas is its low oxygencontent, but that it may also contain toxic gases

The main toxic constituents of inert gas: low oxygen content carbon monoxide has a TLV TWA of 50 ppm

nitrous gases: nitrogen monoxide (NO), TLV of 25 ppm (vol.) nitrogen dioxide (NO 2), TLV of 5 ppm (vol.).


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Lead poisoning is a medical condition caused by increasedlevels of the heavy metal lead in the body. Lead interfereswith a variety of body processes and is toxic to many organsand tissues including the heart, bones, intestines, kidneys,and reproductive and nervous systems. It interferes with

the development of the nervous system causing potentiallypermanent learning and behaviour disorders. Many petroleum cargo contains lead that are poisonous.

Poisoning may occur: Orally

Skin contact Inhalation


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Most of the cargoes on tankers have some hazardousproperties.It may pose health , fire and e nvironmental hazards

HEALTH HAZARDS 1.skin contact with liquid petroleum 2.ingestion (swallowing) of liquid petroleum 3.inhalation (breathing) of liquid petroleum

4. oxygen deficiency 5. toxicity of inert gas 6. presence of lead in petroleum cargo


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Ingestion The risk of swallowing significant quantities of

liquid petroleum during normal tanker and

terminal operations is very slight. Petroleum haslow oral toxicity to man, but when swallowed itcauses acute discomfort and nausea. There is thena possibility that liquid petroleum may be drawn

into the lungs during vomiting and this can haveserious consequences, especially with highervolatility products such as gasoline and kerosene.


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Inhalation The main effect of petroleum gas on personnel is to

produce narcosis. The symptoms include headache andeye irritation, with diminished responsibility and dizzinesssimilar to drunkenness. At high concentration these lead toparalysis, insensibility and death.

The vapors from some chemicals are toxic by inhalation The human body can tolerate concentrations somewhat

greater than the TLV for short periods. The following aretypical effects at higher concentrations

d


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TOXICITY and OTHER HAZARDSConcentration % LEL Effects 0.1% vol. (1,000 ppm) 10% Irritation of the eyes within

one hour.

0.2% vol. (2,000 ppm) 20% Irritation of the eyes, noseand throat, dizziness and Unsteadiness within half an

hour. 0.7% vol. (7,000 ppm) 70% Symptoms as of drunkennes

within 15 minutes.

1.0% vol. (10,000 ppm) 100% Rapid onset of drunkenness

which may lead tounconsciousness and death ifexposure continues.

2.0% vol. (20,000 ppm) 200% Paralysis and death occurvery rapidly.

d


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Oxygen deficiency The oxygen content of air is 21% by volume (21.7%) The reasons of oxygen deficiency in an enclosed space

could be: an inert atmosphere displaced oxygen due to presence of cargo vapour Combustion chemical reactions

Rusting drying paint

TOXICITY d OTHER HAZARDS


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SYMPTOMS OF OXYGEN DEFICIENCY At levels below about 19%:

general indisposition headache dizziness sleepiness noises in the ears

nausea vomiting

TOXICITY d OTHER HAZARDS


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MATERIAL SAFETY DATA SHEET (MSDS) this may haveseveral names such as Cargo Data Sheet (CDS) orProduct Safety Data Sheet (PSDS).

it is intended to provide workers and emergencypersonnel with procedures for handling or workingwith that substance in a safe manner, and includesinformation such as physical data (melting point,boiling point, flash point, etc.), toxicity, health effects,first aid, reactivity, storage, disposal, protective

equipment, and spill-handling procedures. MSDSformats can vary from source to source within acountry depending on national requirements.

MSDS


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MSDS Section 1 Materials and Company Identification

Chemical name; CAS Registry number; Date prepared Identification of Company and its contact details

Section 2 Material composition and information on Ingredients Composition of mixtures; TLV or max. Exposure concentration of that cargo to the person

and recommended max. exposure limits

Section 3 Hazards Identification Health effects when in contact by skin/eye, inhaled or ingest; carcinogenetic of materials

Section 4 - First Aid Measures

Treatment for exposure inhalation, ingestion, eye contact and skin contact

Section 5 - Fire Fighting Measures Fire and explosion data Provides basic instructions for addressing fire situation Provides extinguishing medium to be used

MSDS


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MSDS

Section 6 Accidental Release Measures Procedures for cleaning up and cites specific regulations surrounding chemical

spills

Section 7 Handling and Storage

Provides information regarding safe storage and safe usage of materials

Section 8 Exposure Controls and Personal Protection Types of protective equipment to be used Administrative controls and type of shower or eyewash facility to be available

Section 9 Physical and Chemical Characteristics Includes chemical information as boiling point, etc; physical attributes such as

physical state appearance and odor

MSDS


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MSDS

Section 10 Stability / Reactivity Indicates stability materials, what causes instability, incompatibilities

and if hazardous decomposition products are possible Also includes conditions to avoid

Section 11 Toxicological Information Includes information about reproductive effects and toxic effects

Section 12 Ecological Information Provides information on the effects of the materials to animals and

plants

Section 13 Disposal Considerations Appropriate waste disposal methods

MSDS


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MSDS

Section 14 Transport Information Provides basic shipping requirements, shipping name and

classification, packaging requirements and quantitylimitations

Sections 15 Regulatory information Cites pertinent EPA And OSHA regulations; rules and

regulations governing the materials

Section 16 Others Cites references used for construction of the document May indicate author of document and provide legal disclaimer

ENVIRONMENTAL HAZARDS


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Pollution is inconvenience or damage, caused by humanactivities, animals, plants and to our environment as a whole,by spreading of hydrocarbons and chemical compounds to air,water or lend

Crude oil tankers, product tankers and chemical tankersare chiefly responsible for marine pollution

about 700,000 tons a year

dry docking (30,000 tons) non- tanker accidents (20,000 tons)



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Cargoes in tankers may be harmful to theenvironment in different ways: blanket the surface interfering with the oxygen

exchange between the sea and the atmosphere asresult

blanket the seafloor interfering with growth ofmarine life as result

toxic into the sea food deposition on tidal mud flats.



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Most chemicals carried represent a pollution risk: bioaccumulation damage to living resources human health harm reduction of amenities

Hazards caused to the environment, covering the effect onhuman and marine life from the release of oil, chemicals orgases

bioaccumulation of substances are liable to produce tainting ofseafood

Bioaccumulation to significant extent substances can produce a hazardto aquatic life or human health damage to living resources hazard to human health by skin and eye contact or inhalation



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Effect that the specific gravity and solubility of the cargohave on the hazards to the environment in the event of aspillage more heavier than sea water substances sinks more lighter than sea water substances floats non soluble floating substances spread on a huge area

producing a vapour cloud if a fully refrigerated liquid is spilled the rapid evolution of

vapour occurs

spillage of a liquid gas from a pressure vessel: the high pressure at release quickly falls to ambient, and this

results in extremely rapid vaporization. This is called flashevaporation .


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REACTIVITY HAZARDS


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REACTIVITY HAZARDS

Chemical cargo may react in a number ofways, such as: with itself (self reaction)

with air with water with another cargo

with other materials

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

Polymerization , is self reaction. Polymerization isa chemical reaction whereby two or moremolecules of the same substance monomer

combine with one another, so that a newcompound polymer develops of the same grosscomposition as the original monomer, however,with a double or multiple molecular weight. Example: n(CH 2 CH2) ( CH2 CH2 )n

Ethylene Polyethylene

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

Polymerization is the formation of larger molecules as a result of

self-reaction

Polymerization takes place when a single molecule(a monomer) reacts with another molecule of thesame substance to form a dimer.

This process can continue until a large-chainmolecule is formed, possibly having manythousands of individual molecules (a monomer).

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

POLYMERIZATION The process may be catalyzed by the presence of

oxygen (or other impurities) or by heat transferduring cargo operations.

During the transport the polymerization reactionshave to be prevented to avoid problems such asheat generation, formation of a layer of solidpolymer on the inner side of the roof of the cargotank, formation of solid particles which block thepumps, etc.

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

POLYMERZATION may be catastrophic to the ship, and when

transporting such liquids it is important to monitorthe temperature of the cargo at certain intervals.

A rise in temperature may indicate that a reactionis in progress, and some measures should be takento bring the situation under control.

Such liquids will normally be added an inhibitor and may require Inerting, and the shipper shouldgive a clear loading instruction and voyageinstruction in relation to control of inhibitor.

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

INHIBITOR

one that inhibits : an agent that slows or interferes with a chemical

action a substance that reduces or suppresses the

activity of another substance (as an enzyme)

REACTIVITY HAZARDS
http://www.merriam-webster.com/dictionary/inhibitshttp://www.merriam-webster.com/dictionary/inhibits


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REACTIVITY HAZARDS

Inhibitors slow the rate of reaction. Sometimes they even

stop the reaction completely. You could use aninhibitor to make the reaction slower andmore controllable. Without them, somereactions could keep going and going and

going. If they did, all of the molecules would beused up.

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

The combination of an elementwith oxygen is called an oxide,

and the phenomena which isproduced by this oxidizedcompound is an oxidation reaction.

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

Auto-oxidation

is a chemical reaction whereby thesubstance itself produces the oxygen foroxidation. But auto-oxidation reactions arestarted by oxygen from the air.

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

Some substances can combine with water orcan be decomposed by water, as a result of

which either a hazardous situation arises orthe quality of the product strongly changes, orproducts develop which cause a corrosion of

materials. In this case, contamination withwater must be prevented.

REACTIVITY HAZARDS


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REACTIVITY HAZARDS

To avoid dangerous chemical reaction betweendifferent kinds of cargoes there is the cargocompatibility chart.

HAZARDS ON GAS CARRIER


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Low temperature ( frost bite) liquefied gas cargoes are transported at or

close to their boiling point

the boiling temperatures of these cargoesrange from 162 oC for methane to 0 oC forbutane

these low temperatures can cause brittlefracture if cold cargo comes in sudden contactwith metals



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Asphyxia Oxygen deficiency in an enclosed space can occur with

any of the following conditions: When large quantities of cargo vapour are present

When large quantities of inert gas or nitrogen are present, and

Where rusting of internal tank surfaces has taken place .

For the above reasons, it is essential to prohibit entryto any space until an oxygen content of 21 per cent isestablished.



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Flammability an explosive mixture may be produced when most

cargo vapors are mixed with air

All liquefied gases transported in bulk by sea, withthe exception of chlorine, are flammable.

The vapors of other liquefied gases are easilyignited. The exception to this is ammonia whichrequires much higher ignition energy than theother flammable vapors.



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Toxicity is the ability of a substance to cause damage to living tissue,

including impairment of the nervous system. Illness or, in extremecases, death may occur when a dangerous gas or liquid is

breathed, taken orally or absorbed through the skin.

the vapors from some liquefied gas cargoes aretoxic by inhalation

some toxic gases carried in gas tankers can beabsorbed into the body through the skin


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Symptoms of a Chemical Burn A burning pain with redness of the skin An irritating rash Blistering or loss of skin

Toxic poisoning

Otherwise, the treatment is as for burns, details of whichare contained in the IMO Medical First Aid Guide .

On some gas carriers deck showers and eye baths areprovided for water dousing; their locations should beknown.

HAZARD CONTROL


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HAZARD CONTROL Information of cargo to be handled should be

available and essential ICS, Tanker Safety Guide MSDS

IMDG Code, IBC Code & BCH Code ICS, Safety in Oil Tankers ICS, Safety in Chemical Tankers SIGTTO, Liquefied Gas Handling Principles on Ships and

in Terminals ISGOTT MARPOL

HAZARD CONTROL


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HAZARD CONTROL

ICS International Chamber of Shipping

IBC Code International Code for the Construction and Equipment of Ships

Carrying Dangerous Chemicals in Bulk (chemical tanker built on or after 1July 1986 )

BCH Code IMO Code for the Construction and Equipment of Ships Carrying

Dangerous Chemicals in Bulk (chemical tanker before 1 July 1986)

ISGOTT International Safety Guide for Oil Tankers & Terminals

SIGTTO Society of International Gas Tanker and Terminal Operators

HAZARD CONTROL


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HAZARD CONTROL

IGC Code International Code for the Construction and

Equipment of Ships Carrying Liquefied Gases in Bulk applies to gas carriers constructed on or after1 July

1986. Gas carriers constructed before that date should

comply with the requirements of the Code for the

Construction and Equipment of Ships CarryingLiquefied Gases in Bulk or the Code for Existing ShipsCarrying Liquefied Gases in Bulk.

HAZARD CONTROL


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HAZARD CONTROL

All cargoes can be handled safely by showingthe greatest care throughout operation and byfollowing standing instructions at all times

Chief Officers Standing Order Company Operations Manual MSDS

IMO Publications


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HAZARD CONTROL


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HAZARD CONTROL

Permit to work should be issued and shouldbe specific as to date, time, space and natureof work to be done

Continuous monitoring of the atmosphere inworking spaces for toxic gases

Continuous ventilation to prevent accumulation offlammable and/or toxic vapor

HAZARD CONTROL


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HAZARD CONTROL

Gas Measuring Equipment

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