Here is the classification for each item on your list:
- Pyroclastic flows - H (Hazard)
- Volcanic ash - HB (Hazard and Benefit)
- Geothermal energy - B (Benefit)
- Lahars - H (Hazard)
- Lava flows - H (Hazard)
- Volcanic materials (pumice, lava rock) - B (Benefit)
Let me know if you need further assistance!