Metal filing cabinets are a common fixture in many offices and businesses. Their sturdy construction and ability to protect important documents makes them a staple for record keeping. However, in the event of a fire, how well do metal filing cabinets really hold up? Here is a comprehensive look at how metal filing cabinets perform when exposed to fire.
Overview of Metal Filing Cabinets
Metal filing cabinets are typically made of steel and come in 2, 3, 4, or 5-drawer models. The most common metal used is steel ranging from 16 to 22 gauge thickness. The heavier gauge steel provides more rigidity and strength.
Key features of metal filing cabinets:
- Sturdy steel construction
- Locking drawers with steel slides
- Fire resistant ratings from 30 minutes up to 2+ hours
- Insulation inside the drawers and cabinet body
Manufacturers use various techniques to make metal filing cabinets fire resistant:
- Thicker gauge steel construction
- Double walled and insulated sides
- Fireproof insulation like gypsum or mineral wool
- Tight sealing drawers with compression joints
These protective features allow metal cabinets to withstand fire exposure for a rated period of time.
Fire Performance Ratings
Metal filing cabinets are typically rated fire resistant for:
- Class A – 1 hour fire protection
- Class B – 2 hour fire protection
- Class C – 3 hour fire protection
The hour ratings indicate how long the internal temperature can stay below 350°F when exposed to external temperatures over 1700°F. This protects documents inside.
Some key notes on fire ratings:
- Ratings are tested without water sprinklers
- Higher ratings have more fireproofing features
- Ratings do not indicate fireproof, just resistant
While not completely fireproof, these ratings give an expectation of how well metal filing cabinets can withstand fire.
How Metal Filing Cabinets Perform in Fires
When exposed to high heat and direct flames, metal filing cabinets provide varying degrees of protection:
In minor fires, metal cabinets confine the fire and provide adequate protection. Internal temperatures remain safe for documents.
In moderate fires, Class B and C cabinets provide 2+ hours of protection before internal temperatures rise. Contents have a high chance of staying intact.
In severe fires, Class A cabinets provide basic short-term protection. Content damage is likely after 1 hour. Higher class cabinets maintain lower internal temps for longer.
In extreme fires, such as over 2000°F, unsprinklered rooms, or direct high-heat exposure, all classes of cabinets will eventually fail. Severe external conditions overpower insulation.
While metal cabinets cannot guarantee full fireproofing in extreme conditions, they generally perform well:
- Provide short-term containment of fire and heat
- Internal temperatures stay significantly lower than room
- Documents have high chance of staying intact unless fire is severe
Proper installation against walls, with fireproof barriers above cabinets, can further improve performance in fires.
Factors That Impact Fire Performance
Several factors influence how well a metal filing cabinet will hold up when exposed to fire:
- Fire intensity – More severe fires can overwhelm insulation and cause failure before the rated time. Sprinklers help control intensity.
- Direct exposure – Direct contact to flames reduces protection time as insulation gets compromised quicker.
- Gauge of steel – Heavier gauge steel withstands fire longer before heat transfer occurs.
- Quality of insulation – Mineral wool and gypsum provide better heat resistance than cellulose or fiberglass.
- Joints and seals – Tight compression joints prevent heat intrusion better than looser fittings.
Considering these factors can help determine the best type of fire resistant cabinet for an application.
Best Practices for Fire Protection
To get the most fire protection from metal filing cabinets, follow these guidelines:
- Choose cabinets rated for at least 1 hour fire resistance.
- Use Class B or C if available for better protection.
- Install against fireproof walls, away from potential direct fire sources.
- Shelves and covers above cabinets create barriers to trap heat.
- Ensure drawers and cabinets close and seal properly.
- Store most vital documents in the bottom drawers.
- Avoid overstuffing drawers which can compromise insulation.
- Place cabinets away from drafts or vents that could spread fire internally.
Following fire codes and precautions increases the effectiveness of fire resistant cabinets.
Conclusion
Metal filing cabinets are a reliable solution for protecting important paper records and documents from fire damage. While not completely fireproof, metal cabinet construction provides ample short-term containment of heat and flame. Fire ratings give a minimum expectation of fire resistance, with higher ratings indicating better protection. Following best practices for installation and use ensures metal cabinets perform optimally to safeguard contents in the event of a fire emergency.
Frequently Asked Questions
Q: How long can a standard metal filing cabinet withstand a fire?
A: Most standard metal filing cabinets are rated for 1 hour fire resistance or Class A protection. This means they can maintain internal temperatures under 350°F for 1 hour when exposed to external temperatures over 1700°F. Performance depends on factors like fire severity and direct exposure.
Q: Do all metal filing cabinets have a fire rating?
A: No, not all metal filing cabinets have an official fire resistance rating. Less expensive cabinets may provide basic fire protection but no official laboratory rating. Check specifications to confirm the class and hourly rating. Higher priced commercial fireproof cabinets will be rated.
Q: Should I expect all contents to survive a fire in a metal cabinet?
A: It depends on the fire severity and cabinet rating. In minor fires or short exposure, contents have a good chance of remaining intact. In extreme fires that overwhelm the cabinet insulation, expect severe damage to contents after the rated time of resistance expires.
Q: What type of insulation do fire resistant filing cabinets have?
A: Quality fireproof cabinets contain materials like gypsum, mineral wool, or calcium silicate inside the walls and drawers. Lesser quality insulation includes fiberglass and cellulose. Look for thick, rigid walls and well-sealed joints as indicators of effective insulation.
Q: Can extreme heat or flames cause a metal filing cabinet to explode?
A: It is unlikely, but possible under extreme conditions. As moisture trapped inside the cabinet turns to steam, pressure could build up and cause the cabinet to rupture or explode. This is a rare circumstance dependent on the moisture content within the cabinet and severity of the fire.