Developing Faster Safety Tests for Plastic Food Packaging with LC-MS/MS

Japanese researchers developed a model system was prepared by adding ten types of additives to eight types of synthetic resins that are frequently used in utensils, containers, and packaging to establish accelerated test conditions to ensure the safety of plastic food utensils, containers, and packaging. An analytical approach based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) was evaluated and confirmed to be applicable for use with the various food-simulating solvents. A paper based on this work was published in Food Safety.¹

While synthetic resin utensils, containers, and packaging materials are essential in the distribution, display, and storage of food, they can potentially contain monomers, additives, degradation products, or impurities, all of which possibly posing a threat to human health.² Japan implemented the Food Sanitation Act to ensure the safety of such food-contact materials and prevent these chemical substances from migrating into food and causing health hazards. Traditionally, Regulations were traditionally based on the Negative List (NL) system (Standards and Specifications for Apparatus, Containers and Packages; Ministry of Health and Welfare (MHLW) Notification No. 370, 1959),³ which only restricted only substances with safety concerns. Recent amendments to the Food Sanitation Act, led to a Positive List (PL) system introduced for utensils, containers, and packaging (MHLW Notification No.196, 2020, issued on May 1, 2020).⁴ Related notifications were subsequently revised (MHLW Notification No.324, 2023),⁵ leading to the PL system became fully applicable on June 1, 2025. Per these systems, only substances that have undergone safety evaluations are to be used as raw materials for synthetic resins; when adding new raw materials to the PL, a risk assessment is required. The method for this assessment is outlined in the “Guidelines for the Risk Assessment of Food Apparatus, Containers, and Packages” (revised by the Food Safety Commission of Japan in April, 2024).⁶

To make sure plastic food containers and packaging are safe, scientists test them to see if any chemicals leak from the plastic into the food. For foods that sit on shelves for months or years, doing these tests in real-time simply takes too long. To speed things up, scientists try to create faster tests that mimic those long-term results. However, creating these fast tests is tricky because the liquids used to simulate food during long-term testing can spoil, or the leaked chemicals might just stick to the container itself.¹

To build these faster testing methods, researchers created sample plastics mixed with 10 different chemicals and tested them using four liquids that mimic food (water, diluted acid, alcohol, and olive oil). They found that using LC-MS/MS reliably measured the chemicals across all these liquids. During a long-term test using water, they noticed that bacteria growing in the water ruined the results by eating up some of the leaked chemicals. Fortunately, they discovered that adding a specific preservative to the liquid successfully prevents this spoilage. The researchers also confirmed that the chemicals tested generally do not stick to the glass testing containers, meaning the measurements remain accurate.¹

“Using the LC-MS/MS-based long-term migration test protocol established in this study,” write the authors of the paper,¹ “it becomes possible to examine conditions for setting accelerated test parameters.”

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References

1. Mizuguchi-Fukase, C.; Ozaki, A.; Kishi, E. et al. Development of a Long-term Migration Test Method for Plastic Food Utensils, Containers, and Packaging. Food Saf (Tokyo) 2026, 14 (1), 25-36. DOI: 10.14252/foodsafetyfscj.D-25-00028
2. Guidance on Best Practices on the Risk Assessment of Non-Intentionally Added Substances (NIAS) in Food Contact Materials and Articles. ILSI Europe website. 2015. https://ilsi.org/europe/wp-content/uploads/sites/3/2016/04/2015-NIAS_version-January-2016.pdf(accessed 2025-11-06)
3. Specifications and Standards for Food, Food Additives, etc. Ministry of Health, Labour and Welfare, Japan website 1959, Notification No. 370, 1959. https://www.mhlw.go.jp/english/topics/foodsafety/positivelist060228/dl/r01_a.pdf (accessed 2025-11-06).
4. Ministry of Health, Labour and Welfare, Japan. https://www.caa.go.jp/policies/policy/standards_evaluation/appliance/positive_list/assets/000625486.pdf(accessed 2025-12-15).
5. Ministry of Health, Labour and Welfare, Japan. https://www.caa.go.jp/policies/policy/standards_evaluation/appliance/positive_list_new/assets/001206775.pdf (accessed 2025-12-15).
6. .Food Safety Commission of Japan. Guidelines for the Risk Assessment of Food Apparatus, Containers and Packaging. Food Safety Commission of Japan website, 2020. https://www.fsc.go.jp/english/what_we_do.data/For_HP_revised2024_guidelines_food_apparatus_containers_packaging.pdf. (accessed 2025-11-06).