Table 2.
Risk indicator classification criteria for the hot work operation.
| Primary indicators | Secondary indicators | Risk classification and assignment of values | ||||
|---|---|---|---|---|---|---|
| Class I | Class II | Class III | Class IV | Class V | ||
|
Human factors |
Pre-job safety training (X1) | Reasonable | More reasonable | General | Unreasonable | Highly unreasonable |
| PPE usage (X2) | Perfect | Irregularities | Incomplete | More incomplete | Not wearing | |
|
Proper operation (X3) |
Reasonable | More reasonable | General | Unreasonable | Highly unreasonable | |
| Licensed operation(X4) | Licensed and number ≥ 3 | Licensed and number ≥ 2 | Licensed and number ≥ 1 | Licensed but not valid | Unlicensed | |
| Equipment factors | Hot work caution line (X5) | 8–10 m | 6–8m | 4–6 m | 2–4 m | < 2 m |
| Safety distances for gas cylinders (X6) | ≥ 5 m | 4–5 m | 3–4 m | 2–3 m | < 2 m | |
| Cylinder stabilization (X7) | High stability | Strong stability | Moderate stability | Limited stability | No stability | |
| Grounding of welding machine shell (X8) | Adequate grounding | Partial grounding | Limited grounding | Minimal grounding | No grounding | |
| Flame-resistant cable (X9) | Completely flame resistant | Highly flame resistant | Moderately flame resistant | Limited flame resistance | Not flame resistant | |
| Environmental factors | Toxic and hazardous gas detection (X10) | Reasonable | More reasonable | General | Unreasonable | Highly unreasonable |
| Worksite combustibles (X11) | Safety distance > 10 m | Safety distance 8–10 m | Safety distance 5–8 m |
Safety distance site 2–5 m |
Safety distance < 2 m | |
| Worksite lighting(X12) | Good lighting | Better lighting | General lighting | Poor lighting | No lighting | |
| Pumice on the work site slab (X13) | No pumice | Low pumice presence | Moderate pumice presence | High pumice presence | Excessive pumice presence | |
| Management factors | Hot work operations classification and procedures (X14) | Expository | Preferably | General | Relatively chaotic | Indefinite |
| Hot work permit (X15) | Standardize | Relatively standardize | General | Relatively poor | Poor | |
| Risk factor identification (X16) | Comprehensive | Relatively comprehensive | General | Relatively poor | Poor | |
| Specialized emergency protocols (X17) | Match | Relatively matched | General | Relatively poor | Poor | |
| Fire extinguisher (X18) | Comprehensive | Comprehensive but substandard | Missing 1–2 pieces | Missing 3–4 pieces | None | |
| Warning sign (X19) | Good location and layout | Reasonable location and poor layout | Poor location and reasonable layout | Poor location and confusing layout | No visible warning signs | |
| Assignment of qualitative indicators | 5 | 4 | 3 | 2 | 1 | |