Polyethylene
PE（HDPE・LDPE） / resin identification code 2（高密度）・4（低密度）
Bags, wrap, caps. Most often reported in human-body studies, but the measurement method is strongly criticized.
Main uses
- Plastic bags and food bags
- Polyethylene wrap
- Plastic bottle caps (high-density polyethylene)
- Coating on the inside of paper cups
Found in food, water and the human body
- Plaque in the neck artery: found in 150 of 257 people who had surgery (58.4%), at an average of 21.7 μg per mg of plaque (Marfella et al. 2024, NEJM)
- Brain: in brains autopsied in 2024, an average of 75% of the plastic was polyethylene (Nihart et al. 2025)
- Placenta: 54% by weight (Garcia et al. 2024)
- Digestive tract of Japanese anchovy in Tokyo Bay: 52.0% of the particles (Tanaka & Takada 2016)
- Opening and closing the cap increased particles from the cap surface (Winkler et al. 2019)
- Note: a method that measures body tissue by pyrolysis (Py-GC/MS) has trouble telling fat apart from polyethylene, and one study says it is “currently not suitable for measuring polyethylene in biological samples” (Rauert et al. 2025). The human-body values above were obtained with this method
Detailed numbers by food: Fish, PET bottle caps and opening packaging, Paper cups and coffee, Rice, Cutting boards, Microwave heating and takeout containers
Evaluations of raw materials and additives
- Polyethylene itself is IARC (International Agency for Research on Cancer) Group 3 (not classifiable as to its carcinogenicity)
IARC classifications rate the strength of evidence that something can cause cancer, not the size of the risk at everyday amounts.
Japan's standards (utensils, containers and packaging that touch food)
- MHLW Notification No. 370 (specifications and standards for food, food additives, etc.) (polyethylene and polypropylene): evaporation residue 30 μg/mL or less (150 μg/mL in heptane for foods such as fats and oils), potassium permanganate consumption 10 μg/mL or less
- Positive list material category 2 (hydrocarbons)
General standards for all synthetic resins: cadmium and lead in the material 100 μg/g or less each, heavy metals migrating (as lead) 1 μg/mL or less, and others. Since June 2020, synthetic resins that touch food have been under a “positive list system” that sets which substances may be used (the transition period ended May 31, 2025). → Rules and regulation
Production in Japan
| Item | 2023 | 2024 | 2025 |
|---|---|---|---|
| Polyethylene, total | 2,043,604 t | 1,937,747 t | 1,990,893 t |
Compiled by the Japan Plastics Industry Federation (based on METI's production statistics). This is the amount made in Japan, not the amount used in Japan.
Sources
- Marfella R, et al. N Engl J Med 2024;390:900-910 (PMID 38446676)
- Nihart AJ, et al. Nat Med 2025;31:1114-1119 (PMID 39901044)
- Garcia MA, et al. Toxicol Sci 2024;199(1):81-88 (PMID 38366932)
- Rauert C, et al. Environ Sci Technol 2025;59(4):1984-1994 (PMID 39851066)
- Winkler A, et al. Water Res 2019;166:115082 (PMID 31542550)
- Consumer Affairs Agency, standards for utensils, containers and packaging (Notification No. 370, Part 3) (Japanese)
- IARC List of Classifications
- Japan Plastics Industry Federation, statistics (Japanese)
Last checked 2026-10-01. This page is a translation of our Japanese page; if they differ, the Japanese page is the reference.