Risk Management

Risk Management Advisories


Wired Glass for Fire, Not for Strength

Injuries arising from accidental glass breakage occur infrequently but are typically severe particularly with wire glass.  Although the wire may seem to reinforce the glass from breakage it is designed primarily to inhibit the spread of fire, not resist impact. Actually, wire glass requires less force to fracture and once it shatters the exposed mesh wire can worsen the injury.

Wire glass is a type of fire safety glass required by fire code to be installed in fire doors or windows within the interior of the building. When exposed to intense heat plain, heat treated or tempered glass shatters breaching fire separation by causing an opening allowing the fire to spread. Alternately the wire mesh holds the glass in place maintaining a barrier and reducing the spread of fire. While wired glass protects against fire, it is less impact resistant than other types of glass. Wired glass or "Georgian Polish" glass should only be used in fire separations and fire doors in accordance with the Canadian Building Code.

In areas where wire glass is required applying a tough, trans-parent film to one surface of the glass can make both new and existing installations of wired glass less susceptible to impact.

Glass Installation and Replacement

Glass installation or replacement requires selection of the most suitable type of glass when considering the specific function and requirements of the location. Different choices of glass are appropriate for different areas in a school. For example, plexi-glass or Lexan might be best for a gymnasium door. This would lower the risk of injury from broken glass due to incidental contact.

The following chart can help in the process in choosing the safest type of glass for each location in a school building.

(Georgian Polish)
  • fire separations
  • fire doors
  • usually stays in place when broken
  • relatively inexpensive
  • less impact resistant than plate glass
  • breaks into sharp, jagged pieces
  • windows not subject to impact
  • inexpensive compared to other materials
  • more impact resistant than wired glass
  • breaks into sharp, jagged pieces
  • windows in hallways, display cabinets
  • windows in non-fire rated doors
  • windows in standpipe hose cabinets, fire extinguisher cabinets

  • breaks into small pieces
  • can get in eyes, if broken.
  • Must be precut before being tempered (expensive)
(Plexi-glass etc., Lexan)
  • non-fire doors and windows
  • gymnasium windows areas
  • where high impact resistance or security is required
  • extremely resistant to breakage
  • light weight
  • good for security areas (special plastics are made which resist bullets, and other projectiles)
  • easily scratched
  • can melt or burn
  • windows, partitions

  • aesthetically pleasing
  • break resistant due to thickness
  • heavy
  • expensive
  • windows and non fire-rated doors subject to impact
  • security areas
  • hallways, display cabinets
  • sound absorbing qualities
  • high impact resistance
  • doesn't shatter
  • can be cut to fit
  • expensive


Risk Management Recommendations

Presently there is no legislative requirement to retroactively upgrade existing buildings i.e. remove wired glass panels in existing installations.  However, we recommend that all existing wire glass locations be evaluated for potential impact and injury. Where practical there are alternatives available to remedy locations determined to be at risk, such as replacement with impact and fire resistant materials, coating the glass with specialty films and installing protective bars and railings.

Whether wire glass or other types of glass setting and implementing the following rules may help to reduce the number of injuries related to glass:

  1. Reinforce the message that any contact with a glass window is potentially unsafe and that only the appropriate mechanisms i.e. push-bars should be used. 
  2. Post signs on doors and windows to the effect, “do not push on glass”.
  3. Avoid running in the hallways.
  4. Avoid holding track and field practice indoors in locations where there is a chance to impact with glass.
  5. Ban skateboarding in hallways.
  6. Be sure to have signage if floors are wet or slippery.
  7. Make sure through regular inspections and documentation that all door glass and windows are in good repair.
  8. Warn students when doors will be locked after hours, and that doors can only be opened with the panic bar.
  9. Install mats over glass in gymnasiums.
  10. When replacing wired class consider whether it is necessary to the locations and alternatives.

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