How We Solved the Problem of Additive Migration from Plastic Packaging into Cosmetic Products: A Practical Case Study from Production
Additive migration from plastic packaging can compromise the quality and safety of cosmetic products. How we identified and eliminated the cause of contamination in real-world production – step by step.
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Cosmetic manufacturers often face an invisible problem: the migration of additives from plastic packaging into the product itself. This phenomenon can cause changes in color, odor, or even reduce the effectiveness of active ingredients. In one specific case, we encountered complaints about cloudiness and changes in the consistency of a cream packaged in newly introduced containers. Analysis showed that the culprit was not the formulation, but an unsuitable combination of plastic material and additives used in its production. How did we diagnose the problem, and what measures led to its permanent solution?
The Problem: How Additives from Packaging Migrated into Cosmetic Products
A manufacturing company contacted us with repeated customer complaints about changes in the consistency and odor of creams packaged in plastic containers. Laboratory analyses confirmed that the cause was the migration of additives from the packaging material into the product itself. Specifically, these were plasticizers and stabilizers that gradually leached from the polypropylene packaging and contaminated the cosmetic formulation. This phenomenon is known in the packaging industry but often underestimated—particularly for products with a long shelf life or sensitive chemical composition.
The migration of additives occurs through two main mechanisms: diffusion (the passage of substances through the polymer structure) and extraction (leaching of additives by the liquid or fatty phase of the product). In this case, storage temperature played a key role, accelerating diffusion, as did the interaction between the container’s contents and its walls. The problem only became apparent after several months, making it difficult to identify the source. A comprehensive analysis of both the packaging material and the cosmetic product itself was necessary to determine the specific migrating substances and their concentration.
Analysis: How we identified the specific causes of migration
The first step was to determine the migration profile of the packaging material using standard testing methods. Samples of the plastic containers were exposed to simulated storage conditions (temperature, humidity, contact with a model liquid) and subsequently analyzed using chromatographic techniques. The results showed that phthalates and phenolic antioxidants, which were part of the additive mixture used in the production of the packaging, migrated most significantly. These substances not only affected the organoleptic properties of the product but could also pose a risk in terms of REACH regulation compliance.
We also investigated the influence of packaging wall thickness, polymer type, and production technological parameters (e.g., injection temperature). It turned out that the key factor was the non-optimal combination of additives – specifically, an excessively high content of plasticizers, which were not sufficiently compatible with the polypropylene matrix. This finding directed us toward searching for alternative additive systems that would minimize migration while maintaining the required mechanical properties of the packaging.
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Solution: Optimization of the additive system and material composition
Based on the analysis, we proposed several changes to the packaging material formulation. The first step was to reduce the concentration of phthalate plasticizers and partially replace them with polymeric plasticizers, which exhibit significantly lower migration potential. We also adjusted the ratio of primary and secondary antioxidants to ensure polymer stability without excessive release of additives. These modifications were tested under laboratory conditions, where we monitored migration using simulated extraction tests.
In addition to modifying the additive system, we recommended changes to the packaging production technology. Specifically, this involved reducing the injection temperature and extending the cooling time, which led to better homogenization of additives in the polymer matrix and reduced internal stress in the material. These technological adjustments alone reduced additive migration by approximately 30%, while the combination with the new additive formulation resulted in an overall migration reduction of over 70% compared to the original state.
Results and Recommendations for Packaging and Cosmetics Manufacturers
After implementing the proposed changes, verification was carried out under real-world conditions—cosmetic products were packaged in the new containers and stored for 12 months. Control analyses confirmed that no significant additive migration occurred, and customers no longer reported any complaints about changes in product properties. This case clearly demonstrated how important it is, when developing packaging, to consider not only mechanical properties but also chemical compatibility with the contents.
For packaging and cosmetic product manufacturers, we recommend the following measures: 1) Regularly test the migration potential of packaging materials, especially for new formulations or when changing raw material suppliers. 2) Prioritize additives with low migration, such as polymeric plasticizers or high-molecular-weight stabilizers. 3) Optimize manufacturing processes to minimize internal stress in the material. 4) Collaborate with chemical raw material suppliers who provide technical support and analytical services to verify packaging safety and compatibility.
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Technical Details of Migration: How Additives Penetrate the Polymer Barrier
Migration of additives from plastic packaging into cosmetic products is not a random process but is governed by the physico-chemical principles of diffusion and solubility. A key factor is the compatibility of the additive with the polymer and the packaging contents. For example, plasticizers such as phthalates or adipates have low molecular weight and high mobility within the polymer matrix, which facilitates their migration. In cosmetic products with high alcohol or oil content, the process is accelerated because these components act as extraction agents and increase the solubility of additives in the contents.
Temperature and storage duration play a crucial role – at temperatures above 40 °C, migration can accelerate up to tenfold compared to room temperature. The surface-to-volume ratio of the packaging is also important: for small samples or thin-walled packaging, the risk of migration is higher. Standard testing methods measure migration by simulating real conditions, where the packaging is exposed to model solutions (e.g., water, ethanol, or oil) and, after a defined period, the content of migrated substances is analyzed using chromatographic techniques.
Selecting Alternative Additives: Criteria for Safe and Functional Replacement
When searching for replacements for problematic additives, several technical and regulatory requirements must be considered. The first step is selecting substances with higher molecular weight (above 1000 g/mol), which have significantly lower migration potential. Examples include oligomeric plasticizers or polymeric stabilizers, which remain firmly bound within the polymer structure. It is also necessary to verify compatibility with the specific type of polymer – for instance, polyethylene requires different additives than polypropylene or PET.
Regulatory aspects play a key role: additives must comply with REACH regulations and be approved for contact with cosmetic products. Special attention should be paid to substances with potential endocrine effects or sensitising properties. In practice, combining several types of additives with different functions (e.g. stabilisers + lubricants) has proven effective to achieve a synergistic effect at lower concentrations. Migration testing is carried out according to standard protocols using long-term storage simulation.
Optimising the Manufacturing Process: How to Prevent Contamination During Packaging Production
Contamination by additives can occur not only during storage but also directly in the manufacturing process. A key measure is the separation of production lines for different types of packaging – for example, packaging for cosmetics should not be produced on the same equipment as packaging for industrial chemicals. Temperature profile control during polymer processing is also important: excessively high temperatures can cause additive degradation and the formation of migrating decomposition products.
The purity of raw materials is another critical factor. Polymers and additives should be stored in closed systems with controlled humidity and temperature to prevent moisture absorption or dust contamination. When mixing additives into the polymer, homogeneous distribution must be ensured to avoid local excess of the additive, which would increase the risk of migration. Regular cleaning of production equipment and process validation using analytical methods (e.g. spectroscopy) help keep contamination to a minimum.
Need a Custom Solution?
Every raw material combination requires an individual approach. GCG Group provides not only high-quality chemical raw materials but also technical support, including migration risk analysis and material compatibility. You have access to detailed safety data sheets and expert consultations for your specific applications. Contact us – or browse our catalog of over 1,300 products.
