Examinations of food contact materials

Where can I ask for help to find out what tests must be performed on the contact material to verify compliance?

Laboratories familiar with examining contact materials are experts in telling what material needs to be examined to verify its regulatory compliance. However, to do this the laboratory needs to have access to all the necessary information on the raw materials of the food contact material and the process chemicals used in the manufacturing process.

How is the amount of migration calculated for different sizes of food contact materials that have the same shape and which are made from the same material and in the same way?

In the case of containers of the same shape and made from the same material, migration is tested using the container having the greatest surface-to-volume ratio, i.e. the migration in the smallest container. The amount of migration in this smallest container is the highest. This is illustrated in the following diagram:


What is meant by the surface-to-volume ratio of the plastic packaging material used in tests to establish compliance with requirements?

This surface-to-volume ratio refers to the ratio prevailing in testing the total migration of the plastic material. Total migration is expressed in mg / dm2 for each material. The ratio laid down in the Plastics Regulation is 60 mg/kg = 10 mg/dm2. This means that 1 kg of food has been packed in a cube-shaped container, with each side having a surface area of 1 dm2, i.e. the total food (1 kg) is in contact with six 1 dm2 material surfaces.

When can plastic material tests be replaced by mathematical calculations?

The total migration test for plastic cannot be done by calculation but must always be performed on the final material. However, mathematical calculations can be used to partly replace specific migration tests of individual substances contained in plastic materials. In this case, calculation determines whether migration remains below the  limits set out in the Plastics Regulation, even if all the substance contained in the material would migrate. The preferred method is to first calculate the worst case migration and then have examinations performed on those products where the calculated migration of substances approaches the limit.

What fibre-based contact materials must be tested?

With fibre materials, the tests depend essentially on whether it is virgin material or recycled material. Also, the safety reference used affects what needs to be examined. The authority may give guidance with examinations, for example, based on the Norden publication   . This provides limit values for individual harmful ingredients and specifically takes into account paper and board made of virgin and recycled material. If the safety reference is BfR's recommendation on paper and board, then the examinations must be performed based on the limits given in them.

TemaNord's publication Paper and Board in contact with food has stated that the maximum quantities of cadmium, lead, mercury and pentachlorophenol must not exceed the limits laid down in the guidelines. The Ministry of Trade and Industry's Decree on heavy metals lays down much higher limits for cadmium and lead. Which one is to be complied with? However, after calculations/tests/assurances is it still necessary to demonstrate the other metals (Cr and Ni) in the KTM Regulation? If foods other than those requiring peeling and washing are involved?

Ministry of Trade and Industry Decision 268/1992 is national legislation binding on all contact materials. Migrations of heavy metals in contact materials must be below the limits provided in the Decision. The TemaNord publication is just a guide as to what kind of paper/board product is considered as being in regulatory compliance. Since there is no material-specific legislation for paper and board, compliance depends largely on which legal provision/official recommendation the operator has chosen as a safety reference. If this is TemaNord's guideline, then the limits must be below them, if it is BfR's recommendation on paper and board, then its limits must be below them, etc.

Regulators can use the TemaNord publication to guide operators as to what must be examined. However, rather than compelling operators to comply, operators themselves determine the safety reference.

Must the dioxide from pulp be tested?

As there is no material-specific EU or national legislation on fibre materials, there is no provision on essential examinations. Under the Paper and Board recommendation, made in Nordic cooperation, dioxin testing is only required for paper and board bleached with elemental chlorine, in which case a limit of 120 pg TEQ / 1 kg food or food simulant may be used.

What limit values have been defined for cellulose with lead, mercury and cadmium? Are they the same as with paperboard?

Cellulose is a so called intermediate material that is bound by the same regulations as paper and paperboard. Basically this means the fulfilment of the requirements in regulation 1935/2004. At the moment, there is no material-specific legislation at the EU level. Usually operators explain the fulfilment of the requirements in regulation 1935/2004 with another recommendation, for example the BfR recommendation. If the operator confirms that the cellulose fulfils the recommendations of BfR, the limit values for various test parameters must also be sought from there. In Finland, the national decision 268/1992 on heavy metals (Ministry of Trade and Industry) is still valid, and it covers all materials and articles that come into contact with food. It presents limit values for lead, cadmium, chrome and nickel migration in materials. It also presents stricter limits for heavy metals in children’s products.

How much bacteria in paper and board is harmful to health?

There are no legal limits for the overall microbiological quality of paper and board. The relevance of microbes in paper or board depends essentially on the food with which the material comes into contact. Whether the conditions relating to the food are favourable for the reproduction of the microbes in the packaging. For example, the chance of microbial growth in moist food is greater than in dry food.

It also greatly depends on what any microbes are. The presence of pathogenic or disease-causing microbes is generally not acceptable and when limiting the quantity of microbes, the focus must be on limiting the amount of microbes that cause disease and produce toxin rather than on those reflecting general hygiene. In favourable conditions (heat, light, humidity), microbes can reproduce rapidly to such an extent that they can make people ill.

What could be the causes of microbial growth in paper or board?

Large numbers of microbes on paper and board may indicate post-contamination of the material. For example, various paper coatings and adhesives can act as a growth medium for microbes. Also, paper handling during further processing is of great relevance for microbiological purity.  

Generally speaking, the use of recycled fibre always entails a higher risk to the microbiological purity of a material than the use of virgin fibre does. It is important to use only recycled fibre from selected sources to maximise the microbiological quality of the end product.

Do plastic containers intended for packing unpeeled fruits and vegetables require testing for total and specific migration?

The original Plastics Regulation 10/2011 did not include a requirement to test plastic material coming into contact with unpeeled vegetables and fruits, but this was amended in 2016. Regulation (EU) 2016/1416 amending and correcting the Food Contact Plastics regulation deals with the testing of plastic materials that come into contact with unpeeled fruits and vegetables. They should be tested with simulant E. They have been added to Table III in Table 2 with food simulant E with a correction factor of 10 (page 36). https://eur-lex.europa.eu/legal-content/FI/TXT/PDF/?uri=CELEX:32016R1416&from=EN


Is it mandatory to test migration of all food contact materials by the Finnish heavy metal degree 268/1992 (KTM)?

The Finnish heavy metal degree 268/1992 (KTM) concerns of all food contact materials regardless of the quality of the material.

However, In Finland we have made interpretation that if material have a specific legislation in the EU-level, then the business operators do not have to test heavy metals by this nationally degree.

In the EU-level we have material specific legislation for plastic (including recycled plastic), ceramic, regenerated cellulose and active and intelligent materials and articles.

Are the heavy metal assays in EU Directive (94/62 / EC) on Packaging and Packaging Waste adequate to ensure that no heavy metals are transferred from food contact material to food?

They are not adequate. The EU Directive on Packaging and Packaging Waste does not take food safety into account and the limits it lays down are based on environmental considerations. The limits concerned are too high to ensure food safety.

What kind of own-check samples are required and how frequently is a food ceramics manufacturer required to provide them? What else does a ceramics manufacturer's own-check include?

Under Ministry of Trade and Industry Decree 165/2006, a ceramics manufacturer is required to take samples to determine the migration of lead and cadmium. Examinations must also include examination of the migration of nickel and chromium as provided by the national Decree of the Ministry of Trade and Industry on the Migration of Heavy Metals from Food Contact Materials (268/1992).

Examinations can be carried out on the principle of worst case. In other words, examining the smallest container of the same shape. This test then covers other similarly shaped containers made of the same raw materials.

Examinations must be carried out regularly until they encompass well the products made. After this, examinations must be repeated whenever there is a change in the raw materials or the manufacturing process. Amendments to legislation also tend to give rise to a new obligation to have examinations carried out. The frequency of the tests also depends on how well the manufacturer controls process temperatures and firing times because these impact migration from final product.

Process conditions must also be monitored and records kept. Initially, it is advisable to monitor frequently (e.g. every firing) to check that the controls of the equipment are correct. Then, when it can be established that the controls are at the correct temperature and consistent, the recording rate can be less frequent. It is advisable to decide on the recording rate according to how much is manufactured and how well the adjustments remain in place. Records are also a good way to verify that the temperatures given by the raw material supplier are complied with when glazing the product.


Page last updated 4/24/2019