How We Solved the Plasticiser Migration Problem in PVC Packaging for Cosmetics: A Practical Approach

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A cosmetics manufacturer approached us with a recurring issue: after several months of storage, clouding occurred in transparent creams packaged in PVC containers. Analysis revealed the migration of phthalate plasticizers from the packaging material into the product, which not only threatened the stability of the formulation but also compliance with EU safety requirements for cosmetic products. The problem was further complicated by the customer's demand to maintain the flexibility and transparency of the packaging. In this article, we describe how we proceeded in identifying the cause, testing alternatives, and implementing a final solution that eliminated the risk of migration while preserving all functional properties.

Problem: Plasticizer migration and its impact on the quality of cosmetic packaging

Migration of plasticizers in PVC packaging for cosmetics is a common but serious issue that can affect both the functionality of the packaging and the safety of the final product. Plasticizers, such as phthalates or adipates, are added to PVC to improve flexibility and processability; however, their gradual release into the surrounding environment can lead to undesirable effects. In cosmetic packaging, migration results in the loss of mechanical properties—packaging becomes brittle, cracks, or deforms, compromising its seal and protective function. Additionally, there is a risk of contaminating the cosmetic product, which can lead to complaints, loss of customer trust, or even violations of packaging safety regulations.

Another risk is the aesthetic degradation of the packaging. Migrating plasticizers can cause a sticky surface, dulling, or color changes, which is unacceptable for cosmetic products where appearance plays a key role. The problem is often detected only in the late stages of production or during storage, when remediation is costly. Identifying the causes requires a systematic approach—from analyzing the composition of the PVC blend to assessing processing and storage conditions. It is crucial to understand that migration is not caused solely by the quality of the plasticizer but also by interactions with other components of the formulation and external factors such as temperature or humidity.

Diagnostics: How We Identified the Cause of Migration

The first step toward solving the problem was detailed laboratory testing of defective packaging samples. Using standard analytical methods, we determined the plasticizer content in the material before and after exposure to various conditions. Infrared spectroscopy (FTIR) played a key role, allowing us to monitor changes in the chemical structure of PVC and identify specific types of plasticizers. In parallel, we conducted mechanical tests to assess how migration affects the strength and elasticity of the material. The results showed that the greatest loss of plasticizers occurs at elevated temperatures and during long-term storage.

Subsequently, we focused on evaluating the production process. We analyzed the temperature profiles during PVC processing, mixing and homogenization times, as well as cooling and storage conditions for semi-finished products. We found that the key factor was insufficient compatibility between the plasticizer and stabilizers in the formulation. Some stabilizers, particularly metal-based ones, can accelerate the degradation of plasticizers, leading to their faster migration. This finding directed us to adjust the formulation and optimize production parameters to minimize the undesirable impact on plasticizers.

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Solution: Formulation and Production Process Optimization

Based on diagnostics, we proceeded to modify the PVC compound formulation. The key change was the replacement of part of the traditional phthalate plasticizers with alternative, less migratory types, such as trimellitates or polymeric plasticizers. These substances exhibit higher molecular weight and thus a lower tendency to migrate. We also adjusted the ratio of stabilizers to prevent their undesirable interaction with plasticizers. We selected calcium- and zinc-based stabilizers, which are gentler on plasticizers and simultaneously ensure sufficient thermal stability during processing.

We optimized the production process with regard to the temperature regime and processing time. We reduced the temperature during mixing and extrusion by 10–15 °C, which significantly limited the degradation of plasticizers. Furthermore, we introduced controlled cooling of semi-finished products to prevent sudden thermal shocks that could accelerate migration. To verify the effectiveness of the changes, we implemented regular testing of production samples, including simulation of long-term storage at various temperatures. The results confirmed that plasticizer migration decreased by more than 60%, and the mechanical properties of the packaging remained stable even after several months of storage.

Prevention: How to Avoid Similar Problems in the Future

To minimize the risk of plasticizer migration in the future, it is essential to adopt a systematic approach to the selection and testing of raw materials. We recommend conducting compatibility tests of new plasticizers and stabilizers before incorporating them into the production formulation. It is also important to monitor developments in the field of alternative plasticizers, which offer lower migration and better stability. For example, bio-plasticizers based on vegetable oils or special polymeric additives may be a suitable choice for applications requiring high safety and stability.

In addition to formula adjustments, adhering to correct manufacturing procedures is crucial. Regular staff training on the impact of temperature, processing time, and storage conditions on the quality of PVC packaging can prevent many issues. We also recommend implementing a regular quality monitoring system that includes testing mechanical properties, migration analysis, and visual inspection of packaging. These measures can not only prevent migration problems but also enhance the overall reliability and lifespan of cosmetic packaging, which will positively reflect on customer satisfaction and product competitiveness.

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Impact of Plasticizer Migration on the Safety and Compatibility of Cosmetic Products

Migration of plasticizers from PVC packaging into cosmetic products is not just an aesthetic issue, but primarily a matter of safety and compatibility. Plasticizers such as phthalates or adipates, when released into the product, can react with active cosmetic ingredients, leading to changes in pH, reduced effectiveness of preservative systems, or even degradation of sensitive substances like vitamins or essential oils. In practice, we have observed cases where migration caused emulsion clouding, phase separation, or changes in viscosity, which directly impacted user experience and product stability.

Another critical aspect is the potential toxicity of migrating substances. According to REACH and CLP regulations, all packaging components that come into contact with cosmetics must be evaluated for safety. Migration of plasticizers can lead to exceeding limits for specific substances, which means not only a violation of legislation but also a risk to end consumers. In our case, it was crucial to verify whether the migrating substances were classified as endocrine disruptors or substances suspected of carcinogenicity, which would require immediate withdrawal of products from the market.

Practical testing and validation of the new solution under real-world conditions

After optimizing the formulation and production process, it was essential to test the new solution under conditions as close to real-world operation as possible. For validation, we chose a combination of accelerated aging tests and long-term monitoring. Accelerated tests were conducted at elevated temperature (60 °C) and humidity (80 % RH) for 4 weeks, simulating approximately 6 months of storage under normal conditions. Packaging samples were filled with reference cosmetic formulations and regularly analyzed for migrating substances using gas chromatography with mass detection (GC-MS).

Simultaneously, we conducted long-term tests in a real storage environment for 12 months. Samples were taken every 3 months and tested for mechanical properties (strength, elongation), optical parameters (transparency, haze), and chemical stability. Special attention was paid to interactions with various types of cosmetic formulations – from aqueous solutions to oil-based systems. The results confirmed that the new formulation exhibits less than 10% of the original migration rate and fully meets the requirements for compatibility with cosmetic products.

Economic and Environmental Benefits of the Optimised Solution

The optimisation of the formulation and production process brought not only technical but also significant economic advantages. The reduction in plasticiser migration led to an extended lifespan of the packaging and, consequently, lower costs for complaints and replacement of defective batches. In our case, the complaint rate was reduced by more than 70%, resulting in savings of tens of thousands of crowns annually. Additionally, the time required for quality control was shortened, as repeated migration tests were no longer necessary.

From an environmental perspective, the solution has a positive impact due to the reduction in waste and lower raw material consumption. The new formulation uses less toxic and more recyclable plasticisers, which facilitates the subsequent processing of packaging at the end of its lifespan. Furthermore, we observed a reduction in the energy demands of the production process, as the optimised formulation requires lower processing temperatures and shorter mixing times. These factors contribute to an overall reduction in the product's carbon footprint and support sustainability in line with the principles of the circular economy.

Need a Custom Solution?

Every application requires an individual approach – whether it’s selecting the right plasticizer, testing compatibility, or optimizing the production process. GCG Group provides detailed technical data sheets and safety data sheets (SDS) for the supplied raw materials and offers advice on selecting materials that meet REACH requirements as well as the specific needs of your production. Contact us – or browse our catalog of over 1,300 products.