Can one of the cooking oils evaporate

Information about the goods

Product name

GermanRapeseed oil, rapeseed oil
EnglishRape oil (colza oil)
FrenchHuile de colza (navette)
SpanishAceite de colza (nabina)
ScientificBrassica napus
KN / HS number *1514 1 ff.

(* Combined nomenclature / harmonized system of the EU)

Description of goods

Oils are a collective term for more or less viscous, mostly organic-chemical liquids. Depending on their chemical composition, a distinction is made between fatty, essential, mineral and silicone oils. The fatty oils include liquid, semi-solid and solid products of vegetable and animal origin. They are also known as sweet oils.

Rapeseed oil is of vegetable origin and is obtained from crushed rapeseed by pressing or extraction. It is a light yellow to brownish yellow oil. Rapeseed oil is one of the most important vegetable oils.

For many centuries, rapeseed oil could not be used for human or animal nutrition because it was high in erucic acid. In the meantime, however, it has been possible to grow rapeseed varieties whose erucic acid content is not that high.

Quality / storage time

The acid number of an oil can be used as a measure of quality. However, the acid number of the oil must not be too high, as this means too high a proportion of free fatty acids, which leads to the oil becoming acidic. It can also cause discoloration. Rapeseed oil should have an acid number of a maximum of 0.6… 2.0%.

Oils and fats spoil by turning rancid easily. Rancidity is promoted by light, atmospheric oxygen and moisture and leads to changes in smell and taste. This means that the tanks and barrels must be filled as high as possible, taking into account the cubic expansion coefficient (see density), so that the air space above the cargo remains as small as possible. Rancid oil may no longer be loaded because it does not meet the quality requirements.

If the rapeseed oil is contaminated by iron and rust particles or by seawater, it should not be loaded.

If the corresponding temperature ranges are adhered to, the storage period does not represent any restriction in terms of transport and storage life.


Rapeseed oil is used as edible oil, machine oil, and to make margarine and soap. It can also serve as a substitute for diesel fuel (bio-diesel).

Countries of origin

The table shown here is only a selection of the most important countries of origin and cannot be described as complete.

EuropeFrance, Germany, Sweden, Poland
AsiaIndia, China, Japan
AmericaUSA, Canada

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The transport takes place mainly in tanks, rarely in barrels.

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Liquid goods

General cargo

Means of transport

Ship, truck, train

Container capability

Tank container


Normally the oil does not have to be heated because the freezing point is relatively low. If, however, temperatures should come up during the voyage that are in the range of the solidification temperature, the following must be observed: In order to be able to pump the oil out of the tanks, it must have the required pumping temperature. However, this is only possible if the oil was kept liquid - above a minimum temperature - during the trip. It is important to ensure that the loading, travel and pumping temperatures are strictly adhered to, because any change in consistency that occurs during the period of transport can turn out to be an irreversible process.

If the oil has solidified in the tanks, it cannot be liquefied again even with forced heating. In the vicinity of the heating coils, the oil melts, scorches, discolors and goes rancid.

Difficulties can arise when pumping in cold weather. The oil can cool down too quickly in the long lines, and solid components form on the outer walls that cannot be pumped out and block the flow of the still liquid charge to the suction valve. This problem can be solved by appropriate heating options or insulation of the lines.

If the oil is bottled in barrels, these must be treated with appropriate care. Damaged barrels quickly lead to leakage of the oil and thus to volume losses or damage to other parts of the load.


0.908 ... 0.917 g / cm3 [1]
0.913 ... 0.916 g / cm3 [2]
0.920 g / cm3 [11]

All fats and oils have a certain density (approx. 0.9 g / cm3). However, as the temperature rises, the density decreases, which at the same time leads to an increase in volume. This behavior is described by the cubic expansion coefficient and referred to as thermal dilation.

The cubic expansion coefficient is: g = approximately 0.000675 K.-1

Roughly, one can assume that the oils increase their volume by 1% of the total volume for each 15 K temperature increase.

When filling the barrels, however, attention must be paid to the expansion behavior of the cargo when the temperature rises (risk of the barrels bursting).

Stowage space requirements

Special tank


Not applicable to liquid cargoes in tanks

Load securing

In the case of liquid cargoes, it is important that the air space above the cargo is as small as possible so that the cargo can only move a little. Moving liquid cargo can have a negative effect on the stability of the means of transport (e.g. when trucks and trains take curves or when ships roll and pitch).

Barrels must be secured in such a way that they cannot slip in the hold or on the loading area and be damaged.

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Risk factors and loss prevention

RF temperature

Rapeseed oil does not require any particular storage climate conditions (SC 0).

The solidification temperatures play an important role in the transport of fatty oils and fats. It is important that they maintain the liquid state of aggregation during charging, travel and unloading. The cold cloudiness (segregation) starts when the temperature of the oil approaches the solidification point due to cooling, the oil becomes ointment-like and finally solid, so that it can no longer be pumped.

The segregation and the associated change in consistency from the liquid to the solid state of aggregation occurs the sooner the cooling point, the higher the freezing point.

The oils may only be heated by a few K / day, otherwise there is a risk of becoming rancid and other negative changes.

The following table is only intended to provide a rough estimate of the corresponding temperature ranges. Depending on the specific circumstances of the transport, the temperatures can vary.

descriptionTemperature rangesource
Travel temperature

(favorable temperature range)
15 ° C (12 ... 24 ° C)[1]
Solidification temperature0 ... -15 ° C[1]
approx. 0 ° C[2]
Pump temperatureapprox. 15 ° C 

Rapeseed oil is liquid under normal transport conditions and therefore does not need to be heated. However, if temperatures in the range of the solidification temperature occur during the trip, the oil must be heated to maintain pumpability.

The travel temperature must be maintained as much as possible during transport in order to minimize the oxidation processes.

Rapeseed oil from pressed seeds can be temporarily supercooled down to -14… -15 ° C. After standing for a long time, the oil begins to solidify to a white mass without losing any of its quality.

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RF humidity

Fats and oils are insoluble in water. However, when it comes into contact with water, soluble lower fatty acids and glycerine can develop, which lead to rancidity, combined with changes in color (yellow to brown), smell and taste, as well as gelling and becoming thick. That is why the tanks must be absolutely dry after cleaning.

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RF ventilation

Under no circumstances should it be ventilated, as otherwise new oxygen will be added to the cargo, which contributes to increased oxidation processes and premature rancidity.

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RF Biotic Activity

Rapeseed oil displays biotic activity3. Order.

It is one of the goods with interrupted respiratory processes, but where biochemical, microbial and other decomposition processes continue to take place.

The care of the cargo during the voyage must be aimed at keeping the decomposition processes to a minimum.

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RF gases

Before entering the empty tank, it must be ventilated and a gas measurement must be carried out. Due to the oxidation processes, life-threatening O can occur2- Shortage coming.

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RF self-heating / self-ignition

The oil can spontaneously ignite in contact with sawdust or material residues.

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RF smell

Active behaviorIn its raw state, rapeseed oil has an unpleasant smell and taste. Refined, it is odorless and tasteless.
Passive behaviorTanks and barrels must always be odorless, as there is a risk of loss of quality, especially if they have been loaded with a strong smell.

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RF pollution

Active behaviorLeaking oil leads to enormous contamination and can render entire loads unusable.

The iodine number is important for tank cleaning. The iodine number is a measure of how strongly the oil tends to oxidize and thus to dry out. Drying out is particularly disadvantageous for tank cleaning, as the oil / fat sticks to the walls and is difficult to remove. Due to the drying capacity, a distinction is made between non-drying, semi-drying and drying oils.

With an iodine number of 94… 106, rapeseed oil is one of the semi-drying oils, so that the oil dries up to a certain extent when it comes into contact with atmospheric oxygen. However, this is done within reasonable limits, so that cleaning the tank is only insignificantly difficult.
Passive behaviorRapeseed oil is sensitive to contamination from iron and rust particles as well as water (especially seawater).

The tanks or barrels must be clean and hygienically perfect before filling.

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RF mechanical influences

When transported in barrels, extreme mechanical loads, such as dropping, tipping or bumping, can lead to the barrels breaking and thus leakage.

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RF toxicity / health hazard

Before entering the tank, it must be ventilated and a gas measurement must be carried out. Due to the oxidation processes, life-threatening O can occur2- Shortage coming.

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RF loss / loss

Loss of mass due to leaks is always to be expected when loading barrels.

Rapeseed oil shows only a slight tendency to evaporate. Regular losses of up to 0.3% due to the cargo sticking to the tank walls are to be regarded as normal.

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RF pest infestation / diseases

No risk!

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