Table 2.
Life cycle inventory of four masks for different life cycle processes.
| Life cycle process | Category | Inventory | Unit | Amount |
|||
|---|---|---|---|---|---|---|---|
| Reusable cotton mask | Disposable medical mask | Disposable surgical mask | KN95 respirator | ||||
| Raw material processing | Material | Polypropylene spun-bonded non-woven fabric | g/mask | / | 1.700 | 1.624 | 2.438 |
| Polypropylene melt-blown non-woven fabric | g/mask | 0.840 | 1.020 | 0.725 | 1.625 | ||
| Cotton fabric | g/mask | 13.960 | / | / | 1.625 | ||
| Aluminum strip | g/mask | 0.330 | 0.320 | 0.430 | 0.400 | ||
| Polyester/nylon blends | g/mask | 1.600 | 0.440 | 0.460 | 1.600 | ||
| Chemical | Electret masterbatch | g/mask | 0.013 | 0.041 | 0.035 | 0.061 | |
| Mask production | Chemical | Ethylene oxide | g/mask | 0.902 | / | 0.176 | 0.417 |
| Energy | Electricity | kW·h/mask | 0.010 | 0.004 | 0.008 | 0.009 | |
| Water resource | Water | m3/mask | 0.797 | 0.035 | 0.035 | 0.288 | |
| Mask packaging | Material | Polyethylene film | g/mask | 5.420 | 0.062 | 3.350 | 4.540 |
| Ivory board | g/mask | / | 0.988 | 0.974 | 6.070 | ||
| Corrugating medium | g/mask | 2.000 | 0.480 | 0.554 | 2.000 | ||
| Transport | Energy | Gasoline | km | 1007 | 1007 | 1017 | 1007 |
| Mask use | Chemical | Detergent | g/(mask·wash) | 6.240 | / | / | / |
| Water resource | Water | L/(mask·wash) | 12.000 | / | / | / | |
| End-of-life disposal | Waste | Waste | g/mask | 24.163 | 5.051 | 8.152 | 20.358 |