A coolant fire on a deep hole drilling machine develops fast. High-pressure coolant mist, hot chips, and electrical components create conditions where a small ignition becomes a large fire in seconds. Every operator must know where the fire extinguisher is, what type it is, and how to use it. Seconds matter.
Fire Hazards in Deep Hole Drilling
Hazard Classification
| Hazard | Fire Class | Location | Ignition Source |
|---|
| Oil-based coolant | Class B (flammable liquid) | Coolant tank, lines, pump | Hot chips, electrical fault |
| Coolant mist | Class B (flammable liquid aerosol) | Around drill entry point, chip conveyor | Hot chips, static discharge |
| Hydraulic oil | Class B | Hydraulic lines, valves, cylinders | Leak onto hot surface |
| Electrical cabinets | Class C (electrical) | Control cabinet, motor junction box | Fault, short circuit, dust |
| Chip accumulation | Class A (ordinary combustibles) | Chip conveyor, chip bin, tank | Hot chips, friction |
| Coolant-soaked rags | Class A | On machine, in waste bins | Spontaneous combustion, hot chips |
| Plastic / rubber components | Class A | Hoses, seals, wipers | Hot chips, radiant heat |
High-Risk Scenarios
| Scenario | Risk Level | Why |
|---|
| Oil-based coolant in use | High | Flammable — mist is ignitable |
| Machine running unattended | High | Fire can develop before discovery |
| Chip conveyor jam — chips pile up | Moderate | Hot chips accumulate — no cooling |
| Electrical cabinet door open | Moderate | Chips and mist enter — short circuit risk |
| Coolant leak onto hot surface | High | Flash fire when coolant contacts hot motor or exhaust |
| Grinding after drilling | Moderate | Sparks in coolant mist area |
Fire Extinguisher Types
Extinguisher Comparison
| Extinguisher Type | Fire Classes | Coolant Fire | Electrical Fire | Chip Fire | Residue |
|---|
| Water (APW) | A only | NO — spreads fire | NO — shock hazard | Yes | Wet |
| Carbon Dioxide (CO₂) | B, C | Yes — smothers | Yes — safe | Limited | None — clean |
| Dry Chemical (ABC) | A, B, C | Yes | Yes | Yes | Powder residue |
| Dry Chemical (BC) | B, C | Yes | Yes | Limited | Powder residue |
| Foam | A, B | Yes — blankets | NO | Yes | Foam residue |
| Wet Chemical (K) | K (kitchen) | Not suitable | Not suitable | No | Specialized only |
| Clean Agent (Halon/ Novec) | B, C | Yes | Yes | Limited | None — clean |
| Purple-K (PKP) | B, C | Yes | Yes | Limited | Powder residue |
Recommended Extinguisher for Deep Hole Drilling
| Machine Area | Recommended Type | Class | Why |
|---|
| Coolant tank area | CO₂ or ABC dry chemical | B, C | Coolant fire — no residue in coolant tank |
| Electrical cabinet | CO₂ or clean agent | C | No residue on electrical components |
| Chip conveyor | ABC dry chemical | A, B | Wood, paper, coolant-soaked chips |
| General machine area | ABC dry chemical | A, B, C | All-purpose — any fire type |
| Oil-based coolant system | Foam or ABC dry chemical | B | Blankets burning liquid |
| Near exit paths | ABC dry chemical | A, B, C | General evacuation use |
Size Requirements
| Hazard Level | Minimum Extinguisher Rating | Maximum Travel Distance |
|---|
| Low (water-based coolant, good housekeeping) | 2-A:10-B:C | 30 m |
| Moderate (oil-based coolant, chip accumulation) | 3-A:20-B:C | 20 m |
| High (oil-based coolant, confined space) | 4-A:40-B:C | 15 m |
| Electrical cabinet area | CO₂ — 5 lb minimum | 15 m |
Placement and Mounting
| Requirement | Specification | Reason |
|---|
| Mounting height | Top of extinguisher ≤ 1.5 m above floor | Accessible to all operators |
| Clearance around extinguisher | 300 mm minimum on each side | Easy to grab |
| Location | On exit path — not behind equipment | Accessible during fire |
| Distance from machine | 3–10 m from machine | Close enough to reach — far enough to access safely |
| Signage | Visible sign above extinguisher | Quick identification |
| Obstructed visibility | Fire extinguisher must be visible | No storage in front of extinguisher |
Inspection and Maintenance
Monthly Inspection
| Check | Acceptable | Corrective Action |
|---|
| Extinguisher in designated location | Present — no obstruction | Return to location or clear obstruction |
| Locking pin intact | Pin in place — seal unbroken | Replace seal |
| Pressure gauge (if equipped) | Needle in green zone | Replace or recharge if in red |
| Physical damage | No dents, corrosion, leakage | Replace if damaged |
| Hose and nozzle | Clear — no damage | Replace if cracked or blocked |
| Operating instructions | Legible | Replace label |
| Inspection tag | Present — last inspection date within 1 month | Record inspection |
Annual Maintenance
| Task | Detail |
|---|
| Professional inspection | By certified technician |
| Internal examination | Check for corrosion, damage |
| Weigh CO₂ extinguishers | Compare to full weight — recharge if below |
| Recharge if discharged | Even partially |
| Replace if beyond service life | Per manufacturer — typically 12 years |
| Hydrostatic test | Per local regulations — typically 5–12 years |
Extinguisher Lifecycle
| Extinguisher Type | Service Life | Hydrostatic Test Interval |
|---|
| CO₂ | 20 years | 5 years |
| Dry chemical (stored pressure) | 12 years | 12 years |
| Dry chemical (cartridge) | 12 years | 12 years |
| Clean agent | 12 years | 5 years |
| Foam | 12 years | 5 years |
| Water | 12 years | 5 years |
Emergency Response Procedures
Coolant Fire Response
| Step | Action | Detail |
|---|
| 1 | Sound alarm | Alert other personnel |
| 2 | Shut down machine | Emergency stop — stops coolant pump |
| 3 | Shut off coolant pump | Stops fuel source for fire |
| 4 | Grab nearest appropriate extinguisher | CO₂ or ABC dry chemical for coolant fire |
| 5 | Approach from upwind | Stay out of smoke and heat |
| 6 | Aim at base of flames | — |
| 7 | Sweep side to side | — |
| 8 | If fire is not controlled in 10 seconds | Evacuate — call fire department |
Electrical Fire Response
| Step | Action | Detail |
|---|
| 1 | Sound alarm | — |
| 2 | Shut down machine | Emergency stop |
| 3 | Shut off main electrical power | If safe to reach |
| 4 | Use CO₂ or clean agent extinguisher only | Never water or foam on electrical fire |
| 5 | Aim at base of flames | — |
| 6 | Sweep side to side | — |
| 7 | Keep minimum 1 m distance from electrical | Flashover risk |
Evacuation
| Step | Action | Detail |
|---|
| 1 | Sound alarm | — |
| 2 | Shut down machine if safe | — |
| 3 | Exit through nearest emergency exit | Know two exits from every location |
| 4 | Close doors behind you | Contains fire |
| 5 | Proceed to designated assembly point | — |
| 6 | Report to fire warden or supervisor | — |
| 7 | Do not re-enter building | Until cleared by authorities |
Preventive Measures
| Measure | Benefit | Implementation |
|---|
| Good housekeeping — remove chip accumulation | Removes fuel source | Clean chip conveyor — empty chip bins daily |
| Maintain coolant concentration | Water-based coolant is less flammable than oil-based | Test concentration weekly |
| Inspect electrical wiring | Prevents electrical fires | Monthly thermal imaging of electrical cabinets |
| Use fire-resistant coolant | Reduces fire risk | Consider water-based over oil-based coolants |
| Install automatic fire suppression | Responds faster than human | CO₂ or sprinkler system in electrical cabinet |
| Keep flammable materials away from machine | Removes fuel | Store rags, paper, packaging away from machine |
| Train operators on extinguisher use | Faster response | Annual hands-on training |
FAQ
What type of fire extinguisher should I use on a coolant fire?
Use a CO₂ or ABC dry chemical extinguisher for coolant fires. CO₂ is preferred for coolant tank areas because it leaves no residue — dry chemical powder must be cleaned out of the coolant system after discharge. Never use water on a coolant fire — water spreads flammable liquid fires and creates a shock hazard near electrical components. Foam extinguishers also work on coolant fires but leave residue that requires cleanup.
Where should fire extinguishers be located in a deep hole drilling shop?
Mount extinguishers on exit paths from each machine area — within 15–30 m travel distance depending on hazard level. Each extinguisher should be 3–10 m from the machine: close enough to reach quickly but not so close that the fire blocks access. Height should be 1.5 m maximum to the top of the extinguisher. One extinguisher should be near the coolant tank area and one near the electrical cabinet. Extinguishers must be visible and unobstructed.
How do I use a fire extinguisher?
Use the PASS technique: Pull the pin (breaks the seal), Aim at the base of the flames (not at the top), Squeeze the handle (releases the extinguishing agent), and Sweep side to side (covering the base of the fire). Stand 2–3 m from the fire and approach from upwind. If the fire is not controlled within 10 seconds of continuous discharge, evacuate immediately and call the fire department.
How often should fire extinguishers be inspected?
Monthly visual inspection by operators: check location, pressure gauge (needle in green), locking pin, physical damage, and inspection tag. Annual maintenance by a certified technician: internal examination, weigh CO₂ extinguishers, recharge if needed. Hydrostatic pressure test per local regulations (typically every 5–12 years depending on extinguisher type). Replace extinguishers at end of service life (typically 12–20 years).
What are the fire risks specific to deep hole drilling?
The primary fire risks are: oil-based coolant mist (ignites from hot chips or electrical sources), hydraulic oil leaks onto hot surfaces (motor, exhaust, hot piping), electrical cabinet fires from chip dust and coolant mist intrusion, chip accumulation (hot chips ignite coolant-soaked debris), and coolant-soaked rags (spontaneous combustion in waste bins). Water-based coolants significantly reduce fire risk compared to oil-based coolants. Good housekeeping is the most effective prevention.
Fire extinguishers are the first line of defense in a deep hole drilling fire — but only if they are the correct type, properly maintained, and within reach. Every operator should know the extinguisher location, the PASS technique, and when to evacuate. The first 10 seconds of extinguisher use determine whether the fire is controlled or becomes an emergency. This article reflects industry practice as of 2026.
