| Treatment | Plastic (1% w/w) | Substrate base | ID |
| 1 | OXO-PE | WS | OXO-PE |
| 2 | UV-OXO-PE | WS | UV-OXO-PE |
| 3 | PLA | WS | PLA |
| 4 | C-PE | WS | C-PE |
| 5 (control) | None | WS | WS-I |