Packaging is an essential tool to make products stand out from the competition. Beyond the shelf appeal, packaging also provides protection to the contents from physical, chemical and microbiological hazards.

However, a lesser-known fact is that the same packaging material could also be a source of chemical contaminants, and hence, may impact food safety as well as food quality.

Among the different components of packaging material, packaging inks play a critical role as they might hamper product and consumer safety.

Each packaging ink is a mixture of different chemicals and some of these chemicals might be harmful with the potential to migrate to the foodstuff when getting in contact.

In terms of risk, the chemicals could be toxic, carcinogenic, mutagenic, repro-toxic and even endocrine disruptors.

The chemical contaminants from the packaging inks can get transferred to the foodstuff by a process called migration.

Over the last two decades, a number of scientific papers have been published, revealing the migration potential of substances from the printed matter.

However, the first big scandal that brought the subject alive was about the findings of isopropyl thioxanthone (ITX, a low molecular photo initiator used in UV inks) in baby milk and other liquid foodstuffs all over Europe, resulting in a product recall in the year 2005.

The food scandal alerted the packaging chain about the linkage between packaging inks and food safety.

Consequently, the authorities issued strict regulations for the application of printing inks as well as general food control measures.

Food safety and migration
Migration can be described as a transfer of chemical contaminants from the food packaging material to the food, thereby making it unsafe.

Migrants are substances which, due to their chemical characteristics and molecular size, move from a printed layer into the packed food.

There are different types of migration, which are as follows:

Set-off migration

Migrations can happen from one layer to another, such as a surface printed layer to the non-printed food-contact surface, which is later brought into contact with food.

If these are in direct or close contact, like in a reel or a stack after printing, set-off migration can easily occur due to the pressure existing in the reel or stack.

Diffusion migration
Small and mobile molecules can easily penetrate and diffuse across packaging material layers.

This can occur even if the printed material has not yet been converted into a food package and filled with food, or later when the printed package is filled with food and the food starts to extract the migrants from the packaging material.

Gas-phase migration

Migration can also happen from a cardboard (the releasing reservoir) via the gas phase within the pack, to end up in food which acts as the recipient reservoir (gas phase migration).

This can, for example, occur with migrants like mineral oils or some UV photo-initiators that might not be generally known as being volatile, such as organic solvents.

This process of migration is influenced by several factors like the physico-chemical properties of the migrant, of packaging material and of the food product; the storage time and temperature, and the size of packaging in proportion to foodstuff volume.

Concept of safe, compliant and migration optimised inks
Compliance in packaging safety needs to be based on these three pillars:

  • Legal requirements
  • Brand owner requirements
  • Self-commitments

Each supply chain partner (including the ink manufacturer, adhesive manufacturer and substrate manufacturer) needs to be aware of the legal requirements (relevant for a particular region) for their component of the packaging structure and must build systematic processes to ensure delivery of consistent and safe products. If the packaging material needs to be exported, the legal requirements of the importing country must also be given due consideration.

Brand owners, with their global footprints, sometimes have their own specific requirements for packaging safety beyond the legal requirements of the countries (especially developing countries like India). Each supply chain partner needs to make themselves aware of such requirements and upgrade their products to comply with such norms, in order to offer same level of consumer safety across all regions.

Each supply chain partner is responsible for their own products and formulations. Hence, it becomes the ethical responsibility of supply chain partner to deliver safe products (with only safe chemicals in their formulations) and also update the authorities and brand owners on such initiatives to benefit the society at large.

Compliance can never be achieved through an isolated approach since each packaging structure is a mixture of different components (including substrate, ink and varnishes), and hence, there should be an open and transparent communication across the supply chain on the requirements, as well as on the risk assessment of the individual components of the packaging structure.

It is the responsibility of the brand owner [also referred to as the food business operator (FBO)] to update the entire supply chain on the brand owner requirements as well as legal requirements.

It is to be highlighted that packaging supply chain partners do not come under the scope of FSSAI, and hence, FBOs have the onus to update the packaging supply chain on the same.

Hence, logically a safe ink (or compliant ink or migration optimised inks) should satisfy the applicable legal and brand owner requirements as well as self-commitments.

Migration-optimised inks – The future
In the Indian market, there is a demand for the so-called non-toluene (NT) inks, non-toluene non-ketone (NTNK) inks, mineral oil-free inks, etc. However, safe inks should not be misled with such terminology adopted by the market, as such inks may not be safe.

Each printing ink consists of four general components – binder/resin, solvent, additives and pigment/colorant.

By excluding a solvent like toluene, ketone, mineral oils, etc., one cannot assume and be assured that the inks are safe.

Safe inks (or migration-optimised inks) are inks with careful selection of raw materials in all four categories, so that none of the component of the printing ink formulations impact consumer safety.

Hence, the next time one is looking for safe inks, he/she should ask for migration-optimised inks.

Good manufacturing practices
Packaging materials and articles shall be manufactured in compliance with good manufacturing practices (GMPs), so that, under normal or foreseeable conditions of use, they do not transfer their constituents to food in quantities which could endanger human health; bring about an unacceptable change in the composition of the food, or bring about a deterioration in the organoleptic characteristics. GMPs should be exercised across the supply chain if packaging safety needs to be ensured.

There are several parameters and conditions that need to be controlled at the converters’ shop floor to make sure that the final intended article is safe.

Even if one hasn’t procured the safe raw materials (such as substrate, inks, adhesives etc.), if they are not processed in the right manner, the final intended article would never be food safe.

For example, in case of solvent-based inks, solvent drying is an essential part of manufacturing process of the final packaging material, which is carried out at the converter’s end.

In case solvent drying is not handled appropriately at the converter shop floor, retained solvent in the final packaging material can migrate into the product, thereby not only endangering human health, but also impacting the organoleptic properties of the product.

Converters also need to ensure that cross-contamination at the facility is well taken care of and there are adequate validated controls to ensure that.

Regulatory update
There is a lot of scientific literature available on packaging contaminants as well as packaging safety.

The subject of packaging safety is quite evolved in developed countries. However, in India packaging contaminants and packaging safety are also being widely discussed now.

In 2016, there was a report on the presence of toxins in PET bottles of five soft drink brands. FSSAI also recognised the threat of packaging inks and issued a nation-wide advisory to stop using newspapers for wrapping food items, specifically highlighting the impact of printing inks on consumer health.

The country’s apex regulator is now revising the norms of packaging safety and has released a draft notification, the Food Safety and Standards (Packaging) Regulations, 2018. The standards are much more evolved over the previous version and have brought in more components in the packaging structure under the regulations.

It now also regulates aluminum, glass, paper and printing inks to just mention a few. The upgraded standard also gives a list of suggestive packaging material for different product categories.

FSSAI, in the released draft, mandates the printing inks to conform to the IS 15495 standard, which is primarily based on a negative list principle and prescribes requirements under different categories of packaging material – external packaging, immediate food packaging, direct food contact and disposables.

However, the Bureau of Indian Standards (BIS) has realised that the IS 15495 standard has not been revised over a decade, and therefore, discussions are going on to upgrade the standard with new chemical contaminants such as toluene.

A recent report updated the market on the changing norms for printing inks.

Safe solutions from Siegwerk
Siegwerk has always been committed to food safety, which is a non-negotiable aspect for any converter, brand owner and end user (customer).
In terms of food safety and systematic processes, Siegwerk’s expertise has always helped brand owners to avoid regulatory problems and food contamination risks. Due to its commitment, Siegwerk has established itself as a global leader in safe packaging solutions.
Siegwerk’s philosophy on safe solutions stands on four pillars, which are as follows:
Safe products: Siegwerk offers migration optimised formulations for food applications. The portfolio includes formulations compliant to regional regulations, stringent regulation across the globe and even compliant to specific brand owner requirements.
Systematic processes: Siegwerk compliances are substantiated by systematic processes which give consistently safe and quality products. These include processes like raw material introduction, formulation guidelines and good manufacturing practices. It becomes very critical to choose reliable partners in this regard as final validation of packaging material is not exercised normally in the Indian packaging industry. Siegwerk has launched its transparency label to mark its unconditional commitment to product safety.
Product safety guidance: Siegwerk has always been a reliable partner in the supply chain, providing all the necessary information required to assure the compliances for the final printed article. This includes technical data sheets, compliance statements as well as statements of composition. Siegwerk, being the leader in the segment, also supports other members in the supply chain by providing guidance and training, thus serving as a trustworthy partner. Siegwerk has recently launched its ink safety portal to give customers 24×7 online support in terms of product safety and regulations for packaging inks.
Proactive safety work: Siegwerk has always advocated the need for compliant ink systems for food and food-alike segments. Siegwerk has been instrumental in upgrading the regulations across the globe due to their close liaisoning with brand owners, converters as well as authorities.