FAQs for food safe packaging

The FAQ section contains valuable hints and in-depth information on various packaging related topics. Most of the questions were asked from our customers and business partners in personal meetings or in our webinars.

If adhesives use "plastics" as a reference, what do films and paperboards use as a reference?

The largest positive list of evaluated substances is the Union list of the plastic regulation. So, all food contact materials for which no specific measures exist refer to the Union list. If substances are not listed there because they are not used for plastics, you have to check national legislation or you have to make your own toxicological assessment. For paper and boards, the German BfR recommendation 36 is used very often. In case of plastic films the plastic regulation can be applied, in case of celloluse the directive for regenerated cellulose can be used.

What organizations are you a part of to help understand these regulations?

We are member of the European adhesive association FEICA and therefore always informed about legislative issues. We can influence the draft forms of upcoming legislation and can discuss new legislation regarding the transfer on our products. Click here for more information.

REACH assessments are more likely to focus on the tox properties of a substance in relation to worker exposure - this may not include oral ingestion as would be the case for migration/food contact applications - how beneficial is any data from ECHA?

The main intention of REACH is to derive safe levels of exposure for workers but also for the general population. In that respect, toxicological tests have to reflect the main route of exposure. In fact, often the oral route is not the most relevant one. However, in principle we can often also use data obtained from inhalation or dermal studies. This is because in case of food contact the most important aspect is the dose, which becomes systemically available after oral ingestion. If there are data available from inhalation or dermal studies, we can use them if for example we have also toxicokinetic data showing how much of the respective substance becomes systemically available, e.g. by skin penetration. If no toxicokinetic studies are available, we can still work with the data but have to reflect this uncertainty by introducing additional safety factors.

Is there a distinction between direct and indirect contact? What about "incidental" direct?

In the European legislation there is no differentiation between direct and indirect food contact. As long as the specific limits are respected the food contact is allowed. If a migration limit of a certain substance is exceeded then the contact area must be modified.

How often do you re-assess products? What is your control plan?

When a product is assessed for food contact we block the formulation and we re-assess it when new raw material information are available, when the formulation was changed or when the legislation changes.

How do your adhesives impact regulatory documentation for food/ beverage companies?

The food packager and the beverage companies need our food contact statement to have "adequate information" in the supply chain for making their risk assessment for their products. Without the result of our risk assessment they cannot take their responsibility. There is also a white paper available on Food Contact Statements.

Go to white paper "Food Contact Statements"

What is the receptivity of your raw material suppliers to the food safety topic? How can the supply chain collaborate to drive greater activity even further upstream?

Each member of the supply chain has to exchange information to improve the risk assessment. The better the information flow the better the risk assessment for the final product. The EU Guidance as regards information in the supply chain defines the roles and the responsibility of all members within the supply chain.

What factors most significantly contribute to migration?

Basically, migration is considered to be a diffusion process, mostly influenced by contact time, contact temperature, chemical properties of the compounds and size of the molecules. Molecules with molecular weights > 1000 Daltons are not considered to contribute to migration. There is also a white paper available on the topic "Influenceable factors for migration".

Go to white paper "Influenceable factors for migration"

What are the most effective absolute and functional barriers for preventing migration?

Metal foils like aluminum or materials like glass are considered to be an absolute barrier. Concerning aluminum, this would not be applicable to acidic foodstuff in direct contact, as the aluminum would be corroded. In addition, damages in the metal foil like pin holes can lead to migration, which especially can be observed in the case of metalized foils. Concerning functional barriers like thick PET layers, it depends on the conditions of use and shelf life of the packed foodstuff. For materials like EvOH it is known that they do have good barrier properties, which on the other hand are greatly deteriorated when getting in contact with moisture.

If we had to conduct migration test for NIAS, and the migration quantity is under 0.01ppb, do we also need conduct a toxicological test for the NIAS?

Actually, from a toxicological point of view there is no concern with a substance which is not detected with a LoD of 0.01 ppb. This would be true even in case of a hazardous substance except for cmr-substances - no relevant health risk would be expected.

Why is it important to check the food contact status of labeling adhesives?

As bottles are labeled post filling and with the crown already in place, a direct contact between the adhesive and the bottle content is not realistic, due to the fact that glass and PET walls form full barriers. There is, however, a possibility of indirect contact when crowns are covered with aluminum foil, as the beverage might come in contact with the ripped foil when poured out of the bottle. This is normally avoided by leaving the aluminum foil section that is to cover the crown free from adhesive. In any case, beverage companies need our food contact statements to have "adequate information" in the supply chain in order to conduct their own risk assessments for their products. Without the results of our risk assessment they cannot fulfill their responsibility. There is also a white paper available on "Food Contact Statements".

Go to white paper "Food Contact Statements"

When should products be tested and re-tested?

Products should be tested anytime there is a significant change in the composition or application as part of the packaging material.

How can I conduct a risk assessment for substances that are not listed?

A risk assessment in terms of human health is always a complex process. It should of course follow basic principles of toxicological risk assessment. Unfortunately, it is not possible to provide any general guideline - it always depends on the particular case. It will definitely be difficult to conduct a risk assessment if you are not skilled in toxicology. If you do not have an own toxicologist, we would recommend to work with consultants. Of course, if the concerned substance is related to a Henkel adhesive, you can contact us and we will be happy to support you.

Is it mandatory to perform lab test for NIAS? Are the suppliers´ declarations sufficient?

In general, the company placing the FCM onto the market is responsible for compliance with the respective legislation and must make sure that there are no health risks connected to the materials. This also includes an evaluation of NIAS. Of course, you can only do an evaluation if you know that a certain substance is present in the material. Therefore, you should know the NIAS relevant for your material. We are not aware of a requirement to conduct own analytical investigations in order to identify NIAS. Therefore, it could also be a possibility to rely on supplier certificates. However, there might be legal issues with respect to potential liabilities if it turns out that your supplier did not declare correctly, maybe because even he just did not have enough information. We would recommend deciding this on a case-by-case basis depending on your relationship to the supplier and whether or not you really think you can trust him. Furthermore, analytical spot checks from time to time might be helpful. There is also a white paper available on the topic "Risk Assessment of NIAS in Food Contact Adhesives".

Go to white paper "Risk Assessment of NIAS in Food Contact Adhesives"

Who is ultimately responsible for certifying the products used in food packaging? Is it the supplier (adhesive supplier) or the user (end-customer)?

In general the company placing the FCM onto the market is responsible for compliance with the respective legislation and must make sure that there are no health risks connected to the materials. This includes also an evaluation of NIAS.

What chemicals can cause off-odor/ off-taste?

A lot of chemicals can influence the organoleptic characteristic of a foodstuff. This is depending on the kind of foodstuff.

How long does it take to assess an adhesive?

The more information is available on all used raw materials, including statements on food contact status or specifications on by-products or impurities, the quicker an assessment can be done. It is not possible to define a general time frame. For example, if toxicological assessments are necessary, but no toxicological data can be found in literature, time-consuming studies could be necessary.

What is the most effective simulant? Why?

It depends on the interaction of the food simulant with the packaging material and its constituents. For example, acidic food simulants like 3% acetic acid tend to protonize amines, thus making them more soluble in the aqueous food simulant. Organic solvents or solvents with a high amount of ethanol tend to readily solve lipophilic compounds.

How do you manage changes in your raw materials?

In Europe, our raw material suppliers sign a commitment that they inform us in case of changes in the raw materials (presevatives, stabilizers etc). In case of changes we must trigger again our risk assessment and must update our statement, so that our customers can renew their assessment.

How often do you re-assess products? What is your control plan?

When a product is assessed for food contact we block the formulation and we re-assess it when new raw material information are available, when the formulation was changed or when the legislation changes.

What are techniques to determine Primary Aromatic Amines (PAAs)?

Two different methods are used to detect PAAs in laminates used for food packaging: the photometric method and the HPLC technique. The photometric method is often called the BfR method since it is described by the German Bundesinstitut für Risikobewertung, BfR. It is a fast screening method for acceptable costs but holds the risk for false positives. It has a limited sensitivity and cannot distinguish between different PAAs, it delivers the sum of all PAAs. If photometric results appear not reliable, the HPLC method can be used. HPLC stands for high pressure liquid chromatography. This technique has an excellent sensitivity, there are nearly no interferences and it can distinguish different PAAs. Read our white paper with more information on PAAs.

Go to white paper "Primary Aromatic Amines"

Why do the different PAA test methods have different detection limits?

The sample preparation for both techniques is the same: PAAs are extracted by 3% acetic acid out of a freshly produced laminate. From this point, the techniques are different. For the BfR method, the amines are converted into a purple color, the calibration is done with a reference amine: Aniline hydro chloride. This gives the reference color. The amines occurring during a curing reaction of a polyurethane system are MDA and TDA isomers and these respond differently to the coloration. One of these isomers has a response factor of ~20% compared to the Aniline hydro chloride. From the EU legislation, the 10ppb limit is given. The photometric test does not distinguish between the PAAs, so it need to be assumed that the amine with the lowest response factor is the one in laminate, that’s why it has to be calculated with factor 5 to be sure to have less than 10ppb. The HPLC method is precise and the given limit of 10ppb can be taken as detection limit. The LOD for the single PAAs is 1.5 ppb.

Can aromatic SF systems be used for retort applications?

Can aromatic SF systems be used for retort applications? Limited yes. At high temperatures, fully cured aromatic PU adhesives can decompose and react back into their starting materials, OH and NCO. This starts being critical as soon as anything hazardous or even toxic appears that is small enough to migrate into the food. As soon as a newly built (aromatic) NCO meets a water molecule, it reacts to an aromatic amine which can be carcinogenic. > Aromatic PUs should not be used for high retort applications, the safer choice are aliphatic systems. > Or the temperatures are limited to ~121°C, up to that temperature, also special designed aromatic systems can safely be used.

Does the BfR method always lead to wrong results for PAA tests after retort?

Not necessarily. If PAAs are checked after retort by photometer and values are below 2ppb, the laminate is food compliant. Only if values above 2ppb are found, it is not clear if these are real values or false positives (that might come e.g. from the additives of a CPP films).

Why are PAA times on OPA or CPA so long?

Polyamide attracts and keeps water inside its structure, it is a kind of water buffer. When PU adhesive is applied onto a nylon film, there is a competition between the PA-film and the PU adhesive for water. The PU cannot finally cure without enough water, if the water is hold back, it takes longer.

Can triacetin be used as food additive for all foodstuffs?

Triacetin is permitted as food additive according to regulation (EU) No 1129/2011. But only for use in chewing gum. For all other foodstuffs we have to apply the SML value of the plastics regulation. Tiracetin is listed in the plastics regulation under FCM 40 and has no specific SML value. In this case it is allowed that the substance migrates into foodstuff up tot the OML value, which is 60 mg/kg.

Is it necessary to make migration tests or can we make worst-case-calculations for plasticizers?

Plasticizers are present in the formulation in the range of percent and this is too high to make worst-case-calculation. As it is well known that plasticizers are migrating quickly and completely into foodstuff, you have to carry migration tests when using plasticizer containing adhesives.

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