What is BPA and why does it affect chocolate moulds so much?

BPA (Bisphenol A) is a chemical compound that is considered to cause health risks when it is digested. It can migrate into food from a plastic part that is in contact with it.
Industrial and most other chocolate moulds are made of Polycarbonate (PC) which contains BPA in its molecular structure either as a necessary component or as excess BPA that could not be removed during the manufacture of PC.
Currently there is a specific migration limit of 0.05 mg/ kg for Polycarbonate. This limit is not exceeded by chocolate moulds, so the use of PC in chocolate moulds is not a problem at the moment.
However, the EU is going to ban BPA completely for food contact applications. This means that Polycarbonate is no longer allowed to be used for chocolate moulds. Presumably this will apply from 2028 on.
One positive and important information is that all moulds that were placed on the EU market before that deadline are allowed to be used for unlimited time.

The challenge for us as a chocolate mould manufacturer is to develop an alternative solution during the 36-month transition period. This is not easy, considering that Polycarbonate was used for chocolate moulds nearly exclusively for more than 50 years. There were also many good reasons why this material was used and no other plastics.

How is the current legislation situation (autumn 2024)?

The EU commission has finalized its coordination processes regarding the new draft law that should ban BPA for food contact applications. The EU parliament and EU Council will have now a 3-month evaluation period. It is expected that the law will be in force at the beginning of 2025. In most of the BPA- containing food contact applications, the transition period will be 18 months. For chocolate moulds it will be 36 months. This exemption was achieved through the efforts of European chocolate producer associations supported by chocolate mould manufacturers.

What are the essentials of the law’s regulation?

BPA will be banned from food contact applications.
For most of the BPA- containing plastics there is an 18-month transition period.
Chocolate moulds have got an exemption.
For chocolate moulds there will be a 36-month transition period in which BPA containing chocolate moulds (made of Polycarbonate) are allowed to be placed into the European market.
From 2028 on it will then be forbidden to place BPA- containing chocolate moulds on the European market.
There will be an additional sales regulation of items which have been produced before (e.g. stock items). They can be placed on the market in an additional 12-month period.

Important: All Polycarbonate chocolate moulds that were placed legally on the European market can be used for unlimited time.

What is the background of this strict regulation?

Based on a new risk evaluation of the EFSA (European Food Safety Authority) of April 2023 the EU commissions followed EFSA’s advice and reduced the Tolerable Daily Intake (TDI).
They set the TDI for BPA from 4 micrograms per kg body weight to 0.2 nanograms per kg body weight.
This is 20,000 times less than the current limit.

However, due to the exposure to different sources of BPA, the new TDI of 0,2 nanograms will be exceeded for most of the humans, and thus BPA is considered as a health risk. Therefore, BPA will be banned completely from food contact applications. This means that Polycarbonate is no longer allowed to be used for chocolate moulds.

Are there alternative materials?

There is a copolyester commercially available on the market that already has replaced Polycarbonate in many food contact applications.

Maybe you have noticed a lot of products that are now marked as „BPA free “. For example, you will hardly find any plastic drinking bottle without this label.
After the ban of PC for baby drinking bottles from 2008, this material has widely been used as PC replacement.

This copolyester has many strong material properties but of course it is different from PC. Consider at least 15 material properties/ characteristics that are important for well performing chocolate moulds.
Remember that after 50 years using Polycarbonate there was a long learning curve associated with the design and manufacture of PC chocolate moulds. All this accumulated knowledge is currently missing for an alternative material.

For artisanal moulds or small-scale industrial applications, we believe this material is already a sufficient alternative.

For industrial moulds and its diverse requirements, e.g. to withstand mechanical and chemical stress without causing foreign body risks or providing a long lifetime, it will be a new challenge. This has never been tested sufficiently before.

Apart from this copolyester the entire group of chocolate mould manufacturers survey the material market and keep their eyes open for other alternatives.

Why is it so difficult to replace Polycarbonate for chocolate moulds?

When more than 50 years ago metal moulds were replaced by plastic moulds, engineers monitored the available kinds of plastic.
They ended with Polycarbonate.
It is
•    Mechanically strong to resist the stress in a moulding line (hammering, twisting, vibrations, exposure to different temperatures)
•    Food safe
•    Clear with perfect visual reproduction properties (defined level of shine, extreme small structures…)
•    Chemically strong to withstand the necessary cleaning requirements
•    Humidity stable by a low humidity absorption
•    Shape stability over a long period of time within the temperature differences and geometric requirements of a moulding line (e.g. bending stability)

The stakeholders (mould manufacturers, moulding line manufacturers and chocolate manufacturers) have gathered a lot of experience during the last 50 years of the sole use of Polycarbonate

Examples:
•    Foreign body risks due to mould breakage could be eliminated by far
•    Early mould degrading could be avoided because the industry optimized their manufacturing processes and uses specialized equipment

As the industrialization and automation of the chocolate industry happened in parallel to the optimization of the Polycarbonate moulds, it was a long-lasting, steady process.

Now there is a challenge to replace a best suitable plastic material in an extremely short time by a new one in a highly industrialized environment.
There is zero experience with these alternative materials in industrial manufacturing surroundings.
Moreover, the new materials need to be selected and tested in an extremely short time.

Due to the experience with Polycarbonate and the structure of the chocolate manufacturing industry, a test on the production line is the only significant way to address all the challenges that a mould is faced with.
These tests, however, may take months to be performed. For cost reasons and waste saving, they can only be done on actual production processes.  This means a high level of risk if all manufacturers do it in parallel.

Can existing toolings be used for the alternative materials?

Alternative materials will have different shrinkage or heat expansion behaviours. Thus, they will require specific processing temperatures and tooling settings for the injection process.
Therefore, it is difficult to predict whether the existing tooling can be used, requires an adjustment, or parts of it need to be newly manufactured.

Our experience with copolyester shows that moulds will be bigger if we use the existing tooling and the applicable processing parameters.

Therefore, it strongly depends on the size allowance of moulding lines whether the mould can be used. This is more likely for smaller moulds.

For processes that require ambitious precision such as cold stamping or double moulds (book moulds), it is also a real challenge.

In the end it is a case- by- case evaluation based on trial results after a feasibility analysis.

How can mould manufacturers and chocolate manufacturers handle this transition?

Currently we see no other realistic alternatives on the market than the mentioned copolyester. Therefore, Brunner will focus on using this material. Of course, we and our entire industry branch continue to scan the market for other alternatives or engage with the polymeric industry to develop specific materials. However, this will be a long-term process.

Brunner requests its customers to evaluate their need of moulds within the next 36 months of the transition period and for the following period. Customer feedback showed us that there will be a high demand of replacement moulds in the next years.  The purpose is to gain time and take advantage of the regulation that chocolate moulds can be used for an unlimited time when supplied before the end of the transition period.

To evaluate the use of BPA- free moulds, chocolate manufacturers should start to test moulds made from the alternative material as soon as possible. During the transition period, there should be tests with complete mould sets made of the alternative material or with at least a defined number of moulds (if this is feasible).

Depending on the risk management strategy of the chocolate manufacturer this can be done with the most challenging mould (worst-case scenario) or with a less progressive approach by testing a less critical mould, or something in between.

Comparing Polycarbonate and the copolyester- What are different material characteristics, and which are similar?

Notch impact strength: the copolyester shows about 25% higher values compared to PC

Tensile strength: PC shows more than 20 % higher values compared to the copolyester. For bending strength, the value is even higher.  

Chemical stability: The copolyester is more chemical resistant and dishwasher safe. Chemicals are less likely to initiate stress cracking with it.

The main differences that need to be evaluated are:
•    Lack of experience in the long-term use of the alternative materials
•    Reduced tensile strength may be a challenge with bending performance and shape stability
•    Insufficient understanding of the breakage behaviour of moulds made from new materials in cases of mould crash situations in moulding lines. This needs to be analysed in practical tests and subjected to a risk assessment

Can new plastic be developed for this special application?

Like for Polycarbonate, the market power of the mould manufacturers for this relatively small niche is quite limited to claim a special material development. This would require huge financial resources and a considerable amount of time.
Additionally, Polycarbonate was an already developed material when the chocolate industry started using it.  
There are attempts to bring all stakeholders together and consider that issue.

It is however more likely that an existing plastic in its current specification or with some modifications will be used.
Just to make this understandable:  Food safety is the first hurdle for a plastic and this eliminates many materials that may be mechanically suitable.