Flax tow [German version]

Table of contents

Product information
  Container transport
  Cargo securing

Risk factors and loss prevention:
Temperature Odor
Humidity/Moisture Contamination
Ventilation Mechanical influences
Biotic activity Toxicity / Hazards to health
Gases Shrinkage/Shortage
Self-heating / Spontaneous combustion Insect infestation / Diseases

Product information

Product name

German Flachsgrünwerg
English Flax tow
French Lin étoupe
Spanish Lino estopa
Scientific Linum usitatissimum
CN/HS number * 5301 30 10

(* EU Combined Nomenclature/Harmonized System)

Product description

When pure flax fiber (see flax) is produced from flax straw by combing with steel combs, the short fibers or tow are left behind; these short fibers are traded as flax tow or pluckings.

Tow comprises the random fibers arising as waste from the processing of stalk fibers.

Lower grade unretted flax straw is converted into flax tow by tow finishing.

Quality / Duration of storage

Wet, moist or oil-stained bales must not be accepted.

Subject to compliance with the appropriate temperature and humidity/moisture conditions, duration of storage is not a limiting factor as regards transport and storage life.

Intended use

Flax tow is used in the production of cigarette paper. It is also used in the cottonized bast fiber and papermaking industries, as crop baling twine, elephant thread, sacking and packaging fabrics, upholstery stuffing in the furniture industry, as stuffer yarn for wire ropes and cords and as a seal material.

Countries of origin

This Table shows only a selection of the most important countries of origin and should not be thought of as exhaustive.

Europe Belgium, Ireland, Netherlands, Romania, Russia, Hungary, Poland, France, Italy
Africa Egypt
Asia India
America USA, Argentina
Australia Australia, New Zealand

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Flax tow is transported unpackaged in bales. The bales are strapped with steel strapping to ensure that they hold together better.

Marking of packages
Mark07.gif (2224 bytes)

Keep dry
Mark02.gif (2816 bytes)

Use no hooks
Mark04.gif (3269 bytes)

Keep away from heat
(solar radiation)

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Symbol, Class 4.2

Spontaneously combustible,
Class 4.2 IMDG Code
Symbol, Class 4.1

Fire hazard
(Flammable solids),
Class 4.1 IMDG Code
Symbol, general cargo

General cargo

Means of transport

Ship, truck, railroad

Container transport

Standard containers, subject to compliance with water content of goods and flooring.

Cargo handling

In damp weather (rain, snow), the cargo must be protected from moisture, since flax tow is strongly hygroscopic and readily absorbs moisture. This may lead to discoloration, decay, staining and a musty odor. Flax tow is less rot-resistant than cotton. In addition, smoking is absolutely prohibited during cargo handling.

Stowage factor

2.4 – 3.0 m3/t (bales) [1]

Stowage space requirements

Cool, dry


Fiber rope, thin fiber nets

Cargo securing

The cargo is to be secured in such a way that the bales or strapping are not damaged. Undamaged strapping is essential to maintain compression of the bales during transport. If the strapping is broken, compression is diminished, which at the same time results in an increased supply of oxygen to the inside of the bales. This in turn increases the risk of combustion or feeds a fire which has already started. Bursting or chafing of steel strapping may lead to sparking and external ignition.

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Risk factors and loss prevention

RF Temperature

Flax tow requires particular temperature, humidity/moisture and possibly ventilation conditions (SC VI) (storage climate conditions).

Favorable travel temperature range: no lower limit – 25°C

Every hold should be equipped with means for measuring temperature. Measurements must be performed and recorded daily.

Flax tow must be stowed away from heat sources.

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RF Humidity/Moisture

Flax tow requires particular temperature, humidity/moisture and possibly ventilation conditions (SC VI) (storage climate conditions).

Designation Humidity/water content Source
Relative humidity 65% [1]
Water content 10 – 12% [1]
Maximum equilibrium moisture content 65% [1]

Flax tow behaves strongly hygroscopically (hygroscopicity). It must be protected from sea, rain and condensation water and also from high levels of relative humidity, if discoloration, staining and a musty odor are to be avoided. In the event of severe exposure, decay occurs which consequently impairs the tensile strength of the fibers.

In addition, it may swell by absorbing water vapor, resulting in an increase in volume of approx. 20%. An elevated water content is difficult to identify from external signs.

Moisture measurements are recommended prior to loading. Moisture-damaged bales must not be accepted.

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RF Ventilation

Flax tow requires particular temperature, humidity/moisture and possibly ventilation conditions (SC VI) (storage climate conditions).

If the product is loaded for shipment in a dry state, it does not have any particular ventilation requirements.

Problems arise if the product and/or ceiling/flooring are too damp. In this case, the following ventilation measures should be implemented:

Air exchange rate: 10 changes/hour (airing)

Moisture must constantly be eliminated, to reduce mold and bacterial activity.

Since flax tow very readily absorbs oxygen, before anybody enters the hold, it must be ventilated and a gas measurement carried out, since a shortage of oxygen may endanger life.

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RF Biotic activity

Flax tow displays 3rd order biotic activity.

It belongs to the class of goods in which respiration processes are suspended, but in which biochemical, microbial and other decomposition processes still proceed.

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RF Gases

Flax tow very readily absorbs oxygen. An oxygen shortage may therefore arise in closed holds and containers. Before anybody enters such holds, the holds must be ventilated and, if necessary, a gas measurement carried out.

An increase in CO2 and CO content indicates a cargo fire. The TLV of the hold air is 0.49 vol.%. As a result of the oxygen-rich lumen, bales often burn for weeks without being discovered.

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RF Self-heating / Spontaneous combustion

Flax tow has an oil content of 1 – 2% (waxes).

Flax tow is assigned to Class 4.1 of the IMDG Code (Flammable solids). However, its specific characteristics and negative external influences (see below) may cause it to behave like a substance from Class 4.2 (Substances liable to spontaneous combustion) of the IMDG Code or ADR.

Its high cellulose content makes flax tow particularly liable to catch fire through external ignition. Therefore, it must always be protected from sparks, fire, naked lights and lit cigarettes. Smoking is absolutely prohibited. Chunks of ferrochromium ore may produce sparks when they strike together. These cargoes must not therefore be carried together in combined transport operations (e.g. as are frequent in the North Sea/Baltic region). In accordance with the IMDG Code, ventilation openings leading into the hold should be provided with spark-proof wire cloth.

Spontaneous combustion may occur as a result of exposure to moisture, animal and vegetable fats/oils, oil-bearing seeds/fruits, copra and raw wool. As a result of the very well developed oxygen-rich lumen of the flax fiber and the oxygen supply contained in the capillary cavity system, smoldering fires inside the bales often last for weeks.

Fire-fighting is best performed using CO2. It is very difficult to extinguish a fire because of the excess of oxygen in the flax fiber, which maintains the fire from the inside.

Water must not be used for fire-fighting, since the swelling capacity of the flax tow (20% increase in volume) may cause damage to the hold or container walls.

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RF Odor

Active behavior Flax tow has a slight, unpleasant odor. A conspicuous musty odor indicates mold growth inside the bales.
Passive behavior Flax tow is sensitive to unpleasant or pungent odors.

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RF Contamination

Active behavior Flax tow does not cause contamination.
Passive behavior Flax tow is sensitive to contamination by dust, dirt, fats/oils and rust as well as oil-containing goods, such as oil-bearing seeds/fruits, copra, raw wool etc., since oil-impregnated fibers promote self-heating/cargo fire. Increased contamination provides microorganisms with an excellent nutrient medium, which means that holds or containers must be suitably clean and in a thoroughly hygienic condition. Residues from previous cargoes, such as ores, stones, coal, metal filings, fertilizers etc., result in losses. Contamination by plastic beads from accompanying cargoes result in rejection of the goods by the receiver.

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RF Mechanical influences

Care must be taken to ensure that mechanical influences do not cause damage to strapping, which increases the risk of fire by relieving the compression of the bales and allowing a greater supply of oxygen.

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RF Toxicity / Hazards to health

Since flax tow is highly oxygen-absorbent, a life-threatening shortage of oxygen may arise in the hold or container. Thus, before anybody enters the hold, it must be ventilated and, if necessary, a gas measurement carried out. The TLV for CO2 concentration is 0.49 vol.%.

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RF Shrinkage/Shortage

Unclearly marked bales may result in losses of volume due to incorrect delivery.

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RF Insect infestation / Diseases

Flax tow is highly susceptible to attack by fungi and bacteria.

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