Lignin is a chemical compound of wood along with cellulose and other components. It causes the additional stiffening of the fibers there. In the paper is an undesirable addition that causes the paper to yellow quickly. During pulp production, it is largely chemically separated from the cellulose.

Our cardboard is made from 100% mixed waste paper grade 1.02 raw material. Due to this use of raw materials, we can not guarantee the ingredients. Thus, we cannot exclude the presence of trace elements of lignin within our paperboard.

Nonylphenol is a precursor for nonylphenol ethoxylates (NPEs), the most important subgroup of alkylphenol ethoxylates (APEs), which are mainly used as detergent-active substances (surfactants). In the environment, NPEs revert to toxic nonylphenol. APEs can be found in pesticides, detergents and disinfectants as well as in food packaging, e.g. PVC films. They are also present in printing inks and wall paints or chemicals used in crude oil production. They are also used in the production of plastics, textiles, leather and paper.

Nonylphenols and nonylphenol ethoxylates are substances that can be used specifically in auxiliaries (cleaning agents).

We hereby confirm that both substances are not contained in any of the auxiliary materials (cleaning agents) that are important for our production. Thus, we can exclude a transfer of the substances to our cardboards.

Perfluorooctane sulfonate (PFOS) has been used in the manufacture of perfluorinated products, which are in use in the electroplating industry.

Due to the use of our raw material mixed waste paper (1.02), we cannot exclude the presence of components in our products, but these are normally below the applicable limits for products of 0.1% (1000 ppm).

The perfluorinated surfactants (PFT) used in the paper industry for grease repellency and mentioned in Recommendation XXXVI also do not contain PFOS in the order of magnitude mentioned above.

O-phenylphenol is explicitly permitted in the paper industry in contact with food packaging in the recommendation XXXXVI (LMBG) Papers, cardboard and paperboard for food packaging.

Nevertheless, we do not use it in our production. However, this does not rule out the possibility that traces of O-phenylphenol in the range of the analytical detection limit may be present in our products via the raw material recovered paper (1.02) that we use.

Incidentally, we would like to point out that O-phenylphenol is used as an approved preservative in orange and citrus fruits.

Phthalates are used, for example, as plasticisers for plastics, but are not used in the production of paper, cardboard and paperboard. Studies on infant food showed very low levels of phthalates. It has been shown that these substances do not originate from the packaging. The reason is more likely their ubiquitous occurrence, as phthalates in comparable quantities were also found in other foods and even in breast milk. [Source: C. Böhme: „Toxizität und Exposition einiger Bestandteile von Lebensmittelverpackungen“, Bundesgesundhbl. 10/97, page 392-393]

Since phthalates can be found in all substances and products surrounding us, we cannot rule out the possibility that this substance is also present in the cardboard we manufacture.

Elemental sulfur is not used in the production of paperboard. Inorganic (e.g. sulfuric acid, aluminum sulfate, dithionite) and organic sulfur compounds (e.g. formamidinesulfinic acid), on the other hand, are used for pH adjustment, board gluing or bleaching of recovered paper fibers. Most of these organic and inorganic sulfur compounds are found in the wastewater of a cardboard factory. In wastewater treatment plants, organic sulfur compounds are converted into stable sulfate.

The contents of organic and inorganic sulfur compounds in produced paperboard are low. Thus, the sulfate contents exceed 2,000 mg/kg of board only in exceptional cases. The content of total sulfur as the sum of organic and inorganic sulfur compounds, an important parameter in combustion, is usually less than 1,000 mg S/kg of board. It is thus significantly lower than the total sulphur content in hard coal, lignite or crude oil.

Our cardboards comply with the requirements of DIN EN 71, Part 3 regardIing the content of antimony, arsenic, barium, lead, cadmium, chromium, mercury and selenium.

Recommendation XXXVI “Papers, cardboards and paperboards for food packaging” of the Federal Health Office:

We hereby confirm that our cardboard is manufactured in accordance with the generally recognised rules of technology and, when used as intended in contact with dry, non-greasy foodstuffs, complies with the requirements of the Foodstuffs and Consumer Goods Act (LMBG) of 08.07.1993, revised on 09.09.1997.

We produce our paperboard in accordance with Recommendation XXXVI of the Federal Institute for Consumer Health Protection and Veterinary Medicine (BgVV – formerly the Federal Health Office). The recommendation is entitled: “Papers, cartons and cardboard for food packaging”. This means that in particular the requirements of §§ 30 and 31 LMBG (“Prohibitions for the protection of health” and “Transfer of substances to food”) are also met.

Until September 2003 we were certified according to DIN EN ISO 9002:1994. The repeat audit was not carried out in our company. Customer processing as well as production are carried out according to the specifications of the original certification documents.

A new certification according to the now valid standard is currently not planned.

Our qualities KÖHLERBOARD, KÖHLERBOX and KÖHLERPAC were measured in our laboratory for temperature contact.

We can guarantee that our board is suitable for direct contact with corresponding materials up to a temperature of max. 200 °C board.


  • at 200 °C – no discolouration detectable
  • at 250 °C – slight brownish discolouration
  • at 300 °C – strong brownish discolouration

Our raw material mixed waste paper (1.02) has changed negatively in terms of bulk density (specific weight) over the years due to repeated recycling. By adjusting the bulk density to this situation, the smoothness of the smoothed versions will be slightly lower.

No substances named in the SVHC lists of the REACH regulation are used in the production of the recycled and wood-based boards we supply.

If such substances were present in the recovered paper used, it is possible that traces of them would also be present in the end product after our fibre preparation.

However, these are in any case well below the limit specified in the REACH Regulation, so that here too our products are REACH-compliant.

The European paper industry produces around 40 million tonnes of paper, cardboard and paperboard for packaging purposes every year, most of which is used to package food. Most of these are made from recycled fibres. Newspapers, magazines and used cardboard and corrugated cardboard packaging are used as raw materials.

Production is carried out in accordance with the applicable legal regulations, which are aligned with the state of the art and current scientific findings.

Recent investigations have shown that traces of oils from the printing inks used in newspapers can also be found in paper, cardboard and cardboard based on used paper, as well as in the foodstuffs packaged in them.

Our company is in close contact with the manufacturers of printing inks, the printing industry, publishers and the packaging industry through the Association of German Paper Mills (VDP) to solve this problem. All parties involved bear responsibility for products that are harmless to health and for ensuring a sustainable recycling economy for paper, cardboard and paperboard.

At present, there are no findings of a concrete risk to consumers.

Paper products have a strong interaction with the ambient air.

Responsible for this is the hygroscopic property of the (natural) paper fibres, i.e. the ability to absorb moisture or release it to a drier environment.

Only when there is a “moisture equilibrium” between air and paper or board does the fibre come to rest and stop “working”.

Ideally, paperboard should be stored and processed under the same standardised climatic conditions.

Temperatures in the storage and processing areas should be 21° Celsius and relative humidity of 50 – 55 %.

When cardboard is moved from a cold storage room to a heated processing room, the pallets must be given sufficient time to warm up before the moisture-proof wrapping (stretch film) is removed.

When cold cardboard is unpacked in a warm and humid environment, water condenses on the edges (cut edges) of the cardboard and leads to bending up of the edges, wavy cardboard and change of dimensions (length, width, thickness).

So be sure to give the cardboard about 48 hours to acclimatise.

The pH value indicates the hydrogen ion concentration in an aqueous solution. Solutions with a pH value lower than 7 react acidic. Solutions with pH = 7 react neutrally. Those with a pH value greater than 7 react alkaline. Many vital processes take place within certain pH limits.

The term “pH value” is explained like this:

The small “p” stands for “potentia”, the capital “H” for the symbol of hydrogen. “pH” therefore means “potentia hydrogenii” (Latin), which means “potency of hydrogen ion concentration”.

Ongoing measurements show a neutral value of our products of approx. pH 7.0. Due to the use of our raw material mixed waste paper (1.02), we unfortunately cannot give any guarantee for the stated value. Fluctuations may occur due to the raw material. This applies to all KÖHLER products made from 100% mixed waste paper.

For our product KÖHLERlight 400, which is made of 100 % groundwood pulp, current measurements have shown a neutral value of approx. pH 7.0. The fluctuation range due to the use of raw materials is very small, so you can assume a neutral range.

The Kappa number is a measure of the relative hardness, bleachability and degree of pulping of pulps. Like other methods for determining the degree of pulping, the determination of the Kappa number is based on the oxidation of the lignin residues. The consumption of oxidants (potassium permanganate in this case) is a measure of the lignin content. The kappa number is thus a determination method for pulp.

Since the Kappa number refers to the raw material input pulp and our raw material input for the qualities KÖHLERbox Special, KÖHLERbox “S” Special and KÖHLERbook Special (in each case following ISO 9706) is based on waste paper, we have to exclude the Kappa number as a measurand (see our data sheets).

Any questions?

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