1. The Hidden Glue: Polypropylene
Even standard square paper tea bags often contain plastic. To keep the bag sealed in boiling water, manufacturers traditionally add a thin layer of Polypropylene to the paper fibers so they can be heat-sealed. This is plastic code #5.
When these bags rot, the paper disappears, but the polypropylene remains as microscopic dust—Microplastics—in your soil. You then grow vegetables in that soil, effectively eating your own tea bags.
Expert Tip: The "Lighter Test"
Want to know if your tea bag contains plastic? Empty the dry tea out. Hold the empty bag with tweezers and light it with a match.
Clean Ash: It's pure paper/cotton.
Melts/Drips: It contains plastic (polypropylene or PLA).
2. The PLA Problem (Corn Starch Plastic)
Those fancy "silky" pyramid bags? They are usually made of PLA (Polylactic Acid). This is a bioplastic made from corn starch or sugarcane. While it is technically plant-based, it behaves like plastic in nature.
PLA requires specific conditions (high heat, specific microbes) to break down. If you throw a PLA bag into the ocean or a cold compost heap, it will remain intact for years, potentially harming wildlife just like petroleum plastic.
Expert Tip: The "Worm" Test
If you have a worm bin (Vermicompost), avoid PLA tea bags entirely. The tough mesh can tangle up worms, and they cannot digest the bioplastic. Stick to unbleached paper bags or loose leaf tea.
3. What Should I Buy?
To be 100% safe, look for brands that explicitly state:
1. "Plastic-Free" (Not just biodegradable).
2. "Stitched" or "Folded" (No heat seal = no glue).
3. "Unbleached" (Brown color, usually better for soil).
Ready to ditch the plastic?
We've reviewed the top tea brands, highlighting which ones use plastic-free packaging and which ones are guilty of greenwashing. The 5 Best Plastic-Free Tea Bags of 2025 →