Table 2.
Quantification of biofilms on the plastics.
| Component | Material | Wet weight (mg/cm2) | Biofilm dry weight (mg/cm2) | Biofilm growth rate (mg/cm2/year) |
|---|---|---|---|---|
| Air pouch | LDPE | 9.6 ± 1.2 | 0.069 ± 0.029 | 0.067 ± 0.028 |
| Air pouch | HDPE | 14.4 ± 0.2 | 0.129 ± 0.029 | 0.121 ± 0.028 |
| Air pouch | HDPE | 22.2 ± 0.6 | 0.163 ± 0.028 | 0.154 ± 0.027 |
| Tube | Silicon | 24.7 ± 2.8 | n.d | n.d |
| Packaging foam | PS | 10.1 ± 7.8 | 0.115 ± 0.003 | 0.102 ± 0.003 |
| Coffee cup | PS | 16.3 ± 1.8 | 0.195 ± 0.088 | 0.186 ± 0.084 |
| Cup | PP | 39.4 ± 1.8 | 0.311 ± 0.095 | 0.291 ± 0.089 |
| Coffee cup | Cellulose | 29.5a | n.d | n.d |
| Bottle | PET | 32.4 ± 2.3 | 0.398 ± 0.012 | 0.382 ± 0.011 |
| Bottle | PET | 38.7 ± 1.6 | 0.459 ± 0.204 | 0.441 ± 0.196 |
| Fleece clothing | PET | 119.9 ± 1.3a | n.d | n.d |
| Reticulated foam | PU | 1.2 ± 0.9 | n.d | n.d |
| Balloon | Natural latex | 17.5 ± 2.9 | 0.211 ± 0.103 | 0.199 ± 0.098 |
| Cigarette filters | Cellulose acetate | 16.5a | n.d | n.d |
| Compostable postal bag | 7P0059 | 13.3 ± 4.5 | 0.068 ± 0.038 | 0.063 ± 0.035 |
| Compostable trash bag | 7P0069 | 7.07 ± 0.04 | n.d | n.d |
| Compostable food bag | PLA | 44.4 ± 7.9 | n.d | n.d |
| Food tray | PLA | 21.3 ± 11.8 | 0.261 ± 0.136 | 0.232 ± 0.121 |
aThese materials absorbed a significant amount of water.