Nylon (polyamide)
PA / resin identification code 7（その他）
Tea bags, cookware, clothing. The most abundant by particle count in bottled water.
Main uses
- Nylon ladles and spatulas
- Tea bags
- Clothing fibers
- Reverse osmosis membranes for water purification (nylon-based)
Found in food, water and the human body
- Bottled water: nylon was the main type by particle count in all 3 brands (Qian et al. 2024; the authors point out that it may have come from the reverse osmosis membrane)
- Placenta: about 10% by weight (Garcia et al. 2024)
- Tea bags: “11.6 billion per cup” from nylon and PET bags (Hernandez et al. 2019) → Germany's BfR assessed this as possibly too high by 2 to 3 orders of magnitude
- National Institute of Health Sciences: residual cyclic oligomers (short chains) in 23 nylon cooking utensils were 7.8 to 20 mg per g (Abe et al. 2016)
- Of 36 kitchen items including nylon ones, 11 exceeded the EU limit for 4,4'-diaminodiphenylmethane (2019)
Detailed numbers by food: Tea bags, Bottled water, Indoor dust falling onto food during meals
Evaluations of raw materials and additives
- The raw material caprolactam and nylon 6 are IARC Group 3
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 (polyamide): caprolactam 15 μg/mL or less, and other limits
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 |
|---|---|---|---|
| Polyamide resin molding materials (excluding fibers) | 176,284 t | 172,958 t | 160,587 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
- Qian N, et al. PNAS 2024 (PMID 38190543)
- Hernandez LM, et al. Environ Sci Technol 2019 (PMID 31552738)
- Abe Y, et al. PLoS One 2016;11(7):e0159547 (PMID 27453976)
- J Chromatogr A 2019;1602:217-227 (primary aromatic amines) (PMID 31133424)
- 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.